[Federal Register Volume 69, Number 102 (Wednesday, May 26, 2004)]
[Rules and Regulations]
[Pages 30042-30076]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11779]



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Part IV





Environmental Protection Agency





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40 CFR Part 180



Imidacloprid; Order Denying Objections to Issuance of Tolerance, and 
Final Order Imidacloprid; Pesticide Tolerance; Final Rules

  Federal Register / Vol. 69, No. 102 / Wednesday, May 26, 2004 / Rules 
and Regulations  

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2004-0152; FRL-7355-7]


Imidacloprid; Order Denying Objections to Issuance of Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final order.

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SUMMARY: On four occasions in the first half of 2002, the Natural 
Resource Defense Council (NRDC) and various other parties filed 
objections with EPA to final rules under section 408 of the Federal 
Food, Drug, and Cosmetic Act (FFDCA) establishing pesticide tolerances 
for various pesticides. The objections apply to 14 pesticides and over 
70 separate pesticide tolerances. Although the objections raise 
numerous pesticide-specific issues, they all focus on the potential 
risks that the pesticides pose to farm children. This order responds to 
NRDC's objections as to the imidacloprid tolerance on blueberries. The 
objections are denied as moot because this imidacloprid tolerance has 
expired. Because EPA is elsewhere in today's Federal Register 
reestablishing the imidacloprid tolerance on blueberries, EPA has 
treated NRDC's objections as comments on the petition to reestablish 
the blueberry tolerance and has explained in full in this document why 
NRDC's objections are not well taken.

ADDRESSES: EPA has established a docket for this action under Docket ID 
number OPP-2004-0152 All documents in the docket are listed in the 
EDOCKET index at http://www.epa.gov/edocket. Although listed in the 
index, some information is not publicly available, i.e., CBI or other 
information whosedisclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either electronically in 
EDOCKET or in hard copy at the Public Information and Records Integrity 
Branch (PIRIB), Rm. 119, Crystal Mall 2, 1921 Jefferson Davis 
Hwy., Arlington, VA., Monday through Friday, excluding legal holidays. 
The Docket telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: William Jordan, Office of Pesticide 
Programs, 7506C, Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001; telephone number: (703) 308-4099; 
fax number: (703) 308-4776; e-mail address: [email protected].

SUPPLEMENTARY INFORMATION:

Response to NRDC Objections

Table of Contents

I. General Information
A. Does this Action Apply to Me?
B. How Can I Get Additional Information, Including Copies of this 
Document and Other Related Documents?
 1. Electronically.
 2. In person.
II. Introduction
A. What Action is the Agency Taking?
B. What is the Agency's Authority for Taking this Action?
III. Statutory and Regulatory Background
A. Statutory Background
B. Assessing Risk Under the FFDCA
C. Science Policies
 1. Children's Safety Factor Policy.
 2. Aggregate exposure policies.
D. NRDC Farmworker Children Petition
IV. NRDC Objections
A. In General
B. Generic Issues
V. Public Comment
A. General
B. Individual Comments
 1. The FQPA Implementation Working Group.
 2. Inter-Regional Research Project Number 4 (IR-4).
 3. Bayer CropScience.
VI. Response to Objections
VII. Analysis of the Issues Raised by NRDC's Objections
A. Children's Exposure to Pesticides in Agricultural Areas.
 1. Studies Focusing on exposure to children in agricultural areas.
 a. Potential for exposure due to heightened pesticide levels in the 
homes of farm children.
 b. Whether farm children actually experience increased exposure.
 i. Studies allowing comparison of children from agricultural and 
non-agricultural areas.
 ii. Studies focusing solely on children from agricultural areas.
 iii. Ongoing research on farm children exposures.
 c. Conclusion.
 2. Supplemental information regarding spray drift and drift of 
volatilized residues.
 3. EPA data on spray drift and the spray drift model.
B. Failed to Retain Children's 10X Safety Factor
 1. Introduction.
 2. EPA's children safety factor decision.
 a. In general.
 b. Imidacloprid.
 3. Missing Toxicity Data--Lack of DNT.
 4. Missing Exposure Data--General.
 a. Farm children exposure.
 b. Lack of comprehensive DW monitoring data.
 i. Models and data.
 ii. EPA's drinking water models.
 iii. Imidacloprid-specific data.
 iv. Conclusion.
 5. Missing exposure data--specific.
 a. Information on regional consumption.
 b. Residential exposure information.
 c. Prospective ground water monitoring studies.
 6. Missing risk assessment.
 7. Conclusion on children's safety factor issues.
C. LOAEL/NOAEL
 1. Generic legal argument.
 2. Use of LOAELs to assess Imidacloprid risk.
D. Aggregate Exposure
 1. Worker exposure.
 2. Classification of farm children as a major identifiable 
population subgroup.
 3. NRDC's 1998 Petition on Farm Children.
 4. Adequacy of EPA's assessment of the aggregate exposure of 
children, including children in agricultural areas.
 5. Residential exposure as a result of use requiring a tolerance.
 6. Population percentile used in aggregate exposure estimates.
 a. In general.
 b. Choice of population percentile.
 7. Lack of residential exposure assessment for adults.
 8. Percent crop treated.
E. Lack of Emergency
VIII. Response to Comments
A. IWG Comments
B. Citizen Comments
C. IR-4 Comments
IX. Statutory and Executive Order Reviews
X. Congressional Review Act
XI. Time and Date of Entry of Order
XII. References

I. General Information

A. Does this Action Apply to Me?

    In this document EPA denies as moot objections to a tolerance 
action filed by NRDC. In addition to NRDC, this action will be of 
interest to the pesticide manufacturers and pesticide registrants whose 
product was the subject of the objections. Further, this action may be 
of interest to the following parties who have filed similar objections 
with EPA on other pesticide tolerances: Boston Women's Health Book 
Collective, Breast Cancer Action, Californians for Pesticide Reform, 
Commonweal, Lymphoma Foundation of America, NRDC, Northwest Coalition 
for Alternatives to Pesticides, Pesticide Action Network, North 
America, Pineros y Campesinos Unidos del Noroeste, SF-Bay Area Chapter 
of Physicians for Social Responsibility, and Women's Cancer Resource 
Center. Finally, this action may be of interest to agricultural 
producers, food manufacturers, or other pesticide manufacturers. 
Potentially affected categories and entities may include, but are not 
limited to:
     Industry, e.g., NAICS 111, 112, 311, 32532, Crop 
production, Animal

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production, Food manufacturing, Pesticide manufacturing.
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities who may be interested in this 
action.

B. How Can I Get Additional Information, Including Copies of this 
Document and Other Related Documents?

    1. Electronically. You may obtain electronic copies of this 
document, and certain other related documents that might be available 
electronically, from the EPA Internet Home Page at http://www.epa.gov/. 
To access this document, on the Home Page select ``Laws and 
Regulations,'' ``Regulations and Proposed Rules,'' and then look up the 
entry for this document under the Federal Register--Environmental 
Documents. You can also go directly to the Federal Register listings at 
http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has opened a docket for this action under 
docket ID number OPP-2002-0057. Included in the docket are EPA 
documents specifically referenced in this action, any public comments 
received during an applicable comment period, and other information 
submitted by NRDC. The docket does not include any information claimed 
as CBI. The docket is available for inspection in the Public 
Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall 
2, 1921 Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 
4 p.m., Monday through Friday, excluding legal holidays. The PIRIB 
telephone number is (703) 305-5805.

II. Introduction

A. What Action is the Agency Taking?

    On four occasions in the first half of 2002, NRDC and various other 
parties filed objections with EPA to final rules under section 408 of 
FFDCA, 21 U.S.C. 346a, establishing pesticide tolerances for various 
pesticides. The objections apply to 14 pesticides and over 70 separate 
pesticide tolerances. Although the objections raise numerous pesticide-
specific issues, they all focus on the potential risks that the 
pesticides pose to farm children. Further each of the objections makes 
two main assertions with regard to the pesticide tolerances in 
question:
    1. That EPA has not properly applied the additional 10X safety 
factor for the protection of infants and children in section 
408(b)(2)(C) of FFDCA.
    2. That EPA has not accurately assessed the aggregate exposure of 
farm children to pesticide residues.
    NRDC did not exercise the option provided in section 408(h) of 
FFDCA to request a hearing on its objections, but instead asked that 
the Agency rule on its objections on the basis of its written 
objections and attached submissions. Because the objections raised 
questions of broad interest, EPA published a representative copy of the 
objections in the Federal Register for comment, (67 FR 41628) (June 19, 
2002) (FRL-7167-7), and made all of the objections available for public 
review on its website. This order responds to NRDC's objections as to 
the imidacloprid tolerance on blueberries.
    EPA had planned to respond to the four sets of objections in a 
single order. That plan has been superceded by the December 31, 2003, 
expiration of the objected-to imidacloprid tolerance on blueberries, 
the demonstrable agricultural need for continuation of use of 
imidacloprid on blueberries, and NRDC's submission in June, 2003 of 
significant supplemental information on its objections. Technically, 
NRDC's objections to the imidacloprid tolerance on blueberries have 
become moot due to the expiration of the tolerance and this order 
denies them on that ground. Nonetheless, due to the fact that elsewhere 
in today's Federal Register EPA is re-establishing an imidacloprid 
tolerance on blueberries, EPA has treated the objections as a comment 
on the petition to re-establish the imidacloprid tolerance and is 
issuing in this denial order its planned response to the objections as 
a response to comments on the proposed establishment of the 
imidacloprid tolerance. If NRDC files the same objections to the re-
established imidacloprid tolerance, EPA will re-issue this comment 
response as a response to NRDC's objection forthwith. EPA cannot issue 
its response to all four sets of NRDC's objections at this time because 
EPA has not completed reviewing supplemental information on the 
objections submitted by NRDC in June, 2003. As to imidacloprid, 
however, specific facts relating to that pesticide allow EPA to address 
all of the issues raised by the objections to that tolerance.
    The body of this document contains the following sections. First, 
there is a background section which explains the applicable statutory 
and regulatory provisions, the relevant EPA science policy documents, 
and prior NRDC actions with regard to farm children. Second, there is a 
section setting forth in greater detail the substance of the 
objections. Third, a summary of the public comment is presented. 
Fourth, there is a section which denies theobjections to the 
imidacloprid tolerance as moot. Finally, EPA's detailed response to the 
issues raised by the objections on the imidacloprid tolerance is 
included as a part of its action in granting a permanent tolerance for 
imidacloprid on blueberries.

B. What is the Agency's Authority for Taking this Action?

    The procedure for filing objections to tolerance actions and EPA's 
authority for acting on such objections is contained in section 408(g) 
of FFDCA and regulations at 40 CFR part 178. 21 U.S.C. 346a(g).

III. Statutory and Regulatory Background

A. Statutory Background

    EPA establishes maximum residue limits, or ``tolerances,'' for 
pesticide residues in food under section 408 of FFDCA. 21 U.S.C. 346a. 
Without such a tolerance or an exemption from the requirement of a 
tolerance, a food containing a pesticide residue is ``adulterated'' 
under section 402 of FFDCA and may not be legally moved in interstate 
commerce. 21 U.S.C. 331, 342. Monitoring and enforcement of pesticide 
tolerances are carried out by the U.S. Food and Drug Administration 
(FDA) and the U. S. Department of Agriculture (USDA).
    A pesticide tolerance may only be promulgated by EPA if the 
tolerance is ``safe.'' 21 U.S.C. 346a(b)(2)(A)(i). ``Safe'' is defined 
by the statute to mean that ``there is a reasonable certainty that no 
harm will result from aggregate exposure to the pesticide chemical 
residue, including all anticipated dietary exposures and all other 
exposures for which there is reliable information.'' 21 U.S.C. 
346a(b)(2)(A)(ii). Section 408 of FFDCA directs EPA, in making a safety 
determination, to ``consider, among other relevant factors . . 
.available information concerning the aggregate exposure levels of 
consumers (and major identifiable subgroups of consumers) to the 
pesticide chemical residue and to other related substances, including 
dietary exposure under the tolerance and all other tolerances in effect 
for the pesticide chemical residue, and exposure from other non- 
occupational sources.'' 21 U.S.C. 346a(b)(2)(D)(vi). Other provisions 
address in greater detail exposure considerations involving 
``anticipated and actual residue levels'' and ``percent of crop 
actually treated.'' See 21 U.S.C. 346a(b)(2)(E) and (F). Section 
408(b)(2)(C) of FFDCA requires EPA to give special consideration to 
risks posed

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to infants and children. This provision directs that ``an additional 
tenfold margin of safety for the pesticide chemical residue and other 
sources of exposure shall be applied for infants and children to take 
into account potential pre- and post-natal toxicity and completeness of 
the data with respect to exposure and toxicity to infants and 
children.'' 21 U.S.C. 346a(b)(2)(C). EPA is permitted to ``use a 
different margin of safety for the pesticide chemical residue only if, 
on the basis of reliable data, such margin will be safe for infants and 
children.'' Id. [The additional safety margin for infants and children 
is referred to throughout this notice as the ``children's safety 
factor.''] These provisions establishing the detailed safety standard 
for pesticides were added to section 408 of FFDCA by the Food Quality 
Protection Act of 1996 (FQPA), an Act that substantially rewrote this 
section of the statute.
    Tolerances are established by rulemaking under the unique 
procedural framework set forth in FFDCA. Generally, the rulemaking is 
initiated by the party seeking the tolerance by means of filing a 
petition with EPA. See 21 U.S.C. 346a(d)(1). EPA publishes in the 
Federal Register a notice of the petition filing along with a summary 
of the petition, prepared by the petitioner. 21 U.S.C. 346a(d)(3). 
After reviewing the petition, and any comments received on it, EPA may 
issue a final rule establishing the tolerance, issue a proposed rule, 
or deny the petition. 21 U.S.C. 346a(d)(4). Once EPA takes final action 
on the petition by either establishing the tolerance or denying the 
petition, any affected party has 60 days to file objections with EPA 
and seek an evidentiary hearing on those objections. 21 U.S.C. 
346a(g)(2). EPA's final order on the objections is subject to judicial 
review. 21 U.S.C. 346a(h)(1).
    EPA also regulates pesticides under FIFRA, 7 U.S.C. 136 et seq. 
While the FFDCA authorizes the establishment of legal limits for 
pesticide residues in food, FIFRA requires the approval of pesticides 
prior to their sale and distribution, 7 U.S.C. 136a(a), and establishes 
a registration regime for regulating the use of pesticides. FIFRA 
regulates pesticide use in conjunction with its registration scheme by 
requiring EPA review and approval of pesticide labels and specifying 
that use of a pesticide inconsistent with its label is a violation of 
federal law. 7 U.S.C. 136j(a)(2)(G). In the FQPA, Congress integrated 
action under the two statutes by requiring that the safety standard 
under the FFDCA be used as a criterion in FIFRA registration actions as 
to pesticide uses which result in dietary risk from residues in or on 
food, 7 U.S.C. 136(bb), and directing that EPA coordinate, to the 
extent practicable, revocations of tolerances with pesticide 
cancellations under FIFRA. 21 U.S.C. 346a(l)(1).

B. Assessing Risk Under the FFDCA

    In assessing and quantifying non-cancer risks posed by pesticides 
under the FFDCA as amended by the FQPA, EPA first determines the 
toxicological level of concern and then compares estimated human 
exposure to this level of concern. This comparison is done through 
either calculating a safe dose in humans (incorporating all appropriate 
safety factors) and expressing exposure as a percentage of this safe 
dose (the reference dose (RfD) approach) or dividing estimated human 
exposure into the lowest dose at which no adverse effects from the 
pesticide are seen in relevant studies (the margin of exposure (MOE) 
approach). How EPA determines the level of concern, chooses safety 
factors, and estimates risk under these two approaches is explained in 
more detail below.
    For dietary risk assessment (other than cancer), the dose at which 
no adverse effects are observed (the NOAEL) from the toxicology study 
identified as appropriate for use in risk assessment is used to 
estimate the toxicological level of concern. However, the lowest dose 
at which adverse effects of concern are identified (the LOAEL) is 
sometimes used for risk assessment if no NOAEL was achieved in the 
toxicology study selected. A safety or uncertainty factor is then 
applied to this toxicological level of concern to calculate a safe dose 
for humans, usually referred to by EPA as an acute or chronic reference 
dose (acute RfD or chronic RfD). The RfD is equal to the NOAEL divided 
by all applicable safety or uncertainty factors. Typically, a safety or 
uncertainty factor of 100 is used, 10X to account for uncertainties 
inherent in the extrapolation from laboratory animal data to humans and 
10X for variations in sensitivity among members of the human population 
as well as other unknowns. Further, under the FQPA, an additional 
safety factor of 10X is presumptively applied to protect infants and 
children, unless reliable data support selection of a different factor. 
To quantitatively describe risk using the RfD approach, estimated 
exposure is expressed as a percentage of the RfD. Dietary exposures 
lower than 100% of the RfD are generally not of concern.
    For non-dietary, and combined dietary and non-dietary, risk 
assessments (other than cancer), the same safety factors are used to 
determine the toxicological level of concern. For example, when 1,000 
is the appropriate safety factor (10X to account for interspecies 
differences, 10X for intraspecies differences, and 10X for FQPA), the 
level of concern is that there be a 1,000-fold margin between the NOAEL 
from the toxicology study identified as appropriate for use in risk 
assessment and human exposure. To estimate risk, a ratio of the NOAEL 
to aggregate exposures (MOE = NOAEL/exposure) is calculated and 
compared to the level of concern. In contrast, to the RfD approach, the 
higher the MOE, the safer the pesticide. Accordingly, if the level of 
concern for a pesticide is 1,000, MOE's exceeding 1,000 would generally 
not be of concern.
    For cancer risk assessments, EPA generally assumes that any amount 
of exposure will lead to some degree of cancer risk. Using a model 
based on the slope of the cancer dose-response curve in relevant 
studies, EPA estimates risk in terms of the probability of occurrence 
of additional cancer cases as a result of exposure to the pesticide. An 
example of how such a probability risk is expressed would be to 
describe the risk as one in one hundred thousand (1 X 
10-\5\), one in a million (1 X 10-\6\), or one in 
ten million (1 X 10-\7\). Under certain specific 
circumstances, MOE calculations will be used for the carcinogenic risk 
assessment. No further discussion of cancer risk assessment is included 
because imidacloprid has not been identified as posing a cancer risk.

C. Science Policies

    As part of implementation of the major changes to section 408 of 
FFDCA included in FQPA, EPA has issued a number of policy guidance 
documents addressing critical science issues. Of particular interest to 
the NRDC objections are the science policies covering the children's 
safety factor, aggregate pesticide exposure, and the population 
percentile of exposureused in estimating aggregate exposure.
    1. Children's Safety Factor Policy. On January 31, 2002, EPA 
released its science policy guidance on the children's safety factor. 
(Ref. 48), [hereinafter referred to in the text as the ``Children's 
Safety Factor Policy'']. That policy had undergone an intensive and 
extended process of public comment as well as internal and external 
science peer review. An EPA-wide task force was established to consider 
the children's safety factor in March 1998. Taking into account reports 
issued by

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the task force on both toxicity and exposure issues, EPA's OPP released 
a draft children's safety policy document in May 1999. That document 
was subject to an extended public comment period as well as review by 
the FIFRA Scientific Advisory Panel. Id. at 5.
    The Children's Safety Factor Policy emphasizes throughout that EPA 
interprets the children's safety factor provision as establishing a 
presumption in favor of application of an additional 10X safety factor 
for the protection of infants and children. Id. at 4, 11, 47, A-6. 
Further, EPA notes that the children's safety factor provision permits 
a different safety factor to be substituted for this default 10X factor 
only if reliable data are available to show that the different factor 
will protect the safety of infants and children. Id. Given the wealth 
of data available on pesticides, however, EPA indicated a preference 
for making an individualized determination of a protective safety 
factor if possible. Id. at 11. EPA stated that use of the default 
factor could under- or over-protect infants and children due to the 
wide variety of issues addressed by the children's safety factor. Id. 
EPA noted that ``[i]ndividual assessments may result in the use of 
additional factors greater or less than, or equal to 10X, or no 
additional factor at all.'' Id. Because EPA thought that individualized 
assessments would be able to be made in most cases, EPA indicated that 
``this guidance document focuses primarily on the considerations 
relevant to determining a safety factor `different' from the default 
10X that protects infants and children. Discussions in this document of 
the appropriateness, adequacy, need for, or size of an additional 
safety factor are premised on the fact that reliable data exist for 
choosing a `different' factor than the 10X default value.'' Id. at 12.
    In making such individual assessments regarding the magnitude of 
the safety factor, EPA stressed the importance of focusing on the 
statutory language that ties the children's safety factor to concerns 
regarding potential pre- and post-natal toxicity and the completeness 
of the toxicity and exposure databases. Id. at 11-12. As to the 
completeness of the toxicity database, EPA recommended use of a weight 
of the evidence approach which considered not only the presence or 
absence of data generally required under EPA regulations and guidelines 
but also the availability of ``any other data needed to evaluate 
potential risks to children.'' Id. at 20. EPA indicated that the 
principal inquiry concerning missing data would center on whether the 
missing data would significantly affect calculation of a safe exposure 
level (commonly referred to as the Reference Dose (RfD)). Id. at 22; 
see 67 FR 60950, 60955 (Sept. 27, 2002) (finding no additional safety 
factor necessary for triticonazole despite lack of developmental 
neurotoxicity (DNT) study because the ``DNT is unlikely to affect the 
manner in which triticonazole is regulated.''). When the missing data 
are data above and beyond general regulatory requirements, EPA 
indicated that the weight of evidence would generally only support the 
need for an additional safety factor where the data ``is being required 
for `cause,' that is, if a significant concern is raised based upon a 
review of existing information, not simply because a data requirement 
has been levied to expand OPP's general knowledge.'' (Ref 48 at 23). 
Finally, with regard to the developmental neurotoxicity study (DNT), 
EPA listed several important factors addressing the weight of evidence 
bearing on the degree of concern when such a study has been required 
but has not yet been completed. Id. at 24. Moreover, EPA reiterated 
that, like any other missing study, the absence of the DNT does not 
trigger a mandatory requirement to retain the default 10X value, but 
rather depends on an individualized assessment centering on the 
question of whether ``a DNT study is likely to identify a new hazard or 
effects at lower dose levels of the pesticide that could significantly 
change the outcome of its risk assessment . . . '' Id.
    As to potential pre- and post-natal toxicity, the Children's Safety 
Factor Policy lists a variety of factors that should be considered in 
evaluating the degree of concern regarding any identified pre- or post-
natal toxicity. Id. at 27-31. As with the completeness of the toxicity 
database, EPA emphasized that the analysis should focus on whether any 
identified pre- or post-natal toxicity raises uncertainty as to whether 
the RfD is protective of infants and children. Id. at 31. Once again, 
the presence of pre- or post-natal toxicity, by itself, was not 
regarded as determinative as to the children's safety factor. Rather, 
EPA stressed the importance of evaluating all of the data under a 
weight of evidence approach focusing on the safety of infants and 
children. Id.
    In evaluating the completeness of the exposure database, EPA 
explained that a weight of the evidence approach should be used to 
determine the confidence level EPA has as to whether the exposure 
assessment ``is either highly accurate or based upon sufficiently 
conservative input that it does not underestimate those exposures that 
are critical for assessing the risks to infants and children.'' Id. at 
32. EPA described why its methods for calculating exposure through 
various routes and aggregating exposure over those routes generally 
produce conservative exposure estimates--i.e. health-protective 
estimates due to overestimation of exposure. Id. at 40-43. Nonetheless, 
EPA emphasized the importance of verifying that the tendency for its 
methods to overestimate exposure in fact were adequately protective in 
each individual assessment. Id. at 44.
    2. Aggregate exposure policies. As mentioned above, the FQPA-added 
safety standard directs that the safety of pesticide residues in food 
be based on ``aggregate exposure'' to the pesticide. 21 U.S.C. 
346a(b)(2)(A)(ii). Aggregate exposure to a pesticide includes all 
``anticipated dietary exposure and all other exposures for which there 
is reliable information.'' Id. The statute makes clear that in 
assessing aggregate exposure pertaining to a pesticide EPA must 
consider not only exposure to the pesticide in the food covered by the 
tolerance in question but exposure to the pesticide as a result of 
other tolerances and from ``other non-occupational sources.'' Id. 
Section 346a(b)(2)(D)(vi). Further, the statute directs EPA to consider 
aggregate exposure to other substances related to the pesticide so long 
as that exposure results from a non-occupational source. Id. Section 
346a(b)(2)(D)(vi). In November 2001, EPA released a science guidance 
document entitled General Principles for Performing Aggregate Exposure 
and Risk Assessments. This document deals primarily with the complex 
subject of integrating distributional and probabilistic techniques into 
aggregate exposure analyses. (Ref. 49).
    More relevant to the current objections, is the science guidance 
document issued in March 2000 addressing the population percentile of 
exposure used in making acute exposure estimates for applying the 
safety standard under section 408 of FFDCA. (Ref. 52). Traditionally, 
EPA had used the 95\th\ percentile of exposure in acute dietary 
exposure assessments as representing a reasonable worst case scenario. 
Id. at 15. Due to the very conservative (health-protective) assumptions 
used for acute exposure assessments, the 95\th\ percentile was viewed 
as a reasonable approximation of an exposure level not likely to be 
exceeded by any individuals. Id. at 15-17. Generally, such an approach 
assumes that all crops for which there is a tolerance are treated with 
the

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pesticide and all treated crops have residues at the highest level 
legally permitted.
    More recently, because of the availability of better data on 
residue values and new risk assessment techniques, EPA has restructured 
its approach to the use of population exposure percentiles in making 
safety determinations for acute risks under section 408 of FFDCA. (Ref. 
52). EPA has retained the 95\th\ percentile as the starting point of 
analysis for worst case (tolerance level) assessments. EPA, however, 
generally uses higher percentiles of exposure when less conservative 
assumptions are made concerning residue values. Id. For example, 
beginning in the late 1990's, EPA has increasingly relied upon 
probabilistic assessment techniques for assessing acute dietary 
exposure and risk. Because EPA generally uses much more realistic 
exposure values (e.g., monitoring data on pesticide levels in food) in 
conducting probabilistic assessments, a higher population exposure 
percentile was generally found to be necessary to ensure that exposure 
for the overall population was not understated. The Percentile Policy 
explains and defends EPA's choice of the 99.9\th\ percentile as a 
starting point for evaluating exposure and acute risk with 
probabilistic assessments.
    EPA confirmed in the Percentile Policy document that it would 
generally continue to use the 95\th\ percentile of exposure for 
deterministic acute risk assessments that used worst case exposure 
assumptions. Id. at 17, 29. The conservative (health-protective) nature 
of this approach was confirmed by data EPA cited showing that 
deterministic assessments of exposure at the 95\th\ percentile assuming 
residues at tolerance levels regularly result in exposure predictions 
significantly higher than probabilistic exposure estimates of the 
99.9\th\ percentile using monitoring data. Id. at 16-17.
    Importantly, EPA's Percentile Policy makes clear that in choosing a 
population percentile to estimate exposure, EPA is not intending to 
define the portion of the population that is to be protected. The 
policy explicitly states that: ``OPP's goal is to regulate pesticides 
in such a manner that everyone is reasonably certain to experience no 
harm as a result of dietary and other non-occupational exposures to 
pesticides.'' Id. at 28.

D. NRDC Farmworker Children Petition

    On October 22, 1998, NRDC and 58 other public interest 
organizations and individuals submitted a petition to EPA asking that 
EPA ``find that farm children are a major identifiable subgroup and 
must be protected under FQPA when setting allowable levels of pesticide 
residue in food.'' (Ref. 36 at 2). The Petition claims that ``[a]n 
increasing body of scientific evidence, including biomonitoring data 
and residential exposure studies, indicates that farm children face 
particularly significant exposures and health risks from pesticides.'' 
Id. at 3. In addition to requesting the ``major identifiable subgroup'' 
designation, the Petition also asked that EPA use the children's safety 
factor to protect farm children, require additional exposure data on 
farm children exposure and not issue any new tolerances until such data 
are available, deny registration for any pesticide without a validated 
method for detecting residues in food, increase research into issues 
concerning farm children exposure to pesticides, and honor the 
President's Executive order on Environmental Justice.
    Although EPA prior to this action has not issued a formal response 
to the petition, it has undertaken numerous steps to ensure that it is 
adequately protecting farm children including both initiating data 
gathering on exposure of children in agricultural areas to pesticides 
and programs to enhance compliance with label directions designed to 
minimize any bystander exposures to pesticides that could occur. Data 
gathering activities include EPA participation in the following 
studies:
    National Agricultural Workers Survey (NAWS). EPA and the National 
Institute for Occupational Safety and Health (NIOSH) are currently 
providing funding for the NAWS, an ongoing effort by the Department of 
Labor. The NAWS is the only national information source on the working 
and living conditions of U.S. farmworkers and their families. EPA is 
working with the Department of Labor in analyzing over 20,000 
interviews since the survey's onset to look at farm worker experiences 
over time. The interviews include questions concerning the following: 
Demographics, farmworkers' job mobility, day care arrangements, access 
to medical care, participation in pesticide training, exposures to 
pesticides, and reports of pesticide illness. Results from this survey, 
along with other studies, will assist EPA in addressing issues of 
pesticide exposures to farmworkers and any secondary exposures to their 
families. Additional information on the NAWS survey can be found at 
http:// www.dol.gov/asp/programs/agworker/naws.htm.
    Agricultural health study. The National Cancer Institute (NCI), 
EPA, NIOSH, and the National Institute of Environmental Health and 
Safety are conducting a long-term epidemiology study of 90,000 
certified pesticide applicators and their families in North Carolina 
and Iowa. The study is looking at both cancer and non-cancer endpoints 
using periodic surveys of the population. Pesticide use practices and 
health outcomes are being examined in detail. Additionally, scientists 
are conducting other studies on this cohort to learn further about 
exposures and potential effects, including birth defects, Parkinson's 
disease, asthma, and other disease endpoints. As part of the 
Agricultural Health Study, field work in Iowa is being conducted, and 
over the next three years detailed exposure analyses on a sub-sample of 
families using various agricultural pesticides will be completed. Some 
initial results have already been published for high exposure events 
and effects to the eye. A detailed listing of these studies and a 
number of publications already reporting the results of the 
Agricultural Health Study can be found at http://www.aghealth.org/.
    The Agency is also pursuing several other research efforts likely 
to provide additional information about any pesticide exposure to 
farmworkers and their children:
    National Human Exposure Assessment Survey (NHEXAS). EPA developed 
this survey in the early 1990s to provide critical information about 
multi-pathway, multi-media population exposure distribution to 
chemicals. The data have been collected and the database is now being 
compiled. EPA expects to have the information accessible on the 
Internet later this year.
    Children's total exposure to persistent pollutants. This study, 
conducted by EPA, will add to our understanding of any pesticide 
exposures to farmworker families. The data collection for this study, 
initiated this year, should be completed and available in 2004.
    In terms of actions taken to enhance protections to children so as 
to avoid bystander-type exposures, EPA has numerous programs and 
materials focusing upon pesticide safety issues for farm workers and 
their families both at the national and regional level. A brief 
overview of EPA's approaches will be discussed here. However, more 
information about EPA's farm worker efforts across its regional offices 
can be found in the docket for this action.
    An overview of what EPA is doing on the national level includes an 
assessment of the EPA's 1992 Worker Protection Standard (WPS). See 40 
CFR part 170. The Worker Protection Standard is a regulation intended 
to

[[Page 30047]]

help reduce the risk of pesticide poisonings and injuries among 
agricultural workers and handlers of agricultural pesticides. The WPS 
offers protections to over three and a half million people who work 
with pesticides at over 560,000 workplaces. The WPS contains 
requirements for pesticide safety training, notification of pesticide 
applications, use of personal protective equipment, restricted entry 
intervals following pesticide application, decontamination supplies, 
and emergency medical assistance. The national overview of 
implementation and enforcement of WPS programs has been completed and 
recommendations are being compiled. The national assessment of WPS was 
a collaborative effort of EPA, the USDA, the Department of Labor, the 
Department of Health and Human Services (HHS), States, farm workers, 
and farmers. The reassessment effort included a great amount of 
stakeholder input, and has led to the development of a variety of pilot 
programs intended to improve the Agency's outreach to farm workers.
    Other examples of activities conducted at the national level 
include the Agency's cooperative agreement with the Association of Farm 
Worker Opportunity Programs (AFOP) through which EPA funds the National 
Pesticide Safety Education Program for agricultural workers and farm 
worker children. Working with Americorps members, AFOP trains 25,000 
farm workers and farm worker children every year about pesticide safety 
using Americorps members in over 50 sites in 16 states. AFOP conducts 
pesticide safety training for children at childcare centers, schools, 
churches, and community centers, and has developed a handbook in 
Spanish. Also, through EPA funding, AFOP has developed radio programs 
targeted at preventing pesticide poisonings of children.
    Also on the national level, EPA has initiated a program with the 
Migrant Head Start Program (MHS) to develop materials and training for 
MHS on pesticide safety for migrant families with specific attention to 
protecting children from pesticides. MHS is designed to provide 
comprehensive Head Start services and programming to migrant families 
and their children. A total of 25 grantees and 41 delegate agencies 
provide services in 33 States and serve over 30,000 migrant children, 
and 25,000 children of seasonal workers, ranging in age from birth to 5 
years. The MHS program has a unique emphasis on serving infants and 
toddlers as well as pre-school age children, so they will not have to 
be cared for in the fields, or left in the care of very young siblings 
while parents are working. MHS also teams with Americorps to provide 
refresher training on pesticide safety.
    EPA on a national level, has also been involved in the development 
of two videos on pesticide safety for farmworkers and their families. 
The video, ``Chasing the Sun/Siguiendo El Sol,'' is a bilingual 
farmworker pesticide safety training video designed to comply with the 
agricultural worker training requirements mandated under the Worker 
Protection Standard. It was developed by the National Center for 
Farmworker Health and funded through an interagency agreement between 
EPA and HHS Migrant Health Program. This video is available through 
NCEPI and the National Center for Farmworker Health.
    Another video, entitled The Playing Field is a bilingual pesticide 
safety training video for farmworker families. Through a story about a 
girl poisoned by playing in a treated field, the video teaches 
farmworkers and farmworker children about the dangers of pesticides and 
how to protect themselves from pesticides. The video was developed by 
the National Center for Farmworker Health and funded through an 
interagency agreement between EPA and the HHS Migrant Health Program. 
The video is available through the National Center for Farmworker 
Health.
    Finally, EPA's regional offices have performed, and are performing, 
a number of outreach activities. These activities can be divided into 
three general categories: Direct outreach; partnerships, where the 
Agency provides funding and/or technical assistance, and research. 
Examples of EPA's activities on pesticide safety for farm workers and 
their families can befound in EPA's docket.

IV. NRDC Objections

A. In General

    During the first half of 2002, NRDC submitted four separate sets of 
objections on various pesticide tolerances. The dates of the objections 
and the pesticides involved are captured in Table 1 of this unit.

                     Table 1.--Objections Submitted
------------------------------------------------------------------------
                                     Pesticides          FR citations
         Date submitted               involved          (respectively)
------------------------------------------------------------------------
February 25, 2002                Halosulfuron-       66 FR 66,333
                                  methyl,             (December 26,
                                  pymetrozine         2001); 66 FR
                                                      66,778 (December
                                                      27, 2002); 66 FR
                                                      66,786 (December
                                                      27, 2001)
================================
March 19, 2002                   Imidacloprid,       67 FR 2580 (January
                                  mepiquat,           18, 2002); 67 FR
                                  bifenazate, zeta-   3113 (January, 23,
                                  cypermethrin,       2002); 67 FR 4913
                                  diflubenzuron       (February 1,
                                                      2002); 67 FR 6422
                                                      (February 12,
                                                      2002); 67 FR 7085
                                                      (February 15,
                                                      2002)
================================
May 7, 2002                      2,4-D               67 FR 10622 (March
                                                      8, 2002)
================================
May 20, 2002                     Isoxadifen-ethyl,   67 FR 12,875 (March
                                  acetamiprid,        20, 2002); 67 FR
                                  propiconazole,      14,649 (March 27,
                                  furilazole,         2002); 67 FR
                                  fenhexamid,         14,866 (March 28,
                                  fluazinam           2002); 67 FR
                                                      15,727 (April 3,
                                                      2002); 67 FR
                                                      19,114 (April 18,
                                                      2002); 67 FR
                                                      19,120 (April 18,
                                                      2002)
------------------------------------------------------------------------

See Objections to the Establishment of Tolerances for Pesticide 
Chemical Residues: Halosulfuron-methyl and Pymetrozine Tolerances 
(filed February 25, 2002) [hereinafter cited as Halosulfuron-methyl 
Objections]; Objections to the Establishment of Tolerances for 
Pesticide Chemical Residues: Imidacloprid, Mepiquat, Bifenazate, Zeta-
cypermethrin, and Diflubenzuron Tolerances (filed March 19, 2002) 
[hereinafter cited as Imidacloprid et al. Objections], Objections to 
the Establishment of Tolerances for Pesticide Chemical Residues: 2,4-D 
Tolerances (filed May 7, 2002) [hereinafter cited as 2,4-D Objections]; 
Objections to the Establishment of Tolerances for Pesticide Chemical 
Residues: Isoxadifen-ethyl, Acetamiprid, Propiconazole, Furilazole, 
Fenhexamid, and Fluazinam Tolerances (filed May 20, 2002) [hereinafter 
cited as Isoxadifen-ethyl et al. Objections]. NRDC was joined in the 
objections concerning 2,4-D by the following

[[Page 30048]]

public interest and/or advocacy organizations: Boston Women's Health 
Book Collective, Breast Cancer Action, Californians for Pesticide 
Reform, Commonweal, Lymphoma Foundation of America, Northwest Coalition 
for Alternatives to Pesticides, Pesticide Action Network North America, 
Pineros y Campesinos Unidos del Noroeste, SF-Bay Area Chapter of 
Physicians for Social Responsibility, and Women's Cancer Resource 
Center.
    This order responds to the objections filed on March 19, 2002, but 
only to the extent those objections apply to the pesticide imidacloprid 
and the tolerance for imidacloprid on blueberries.

B. Generic Issues

    NRDC raises a myriad of claims in its objections to the 
imidacloprid tolerance. Most of these claims fall fairly neatly into 
three categories:
     Children's safety factor issues.
     Aggregate exposure issues.
     Issues regarding use of findings from hazard studies in 
calculating safe exposure levels-- the ``no observed effect level'' 
(NOEL) versus ``no observed adverse effect level'' (NOAEL) and the 
``lowest observed adverse effect level'' (LOAEL) questions.
    In describing these objections, citation is made generally to the 
objections filed on the imidacloprid tolerance; however, one of the 
other sets of objections is referenced if it provides further 
clarification.
    1. Children's safety factor issues. For imidacloprid, EPA decided 
to use an additional safety factor for the protection of infants and 
children that is different from the default 10X value. NRDC claims that 
EPA erred in doing so due to the ``significant toxicity and exposure 
data gaps'' corresponding to the tolerance established. See, e.g., 
Imidacloprid et al. Objections at 3. Three types of data gaps are cited 
by NRDC. First, NRDC notes that EPA has required a developmental 
neurotoxicity study but such study has not yet been submitted. Pointing 
to various EPA documents recommending that this study be widely 
required and EPA's specific finding that this study is required as to 
imidicloprid, NRDC argues that use of a factor different than 10X is 
precluded. Second, NRDC claims EPA lacks ``pesticide-specific data on 
water-based exposure'' on imidacloprid. See, e.g., Imidacloprid et al. 
Objections at 6. NRDC argues that exposure estimates EPA calculated 
through the use of models cannot qualify as the ``reliable data'' 
needed to vary from the default 10X value. Id. Third, NRDC claims that 
``EPA failed to consider important exposure routes for millions of 
infants and children, including exposure to children living on farms 
and who accompany their parents into farm fields [], and exposure from 
spray drift.'' Isoxadifen-ethyl et al. Objections at 5. Fourth, NRDC 
asserts that EPA is missing a prospective groundwater study on 
imidacloprid and a short-term residential risk assessment. Imidacloprid 
Objections at 5. Finally, NRDC argues that EPA lacks data on regional 
blueberry consumption and thus has potentially underestimated exposure 
in blueberry-producing states.
    2. Aggregate exposure issues. NRDC raises several issues relating 
to whether EPA properly estimated ``aggregate exposure'' for 
imidacloprid. First, NRDC argues that farm children are a ``major 
identifiable subgroup'' and that EPA has failed ``to consider 
information concerning the sensitivities and exposures of farm children 
as a major identifiable subgroup'' in conducting its aggregate exposure 
assessment. According to NRDC, farm children have unique exposures to 
pesticides ``from their parents' clothing, dust tracked into their 
homes, contaminated soil in areas where they play, food eaten directly 
from the fields, drift from aerial spraying, contaminated well water, 
and breast milk.'' Imidacloprid et al. Objections at 12. Further, NRDC 
asserts farm children's exposure is increased because they ``often 
accompany their parents to work in the fields . . . .'' Id. NRDC cites 
various studies collected in its Farm Children Petition as well as more 
recent studies in support of these claims. Imidacloprid et al. 
Objections at 12-13. Second, NRDC argues that EPA's aggregate exposure 
assessment is flawed for these pesticides because EPA did not consider 
the added exposure to pesticides that farmworkers receive as a result 
of their occupation. Id. at 14. NRDC states that EPA's interpretation 
of the statute as excluding occupational exposure is incorrect. Id. 
Third, NRDC argues that for imidacloprid, EPA has, in effect, 
underestimated aggregate exposure by using the 95\th\ population 
percentile of exposure instead of the 99.9\th\ percentile in 
determining whether exposure to the pesticide meets the safety 
standard. Imidacloprid et al. Objections at 19. NRDC claims that this 
is inconsistent with existing Agency policy. Id.
    3. Reliance on LOAELs and NOAELs. NRDC asserts that, in the absence 
of identifying a NOEL in relevant animal studies, EPA cannot make a 
safety finding under section 408(b)(2)of FFDCA. In support of this 
argument, NRDC cites to legislative history using the term NOEL. NRDC 
calls particular attention to the instances where EPA determined safety 
relying on a LOAEL. In this regard, it asserts that EPA used a LOAEL in 
making a safety finding for acute and chronic toxicity for 
imidacloprid. Imidacloprid et al. Objections at 18.
    4. Other issues. NRDC claims that the EPA failed to comply with the 
statutory requirements pertaining to the use of percent crop treated 
for chronic risk assessments with regard to the imidacloprid blueberry 
tolerance. NRDC asserts that the use of national percent crop treated 
data cannot provide a valid basis for estimating exposure in Michigan 
and New Jersey, and, in fact, is likely to understate exposure in those 
states. Further, NRDC argues that EPA erred by relying on national 
consumption data instead of regional data from New Jersey and Michigan 
in estimating the risk posed by imidacloprid. Finally, NRDC, in 
comments it filed on its objections, claims that the emergency 
exemption approved under FIFRA authorizing the use of imidacloprid on 
blueberries in Michigan did not meet the standard in 40 CFR 166.3(d) 
for the granting of such exemptions.

V. Public Comment

A. General

    On June 19, 2002, EPA published a notice in the Federal Register 
calling attention to and requesting comments on the Halosulfuron-methyl 
et al. Objections, Imidacloprid et al. Objections, and the 2,4-D 
Objections. 67 FR 41628 (June 19, 2002). As part of that notice, EPA 
published the full text of the Imidacloprid et al. Objections in the 
Federal Register. A period of 60 days was initially allowed for comment 
but that period was extended twice and was closed on October 16, 2002. 
See 67 FR 58536 (September 17, 2003); 67 FR 53505 (August 16, 2002). In 
addition to a large number of form letters (principally supporting the 
objections) and the NRDC's comments mentioned in Unit V.B., EPA 
received roughly 20 sets of substantive comments. These comments were 
for the most part from pesticide manufacturers and each requested 
denial of the objections. The most significant of these comments that 
pertain to imidacloprid are summarized in Unit V.B. EPA has not 
repeated comments in instances where they were made by more than one 
commenter.

B. Individual Comments

    1. The FQPA Implementation Working Group. Extensive comments were 
filed by the FQPA Implementation Working Group (IWG), an organization 
comprised of associations representing pesticide

[[Page 30049]]

manufacturers, growers, and food processors. (Ref. 21). The IWG 
comments provided two alternative approaches as to why the NRDC's 
objections should be denied. First, the IWG asserted that EPA has 
misinterpreted the concept of ``aggregate exposure'' ever since passage 
of the FQPA, and once this interpretation is corrected, it becomes 
clear that the objections, for the most part, are flawed. Second, in 
the alternative, the IWG, assuming the EPA's aggregate exposure 
interpretation is retained, explained why the objections still are 
without merit.
    The IWG argues that, under the safety standard in section 408 of 
FFDCA, 21 U.S.C. 346a, the concept of aggregate exposure to pesticide 
chemical residues is restricted to aggregate exposure to pesticide 
residues in food. Id. at 5-6. To support this interpretation, the IWG 
cites to language in the safety standard tying aggregate exposure to 
exposure to ``pesticide chemical residues.'' The term ``pesticide 
chemical residue,'' the IWG notes, is defined as ``a residue in or on 
raw agricultural commodity or processed food of . . . a pesticide 
chemical . . . .'' 21 U.S.C. 321(q). Under the IWG interpretation, EPA 
would not be permitted to consider, in making safety determinations on 
tolerances, exposures to pesticides in drinking water, exposures to 
pesticides resulting from application of pesticides in residences or 
public spaces, or most of the farm children exposures forming the basis 
of NRDC's objections. Such an interpretation clearly defeats most of 
the NRDC's claims regarding the children's safety factor and estimation 
of aggregate exposure.
    The IWG also offers a backup legal argument which would, in 
execution, reach much the same result. It asserts that even if non-food 
exposure is properly considered under section 408 of FFDCA, any non-
food exposure must meet the ``reliable data'' requirement in section 
408(b)(2)(ii) of FFDCA. The IWG defines ``reliable data'' to mean 
``information to allow OPP to make a reasonable estimate of the actual, 
real-world exposure distribution to add to information on dietary 
exposure so that probabilistic estimates of aggregate exposure can be 
made.'' Id. at 10. According to the IWG, the EPA generally does not 
have data meeting this standard as to ``exposure from drinking water or 
from residential or other non-occupational exposure routes.'' Id. at 9. 
Thus, the IWG's legal interpretation of the ``reliable data'' 
requirement basically gets the IWG to the same place--EPA should not be 
considering non-food pesticide exposures in making safety 
determinations under section 408.
    Not resting on these legal arguments, the IWG provided detailed 
comments on several other of the claims in the NRDC objections, 
including the following:
    a. Drinking water exposure models. Noting that NRDC claims that 
EPA's drinking water models are not conservative, the IWG points out 
that NRDC ``gives no reasons for this assertion.'' Id. at 12. The IWG 
takes the contrary view arguing that the models are very health 
protective (conservative) ``because their input parameters are 
extremely conservative.'' Id. at 11. In support, the IWG notes that EPA 
models ``assume maximum [pesticide] application rates, 100% of crop 
area treated with a maximum fraction of the watershed planted to the 
modeled crop, maximum number of applications per year, minimum 
application intervals for multiple applications of the pesticide, and 
upper-bound aerobic half-life estimates in soil.'' Id. at 12. The IWG 
also cites to data collected by EPA and the U.S. Geological Survey 
showing ``concentrations of 178 pesticides and their degradation 
products in both raw surface water and finished drinking water from 
twelve water-supply reservoirs were all substantially less than those 
predicted by EPA's computer models, FIRST and PRZM/EXAMS-Index 
Reservoir.'' Id.
    b. Farm children subgroup. The IWG argues that NRDC's farm children 
subgroup is not an ``identifiable subgroup'' within the meaning of the 
statute. Rather, the IWG contends the NRDC's subgroup is ``a whole 
series of different groups, including children who live on farms, 
children who play near agricultural land, children who attend schools 
near agricultural land, children who work on farms, children whose 
family members work on farms, children whose family members handle 
pesticides as part of their jobs (whether on farms or not), and 
children who live in ``agricultural communities'' (whatever that 
means).'' Id. at 13. The IWG asserts that these groups ``have nothing 
in common other than that they are all children.'' Id. Further, the IWG 
argues that the FQPA directs EPA to consider ``major identifiable 
subgroups of consumers'' and that NRDC has not demonstrated that there 
is anything identifiable about the consumption patterns of its farm 
children subgroup. Id. at 14.
    c. Farm children's pesticide exposure. The IWG questions whether 
NRDC has shown that children who live on farms face higher exposure to 
pesticides noting that ``NRDC has cited selective results from 
epidemiological studies that relied on retrospective self-reporting 
regarding use of pesticides.'' Id. The IWG presented preliminary data 
from a study funded by pesticide and chemical companies and 
associations. According to the IWG, the results of this study showed 
that ``urinary concentration [of pesticides] was associated with direct 
handling and application of pesticides. However, for children and 
spouses not involved in pesticide handling and application, exposures 
were low and did not vary appreciably by day of study.'' Id. at 15 
(emphasis in original).
    d. Pesticide exposure from food purchased at farm stands. The IWG 
challenges the NRDC's assertion that levels of pesticide residues in 
foods purchased at farm stands are higher than residue levels in food 
purchased at other retail outlets. The IWG notes that ``NRDC does not 
provide information to support its allegations, and we are not aware of 
any credible data to suggest that this is the case.'' Id. at 16. The 
IWG cites two demonstrable reasons undermining NRDC's claim: First, 
label directions and restrictions on pesticide use apply equally to 
food grown for sale at farmstands and food grown for distribution 
through broader channels of trade; and second, ``[t]he various 
circumstances (weather, pest pressure, etc.) that affect residue levels 
resulting from a given treatment regimen are the same for those who 
grow crops to market through wholesale channels and for those who grow 
crops to sell at retail.'' Id. Finally, the IWG notes that assuming 
residue levels are at the tolerance value would vastly overstate 
exposure amounts given that FDA data has shown ``no pesticide residues 
in 41% and 73.5% of fruit and vegetable samples and either no residues 
or below tolerance residues in 99.5% and 98.9% of fruit and vegetable 
samples.'' Id. at 17.
    e. Regional consumption of blueberries. The IWG disputes NRDC's 
assertions regarding higher consumption of blueberries in regions that 
produce the crop. The IWG notes that there is both a national and 
international market for blueberries that makes blueberries widely 
available throughout the United States for several months of the year 
as a fresh commodity and available year round in the frozen state, the 
condition in which over half of the U.S. blueberry crop is marketed. 
Id. at 18.
    2. Inter-Regional Research Project Number 4 (IR-4). The IR-4 is a 
program sponsored by USDA and land grant universities and directed 
toward obtaining regulatory approval for pesticide uses on minor and 
speciality

[[Page 30050]]

food crops that are not likely to be supported by private sector 
companies. In its comments, the IR-4 notes that several of the 
pesticides covered in the objections--diflubenzuron, imidacloprid, 
halosulfuron-methyl, and fenhexamid--are both ``critical to minor crop 
growers'' and safer, reduced risk pesticides. (Ref. 27). The IR-4 
asserts that diflubenzuron and imidacloprid provide alternatives to the 
organophosphate pesticides and that halosulfuron-methyl is a methyl 
bromide alternative. Id.
    3. Bayer CropScience. Bayer CropScience notes that the required DNT 
has been submitted for imidacloprid. (Ref. 3 at 1). Bayer CropScience 
asserts that the 3X children's safety factor imposed by EPA should now 
be removed because the ``a clear NOEL was established'' in the DNT. Id. 
at 2. Bayer CropScience also claims NRDC errs in contending that 
percent crop treated data was relied upon by EPA for blueberries. Bayer 
CropScience cites 66 FR 18554, 18556 (April 10, 2001) as showing that 
100% crop treated was assumed for blueberries in EPA's risk assessment. 
Id. at 10.

VI. Response to Objections

    NRDC objected to EPA's extension of a temporary tolerance for the 
residues of imidacloprid on blueberries. See Imidacloprid et al. 
Objections at 1. That tolerance extension expired on December 31, 2003. 
See 67 FR 2580 (January 18, 2002). As the objected-to tolerance is no 
longer in existence, NRDC objections are denied as moot. Nonetheless, 
NRDC's objections remain relevant to the petition that Interregional 
Research Project Number 4 filed to establish a permanent tolerance for 
imidacloprid on blueberries. 68 FR 5880 (February 5, 2003) (petition 
for imidacloprid tolerance on the crop group bushberries which includes 
blueberries). EPA has analyzed NRDC's objections, and considering them 
in light of the currently available information on imidacloprid, has 
decided to establish the permanent tolerance for imidacloprid on 
blueberries. EPA's analysis of the NRDC objections and the comments 
received on the objections is below.
    As noted in Unit II.A., if NRDC refiles the same objections to the 
re-established imidacloprid tolerance relying solely on the information 
and arguments already presented, EPA will re-issue this comment 
response as a response to NRDC's objection forthwith. If, however, NRDC 
adds new issues, cites new information, or makes new arguments in 
support of its objections, EPA will have to analyze and respond to 
these new items before issuing a response.

VII. Analysis of the Issues Raised by NRDC's Objections

    EPA has considered all of the issues raised by NRDC in its 
imidacloprid objections in acting on the petition to re-establish the 
imidacloprid tolerance on blueberries. For the reasons explained below, 
EPA concludes that the safety concerns with the imidacloprid tolerance 
asserted by NRDC are without merit.
    One consistent theme emphasized by NRDC in its objections is the 
potential heightened exposure of ``farm children'' to pesticides. 
Accordingly, EPA begins analysis of the issues raised by the 
objections, in Unit VII.A., with an examination of the data bearing on 
children's exposure to pesticides in agricultural areas. Then EPA turns 
to NRDC's more specific claims. Unit VII.B. addresses issues regarding 
the children's safety factor. Unit VII.C. covers aggregate exposure 
questions. Unit VII.D. responds to claims regarding use of LOAELs and 
NOAELs.

A. Children's Exposure to Pesticides in Agricultural Areas

    Children can be exposed to pesticides through multiple sources and 
pathways. The Agency currently considers children's exposure to 
pesticides by three broad pathways: Food, drinking water, and 
residential use. NRDC, however, has asserted that children residing in 
agricultural communities also are significantly exposed to agricultural 
pesticides through additional exposure pathways.
    Children in agricultural areas may be exposed to agricultural 
pesticides through pathways such as contact with treated fields, 
roadsides and other areas; contact with moving spray drift while near 
application areas; contact with spray drift residues left by any spray 
drift that may reach their homes, yards or other areas they frequent, 
such as schools and schoolyards; and contact with pesticide residues 
that have volatilized after application. In addition, some of these 
children may also be exposed to agricultural pesticides in their homes 
via other pathways.
    In analyzing the potential exposure of children in agricultural 
areas, EPA first focused on data from studies relied upon by NRDC or 
otherwise known to EPA that attempted: To measure levels of pesticides 
in the homes of children in agricultural areas; to measure levels of 
pesticide metabolites in body fluids of children in agricultural areas; 
and/or to compare levels of pesticide exposure of farm children to 
those experienced by non-farm children, based on similar types of 
measurements. In addition, EPA examined data NRDC submitted relating to 
airborne levels of pesticides (stemming from spray drift or 
volatilization) in farm communities. Finally, EPA reviewed data it has 
concerning the potential for pesticides to drift offsite during 
application.
    Although EPA discusses its views concerning this data in more 
detail below, those views can be summarized as follows. First, the data 
concerning levels of pesticides in homes or children's bodily fluids 
are limited and inconclusive, and do not demonstrate that children in 
agricultural areas as a group receive more pesticide exposure than 
children in non-agricultural areas. (In fact, some data suggest that 
pesticide residues in houses in urban or non-agricultural areas may be 
higher than those in houses in agricultural areas.) Second, even if 
airborne pathways such as volatilization may lead to significant 
exposures to some pesticides, imidacloprid would not be one of those 
pesticides. Finally, data already gathered by EPA and processed through 
EPA's Spray Drift Model show that the highest off-target deposition 
levels from agricultural applications occur adjacent to the treated 
area and that deposition levels decrease with increasing distance from 
the treatment area; moreover, and in any event, any spray drift from 
agricultural applications of imidacloprid, which has residential uses 
on turf and pets, is largely irrelevant to the pesticide's aggregate 
exposure assessment, because any estimated exposure from spray drift 
would be dwarfed by estimated exposure from the lawn and pet use.
    1. Studies focusing on exposure to children in agricultural areas. 
In examining the first set of data, EPA found it useful to concentrate 
first on what the cited studies showed regarding exposure levels in the 
children's immediate environment. These types of studies have tended to 
focus on exposure levels in the children's homes, with an emphasis on 
the level of pesticide residues in house dust. Second, EPA examined the 
data bearing on the actual exposure children received in agricultural 
areas as compared to the actual exposure levels of children in non-
agricultural areas.
    a. Potential for exposure due to heightened pesticide levels in the 
homes of farm children. NRDC's argument that farm children experience 
higher pesticide exposures than other children relies primarily on 
studies purporting to show that there are higher environmental levels 
of pesticides in and around the homes of farm children.

[[Page 30051]]

 Leaving to one side, for the moment, the issue of whether such 
elevated environmental levels of pesticides actually increase farm 
children's exposures, EPA first has focused on whether such elevated 
levels actually exist. In evaluating this question, EPA has 
concentrated on the levels of pesticides in house dust, because nearly 
all the contemporary literature addressing the potential exposure of 
farmworker children to agricultural pesticides includes a discussion or 
measurements of pesticide concentrations in house dust. This matrix is 
now widely recognized as a potential reservoir for many environmental 
pollutants, including pesticides. In addition, EPA has reviewed not 
only studies submitted by NRDC, but also other studies known to EPA. 
(Ref. 40).
    The house dust evidence, contrary to NRDC's view, is fragmentary at 
best as to whether there exists a potential for higher exposure to 
``farm children'' due to higher environmental contamination of the 
homes of such children. For example, house dust samples collected from 
diverse locations such as Cape Cod, MA; Long Island, NY; Iowa City, IA; 
Detroit, MI; Seattle, WA; and Los Angeles County, CA have been compared 
to house dust samples taken from the homes of farm workers in 
agriculturally intensive Yuma County, AZ. Contrary to NRDC's general 
hypothesis, in Yuma County, the 90\th\ percentile dust concentrations 
([mu]g)/g) for the pesticides chlorpyrifos, diazinon, carbaryl, 
propoxur, and the disinfectant ortho phenylphenol all were lower than 
those in most, if not all, of the aforementioned urban areas.(Ref. 8). 
This may well be due to the fact that, in addition to being 
agricultural pesticides, all of these pesticides are widely used 
residential pesticides, which may be used substantially in urban areas 
as well.
    Studies also have been performed in the agricultural area around 
Wenatchee, WA, which is situated in the heart of the apple growing 
region in that state. For example, Simcox et al. (Ref. 63) designed a 
study of housedust and soil samples in this area in an attempt to 
determine whether children of agricultural families were exposed to 
higher levels of pesticides than children whose parents were not 
involved in agriculture. Forty-eight applicator and fourteen reference 
families were recruited to participate. Families living within 200 feet 
of an orchard were classified as agricultural families, while families 
living in homes more than one-quarter mile from an orchard were 
classified as reference families. Pooled house dust measurements were 
taken from two locations in each house:
     Three feet inside the entry way.
     In the children's play area.
    This study's authors reported significantly higher indoor dust 
levels of azinphos-methyl, chlorpyrifos, and parathion in agricultural 
homes as compared to the reference homes. Analysis of the pesticide 
residues in the soil and house dust samples showed that the pesticide 
residues present were of agricultural origin, demonstrating in the 
authors' view that children of agricultural families have a higher 
potential for exposure to agricultural pesticides than children of non-
farm families. In addition, the authors concluded that proximity to 
agricultural spray areas appeared to be the predominant but not 
exclusive explanation of the increased soil concentrations.
    The study's authors, however, focused on a specific and perhaps 
unique geographic area. As other study authors have reported, 
Wenatchee, WA, can be characterized as being situated in an area of 
canyons ``conducive to wind patterns responsible for spray drift'' 
(Ref. 11). The site-specific characteristics of this area may not 
necessarily apply to other agricultural areas, such as those like Yuma 
County, which, as mentioned in this unit, is situated on a riparian 
flood plain, and is distinct from the canyons of the Wenatchee area in 
terms of cropping systems, application techniques and topography. In 
fact, when University of Washington investigators began assessing house 
dust concentrations of farm worker houses in the Lower Yakima Valley of 
Washington, an area of that state that is more expansive than the 
Wenatchee area, they did not observe an association between proximity 
to fields and house dust concentrations. Rather, these investigators 
observed a stronger correlation between house dust concentrations and 
dust concentrations in vehicles used by farm workers to commute to and 
from work. (Ref. 11). In addition, for chlorpyrifos, a pesticide once 
having both residential and agricultural uses, the range of house dust 
concentrations reported by Simcox (Ref. 63) (<0.02-3.6 [mu]g/g) was 
exceeded by the median value house dust concentration from non-
agricultural family homes (4.7 [mu]g/g; n=9) reported in Jacksonville, 
FL. (Ref. 22).
    b. Whether farm children actually experience increased exposure. 
Assuming for the purposes of argument, moreover, that contaminated 
house dust may indicate activity patterns (in addition to tracked-in 
drift) that can lead to the potential exposure of young children to 
agricultural pesticides in residential environments (Ref. 9 and Ref. 
5), the challenge would remain to find an association between house 
dust concentrations and indications of dose based on measurements of 
biomarkers of pesticides in farm worker's children. The evidence 
likewise is fragmentary, at best, on this point.
    Fenske et al., for example, ``were unable to demonstrate a strong 
relationship between housedust concentrations and biological levels,'' 
i.e., levels in study participants, in Wenatchee area residents. (Ref. 
14). These researchers suggested that this was due to several factors, 
including the tendency of the vacuum system used to capture ``particles 
from deep carpet'' areas that ``may not represent chemical available to 
children during normal residential activity.'' The researchers also 
pointed to ``the complexity inherent in children's exposures'' through 
``intermittent contact with surfaces [and] variable hand-to-mouth 
behaviors,'' as well as the ''relatively high variability'' associated 
with the spot urine sampling method used to obtain biological values.
    Similarly, although Simcox et al. demonstrated the potential 
migration of agricultural chemicals from an application site to a 
residence under the unique circumstances of the Wenatchee study, they 
also questioned the relevance of house dust concentrations in samples 
collected by the vacuum system used in the study. Like Fenske et al., 
Simcox and colleagues were not sure if the house dust measurements 
taken with the system were representative of the house dust routinely 
encountered by children living in those homes. It was suggested that 
biological monitoring of these young children ``may serve as an 
appropriate and noninvasive means of sampling exposure among small 
children.''
    For other reasons as well, these and other studies have provided 
little data to support either the hypothesis that pesticide levels in 
house dust are correlated to exposure levels or the hypothesis that 
children in agricultural areas generally receive significantly higher 
exposure to pesticide residues than children in the general population.
    i. Studies allowing comparison of children from agricultural and 
non-agricultural areas. In Fenske 2000a, for example, Fenske et al. 
compared the DMTP (dimethylthio phosphate) concentrations reported in a 
1995 study of the Wenatchee population with those measured in Seattle 
children, and found that concentrations from the Seattle

[[Page 30052]]

children (Ref. 32) appeared to be similar to those of the Wenatchee 
reference population--i.e., children in an agricultural area. This 
suggested that biological pesticide metabolite levels for agricultural 
and non-agricultural children were very similar. Therefore, even if 
agricultural children could be said to have the potential for more 
routes of exposure, they were not more highly exposed. (Quite possibly, 
the metabolites found in the urine represent exposure to the breakdown 
products themselves rather than to the parent compounds. (Ref. 15).
    Work performed by Higgins et al. (2001) also allows a comparison of 
agricultural children to non-agricultural children. This study measured 
cholinesterase levels as a biomarker of organophosphate pesticide 
exposure in a group of migrant farm workers and their children. The 
researchers collected blood samples from two groups of Hispanic 
children (age 3--6 years) in the summer of 1997 to compare 
cholinesterase levels in populations with varying degrees of contact 
with agriculture, and hypothetically varying levels of contact with 
organophosphate pesticides. Ninety-eight migrant Hispanic farm worker 
children (50% male, 50% female) were recruited from two counties in 
Oregon. (Ref. 25). A seasonally and age-matched comparison group of 53 
Hispanic, non-agricultural family children (64% male, 36% female) was 
also recruited in 1998 from two non-agricultural areas in Oregon. 
Results from these two groups showed that cholinesterase levels were 
not significantly different between the agricultural and non-
agricultural children (analysis of variation (ANOVA), p=0.69). (Ref. 
25). A further analysis of the data using a multiple regression model 
to account for potential age and gender effects also supported the 
conclusion of no significant difference between the two groups. (Ref. 
25).
    Finally, in its report entitled Pesticide Exposure and Potential 
Health Effects in Young Children Along the U.S.-Mexico Border, EPA 
concluded that:
    population distributions of OP [organophosphate] pesticide 
exposure in children (either living in close proximity to 
agricultural fields, i.e., Yuma Study, or being admitted to health 
clinics with flu-like symptoms, i.e., Symptomatic Children Study) as 
measured by alkyl phosphate metabolites are not significantly 
different than population distributions of OP pesticide exposure for 
the general population as measured by NHANES III Studies [National 
Health and Nutrition Examination Survey conducted by the Department 
of Health and Human Services].
(Ref. 67)
    ii. Studies focusing solely on children from agricultural areas. 
Other studies have focused solely on children in agricultural areas, 
including studies performed in the Wenatchee area by Fenske and his 
colleagues at the University of Washington. Loewenherz et al. (1997), 
for example, used members of the Wenatchee study population (48 
applicator families and 14 Wenatchee-area reference families) to 
evaluate and compare levels of OP pesticide metabolites in urine. Their 
study aimed specifically to:
     Measure urinary metabolite levels of OP pesticides in 
children living with occupationally exposed parents.
     Compare these with a reference population.
     Evaluate the relative importance of the para-occupational 
exposure pathway.
 One hundred sixty spot urine samples were collected from 88 children, 
including repeated measures 3-7 days apart. Because the researchers 
detected DMTP with far greater frequency than any other alkylphosphate, 
they chose it as this population's most appropriate biomarker of 
exposure. Over two sampling rounds, however, Loewenherz and colleagues 
detected statistically significant differences in the frequency of DMTP 
detectability among applicator and reference children in only one 
round, and those differences were only marginally statistically 
significant. From this one exposure event, there was no way to conclude 
what the potential for exposure could be for each population 
participating in this study. Moreover, the sample sizes represented by 
the populations were small, and thus diminished the value of the study 
in general.
    The Loewenherz team, moreover, did not address the potential 
sources of exposure to pesticides from gardens, pets, lawns, and diet. 
Although the researchers recognized that this population's use of 
residential pesticides was less than the national average, it is still 
possible that exposures from air, dietary intake, and pesticide use in 
other settings where the children may have spent time (i.e., day care 
centers, homes of others) may also have contributed to observed urinary 
metabolite concentrations. (Ref. 31). In fact, misuse of a non-
residential pesticide for residential purposes was reported in the 
study. This may have had a significant impact on the urinary metabolite 
levels reported in this paper, as two of the three highest measurements 
in the study came from these households.
    In addition, a comparison of the exposures of the farm worker 
children to the farm workers themselves suggested that it was unlikely 
that the exposures experienced by the applicator children in the 
Loewenherz study were sufficient to produce acute health effects. (Ref. 
31). Finally, a strong relationship between pesticide house dust 
concentrations and biological levels in these children was not found. 
(Ref. 14).
    Using a larger cohort (109 children) from the same region, Lu et 
al. (2000) collected environmental and biological samples to evaluate 
the total potential exposure of agricultural and reference children. 
The researchers took spot urine samples, as well as hand wipe samples, 
house and vehicle dust samples, and surface wipe samples from various 
surfaces (including steering wheels and work boots). Environmental 
measurements indicated that children living with parents who work with 
agricultural pesticides (applicator children), or who live in close 
proximity to pesticide-treated farmland, have the potential for higher 
exposures than do other children living in the same community. (Ref. 
33). However, dimethyl OP pesticide metabolite levels in the urine of 
agricultural and reference children showed only a marginally 
significant difference. Id. The children of farm workers, moreover, had 
the same range of urinary DMTP as the reference children, and less 
urinary DMDTP (dimethyldithio phosphate) than applicator children. Diet 
is likely to have been an important contributor to metabolite 
concentrations. Id. Interestingly, 23 agricultural families that 
participated in this study also participated in the study reported by 
Simcox et al. (Ref. 63). Of these, the four homes that had the highest 
house dust concentrations in 1992 had lower concentrations in 1995. 
Overall, 16 of 23 households reported lower house dust concentrations 
than in the previous study, suggesting that changes in activity 
patterns can influence levels of pesticides in house dust.
    In addition to the azinphos-methyl and phosmet results reported in 
Lu et al. (2000), Fenske et al. (2002) measured chlorpyrifos and 
parathion in environmental samples from the homes of the same 109 
children and those chemicals' metabolic by-products in biological 
samples from the children themselves. In their study, Fenske et al. 
relied on more specific urinary metabolites of the diethyl, OP parent 
compounds. For chlorpyrifos, the researchers used the metabolite 3,4,6-
trichloro-2-pyridinol (TCPy) as a biological measure, and for parathion 
they used 4-nitrophenol as the biological measure. Environmental

[[Page 30053]]

pesticide loadings, however, could not explain the biological levels 
measured. (Ref. 13). Fenske et al., stated that the use of OP 
pesticides in gardens was associated with an increase in the TCPy 
concentrations in children's urine. However, no explanation was offered 
for this association. Unfortunately, TCPy is a ubiquitous compound in 
the environment and exposure could still be associated with exposure to 
both chlorpyrifos and TCPy. The authors reported that most children 
studied did not have measureable urinary levels of metabolites of 
either chlorpyriphos or parathion. The study concluded that children 
living in homes including household members who worked with 
agricultural pesticides or that were close to pesticide treated 
farmland did not appear to have increased pesticide exposures, even 
though their homes showed elevated levels of pesticide concentrations 
in house dust.
    Using the data gathered in their field studies, Fenske and 
colleagues (2000b) also compared spray season and single-day dose 
estimates for agricultural and reference children, but only showed a 
marginal difference between the two cohorts. (Ref. 15). Moreover, a 
majority of the children classified as reference children had 
measurable dialkylphosphates in their urine, and a substantial fraction 
had doses that exceeded the reference values for azinphos-methyl. Id.
    An additional team based at the University of Washington examined 
571 farm workers involved in a community intervention project in the 
Washington State's Lower Yakima Valley. This project is presented in 
Thompson et al. (2003) and Curl et al. (2002) (Refs. 66 and 11). The 
cohort consisted of field workers and pesticide handlers (e.g., 
applicators). Questionnaires regarding self reported pesticide exposure 
and common sense methods to reduce para-occupational exposure were 
evaluated. Sub-samples of urine and other environmental media (house 
and vehicle dust) were taken to establish baseline exposure levels of 
the intervention and control groups. Intervention was described as 
individuals performing common sense hygiene practices such as removing 
footwear prior to entering the house.
    Based on this research, both Thompson et al and Curl et al. 
reported a significant association between levels of dialkyl phosphates 
(DAP, a class of breakdown products of organophosphate pesticides) in 
urine of adults and their children. There was also a significant 
association between house dust and vehicle dust. However, Curl et al 
did not report an association between house dust and proximity to 
fields and orchards. The DAP metabolites measured were DMP (dimethyl 
phosphate), DMTP, DMDTP, DEP (diethyl phosphate), and DETP (diethylthio 
phosphate), and may represent exposure to numerous pesticides from 
several pathways including diet and pathways associated with 
residential use of pesticides. The authors speculate that it is also 
possible that some workers may have taken agricultural chemicals from 
work for home use.
    It has been suggested that the removal of shoes prior to entering 
the house, or the use of entry mats, can significantly lower the amount 
of pesticide tracked-indoors. (Ref. 38). Other investigators have 
observed mixed or inconclusive results. (Refs 33, 11 and 66). When Curl 
et al. (Ref. 11) compared concentrations of urinary DAPs and OP 
concentrations in house dust and vehicle dust between two groups 
(Intervention and Control, Lower Yakima Valley), no significant 
differences were seen. The intervention group performed activities such 
as washing hands after work, removing footwear prior to entering the 
house, washing work clothing separately, and removing work cloths 
before holding children. If intervention has no impact, it is not clear 
then whether para-occupational pathways are indeed significant. In 
general, Thompson et al. (Ref. 66) saw no differences regarding hygiene 
practices such as removing shoes prior to entering the house between 
households having children and those that did not. However, the authors 
suggested the need for continuing current educational efforts. As 
compared to field workers, pesticide handlers were more likely to 
perform protective practices such as washing hands immediately after 
work and removing work clothing before holding children. Yet, in other 
studies, concentrations in urine were higher among children of 
applicators than among children of field workers. (Ref. 33).
    Finally, Mills and Zahm (Ref. 34) conducted a feasibility study to 
obtain urine samples from farm workers and their children in an area of 
extensive OP use. They tested for six urinary metabolites of OPs, 
including DMP, DEP, DMTP, DMDTP, DETP, and DEDTP. They also compared 
the levels between adults and children living in the same households. A 
total of 27 individuals from 9 families (18 adults and 9 children) were 
selected to participate. Levels of OP metabolites were generally very 
low in both adults and children in this survey. The frequencies of 
detection of DMP, DMTP, and DETP were higher among Fresno-area farm 
workers and their children than among the general population sampled 
during the National Health and Nutrition and Examination Survey 
(NHANES) II survey. However, informational data on pesticide use 
practices in the U.S. general population supplied by the authors 
suggested that this comparison was unfair, since NHANES II was survey 
data collected through 1980, when the prevalence of OP pesticide use 
was only just beginning to increase. In a second comparison, Mills and 
Zahm showed that the frequencies of detection and mean levels of DMTP 
among Fresno children were intermediate between those found by Fenske 
and his co-workers among Wenatchee, Washington applicator and reference 
children. Id. No statistical analyses were conducted on these data 
comparisons. Thus, it was unclear whether the urinary metabolite levels 
seen in the Fresno children were significantly different from the 
applicator and reference children studied in Washington State.
    iii. Ongoing research on farm children exposures. Preliminary 
information from the Farm Family Exposure Study (FFES) conducted by 
investigators at the University of Minnesota and Emory University bears 
on the question of whether farm children have higher levels of 
pesticide exposure than non-farm children, and whether farm children 
should be identified as a major, identifiable subgroup of consumers. In 
this study, researchers identified urinary pesticide concentrations for 
95 farm families before, during, and for 3 days after an application of 
glyphosate, 2,4-D or chlorpyrifos. In their preliminary reporting of 
results, the researchers stated that they found `` appreciable 
variation by chemical in the proportion of farm family members with 
detectable urinary concentrations.'' See http://www.farmfamilyexposure.org/html/abstracts.html#ser/. However, it was 
only in the case of farmers--not spouses and children--that the 
researchers claimed to have detected significant differences in urinary 
pesticide concentrations and patterns of uptake and elimination. Id. 
``For the vast majority of spouses and children, urinary concentrations 
did not change appreciably after pesticide application.'' Id. Moreover, 
the researchers asserted, based on their findings, that ``little 
pesticide exposure is received through . . . living on a farm, per 
se,'' and that it is the following, specific behaviors instead that are 
associated with elevated pesticide exposure for farm children:
     ``[d]irect contact with chemicals in the mixing or 
application area.''

[[Page 30054]]

     ``[w]orking as a co-applicator.''
     ``[t]ouching containers without gloves.''
     ``[p]laying barefoot in the area where pesticides are 
being mixed and loaded[.]''
See http://www.farmfamilyexposure.org/html/the_study.html html.
    EPA recognizes that these representations of the researchers are 
only preliminary. Nevertheless, the fact that the FFES researchers' 
preliminary views point in the same direction as the analysis above 
should not escape note.
    In sum, as discussed in this unit the studies and information, 
whether concerning children in agricultural areas and non-agricultural 
areas or children in agricultural areas alone, and whether concerning 
environmental levels, biological levels, or both, shows that there is 
little or no evidence to indicate that EPA has ignored a significant 
source of exposure in calculating the potential aggregate exposure from 
pesticides.
    c. Conclusion. In conclusion, the limited number of studies 
containing data relevant to NRDC's arguments, taken together, fail to 
demonstrate that children in agricultural areas experience 
significantly higher levels of exposure than children in non- 
agricultural areas. In EPA's judgment, the weight of currently 
available evidence relating to pesticide residues in house dust or on 
other surfaces fails to establish that children living in agricultural 
areas or children living nearer to agricultural pesticide use areas 
experience higher exposures to pesticides than children in the general 
population. Similarly, biomonitoring data available for comparing the 
levels of pesticide exposure experienced by agricultural children with 
other children is fragmentary and does not show that there are 
significant differences between these groups of children. Thus, 
regardless of whether such children constitute a ``major identifiable 
subgroup of consumers,'' it does not appear that such children 
consistently receive more pesticide exposure than the groups of 
children (those at the upper percentile of estimated exposure) used by 
EPA in its current approach to assessing aggregate risk.
    This is not to say, however, that issues addressed in these 
materials do not bear further research. On the contrary, the government 
is engaged in or supporting, or has recently engaged in or supported, 
relevant research in a number of ways. These efforts include, for 
example, the Minnesota and South Carolina study discussed in this unit. 
These efforts also include:
     A similar study which the federal government itself is 
conducting with children in North Carolina and Iowa.
     A systematic analysis which EPA is undertaking to review 
the raw data underlying the Wenatchee, WA area and Yuma County, AZ 
studies discussed in this unit.
     A study of pesticide exposure pathways for farm workers' 
children in the Yakima Valley.
     An assessment of sources of pesticide contamination, 
concentrations in pathways, and exposure-prone behavior in Salinas, CA.
     A study of ingestion of pesticides by children in an 
agricultural community on the U.S./Mexico border.
     An assessment of exposure of children to pesticides in 
Yuma County, AZ.
EPA will review the results of this ongoing research and take 
appropriate steps to address any exposure concerns regarding children 
that are documented.
    2. Supplemental information regarding spray drift and drift of 
volatilized residues. On June 19, 2003, NRDC supplemented its 
submission to the Agency with several pieces of additional information. 
Included was a report generally addressing the issue of spray drift 
from pesticide applications in California (Ref. 7) (hereinafter cited 
as the CFPR Report). Although EPA defines spray drift as the movement 
of droplets off-target during or shortly after application, which is 
independent of the chemical properties of the pesticide being sprayed, 
the CFPR Report looked more broadly at atmospheric pesticide transport 
including pesticide volatilization as a potential mechanism by which 
pesticides travel beyond treated fields.This section of the document 
discusses drift as a result of volatilization. Drift of the pesticide 
spray is addressed in the following section of the document. Also 
included in NRDC's supplemental information was a research article 
entitled ``Community Exposures to Airborne Agricultural Pesticides in 
California: Ranking of Inhalation Risks,'' containing an analysis of 
the degree of inhalation risk posed by certain migrating pesticides in 
California, based on ambient air monitoring data gathered, in part, by 
the California Air Resources Board and the California Department of 
Pesticide Regulation. (see Ref. 29, hereinafter referred to as the 
Ranking Study). EPA is still examining the information in these studies 
but presents its preliminary views on these studies in this unit.
    The Ranking Study conducted screening level assessments for many of 
the pesticides ranked as having the highest potential as toxic air 
contaminants as well as several pesticides categorized as hazardous air 
pollutants. The screening level assessment only identified four soil 
fumigants as potentially presenting non-cancer acute or chronic risks 
of concern. Id. at 1179. The study concluded that ``vapor pressure is a 
significant predictor of [] ranking of inhalation risks.'' Id. at 1182. 
The CFPR Report examined the potential health risks from air levels of 
three pesticides characterized as moderate to highly volatile 
(chlorpyrifos, diazinon, and molinate) measured at the field boundary 
and at more distant locations. The Report concluded that in many 
instances the measured air levels of these pesticides posed risks of 
concern. The Report also concluded that drift due to volatilization was 
not a concern for pesticides that are not highly volatile. CFPR Report 
at 40.
    Even assuming that volatilization may lead to significant exposures 
to some pesticides, imidacloprid would not be one of those pesticides. 
EPA is in general agreement that vapor pressure is the key factor in 
predicting whether a pesticide has the potential to volatilize and 
drift offsite in significant amounts. Because soil fumigants 
traditionally have very high vapor pressures, and thus are highly 
volatile, EPA is now accounting for potential exposure due to 
volatilization of these pesticides in calculating their aggregate 
exposure. Imidacloprid is a solid at room temperature with a low vapor 
pressure (1.5 x 10-\9\ mmHg). In fact, imidacloprid's vapor 
pressure is not only much lower than pesticides used as soil fumigants, 
it is also substantially lower than the pesticides presented in NRDC's 
supplementary submission: chlorpyrifos (1.87 x 10-\5\ mmHg); 
diazinon (1.4 x 10-\4\ mmHg); molinate (5.3 X 
10-\3\ mmHg). Thus, any losses due to volatilization for 
imidacloprid are expected to be minimal at most.
    3. EPA Data on Spray Drift and the Spray Drift Model. EPA has 
gathered substantial data on the potential of pesticides, as applied, 
to drift offsite through the work of the Spray Drift Task Force (SDTF). 
The SDTF is a group of pesticide registrants who have worked 
collaboratively to develop a database to meet the majority of their 
collective spray drift data requirements under 40 CFR 158.440. The 
group was chartered on April 17, 1990, and its formation was announced 
in PR Notice 90-3. Since its formation, the SDTF has generated 
standardized data on spray drift levels resulting from different 
application methods under varying meteorological conditions. The data 
developed by the

[[Page 30055]]

SDTF was reviewed by EPA internally, through external peer review 
workshops, and through FIFRA Scientific Advisory Panel meetings. The 
reviews generally identified the data set associated with aerial 
applications to be the most robust, followed by the data sets from 
ground boom applications, orchard/vineyard airblasting, and 
chemigation, respectively. After the spray drift data were available, 
the SDTF worked with EPA's Office of Research and Development, as well 
as the USDA's Agricultural Research Service and Forest Service to use 
the data in the development/evaluation of the AgDRIFT model. (See 
generally Refs. 4, 24, and 65).
    The AgDRIFT model and the SDTF data show that the highest off-
target deposition levels from agricultural applications occur adjacent 
to the treated area and that deposition levels decrease with increasing 
distance from the treatment area. See Table 2 of this unit.

                                     Table 2.--High-end Downwind Spray Drift Deposition Levels by Application Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Spray drift deposition (percent of application rate)
                                    --------------------------------------------------------------------------------------------------------------------
     Lawn placement relative to                                                                       airblast\3\
          application area                                                          ----------------------------------------------
                                            aerial\1\            ground boom\2\                                 dense or tall           granular\4\
                                                                                        dormant orchards           canopies
--------------------------------------------------------------------------------------------------------------------------------------------------------
10 to 60 ft downwind                 34.1                    9.3                     25.0                   8.4                    0
------------------------------------
20 to 80 ft downwind                 31.6                    6.4                     16.1                   6.0                    0
------------------------------------
40 to 90 ft downwind                 27.9                    4.1                     8.0                    3.7                    0
------------------------------------
80 to 130 ft downwind                22.0                    2.4                     3.0                    1.9                    0
------------------------------------
160 to 210 ft downwind               14.9                    1.3                     0.8                    0.9                    0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ASAE very fine to fine spray, 10 mph wind, 10 ft release height and other standard AgDRIFT 2.01 default inputs.
\2\ Tier 1 AgDRIFT 2.01 ground boom inputs: 90\th\ percentile, high boom, fine spray.
\3\ Tier 1 AgDRIFT 2.01 airblast inputs: model outputs multiplied by 3 to approximate an upper 90\th\ percentile value.
\4\ Particle drift from granular applications is generally considered to be insignificant in EFED assessments.

    The AgDRIFT model helps EPA assess the relative [upper bound] 
magnitude of residues from direct residential use of a pesticide versus 
residues that might occur as a consequence of spray drift. As of yet, 
EPA has not included data from the AgDRIFT model as a standard 
component of its residential exposure assessments. In responding to 
NRDC's objections other than as to imidacloprid, EPA is still examining 
how this data informs the understanding of aggregate exposure generally 
and how this data can be considered in a meaningful way in assessing 
aggregate exposure. Nonetheless, even prior to completing this 
analysis, some conclusions can be made concerning pesticides such as 
imidacloprid which have broad residential uses. What the data for 
imidacloprid show is that predictions of exposure based on the spray 
drift model are largely irrelevant to the pesticide's aggregate 
exposure assessment because any estimated exposure from spray drift 
would be dwarfed by estimated exposure from the lawn and pet use. An 
explanation of EPA's residential exposure assessment for imidacloprid 
and the operation of the AgDRIFT model for imidacloprid will clarify 
this point.
    EPA estimates residential exposure by incorporating pesticide-
specific information in exposure scenarios that are built based on data 
on human behavior and human physical statistics (e.g., body surface 
area). (See Refs. 35, 55, and 61) EPA's scenario for estimating 
exposure due to turf uses assumes that children play for a substantial 
period (2 hours) on lawns immediately after treatment with the 
pesticide. The scenario models both dermal exposure from contact 
between skin (arms and legs) and the lawn and oral exposure resulting 
from soil ingestion, mouthing grass, and hand-to-mouth behavior 
(placing hands repeatedly in mouth after being in contact with treated 
lawn) (Refs. 35, 55 and 61). With the pet treatment, EPA also uses 
scenarios for both dermal and oral exposure. For dermal exposure, EPA 
uses a pet hug scenario which assumes a child hugs the pet immediately 
after treatment. EPA assumes that 20% of the applied dose is available 
on the surface of the pet for transfer to the child and that the child 
essentially wraps its full body around the pet such that one-half of 
the child comes in contact with the pet. The child is assumed to be 
wearing a short-sleeved shirt and short pants. EPA assumes 100% 
transfer where the child's skin touches the pet and 50% transfer to the 
child's skin where the child's clothing touches the pet (Refs. 35, 55 
and 61). For oral exposure, EPA used a combination of imidacloprid 
specific data and its standard exposure scenario. EPA had imidacloprid 
data on the transfer of imidacloprid to hands from petting dogs that 
was gathered by petting a treated dog 10 minutes after imidacloprid 
application wearing cotton gloves. EPA assumed that a child put its 
hand in its mouth 20 times/hour for 2 hours and each time the hand 
contained the exposure level measured on the glove. (See Ref. 44 at 51-
57 and Refs. 35, 55 and 61)
    Using these scenarios, EPA estimated the exposures and MOE's for 
imidacloprid residential exposures presented in Table 3 of this unit.

[[Page 30056]]



                                Table 3.-- Residential Exposures for Imidacloprid
----------------------------------------------------------------------------------------------------------------
                                                                 Exposure in milligram/
                 Use                      Route of exposure       kilogram/day (mg/kg/             MOE
                                                                          day)
----------------------------------------------------------------------------------------------------------------
Lawn                                   oral                                      0.0059                    1,700
                                      --------------------------------------------------------------------------
                                       dermal                                     0.001                   10,000
--------------------------------------
Pet                                    oral                                      0.0027                    3,600
                                      --------------------------------------------------------------------------
                                       dermal                                     0.036                      280
----------------------------------------------------------------------------------------------------------------

(Ref. 44 at 51-52).
    In calculating potential drift, it is important to consider the 
maximum amount that may be applied and the manner of application. 
Imidacloprid is approved for use on residential turf at 0.4 lb/acre/
year. This amount may be applied in a single application. This 
application rate is comparable to the maximum agricultural yearly rate 
(0.5 lb/acre/year) and exceeds most single agricultural application 
rates. Imidacloprid application methods differ for various crops with 
some uses being restricted to soil incorporation of granules and others 
permitting aerial spraying. The agricultural use that has the potential 
for the greatest spray drift is on cranberries. The label permits 
imidacloprid to be applied at 0.5 lb/acre/year for cranberries and that 
amount of pesticide may be applied in a single application. Further, 
the label does not prohibit, and therefore permits aerial application. 
For cranberries this would generally mean application from a 
helicopter. In EPA's experience aerial application to cranberries is 
relatively uncommon. The use having the second highest potential for 
drift is on artichokes where 0.25 lb/acre may be applied aerially in a 
single application.
    To calculate exposure and risk (in terms of MOEs) from imidacloprid 
spray drift, EPA multiplied the agricultural application rates by the 
high-end prediction of spray drift deposition (shown in Table 2 of this 
unit) and then applied the standard residential exposure estimation 
methods. The estimated exposure and MOE's from spray drift from these 
uses are presented in Table 4 of this unit.

                            Table 4.--Spray Drift Exposures for Imidacloprid on Lawns
----------------------------------------------------------------------------------------------------------------
                                                     Exposure in mg/kg/day on lawns 10-
              Use                 Route of exposure      60 feet from edge of field                MOE
----------------------------------------------------------------------------------------------------------------
Cranberries                      oral                                            0.0025                    4,000
                                --------------------------------------------------------------------------------
                                 dermal                                         0.00035                   29,000
--------------------------------
Artichokes                       oral                                           0.00127                    7,900
                                --------------------------------------------------------------------------------
                                 dermal                                        0.000175                   57,000
----------------------------------------------------------------------------------------------------------------

(Ref. 39).
Comparing the potential exposure from spray drift onto lawns from 
cranberries with the highest residential exposure already incorporated 
into EPA's aggregate assessment, the pet hug scenario, shows that worst 
case exposure at the edge of the field from drift is an order of 
magnitude lower. Thus even assuming that a child who received maximum 
exposure from hugging a treated dog was exposed to imidacloprid at the 
edge of a treated cranberry bog, the exposure and risk assessment for 
that child would not be meaningfully different.

B. Failed to Retain Children's 10X Safety Factor

    1. Introduction. NRDC's objections concerning the children's safety 
factor focus on the question of whether EPA properly applied a 
children's safety factor of other than 10X given that EPA is allegedly 
missing data on each of the pesticides. Particular emphasis is placed 
by NRDC on the fact that a DNT has been required for imidacloprid but 
not yet submitted. In addressing the issues raised by these objections, 
EPA first has summarized its children's safety factor decision that was 
relied upon in approving the imidacloprid tolerance and a re-analysis 
of that decision that has been performed in light of the objections and 
the revision to EPA's children's safety policy released in mid-2002. 
Second, EPA addresses NRDC's contentions regarding the lack of a DNT 
study. Third, EPA explains its response to each allegation NRDC makes 
regarding general and pesticide-specific data that NRDC asserts is 
missing and necessitates retention of the 10X factor.
    2. EPA's children safety factor decision--a. In general. In making 
decisions regarding the children's safety factor, EPA's OPP, from 1999 
until early 2002, looked primarily to an internal committee to make 
recommendations on the children's safety factor decision and to 
articulate a rationale for that decision. This committee, the FQPA 
Safety Factor Committee, was constituted solely for this purpose. To a 
lesser extent, during this period, OPP relied upon the another internal 
committee, the Hazard Identification and Assessment Review Committee 
(HIARC) to explain EPA's rationale. Within the last year or so, OPP has 
administratively restructured such that most of the work regarding 
toxicity issues and the children's safety factor falls within the 
jurisdiction of the HIARC. Consideration of exposure issues falls in 
the first instance to the team of scientists of OPPs' HED assigned to 
the specific pesticide. That judgement is then reviewed by the Risk 
Assessment Review Committee (RARC). It is the RARC's responsibility to 
ensure adequate rationale is provided for the decision on the 
children's safety factor and to ensure consistency with current policy 
and similar pesticides/circumstances. The RARC's recommendation and 
complete rationale

[[Page 30057]]

is included in the risk assessment document for the pesticide.
    Two particular aspects of that new policy are worthy of mention. 
First, the policy emphasizes that in applying the provision the focus 
should not be simply on whether the young have a greater sensitivity to 
a pesticide but rather on what reliable data show with regard to the 
safety of infants and children in situations where studies have shown 
that the young are more sensitive to a pesticide. Thus, where increased 
sensitivity is demonstrated, EPA examines how well-defined that 
sensitivity is by the existing toxicity data and whether that 
sensitivity has been adequately taken into account in calculating a 
safe MOE.
    Second, the policy stresses that when data are missing or 
inadequate the focus should be on whether there are reliable data to 
show that any additional safety factor different than the 10X default 
value is protective of the safety of infants and children. This issue 
has arisen frequently with regard to the developmental neurotoxicity 
study (DNT), a study that EPA is now requiring to be submitted for more 
pesticides. In evaluating whether a different factor than 10X would be 
protective of infants and children where a required DNT is absent, EPA 
examines related studies in the database to develop a sense for the 
likely range in which effects may be seen in the DNT (and therefore, 
the range of doses which will be used in the DNT). When the expected 
doses in the DNT are substantially higher than the doses that are 
presently providing the regulatory endpoint, a different and lower 
additional safety factor may be appropriate depending on the degree of 
difference between the doses for the DNT study and the current 
regulatory endpoint. On the other hand, where the range of expected 
doses in the DNT parallels the levels at which effects have already 
been identified in the database, it is less likely that there will be a 
reliable basis for assigning an additional factor lower than 10X.
    b. Imidacloprid. The FQPA Safety Factor Committee recommended an 
additional safety factor of 3X for imidacloprid for the protection of 
infants and children. Although available studies demonstrated no 
indication of increased sensitivity of rats or rabbits to in utero and/
or postnatal exposure to imidacloprid, the Committee concluded that an 
additional factor of 3X was needed due to the fact that there was data 
indicating a potential for developmental neurotoxicity (and, therefore, 
a need for a DNT study) and the potential for exposure to young 
children given the pet and outdoor residential uses of imidacloprid. 
The data indicating a potential for developmental neurotoxicity 
included structure activity relationship information and data from a 2-
year study in rats showing neurotoxic effects following a single oral 
dose. (Ref. 56 at 6).
    The DNT has now been submitted and reviewed. It showed evidence of 
an increased qualitative susceptibility in the rat. At the highest dose 
tested (750 parts per million (ppm)), maternal effects consisted 
largely of slight decreases in food consumption and body weight gain 
during early lactation, while pup effects included decreased body 
weight, decreased motor activity, decreased caudate/putamen width, 
females only (post-natal days 11 and adult), and slight changes in 
performance in the water maze, males only, at the same dose. The NOAEL 
identified in the DNT (20 mg/kg/day) was higher than the NOAELs 
previously identified (ranging from 5.7 to 10 mg/kg/day) and thus the 
DNT results had no impact on regulatory endpoint selection and the risk 
assessment. The HIARC concluded the DNT indicated no residual concerns 
regarding post-natal toxicity based on:
     The effects in pups are well-characterized with a clear 
NOAEL.
     The pup effects occur in the presence of maternal toxicity 
with the same NOAEL for effects in pups and dams.
     The doses and endpoints selected for regulatory purposes 
are protective of the pup effects noted at higher doses in the 
developmental neurotoxicity study.
(Ref. 46 at 9).
    EPA ultimately determined that, other than a 3X factor for acute 
risk assessments to address the lack of a NOAEL in an acute study, no 
other additional safety factors were needed to protect the safety of 
infants and children. This conclusion was based upon:
     There is no quantitative or qualitative evidence of 
increased susceptibility of rat and rabbit fetuses to in utero exposure 
in developmental studies. There is no quantitative or qualitative 
evidence of increased susceptibility of rat offspring in the multi-
generation reproduction study.
     There is evidence of increased qualitative susceptibility 
in the rat developmental neurotoxicity study, but the concern is low 
since:
    1. The effects in pups are well-characterized with a clear NOAEL.
    2. The pup effects occur in the presence of maternal toxicity with 
the same NOAEL for effects in pups and dams.
    3. The doses and endpoints selected for regulatory purposes are 
protective of the pup effects noted at higher doses in the 
developmental neurotoxicity study.
Therefore, there are no residual uncertainties for pre-/post-natal 
toxicity in this study.
     The toxicological database is complete for FQPA 
assessment.
     The acute dietary food exposure assessment utilizes 
existing and proposed tolerance level residues and 100% [crop-treated] 
CT information for all commodities. By using these screening-level 
assessments, actual exposures/risks will not be underestimated.
     The chronic dietary food exposure assessment utilizes 
existing and proposed tolerance level residues and % CT data verified 
by [OPP's Biological and Economic Analysis Division] BEAD for several 
existing uses. For all proposed uses, 100% CT is assumed. The chronic 
assessment is somewhat refined and based on reliable data and will not 
underestimate exposure/risk.
     The dietary drinking water assessment utilizes water 
concentration values generated by model and associated modeling 
parameters which are designed to provide conservative, health 
protective, high-end estimates of water concentrations which will not 
likely be exceeded.
     The residential handler assessment is based upon the 
residential [Standard Operating Procedures] SOPs in conjunction with 
chemical-specific study data in some cases and [Pesticide Handlers 
Exposure Database] PHED unit exposures in other cases. The majority of 
the residential post-application assessment is based upon chemical-
specific [Turf Transferable Residue] TTR data or other chemical-
specific post-application exposure study data. The chemical-specific 
study data as well as the surrogate study data used are reliable and 
also are not expected to underestimate risk to adults as well as to 
children. In a few cases where chemical-specific data were not 
available, the SOPs were used alone. The residential SOPs are based 
upon reasonable ``worst-case'' assumptions and are not expected to 
underestimate risk. These assessments of exposure are not likely to 
underestimate the resulting estimates of risk from exposure to 
imidacloprid. (Ref. 44 at 22).
    Although the HIARC's conclusions regarding exposure are stated in 
terms of the imidacloprid exposure estimates not being expected to 
``underestimate risk,'' in all likelihood, the imidacloprid exposure 
assessments substantially

[[Page 30058]]

overstate exposure. This overestimate of exposure is a result of the 
aggregation of worst case or, at the least, very conservative (health 
protective) estimates of, exposure through each pathway of exposure - 
food, water, and residential. For food, EPA used a worst case approach 
of assuming all food which can be legally treated with imidacloprid 
bears imidacloprid residues at the tolerance level for assessing acute 
risk. Tolerance values are chosen to be slightly higher than any 
expected residue values at the time of harvest assuming maximum 
application practices are followed (See Ref. 51 at 11). Assuming 
tolerance values in food fails to take into account that pesticides are 
infrequently used on more than a relatively small fraction of a crop, 
that pesticides are not uniformly applied at the maximum application 
rate, that even when pesticides are applied at the maximum application 
rate much of the treated crop will have residues well below the 
tolerance level, and that pesticides often degrade substantially 
between the time of harvest and consumption naturally or as the result 
of food processing or cooking. Id. at 10-12, 17-30. For assessing 
chronic risk, EPA took only a slightly less conservative approach by 
incorporating percent crop treated data for approximately 
1/89/21/13/23/87/83/8 of the commodities having tolerances. 
All treated commodities were still assumed to bear tolerance level 
residues.
    For water, EPA estimated possible exposure with a surface water 
exposure model (Pesticide Root Zone Model and the Exposure Analysis 
Model System) that generally produces very conservative (health 
protective) estimates of exposure. As the analysis in Unit 
VII.B.4.b.ii. shows, this model generally substantially over predicts 
residue levels in water, frequently by orders of magnitude. Finally, 
for residential exposure, EPA relied on models using conservative 
(health protective) assumptions that are also likely to overstate 
actual exposure. These assumptions are described in detail in Unit 
VII.A.3.
    3. Missing toxicity data - lack of DNT. NRDC contends that ``the 
absence of required developmental (DNT) tests for imidacloprid, 
mepiquat, and zeta-cypermethrin is a crucial data gap that by itself 
should prohibit EPA from overturning the default 10X safety factor.'' 
See, e.g., Imidacloprid Objections at 6. Given, however, that the DNT 
has now been submitted and incorporated into the imidacloprid risk 
assessment, this objection is no longer relevant to the imidacloprid 
tolerance on blueberries.
    4. Missing exposure data - general--a. Farm children exposure. NRDC 
argues that EPA is lacking data on exposure to farm children and thus 
may not remove the additional 10X safety factor. EPA disagrees. As 
discussed above, the data submitted by NRDC have not shown that there 
are significant exposures to farm children that occur as a result of 
living in close proximity to agricultural operations. EPA concluded 
that the evidence presented by NRDC is fragmentary, at best, as to 
whether pesticide exposure levels in homes of children living in 
agricultural areas are significantly different than levels in other 
homes and whether children living in agricultural areas have 
significantly different exposures than non-agricultural children.
    After reviewing all of this data, EPA concludes it has sufficient 
reliable data to find that an additional 10X factor is not needed to 
protect the safety of infants and children with regard to any 
uncertainties due to lack of data on exposure of farm children to 
pesticides. Specifically with regard to imidacloprid, EPA is confident 
that its exposure assessment is protective of all children given that 
it has taken into account, in its aggregate exposure assessment, that 
imidacloprid is registered for use on pets and turf. EPA's aggregate 
assessment has assumed that children will come in direct contact with 
treated pets and turf. Indirect exposure from agricultural uses is 
unlikely to be significant compared to direct exposure to treated pets 
and turf. Additionally, EPA has found the chance of pesticide exposure 
as a result of the volatilization of pesticide residues in the field to 
be extremely slight given the vapor pressure of imidacloprid.
    b. Lack of comprehensive DW monitoring data. NRDC contends that 
because EPA used a model for calculating drinking water exposure to 
imidacloprid that, as a definitional matter, EPA does not have 
``reliable data'' for choosing a factor different than the 10X default 
value. Similar comments were made during the development of EPA's 
Children's Safety Policy. For the reasons below, EPA rejects NRDC's 
claims.
    i. Models and data. Modeling is a necessary part of both the hazard 
and exposure components of risk assessment. In the absence of perfect 
data, EPA must extrapolate through the use of modeling from the 
individual data available to more general conclusions concerning 
hazard, exposure, and risk. (See Ref. 48 at A-7). As EPA noted in 
responding to NRDC's comments on its Children's Safety Factor Policy, 
''short of measuring the pesticide residues in every sip of water and 
every bite of food as it is being consumed, OPP must model or estimate 
exposure values for residues in drinking water and food. The need for 
models exists whether the exposure estimate is based on monitoring 
values in drinking water and food, residue values from field studies, 
or data on a pesticide's properties and characteristics which are used 
to predict anticipated residue levels in water and food.'' (See Ref. 47 
at 149) Accordingly, NRDC errs to the extent it attempts to cast models 
as the antithesis of data. The question is not whether EPA is relying 
on reliable data or a model but whether the model EPA is using is based 
on reliable data. Id. (``[T]he reliability of any method of estimating 
exposure will have to be evaluated based on what data the method relies 
upon'').
    For imidacloprid, EPA relied on a combination of modeling 
information and pesticide-specific data. EPA concluded that use of this 
information was unlikely to underestimate exposure to the imidacloprid 
in drinking water. EPA believes that a description of its drinking 
water models and their underpinnings, an evaluation of how these models 
have performed generally, and a review of the data pertaining to 
imidacloprid demonstrates that this conclusion was reasonable. Hence, 
EPA finds that in using these models and the pesticide-specific 
imidacloprid data it was acting on the basis of reliable data. (See 
Ref. 48 at A-7) (``OPP does not interpret the reliable data requirement 
in the infants and children's provision as mandating that any specific 
kind of data be available, just that the data and information that form 
the basis for the selection of a different safety factor must be 
sufficiently sound such that OPP could routinely rely on such 
information in taking regulatory action.'')
    ii. EPA's drinking water models. Although the availability of 
drinking water monitoring data has increased dramatically in the last 
several years, EPA still finds it necessary to rely for most pesticides 
upon various exposure models to estimate exposure levels in drinking 
water. As explained below these models are based on generic data 
regarding fate and transport of pesticides in the environment, and they 
operate by combining this generic data with pesticide-specific data on 
chemical properties to estimate exposure.
    EPA has primarily used its drinking water models to ``screen'' 
those pesticides that may pose unacceptable risks due to exposures in 
drinking water from pesticides not likely to result in such exposures. 
To accomplish this

[[Page 30059]]

goal, the models are based on data from studies at sites that are 
highly vulnerable to runoff of pesticides to surface water or leaching 
of pesticides to ground water. If a pesticide fails this conservative 
(health-protective) screen, EPA would investigate whether the model is 
significantly overstating the residue levels that actually occur.
    EPA has developed models for estimating exposure in both surface 
water and ground water. EPA uses a two-tiered approach to modeling 
pesticide exposure in surface water. In the initial tier, EPA uses the 
FQPA Index Reservoir Screening Tool (FIRST) model. FIRST replaces the 
GENeric Estimated Environmental Concentrations (GENEEC) model that was 
used as the first tier screen by EPA from 1995-1999. If the first tier 
model suggests that pesticide levels in water may be unacceptably high, 
a more refined model is used as a second tier assessment. The second 
tier model is actually a combination of the models, Pesticide Root Zone 
Model (PRZM) and the Exposure Analysis Model System (EXAMS). For 
estimating pesticide residues in ground water, EPA uses the Screening 
Concentration In Ground Water (SCI-GROW) model. Currently, EPA has no 
second tier ground water model.
    Whether EPA assesses pesticide exposure in drinking water through 
monitoring data or modeling, EPA uses the higher of the two values from 
surface and ground water in assessing overall exposure to the 
pesticide. In most cases, pesticide residues in surface water are 
significantly higher than in ground water.
    Table 5 describes what models were used to estimate drinking water 
residue levels with regard to imidacloprid both for the 2002 tolerance 
and the 2004 tolerance. The table also indicates which model estimates 
were used in assessing overall exposure to the pesticide.

                                                                   Table 5.--Drinking Water Model Projections for Imidicloprid
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Surface Water      Surface Water       Ground Water        Model Used for
                 Year                         Residue            Surface Water Model       Ground Water Model          acute             chronic       acute and chronic    Exposure Assessment
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1998                                  Imidacloprid parent      PRZM/EXAMS               SCI-GROW                           4.1 ppb            0.1 ppb            1.1 ppb  PRZM/EXAMS (acute);
                                                                                                                                                                           SCI-GROW (chronic)
-------------------------------------
2003                                  Parent and degradates    FIRST                    SCI-GROW                         36.04 ppb          17.24 ppb           2.09 ppb  FIRST (acute and
                                                                                                                                                                           chronic)
-------------------------------------
2003                                  Parent                   FIRST                    SCI-GROW                             35.89              16.52               1.43  N/A
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    The increase in estimated levels in surface and ground water in the 
2003 assessment is due to the use of different models (for surface 
water), the addition of new uses, and more updated information on 
aerobic soil and water half-lives and use of the organic carbon 
normalized soil/water equilibrium partition coefficient 
(KOC) instead of the soil/water equilibrium partition 
coefficient (KD) (Refs. 45 and 59) For the recent tolerance 
action, EPA used the surface water estimates for calculating aggregate 
exposure because they are higher than the levels projected for ground 
water.
    a. Surface water--i. GENEEC. GENEEC uses readily-available 
pesticide properties to estimate peak and time-averaged pesticide 
concentrations in a ``farm pond,'' 20 million liters (5.3 million 
gallons) in capacity, located at the edge of a 10-hectare 
(approximately 25 acres) treated field. GENEEC is designed to simulate 
reasonable worst case pesticide levels in this farm pond following a 
major rainfall event. It assumes that a maximum of 10% of the applied 
pesticide is removed by rainfall and washed into the adjacent waterbed. 
The underlying data supporting GENEEC is an extensive study of the 
level of pesticide residues in runoff studies. (Ref. 69). That paper 
provided a summary of 122 study values and revealed that the amount of 
pesticide transport off of the treated field by rainfall ranged from a 
low of 0.00% to a high of 22% of the applied pesticide, with most of 
the values clustered toward the lower end. Only 4 of the 122 study 
values were above 10%. The study author recommended that percentage 
loss estimates for the pesticides most likely to be carried away by 
runoff should be from 2 to 5% based on slope of the field. (Id.; see 
Ref. 30) (``Under natural conditions, pesticide runoff losses in the 
10% range would be rare.''). GENEEC assumes that the 10% figure 
corresponds to pesticides with the greatest solubility and that 
pesticides which have a greater tendency to bind to soils are 
transported to the farm pond in lower amounts on a percentage basis. 
The capacity of a chemical to dissolve in water or, conversely, to bind 
to soil is generally expressed as the soil/water equilibrium partition 
coefficient (KD) or the organic carbon normalized soil/water 
equilibrium partition coefficient (KOC). The higher the 
KD or KOC value for a pesticide, the greater 
tendency it has to adsorb or bind to soil; there is a partial 
correlation with the solubility of the pesticide with strong adsorption 
generally associated with lower solubility. An individual pesticide's 
KD or Koc value is used to estimate the 
percentage of pesticide applied that is likely to enter the farm pond. 
In estimating the amount of pesticide entering the pond and hence the 
concentration of the pesticide in the pond, the instructions for the 
model recommend use of the assumption that the pesticide was applied at 
the maximum rate permitted on the pesticide label. The concentration of 
the pesticide in the pond over time is calculated taking into account 
the aerobic aquatic metabolic half-life, the hydrolysis half-life, and 
the photolysis half-life, of the pesticide in question.
    GENEEC produces a conservative estimate of levels in surface water 
due to the fact that the model is constructed based on the highest 
values of pesticide residues found in farm ponds and that it assumes 
pesticides are applied at maximum application rates. Further 
conservatism is added by, among other things, the assumption that the 
entire drainage area surrounding the farm pond is planted to crops for 
which the pesticide is registered and 100% of those crops are treated. 
Additionally, GENEEC tends to overstate residue values in a drinking 
water location because it is designed to represent a water body in the 
upper reaches of the agricultural watershed. Drinking water reservoirs 
typically have contributions from multiple sources. (Ref. 54 at 6)

[[Page 30060]]

    In the SAP's review of GENEEC in 1997, ``nearly all the Panel 
members agreed that the pesticide concentration estimates provided by 
GENEEC are most likely overly conservative.'' (Ref. 18 at 18). In late 
1999, EPA revised GENEEC by substituting a reservoir for the farm pond 
in the model. As indicated above, this model is designated the FQPA 
Index Reservoir Screening Tool (FIRST).
    ii. FIRST. FIRST provides a slightly more realistic model for 
estimating pesticide residues in drinking water than GENEEC because it 
models a small drinking water reservoir instead of a static farm pond. 
It maintains, however, many of the conservative features of GENEEC. 
Like GENEEC, FIRST is based on data concerning residue in actual water 
bodies and the data chosen to construct the model represent a 
reasonable worst case scenario.
    The drinking water reservoir that EPA chose to use as the Index 
Reservoir for modeling pesticide levels is Shipman City Lake in 
Shipman, Illinois (Ref. 60 at 17). Shipman City Lake is representative 
of a number of reservoirs in the central midwestern United States that 
are known to be vulnerable to pesticide contamination. Id. at 18. The 
site at Shipman, Illinois was chosen for the IR because of extremely 
high pesticide concentrations found there by the Acetochlor 
Registration Partnership (ARP) monitoring program and because of its 
hydrologic simplicity for modeling purposes (Refs. 1 and 2). In 1996, 
Shipman City Lake had one of the highest atrazine concentrations of the 
lakes monitored. (Ref. 60 at 8). Two or three of the other ARP 
reservoirs had slightly higher annual peak concentrations but presented 
substantial modeling difficulties.
    The FIRST model was constructed in a very similar manner to GENEEC. 
FIRST assumes that up to a given percentage of a pesticide may run off 
into an adjacent drinking water reservoir with the precise percentage 
being a factor of the pesticide's KD or Koc 
value. After considering the concentrations of atrazine found in 
Shipman City Lake and other ARP reservoir monitoring sites, atrazine's 
KD value, atrazine application rates, and various potential 
percentages of pesticide runoff, EPA determined that, with a reservoir 
model, assuming that up to 8% of the pesticide applied could reach the 
reservoir was a conservative (health protective) value. Like GENEEC, 
FIRST assumes that a pesticide is applied at its maximum application 
rate.
    Although FIRST, also like GENEEC, assumes that all cropped area is 
100% treated with the pesticide in question, FIRST attempts to be 
slightly more realistic and does not assume that 100% of the drainage 
area for the reservoir is planted to the treated crop. As to four major 
crops (corn, soybeans, wheat, cotton), FIRST uses a value representing 
the maximum drainage area for a reservoir that could be expected to be 
planted to the crop in question. These values are derived from 
geoprocessing analysis that combines U.S. Department of Agriculture 
data on crop coverage with U.S. Geological Service data on watershed 
boundaries. (Ref. 57 at 8). For all other crops, EPA assumes that 87% 
of the pond's drainage area is cropped and 100% of that cropped area is 
treated. (See Ref. 53 at 24) (explaining choice of 87% is based on fact 
that 87% cropped was the largest cropped area in any 8-digit hydrologic 
unit in the continental United States).
    The SAP has endorsed the concept of using a reservoir as 
reasonable, but questioned the representativeness of the reservoir EPA 
chose to model. (See Ref. 17 at 3). Based on SAP comments, EPA 
undertook a comprehensive review of its Index Reservoir model. EPA 
considered 82 reservoirs as candidates for modeling (Ref. 54 at 15) and 
selected 20 for further investigation. Factors evaluated included depth 
and volume of the reservoirs, percentage of the reservoir that is 
cropped, the ratio of drainage area to normal reservoir capacity, and 
the availability of sufficient years of monitoring data. Following this 
evaluation, EPA again selected Shipman City Lake as the most 
appropriate reservoir to serve as a basis for modeling. The other three 
best candidate reservoirs which were not selected were Springfield, 
Illinois (watershed too large for the model), Gillespie, Illinois (two 
reservoirs used alternatively by the city) and Higginsville (reservoir 
has a pre-settling basin which cannot be accurately modeled.)
    iii. PRZM/EXAMS. The EPA PRZM and EXAMS models used together are a 
more complex modeling system that provide a more realistic estimate of 
residue levels in surface water by incorporating more site-specific 
information than GENEEC or FIRST. The PRZM component of the model is 
designed to predict the pesticide concentration dissolved in runoff 
waters and carried on entrained sediments from the field where a 
pesticide has been applied into an adjoining edge-of-field surface 
water body. The model can simulate specific site, pesticide, and 
management properties including soil properties (organic matter, water 
holding capacity, bulk density), site characteristics (slope, surface 
roughness, field geometry), pesticide application parameters 
(application rate, application frequency, spray drift, incorporation 
depth, application efficiency, application methods), agricultural 
management practices (tillage practices, irrigation, crop rotation 
sequences), and pesticide environmental fate and transport properties 
(aerobic soil metabolism half-life, soil:water partitioning 
coefficients, foliar degradation and dissipation, and volatilization). 
EPA selects a combination of these different properties to represent a 
site-specific scenario for a particular pesticide-crop regime.
    The EXAMS component of the model is used to simulate environmental 
fate and transport processes of pesticides in surface water, including: 
abiotic and biotic degradation, sediment:water partitioning, and 
volatilization. Currently, OPP is using an index reservoir and a farm 
pond as benchmark surface water bodies for human health and aquatic 
exposure assessments, respectively.
    For each component of PRZM/EXAMS, the values used are derived from 
real world data. For example, the EPA-approved product label is the 
source of the application rate, frequency, and method of pesticide 
application. Pesticide environmental fate properties used in PRZM and 
EXAMS modeling come from registrant-submitted data used for pesticide 
registration or reregistration. The values used for soil properties and 
site characteristics are chosen from real world databases appropriate 
for the sites on which the pesticide may be used. For example, if the 
pesticide is approved for use on cotton, OPP uses data reflecting the 
soil types in the Cotton Belt. The index-reservoir being modeled is 
based on and represents an actual, fairly typical, small flow-through 
reservoir used for drinking water. Finally, the weather inputs for the 
model are taken from site-specific weather data, based on the USDA 
Major Land Resource Areas. PRZM modeling is generally simulated for 30 
or 36 years in order to calculate the variability of the pesticide 
concentration in the surface water body due to variations in weather 
over time and the value used for risk assessment is the 90th percentile 
value.
    Despite the fact that PRZM/EXAMS uses much greater site-specific 
information than either GENEEC or FIRST, it still provides high end or 
upper bound estimates of pesticide values in surface water. The high 
end/upper bound estimates result from the conservative manner in which 
PRZM/EXAMS selects and combines values

[[Page 30061]]

derived from real world data. EPA intentionally chooses values for the 
model which are likely not to underestimate the potential levels of 
pesticide residue in surface water. For example, the application rate 
and frequency used in the model are the highest allowed by the product 
label. In addition, PRZM/EXAMS modeling is assumed to be conservative 
because both the farm pond and index reservoir represent a vulnerable 
water supply; conservative fate parameters are used in the model; 100% 
of the cropped area in the watershed is assumed to be treated with 
pesticide; for all but four major crops (corn, soybeans, wheat, and 
cotton) 87% of the watershed is assumed to be cropped and treated; site 
conditions (annual rainfall and soil) are chosen to represent a site 
especially vulnerable to runoff taking into account all of the sites on 
which the specific crop is grown across the United States; and the 
simulation is run for up to 36 years and the results are reported at 
the 90% highest year. For the crops corn, soybeans, wheat, and cotton, 
46%, 41%, 56%, and 20%, respectively of the watershed is assumed to be 
cropped and treated. Further compounding the tendency of these 
assumptions to overstate exposure, EPA also assumes that all of the 
pesticide in the watershed is applied simultaneously using the 
application method most likely to produce maximum runoff. Assuming 
simultaneous application tends to exaggerate residue estimates in 
drinking water because that means all potentially treated area in the 
watershed will have pesticide residues (from a maximum application 
applied with the technique most likely to produce runoff) available 
when the next rainfall event occurs. Assuming staggered application 
between growers would be more realistic but data is not currently 
available that would allow that level of sophistication in the model. 
All these factors lead to an assessment that PRZM/EXAMS is expected to 
predict high end or upper bound concentrations. (Ref. 53 at 20-21).
    EPA sought SAP review of the PRZM/EXAMS modeling system in 1995 as 
part of the SAP's review of the report entitled ``Aquatic Dialogue 
Group Report: Pesticide Risk Assessment and Mitigation''. The SAP was 
complementary of this overall approach to exposure assessment modeling 
(See Ref. 19 at 7-9). In addition, the PRZM/EXAMS model has been before 
the SAP in the context of the issue of the introduction of 
incorporation of a ``percent cropped area'' [PCA] factor in OPP's 
drinking water models. In 1999, EPA requested SAP review of the 
appropriateness of using PCA and presented the results of several 
modeling exercises using PCA in connection with both PRZM/EXAMS and 
GENEEC. Comparisons of these modeling exercises to monitoring data 
showed that in most cases, the models overstated residues by an order 
of magnitude or greater. In other cases, the models overstated residues 
by factors less than 10. Finally, in two instances, the models 
understated values found in vulnerable water bodies.
    The SAP generally endorsed the use of the concept of PCA for 
drinking water models. (See Ref. 16 at 67). Further, the SAP concluded 
that ``[u]se of the maximum PCA appears to result in an appropriately 
conservative assessment for most chemicals for major-use compounds.'' 
Id. The SAP, however, was skeptical of the conservativeness of the use 
of PCA with regard to minor crops. Id. at 68. This appears to have been 
due to the fact that the two instances in which PRZM/EXAMS under 
predicted drinking water concentrations involved minor crops. 
Accordingly, EPA has used a default PCA value of 87% in conducting 
PRZM/EXAMS modeling for minor crops for drinking water assessments. 
Further examination of the two cases of under prediction, however, 
suggest that not too much weight should be attached to these results. 
As to one of the cases (methomyl), the comparison was between PRZM/
EXAMS modeling for minor crop (lettuce and peaches) and monitoring data 
on a major crop (corn). Further, the relatively higher concentration 
value found in monitoring was not from a drinking water reservoir but a 
stream adjacent to a corn field. In the other case (methidathion), the 
monitored value was from a river (the San Joaquim River in California) 
that is largely composed of irrigation return flow from agricultural 
fields. Such a river is generally not a drinking water source (the 
portion of the San Joaquim River where the samples were drawn is not 
used for drinking water) and PRZM/EXAMS is not structured so as to 
predict levels in such an environment.
    Both the PRZM and EXAMS models have been the subject of extensive 
validations. The FIFRA Environmental Model Validation Task Force 
recently completed a review of PRZM. (Ref. 28). That study was an 
industry-sponsored calibration effort, but EPA scientists participated 
in the design and conduct of the study. The study's report concluded 
that PRZM ``provides a reasonable estimate of chemical runoff at the 
edge of the field.'' Id. at 6. The study found that ``[s]imulations 
based on the best choices for input parameters (no conservatism built 
into parameters) are generally within an order of magnitude of measured 
data with better agreement observed both for larger events and for 
cumulative values over the study period.'' Id. When simulations were 
run using conservative input parameters such as employed by EPA, 
according to the study, ``substantial over-prediction of runoff losses 
occur.'' Id. at 6, 8, 49. This conclusion regarding over-prediction 
only considered estimated values at the edge of the field and did not 
take into account the substantial conservatism introduced by EPA's 
assumptions regarding pesticide application amount, the percentage of 
the watershed receiving pesticide treatment, and the timing of 
application on adjacent fields.
    EXAMS has also been the subject of extensive validation efforts. 
Satisfactory validation has been achieved in studies conducted in the 
Monogahela River, USA, an outdoor pond in Germany, a bay on the each 
coast of Sweden, Japanese rice paddies, and rivers in the United 
Kingdom and South Dakota, USA. (Ref. 6).
    The most important validation of these models is not the abstract 
study of these models but how well the models have worked in practice 
when used by EPA in pesticide risk assessment. To do such an 
evaluation, EPA compared its surface water estimates from GENEEC, 
FIRST, and PRZM/EXAMS to data on pesticides in surface water compiled 
through the U.S. Geological Survey's National Water-Quality Assessment 
(NAWQA) Program. NAWQA is designed to provide ``consistent and 
comparable information on water resources in 60 important river basins 
and aquifers across the Nation.'' (Ref. 68)These river basins and 
aquifers account for approximately 60 to 70% of the country's water 
use. Id. EPA found 47 instances in which it had estimated pesticide 
residues in surface water resulting from the pesticide's use on a 
particular commodity using either GENEEC (14), FIRST (3), or PRZM/EXAMS 
(30) and there was also NAWQA data on the pesticide in surface water. 
(Ref. 41)See Table 6 below. In each instance, the peak modeled value 
exceeded the maximum value in the NAWQA data. In fact, in 42 of the 47 
cases, the modeling value was nearly an order of magnitude or more 
higher. This further confirms that reliable data support EPA's 
conclusion that use of these surface water models is not likely to 
underestimate drinking water exposure. To the contrary, these data 
confirm that these models produce

[[Page 30062]]

conservative (health-protective), and often extremely conservative, 
results.

            Table 6.--Comparison of Simulation Model Outputs with Upper Level NAWQA Monitoring Values
----------------------------------------------------------------------------------------------------------------
                                                                                    Peak
             Pesticide                     Model(s)                Crop           Modeled     NAWQA      NAWQA
                                                                                   Value*    95th%ile   Maximum
----------------------------------------------------------------------------------------------------------------
2,4-D                               FIRST                  Sugarcane                132.00       0.35      15(E)
-----------------------------------
2,4-D                               PRZM/EXAMS             Apples                   118.00       0.35      15(E)
-----------------------------------
Acetochlor                          PRZM/EXAMS             Corn                     284.00       0.17    25.1(E)
-----------------------------------
Acifluorfen                         PRZM/EXAMS             Soybeans                  14.00      <0.04       1.10
-----------------------------------
Alachlor                            GENEEC                 Corn/Soybeans            199.00       0.10      10.90
-----------------------------------
Aldicarb                            PRZM/EXAMS             Citrus                     2.03     <0.550    0.51(E)
-----------------------------------
Atrazine                            PRZM/EXAMS             Sugarcane                205.00       2.86     201(E)
-----------------------------------
Azinphos methyl                     PRZM/EXAMS             Peaches                   16.00      <0.05     0.5(E)
-----------------------------------
Benfluralin                         PRZM/EXAMS             Apples                    61.00      <0.01       0.01
-----------------------------------
Bentazon                            PRZM/EXAMS             Not given                122.00       0.15    8.60(E)
-----------------------------------
Bentazon                            GENEEC                 Not given                100.20       0.15    8.60(E)
-----------------------------------
Butylate                            GENEEC                 Corn                      33.10     <0.002       1.40
-----------------------------------
Carbaryl                            PRZM/EXAMS             Citrus                   494.00  <0.041(E)     5.2(E)
-----------------------------------
Carbofuran                          PRZM/EXAMS             Grapes                    39.40   0.043(E)    7.00(E)
-----------------------------------
Chlorothalonil                      PRZM/EXAMS             Tomatoes                  43.80   <0.48(E)    0.29(E)
-----------------------------------
Chlorpyralid                        FIRST                  Canola                    17.10     <0.230     <0.230
-----------------------------------
Chlorpyrifos                        GENEEC                 Sweet corn                56.50       0.01       0.26
-----------------------------------
Chlorpyrifos                        PRZM/EXAMS             Sweet corn                40.60       0.01       0.26
-----------------------------------
DCPA                                PRZM/EXAMS             Cabbage                  160.00       0.02     100(E)
-----------------------------------
Diazinon                            PRZM/EXAMS             Citrus                   540.00       0.02       2.50
-----------------------------------
Dichlobenil                         GENEEC                 Turf                     951.00    <1.2(E)    0.01(E)
-----------------------------------
Disulfoton                          PRZM/EXAMS             Potatoes                  15.51     <0.021       0.43
-----------------------------------
Diuron                              GENEEC                 Orchard                  152.00       0.26      14(E)
-----------------------------------
EPTC                                PRZM/EXAMS             Citrus                    57.35       0.02       7.30
-----------------------------------
Ethalfluralin                       PRZM/EXAMS             Sunflowers                 2.27     <0.009       0.07
-----------------------------------
Ethoprop                            PRZM/EXAMS             Sweet Potato             127.00     <0.005       0.45
-----------------------------------
Linuron                             PRZM/EXAMS             Carrots                    1.30     <0.035       1.40
-----------------------------------
Malathion                           PRZM/EXAMS             Citrus                   324.00     <0.027       0.52
-----------------------------------
Methomyl                            GENEEC                 Lettuce                  409.00     <0.020       0.67
-----------------------------------
Methomyl                            PRZM/EXAMS             Corn                      60.00     <0.020       0.67
-----------------------------------
Metolachlor                         PRZM/EXAMS             Corn                     134.60       1.38    77.6(E)
-----------------------------------
Metribuzin                          GENEEC                 Sugarcane                390.00       0.05       6.61
-----------------------------------
Norflurazon                         GENEEC                 Cane Berry                72.10     <0.040       1.24
-----------------------------------
Norflurazon                         PRZM/EXAMS             Citrus                   396.00     <0.040       1.24
-----------------------------------

[[Page 30063]]

 
Oxamyl                              GENEEC                 Pineapple                321.80     <0.020       0.16
-----------------------------------
Parathion                           GENEEC                 Cotton                   166.00     <0.008       0.14
-----------------------------------
Pebulate                            PRZM/EXAMS             Not given                  2.90     <0.004       0.08
-----------------------------------
Propargite                          PRZM/EXAMS             Cotton                    34.30     <0.023       2.62
-----------------------------------
Propochlor                          GENEEC                 Sorghum                  202.00     <0.010       0.51
-----------------------------------
Propochlor                          PRZM/EXAMS             Sorghum                   64.00     <0.010       0.51
-----------------------------------
Propyzamide (Pronamide)             FIRST                  Ornamentals              390.00     <0.004       0.28
-----------------------------------
Tebuthiuron                         PRZM/EXAMS             Pasture/Range             15.10       0.02       0.95
-----------------------------------
Terbufos                            PRZM/EXAMS             Sorghum                   21.70     <0.017       0.56
-----------------------------------
Thiobencarb                         GENEEC                 Celery                   186.00     <0.005       3.66
-----------------------------------
Triallate                           PRZM/EXAMS             Wheat                      5.50     <0.001       0.65
-----------------------------------
Triclopyr                           GENEEC                 Pasture                  364.00      <0.25      16(E)
-----------------------------------
Trifluralin                         PRZM/EXAMS             Sugarcane                  3.44     <0.009       0.17
----------------------------------------------------------------------------------------------------------------
* = 1-in-10 year peak value; (E) = NAWQA Estimate

    A review of drinking water assessments by the pesticide industry 
reached a similar conclusion. In this study, results from FIRST 
modeling (conducted for the purpose of the study) and PRZM/EXAMS 
modeling (from EPA exposure assessments) were compared with data from a 
USGS/EPA monitoring program.(Ref. 23). The monitoring data was gathered 
from small drinking water reservoirs in areas with high pesticide use 
in 12 geographically disparate regions in the United States. The study 
compared acute prediction values with the maximum value from the 
monitoring data and the chronic prediction values with 95th percentile 
of a time weighted average of monitored values. The result was that 
``[f]or both acute and chronic exposure the models systematically 
overestimate measured exposure typically by 10 to 10,000 fold for the 
majority of cases.'' Id. There was no instance in which a model 
underestimated exposure. Id. The study concluded that the 
overestimation occurred due to ``[c]ompounding conservative 
assumptions, without considering associated probabilities of 
occurrence/co-occurrence.'' Id. The conservative assumptions identified 
as most likely leading to this result are (1) maximum label rate 
application on the highest percent cropped area in the United States; 
(2) reservoir immediately bordered by treated field; and (3) highest 
mobility, upper percentile half life, no reservoir dilution effects, 
and no soil photolysis. Id.
    b. Ground water. As mentioned above, EPA uses the SCI-GROW model 
for estimating residues of pesticides in ground water. SCI-GROW is a 
regression model that uses chemical-specific data on a pesticide's 
adsorption (i.e. the soil/water partition coefficient of KD 
or Koc value) and the pesticide's persisence (i.e. the soil 
metabolism half-life) in combination with the assumption that the 
pesticide is being applied at its maximum application rate. The model 
is based on data obtained from ten prospective monitoring studies 
measuring the degree to which various pesticides leached to ground 
water. These studies were conducted in hydrogeologically-vulnerable 
sites (i.e., shallow aquifers; sandy, permeable soils; and substantial 
rainfall or irrigation to maximize leaching). SCI-GROW provides a 
screening value which is applied to both peak and chronic exposure 
screening.
    In its review of the SCI-GROW model in 1997, a majority of the SAP 
concluded that it was ``highly conservative.'' (See Ref. 18 at 10) The 
SAP summarized the reasons for this conservatism as follows:
    a. SCI-GROW is based mainly on OPP prospective ground water 
studies designed to maximize the opportunity for pesticides to leach 
into ground water:
     Soil site highly vulnerable to leaching (very sandy, 
little clay, low organic matter).
     Rainfall supplemented with irrigation to ensure higher 
than average monthly rainfall for each consecutive month of study. 
Supplementation of rain with irrigation errs on the side of greater 
opportunity for encountering rainfall amounts in excess of normal 
patterns.
     Sites with shallow water tables.
     Sites that represent an unknown but very low percentage 
of the ground water used as drinking water.
     Sites with wells totally surrounded by treatment area; 
no dilution with clean water.
     Sites with wells directly adjacent to treatment area; 
short path to well.
     Maximum rate of pesticide application; multiple 
treatments may be applied as one massive application.
    b. Development of SCI-GROW ignored PGW [prospective ground 
water] studies with no ground water detections; only those that 
produced concentrations were included in the regression data set. 
Therefore, SCI-GROW reflects a filtered data set that implies 
greater frequency of observed concentrations than what actually 
occurred in the PGWs.
Id. at 12.
    As with the surface water models, EPA has examined how well the 
models have worked in practice when used by EPA in pesticide risk 
assessment. To do such an evaluation, EPA compared its ground water 
estimates from SCI-GROW to data on pesticides in ground water compiled 
through the NAWQA program. Comparisons of the SCI-GROW screening model 
have been made to various upper bound distributions (99.0,

[[Page 30064]]

99.5, and 99.8 percentiles) rather than to the absolute maximum values 
in the NAWQA data (as was done with the surface water model). No higher 
percentiles were calculated because such calculation would not be 
reasonable given the sample size. The reason for not using maximum 
values, as was done with surface water evaluation above, is the 
difference in the nature of ground water and most surface water sources 
sampled in the study. Surface water bodies sampled were generally 
streams, reservoirs, or lakes which represent a significant amount of 
mixing of runoff water from a watershed that may be tens or hundreds of 
square miles in area. Well water often is most representative of 
pesticides leaching from a much smaller geographic area. Furthermore, 
there is a significant risk that at least some individual wells in any 
large sample will be severely impacted by pesticides because of either 
poor well construction (allowing direct influx of pesticide residues 
from the surface) or spillage from pesticide mixing/loading activities 
or leakage from pesticide storage facilities. Contamination levels in 
individual wells can be much, much higher from these sources than would 
occur in ground water solely from maximum agricultural applications of 
pesticides to the surface. The consequence of this is that the highest 
values of pesticides observed in a large scale survey of ground water 
cannot be assumed to represent contamination from normal outdoor uses 
of pesticides.
    EPA identified 39 instances in which it had estimated pesticide 
residues in ground water resulting from the pesticide's use on a 
particular commodity using SCI-GROW and there was also NAWQA data on 
the pesticide in ground water. (Ref. 42). In all but three instances, 
the peak modeled value exceeded the 99.8th percentile value from the 
NAWQA data. No exceedances occurred for any of the 39 compounds at the 
99.5 percentile level or below. Most estimates, even at the 99.8th 
percentile, were substantially above the NAWQA value. For example, in 
24 cases, the modeling value was an order of magnitude or more higher 
than the 99.8th percentile NAWQA value. Of the three cases in which the 
monitoring value exceeded the projected value, in each instance the 
difference was less than a factor of 2x. In two of the three cases both 
the projected and monitored values were extremely low both absolutely 
and relative to other exposure values for the pesticide. For example, 
malathion had SCI-GROW and NAWQA ground water values (99.8th 
percentile) of 0.006 ppm and 0.007 ppm, respectively, compared to PRZM-
EXAMS and maximum NAWQA surface water values of 324 ppm and 0.39 ppm, 
respectively. Additionally, tolerance values for malathion range from 
0.1 ppm to 135 ppm with most values for agricultural crops either 4 ppm 
or 8 ppm. The other instance where a monitored value exceeded the 
modeled value involved alachlor. There, SCI-GROW predicted a value of 
0.82 ppm and the monitored value was 1.2 ppm or a factor of 1.5x 
higher. Preliminary results of comparisons with alachlor concentration 
frequency distributions from other large scale surveys, including those 
targeted for alachlor or at least for corn use areas (the major crop 
use for alachlor) are inconclusive with regard to the conservativeness 
of the SCI-GROW prediction. Id. EPA plans to look more closely at the 
data on alachlor to determine if any adjustment of SCI-GROW is 
warranted. Primarily needed for this are the completion of analysis of 
new monitoring data recently submitted to support the registration of 
acetochlor (which includes some very useful concentration distribution 
information for alachlor as well as two other corn herbicides) and the 
analysis of a large amount of additional ground-water monitoring for 
multiple pesticides conducted by USGS in more recent phases of the 
long-term NAWQA project. EPA expects that any adjustment to SCI-GROW 
would be slight.
    iii. Imidacloprid-specific data. EPA has received and reviewed two 
prospective ground water studies for imidacloprid (Refs. 43 and 45). 
Such studies are designed to measure maximum concentrations of 
pesticides likely to occur in ground water under geological conditions 
vulnerable to ground water contamination. The studies were conducted in 
Montcalm County, Michigan and Monterrey County, California.
    At the Michigan study site, imidacloprid parent was consistently 
detected in one of six monitoring well clusters in the treated field 
beginning about 500 days after application and continuing through the 
close of the study some 5 years after application. No degradation 
products were detected in ground water during this period (there were a 
very few detections before application that may have been due to 
previous uses nearby or sample contamination). The maximum 
concentration of imidacloprid parent detected in ground water in any 
one sample at the Michigan study site was 0.24 ppb. EPA concluded that 
the 0.24 ppb level might increase slightly over time as imidacloprid 
continues to leach into ground water; however, the level was not 
expected to increase dramatically given that the levels seen at the 3 
and 12 foot soil depths was 1.63 ppb and 1.31 ppb, respectively. (Ref. 
43)
    Data from the California site is less useful due to the fact that 
there appears to have been very little ground-water recharge occurring 
during the course of the study as evidenced by the almost complete lack 
of detection of the bromide tracer (applied concurrently with 
imidacloprid) in ground water. The maximum combined residue of 
imidacloprid parent and degradates found in the suction lysimeters was 
0.62 ppb at 633 days post application. The maximum combined 
imidacloprid residue in the ground water at the California site was 
0.14 ppb found 149 days post application. EPA concluded that low (sub-
ppb) level contamination of potable ground water might occur in this 
region following application to irrigated vegetable or fruit crops. Id.
    Additionally, extensive ground water monitoring data that has 
recently been submitted from the New York State Department of 
Environmental Conservation, Division of Solid and Hazardous Materials 
for Nassau and Suffolk Counties of New York includes data on 
imidacloprid. Nassau and Suffolk counties have ground water that is 
exceptionally vulnerable to pesticide contamination and have a long 
history of a number of pesticides being banned from use in these 
counties over the years. This exceptional vulnerability to 
contamination is due to the very rapid infiltration of pesticides that 
occurs in the sandy soils present in the agricultural areas of Long 
Island and the tendency for pesticides to persist in the ground water. 
These conditions have been documented from many years of monitoring 
ground water in this area (many of early detections for pesticides that 
were subject to scrutiny for ground-water contamination in the 1960s 
and 1970s were from Long Island. (Ref. 26).
    For imidacloprid, there have been about 27 detections of 
imidacloprid above a detection limit of 0.2 ppb in about 5,000 ground 
water samples taken by the Suffolk County Department of Health 
Services, to date, with much of the monitoring targeted to areas with 
known histories of imidacloprid use and previously documented ground-
water contamination issues. Overall, imidacloprid detections are rare 
in drinking water wells. Three wells had detections above the model-
predicted maximum of 1.4 ppb. After closer investigation, however, EPA 
has concluded that those three wells are not reliable indicators of 
imidacloprid

[[Page 30065]]

values that can be expected in ground water from agricultural use of 
imidacloprid. The first of these wells is a private well in Mattituck, 
Long Island in which imidacloprid was found at a level of 6.69 ppb. An 
investigation by the New York authorities, however, concluded that 
these high levels were due to misuse of the pesticide in a greenhouse 
adjacent to the well where imidacloprid contaminated water was drained 
onto the ground in the immediate vicinity of the well. The second well 
was one of five shallow monitoring wells installed directly down 
gradient from imidacloprid use sites for the purpose of monitoring 
pesticide levels. One of those wells, ``Jamesport B-2'', showed levels 
of imidacloprid as high as 2.06 ppb. It was discovered, however, that 
this well was in all likelihood contaminated as a result of a manmade 
sump nearby that was constructed to alleviate ponding in the field and 
directly connected surface water to ground water. Imidacloprid was 
detected in only one of the other five wells, and the level of 
imidacloprid detected in the other well did not exceed 0.24 ppb. 
Finally, imidacloprid has been detected in shallow ground water wells 
directly downgradient from a site investigating use of tree injection 
treatments of imidacloprid. The highest level of imidacloprid found in 
these wells was 3.9 ppb. These wells, however, are not representative 
of wells used to supply ground water for drinking water. The wells were 
screened at extremely shallow depths (screens beginning only 4 to 10 
feet from surface) due to the fact that the depth to ground water 
averaged about five feet. It was concluded that these wells are ``no 
more representative of what would likely occur in drinking water 
supplies than pesticide concentrations in samples taken from a weir 
draining an agricultural field are representative of what would occur 
in a community water supply drawing from a river or reservoir 
downstream.'' (Ref. 43)
    iv. Conclusion. Based on the above analysis of EPA's drinking water 
models, EPA concludes that they are based on reliable data and have 
produced estimates that EPA can reliably conclude will not 
underestimate exposure to pesticides in drinking water. The model 
estimates EPA used for assessing the aggregate exposure to imidacloprid 
(37.6 ppb for acute and 17.52 ppb for chronic from the FIRST surface 
water model) are substantially higher than any actual data on 
imidacloprid residues in drinking water including the imidacloprid 
prospective ground water study and even the extraordinary and 
unrepresentative values seen in ground water on Long Island as a result 
of pesticide misuse, a direct connection between ground water and 
surface water, or extremely shallow ground water.
    5. Missing exposure data - specific--a. Information on regional 
consumption. NRDC contends that, for imidacloprid, EPA relied on 
estimates of national consumption of blueberries and not regional or 
state-specific data for its granting tolerances in connection with the 
approval of emergency exemptions under FIFRA for use of the pesticide 
on blueberries in the States of New Jersey and Michigan. NRDC argues 
that the fresh nature of the food and the potential for heavy local 
consumption with a strong seasonal component strongly suggests that 
national consumption data may underestimate consumption in localized 
areas in New Jersey and Michigan.
    EPA is confident that the methodologies used in its estimation of 
exposure and the percentile of regulation selected do not 
systematically underestimate exposures to major identifiable 
subpopulations. This is based, in part, on the extensive food 
consumption survey data from USDA (its Continuing Survey of Food Intake 
by Individuals or CSFII) which surveyed more than 20,000 individuals 
from all States and results in more than 40,000 unique person-days of 
consumption. EPA notes that, contrary to the assertion by NRDC, 
consumption is not averaged throughout the year, but instead the CSFII 
includes each reported consumption amount in the form of a frequency 
distribution of actual reported single-day consumptions. Each 
individual consumption event thus can be considered separately when 
such consideration is appropriate to risk assessment as for risk 
assessments estimating acute risks.
    Accordingly, the CSFII survey is adequate to capture the high-end 
consumers about which NRDC raises concerns. The survey is statistically 
designed to be representative of the U.S. population and reflects 
variability in consumption over all seasons and geographic regions. Due 
in part to this design and the fact that fresh blueberries are widely 
available in season in states where they are not grown, EPA does not 
believe that the high-end consumption estimates present in the USDA 
CSFII survey materially or systematically underestimate the consumption 
patterns of consumers in blueberry-producing states (either overall or 
during harvest and other ``high-availability'' seasons). (Ref. 52).
    It should be emphasized that in objecting to EPA's reliance on this 
scientifically designed consumption survey, NRDC has offered nothing 
other than speculation to support its claim that EPA is underestimating 
blueberry consumption. For this reason alone, NRDC's argument lacks 
merit.
    For the reasons detailed above, NRDC's allegations concerning 
blueberry consumption do not indicate that EPA has underestimated 
exposure of consumers in Michigan and New Jersey to imidacloprid. 
NRDC's objection to the children's safety factor decision on this 
ground, therefore, is without merit.
    b. Residential exposure information. NRDC claims that EPA failed to 
include several residential exposure scenarios in its aggregate 
exposure estimate for imidacloprid based on low toxicity. Imidacloprid 
Objections at 16. Previously, EPA had concluded that certain 
residential exposure scenarios did not present any significant risk 
either because the toxicity data did not reveal any relevant adverse 
effects for the duration of exposure in question (intermediate-term 
exposure for all population groups) or because imidacloprid exposure 
was not expected for a particular population group (short-term adult 
exposure). See 66 FR at 56229, 56231. On October 8, 2002, however, the 
Health Effects Division (HED) Hazard Identification Assessment Review 
Committee (HIARC) re-reviewed the hazard and exposure database for 
imidacloprid and established additional endpoints. Endpoints were 
chosen for each of the following exposure scenarios: acute dietary, 
chronic dietary, short-term oral, intermediate-term oral, short-term 
dermal, intermediate-term dermal, long-term dermal, short-term 
inhalation, intermediate-term inhalation, and long-term inhalation. 
Additionally, it was concluded that short-term exposure was likely for 
adults by the dermal and inhalation route. Oral exposure for adults is 
not expected from the residential uses for imidacloprid (e.g., turf, 
ornamental, pets) because adults do not generally engage in the type of 
hand-to-mouth behavior that can produce such pesticide exposure in 
young children. Accordingly, an aggregate risk assessment for short-
term dermal and inhalation exposure for adults was conducted. 68 FR 
61624, 61632 (October 29, 2003). Intermediate-term risk assessments 
(i.e. risk assessments that aggregate exposure from food, water, and 
residential exposures for comparison to intermediate risk endpoints) 
were not conducted because, based on residential application

[[Page 30066]]

practices and the half-lives observed in the turf transferable residue 
study, residential exposures to imidacloprid are not expected to be 
continuous for periods of 30 to 90 days. 68 FR at 61632; (see Ref. 44 
at 51).
    c. Prospective ground water monitoring studies. As discussed above, 
these studies have been received and reviewed. The levels of 
imidacloprid found in ground water were below the levels from modeling 
used to calculate aggregate exposure.
    6. Missing risk assessment. NRDC claims that a short-term 
residential risk assessment is missing as to imidacloprid. Imidacloprid 
Objections at 5. EPA would note, however, that such a risk assessment 
was conducted and is summarized on pages 39,046 and 39,047 of the 
Federal Register notice. 67 FR 39041, 39046-39047 (July 21, 1999). See 
also 68 FR 61624, 61632 (October 29, 2003).
    7. Conclusion on children's safety factor issues. In the challenged 
tolerance action, EPA applied an additional safety factor of 3X to 
address the missing DNT study. As discussed above, that study has now 
been received and reviewed. Taking into account the results of that 
study as well as all of the arguments raised by NRDC, EPA has concluded 
that there are reliable data supporting removal of the additional 
safety factor for infants and children for all risk assessments other 
than the acute risk assessment relying on the acute neurotoxicity study 
in rats to project a safe dose in humans. As to the acute risk 
assessment using the acute neurotoxicity study in rats, there are 
reliable data supporting use of an additional 3X factor instead of 10X. 
See Unit VII.C.2. The 3X safety factor has been incorporated into the 
acute risk assessment by dividing the LOAEL from the acute 
neurotoxicity study by 3 in deriving the acute reference dose.

C. LOAEL/NOAEL

    NRDC argues that EPA cannot legally make the reasonable certainty 
of no harm finding for imidacloprid because EPA has relied on a LOAEL 
in assessing the safe level of exposure to the pesticide. NRDC claims 
EPA ``cannot lawfully establish tolerances in the absence of a no-
observed-effect-level (NOEL).'' Imidacloprid Objections at 18. Implicit 
in this argument is that EPA cannot use a no-observed-adverse-effect-
level (NOAEL) in making a safety finding. In later objections, NRDC 
confirmed that in fact it was contending that section 408's safety 
standard does not permit EPA to rely on a NOAEL in concluding a 
tolerance is safe. Rather, according to NRDC, EPA may only make a 
safety finding for a pesticide where EPA has determined the dose in 
animals at which no effects, adverse or otherwise, are elicited from 
exposure to the pesticide. Isoxadifen-ethyl Objections at 17-18. Below 
EPA identifies the flaws in NRDC's generic argument concerning LOAELs 
and NOAELs and addresses the pesticide-specific concerns NRDC raises 
with regard to use of a LOAEL as to imidacloprid.
    1. Generic legal argument. EPA believes that it can make a 
reasonable certainty of no harm finding based on a LOAEL from an animal 
study (where no NOAEL was found) in appropriate circumstances. Whether 
or not a reasonable certainty of no harm finding can be made when only 
a LOAEL is identified in a study depends on whether EPA has sufficient 
toxicological evidence to estimate with confidence a projected NOAEL 
that is unlikely to be higher than the actual NOAEL. Typically, when a 
LOAEL but not a NOAEL has been identified by a study, EPA will, when 
the data support it, project a NOAEL for that study by dividing the 
LOAEL by a factor, usually 3X.
    There is nothing in the statutory safety standard explicitly 
addressing the use of NOAELs or LOAELs. Moreover, nothing in the phrase 
``reasonable certainty of no harm'' legally precludes use of LOAELs to 
make a finding regarding the likelihood that harm will occur at a given 
dose. Whether a LOAEL provides a sufficient basis for a reasonable 
certainty of no harm finding is a question of scientific fact.
    NRDC correctly notes that the House Commerce Committee indicated 
that its ``expect[ation]'' was that EPA would be able to make a 
reasonable certainty of no harm finding where there was an ample margin 
of safety between exposure levels and -
    the level at which the pesticide chemical residue will not cause 
or contribute to any known or anticipated harm to human health. The 
Committee further expects, based on discussions with the 
Environmental Protection Agency, that the Administrator will 
interpret an ample margin of safety to be a 100-fold safety factor 
applied to the scientifically determined ``no observable effect'' 
level when data are extrapolated from animal studies.
H. Rep.104-669, pt. 2 , 41 (1996).
Congress' expectation, however, that a reasonable certainty of no harm 
finding could be made under one set of circumstances (100-fold safety 
factor applied to the ``no observable effect'' level), certainly does 
not preclude the finding being made in a different set (e.g., 300-fold 
safety factor applied to the lowest observable effect level). Moreover, 
Congress made clear that it was adopting the reasonable certainty of no 
harm standard based on EPA's ``current application of the standard.'' 
Since the passage of FFDCA section 409 in 1958, both FDA and EPA have a 
long history of applying that standard. In no instance, has either 
agency indicated that reliance on LOAELs, although it has been an 
accepted practice generally, (See Ref. 12) was barred by the reasonable 
certainty of no harm standard. To the contrary, EPA has relied on 
LOAELs to make reasonable certainty of no harm findings under section 
409. (See 61 FR 33041 , 33042 (June 26, 1996) (establishing food 
additive regulation for flutolanil); 55 FR 23736 (June 12, 1990) 
(establishing food additive regulation for pirimphos methyl). In fact, 
FDA and EPA interpreted the reasonable certainty of no harm standard to 
permit a safety finding to be made in circumstances where a NOAEL 
cannot be identified - that is, when a substance is believed not to 
have a threshold below which no adverse affect will result - and the 
House Commerce Committee in its Report on the FQPA specifically 
recognized and approved that approach. Id. Thus, the legislative 
history, if anything, supports the proposition that a LOAEL may provide 
a sufficient basis for a reasonable certainty of no harm finding.
    EPA also rejects NRDC's argument that a safety finding for a 
threshold effect can only be made based on a ``no observed effect 
level'' (NOEL) as opposed to a ``no observed adverse effect level'' 
(NOAEL). EPA's Office of Pesticide Programs (``OPP'') in a response to 
comment document has explained the Agency's reasoning. Although noting 
the House Commerce Committee Report uses the term ``NOEL'', OPP 
concluded that:
    the legislative history does not indicate that Congress 
intentionally used the term NOEL because it did not think it 
appropriate for OPP to consider the NOAEL. H. Rept. 104-669, 104th 
Cong., 2d Sess. 41 (1996). In fact, Congress appears to have assumed 
NOELs are NOAELs. For example, in defining ``threshold effect'' 
Congress stated that this ``is an effect for which the Administrator 
is able to identify a level at which the pesticide chemical residue 
will not cause or contribute to any known or anticipated harm to 
human health.'' Id. (emphasis added). If Congress had intended that 
threshold effects be based on NOELs rather than NOAELs, it would not 
have used the word ``harm'' in defining the effect.
    Congress seems to have used the term NOEL because it was common 
usage for OPP at the time FQPA was passed. However, prior to 1998, 
in OPP's discussion of the hazard identification process of 
evaluating pesticide toxicity, the term NOEL was used to describe

[[Page 30067]]

the dose level at which no significant adverse effects were noted. 
OPP's terminology was not consistent with the rest of the Agency, as 
illustrated in EPA's Integrated Risk Information System (IRIS). This 
system included more hazard terms than OPP generally employed, 
including NOAEL, LOAEL, and FEL (Frank Effect Level). On September 
2, 1998, this apparent semantic inconsistency was eliminated by HED 
Standard Operating Procedure (SOP) 98.3 which indicated that OPP 
would commence using the terms NOAEL and LOAEL in their scientific 
reviews and documents. It also stated, ``In a practical sense, the 
terms NOEL and NOAEL have been used interchangeably in OPP. As a 
general rule, OPP would consider as appropriate for hazard 
identification and risk assessment only those effects which are 
adverse or potentially adverse. This inclusion of the term NOAEL 
should not change any of our hazard endpoints for regulation but add 
to the quality of the risk assessment.''
(Ref.47 at 165-166)
    NRDC claims that only by relying on a NOEL can the Agency legally 
make the required reasonable certainty of no harm finding. Isoxadifen-
ethyl Objections at 17-18. Yet, NRDC's legal argument here both ignores 
the language of the statute and relies on unsupported factual 
generalities. NRDC asserts use of a NOEL is required because only by 
use of a NOEL is ``the risk assessor [] assured that regulatory 
decisions are based on a dose at which no effect is elicited.'' 
Isoxadifen-ethyl Objections at 17 (emphasis added). The statute, 
however, defines the safety standard in terms of protecting against 
``harm,'' not ``effects.'' NRDC also argues that the ``adverse'' 
effects used to define NOAELs are ``crude toxicological endpoints,'' 
and that ``a NOAEL may represent a dose high enough to elicit 
significant unpleasant and harmful effects . . . .'' Id. NRDC, however, 
provides no data or explanation to support such assertions. EPA 
believes it applies the NOAEL standard in a way that takes into account 
sensitive indicators of adverse effects. EPA's use of cholinesterase 
inhibition as an adverse effect is only one example of this. (Ref. 50). 
In any event, general claims about the non-protectiveness of NOAELs are 
insufficient to contest a specific finding of safety by EPA. An 
objector must explain why the specific safety finding, taking into 
account its component parts (e.g., the NOAEL or LOAEL identified, the 
safety factors used), does not provide a reasonable certainty of no 
harm. NRDC has not even attempted to make this case with regard to the 
NOAELs used in making the safety finding for imidacloprid.
    2. Use of LOAELs to assess imidacloprid risk. NRDC asserts that EPA 
relied upon a LOAEL in assessing both acute and chronic toxicity to 
imidacloprid. Imidacloprid Objections at 18. NRDC is mistaken as to 
chronic toxicity. In assessing chronic risk, EPA set the RfD using the 
NOAEL of 5.7 mg/kg/day based upon thyroid effects at the next highest 
dose of 16.9 mg/kg/day in the imidacloprid combined chronic/
carcinogenicity study in rats. 64 FR 39041, 39044 (July 21, 1999); see 
Imidacloprid Risk Assessment at 26, Table 4. The acute toxicity 
endpoint was based upon a LOAEL of 42 mg/kg/day from an acute 
neurotoxicity study in rats. This value was adjusted with a safety 
factor of 3X to approximate the value of a NOAEL. EPA has high 
confidence that this value of 3X is sufficient for several reasons. 
First, the LOAEL (42 mg/kg) from the acute neurotoxicity study is 
comparable to the LOAELs seen in adults in the developmental rat study 
(30 mg/kg/d) and the two-generation reproduction study (47/52 mg/kg/d 
(male/female)) and in the offspring in the DNT study (55 mg/kg/d). 
Second, the extrapolated NOAEL of 14 mg/kg (42/3 = 14) is comparable to 
the NOAEL of 20 mg/kg/d established in the offspring in the DNT. 
Importantly, the LOAEL in DNT study like the acute neurotoxicity study 
was based on decreased motor activity, and the DNT established a clear 
NOAEL for that effect. Finally, the neurotoxic effects on motor 
activity in the acute neurotoxicity study showed a good dose response 
which resulted in minimal effects on motor activity and locomotor 
activity at the LOAEL.

D. Aggregate Exposure

    1. Worker exposure. EPA has interpreted ``aggregate exposure'' to 
pesticide residues not to extend to pesticide exposure occurring at the 
workplace based on the language in section 408(b)(2)(D) explaining what 
exposures are included in the term ``aggregate exposure:''

    [T]he Administrator shall consider, among other relevant factors 
. . . available information concerning the aggregate exposure levels 
of consumers (and major identifiable subgroups of consumers) to the 
pesticide chemical residue and to other related substances, 
including the dietary exposure under the tolerance and all other 
tolerances in effect for the pesticide chemical residue, and 
exposure from other non-occupational sources . . . .

This language quite plainly directs EPA to limit consideration of 
aggregate exposure of pesticide residues and other related substances 
to those exposures arising from non-occupational sources. NRDC's claim 
that EPA erred by not considering worker risks in making tolerance 
decisions under section 408 runs afoul of Congress' explicit mandate 
that such exposures not be included. Although there is some ambiguity 
as to precisely how the factors listed in section 408(b)(2)(D) relate 
to the safety finding described in section 408(b)(2)(A)(ii), for the 
reasons set forth below, NRDC's interpretation of the statutory 
language is unreasonable.
    NRDC argues occupational exposures must be considered because the 
general safety standard as set forth in section 408(b)(2)(A)(ii) 
describes ``aggregate exposure'' broadly without any exclusion for 
occupational exposures. This reading, however, renders section 
408(b)(2)(D)'s limitation of aggregate exposure to ``non-occupational'' 
exposures without effect. Three important principles of statutory 
construction suggest that such an approach is insupportable. First, the 
language in the statute should be construed in a manner that accords 
meaning to all provisions. United States v. Menasche, 348 U.S. 528, 
538-539 (1955) (``It is our duty to give effect, if possible, to every 
word, clause and sentence of a statute.'') It is not lightly presumed 
that Congress enacted a meaningless or superfluous provision. Asiana 
Airlines v. FAA, 134 F.3d 393, 398 (D.C. Cir. 1998) (``A cardinal 
principle of interpretation requires us to construe a statute `so that 
no provision is rendered inoperative or superfluous, void or 
insignificant.'''). EPA's interpretation gives meaning to the 
occupational exposure exclusion in section 408(b)(2)(D). Second, and 
similarly, statutory language should be construed in a harmonious 
fashion to the greatest extent possible. Citizens to Save Spencer 
County v. EPA, 600 F.2d 844, 871 (D.C. Cir. 1979) (``[T]he maximum 
possible effect should be afforded to all statutory provisions, and, 
whenever possible, none of those provisions rendered null or void.'') 
``The cardinal principle of statutory construction is to save and not 
to destroy.'' Menasche, 348 U.S. at 538. Although EPA's interpretation 
does not relieve all potential tension between section 408(b)(2)(A)(ii) 
and section 408(b)(2)(D), NRDC's approach treats the two sections as 
directly contradictory, negating the specific language in subsection 
(b)(2)(D)(vi) pertaining to occupational exposure. Third, specific 
language should control over general. Ohio Power Co. v. FERC, 954 F.2d 
779, 784 (D.C. Cir. 1992) (``Of course, it is black letter law that 
when a conflict arises between specific and general provisions of the 
same legislation, the courts should give voice to Congress's specific 
articulation of its policies and preferences.'') Hence, the more 
detailed

[[Page 30068]]

explanation in section 408(b)(2)(D) concerning the scope of aggregate 
exposure should be relied upon to help to provide a harmonious 
construction of the two sections.
    NRDC, pointing to the ``among other relevant factors'' language in 
section 408(b)(2)(D), objects that this section should not be viewed as 
controlling because this section is intended to be ``illustrative'' and 
not ``exhaustive.'' EPA fully agrees that section 408(b)(2)(D) was not 
intended to list exhaustively all of the considerations appropriate to 
making safety determinations under section 408, but cannot accept the 
proposition that the ``other relevant factors'' language somehow undoes 
the express limitation in subsection (b)(2)(D)(vi) concerning 
occupational exposure. Not only does NRDC's approach once again fail to 
give meaning to the occupational exposure exclusion in subsection 
(b)(2)(D)(vi) but it fails to take into account Congress' directive 
that EPA could consider ``other relevant factors.'' When used in this 
fashion, the word ``relevant'' restricts EPA to considering factors 
that are relevant to the safety determination under section 408(b) - 
that is, relevant to whether a pesticide's aggregate exposure meets the 
reasonable certainty of no harm test. Presumably, Congress provided an 
important reference point for determining relevance by the long list of 
factors it required that EPA consider. Relevance, moreover, is 
indicated not only by the factors that Congress included but by the 
aspects of those factors that Congress expressly directed were not to 
be considered. Thus, EPA believes that Congress, by excluding 
occupational exposures from the term ``aggregate exposure'' in 
subsection (b)(2)(D)(vi) was, in effect, determining the relevance of 
occupational exposure to aggregate exposure and the safety 
determination under section 408.
    Finally, NRDC has argued, in a Petition which it has appended to 
its objections, that even if worker exposure generally is excluded from 
aggregate exposure, ``in utero'' exposures resulting from the presence 
of pregnant women in the workplace should not be excluded from 
consideration. NRDC, Petition for a Directive that the Agency Designate 
Farm Children as a Major Identifiable Subgroup and Population (1998). 
NRDC points to the statutory language directing EPA to consider ``in 
utero'' exposures and cases under state worker compensation statutes 
that have held that children who are injured ``in utero'' as a result 
of their mother's employment are not barred by worker compensation 
schemes from bringing an action against the employer. These cases have 
held that the bar to seeking a tort remedy against the employer applies 
only to ``employees'' and an in utero fetus is not an employee. See, 
e.g., Snyder v. Michael's Stores, Inc., 945 P.2d 781 (Calif S.Ct. 
1997).
    Although the statutory language on this issue may permit multiple 
readings here, EPA believes it is reasonable to exclude workplace 
exposures to the in utero fetus from aggregate exposure. EPA is not 
suggesting that the fetus is an employee - the issue involved in the 
worker compensation cases cited by NRDC. The language of section 408 is 
significantly different than worker compensation statutes. Section 408 
does not bar consideration of exposure to ``employees'' but rather 
exposure from ``occupational sources.'' Given this statutory language 
EPA believes it is reasonable to focus upon whether the exposure is 
principally due to exposure in an occupational setting or not. An 
exposure to a fetus that results from the fetus' mother's presence in 
an occupational setting would fall well within this approach. This 
interpretation also makes sense in terms of the overall statutory 
scheme. Presumably, Congress excluded occupational exposures from 
section 408 because it determined that acceptable levels in food for 
the general public should not be set using the discrete, and highly 
regulated (including regulation by EPA under FIFRA), exposures 
occurring in the workplace as an assumed underlying exposure. If 
occupational exposure to pregnant women is included in aggregate 
exposure under section 408, however, occupational exposure will 
invariably be an aspect of the section 408 safety finding for 
pesticides involved in agriculture or other commercial enterprises 
because EPA would generally have to assume that pregnant women may be 
in the workforce.
    2. Classification of farm children as a major identifiable 
population subgroup. NRDC points out that FFDCA section 408 directs EPA 
to consider not just the general population in assessing aggregate 
exposure but also ``major identifiable subgroups of consumers.'' 21 
U.S.C. 346a(b)(2)(D)(vi). In this regard, NRDC argues that children 
living in agricultural communities should be treated as such a major 
identifiable subgroup. These children are an identifiable subgroup, 
according to NRDC, because of the allegedly heightened exposure to 
pesticides that they receive due to their proximity to farm operations 
and farm land and, for some, due to their contact with parents involved 
in agriculture. Isoxadifen-ethyl Objections at 11-12. NRDC claims these 
children comprise a ``major'' subgroup citing statistics showing that 
``320,000 children under the age of six live on farms in the United 
States[], . . . many hundreds of thousands of children play or attend 
schools on or near agricultural land, . . . [and] [t]he nation's 2.5 
million farm workers have approximately one million children living in 
the United States.'' Id.
    Whether or not EPA attaches the label ``major identifiable 
subgroup'' to farm children, EPA's risk assessment approach to 
children, including the major identifiable subgroups of children used 
in its risk assessments, adequately takes into account any pesticide 
exposures to children - whether as a result of living close to 
agricultural areas or otherwise. For some time, EPA has treated infants 
and children grouped by ages (e.g., infants younger than 1 year, 
children 1 - 2 years) as major identifiable subgroups. These age 
groupings have been chosen to reflect different eating patterns of the 
age groups. In evaluating exposure to these or any other subgroup, 
however, EPA considers the range of exposures across the subgroup not 
just as a result of pesticide residues in food but from all non-
occupational exposures. If a significant number of any of the 
population subgroups of children have higher exposures due to a non-
food source (e.g., residential uses of a pesticide, proximity to 
agricultural areas), EPA believes that that exposure is appropriate to 
consider in evaluating the range of exposures for the subgroup. The 
fact that the children in the subgroup receiving the higher exposures 
are not themselves labeled a major identifiable subgroup in no way 
lessens EPA's consideration of their exposures. This approach is nicely 
illustrated by the imidacloprid risk assessment.
    In the imidacloprid risk assessment, EPA not only considered 
imidacloprid exposure from food but also exposures resulting from use 
of imidacloprid on lawns and pets. The residential use scenario that 
produced the highest estimate of exposure was a toddler hugging the pet 
right after imidacloprid treatment. In evaluating aggregate exposure to 
toddlers (children 1-2 years-old), EPA aggregated imidacloprid exposure 
from the pet hug scenario with imidacloprid exposure from food and 
water. This was done even though (1) children living with pets capable 
of receiving a full body hug are not designated a major identifiable 
subgroup; (2) it is likely that only a minority of the children in the 
age subgroup of 1-2 years-old live with pets

[[Page 30069]]

of this size; and (3) the number of 1-2 year-old children that may 
actually experience the exposures estimated by the pet hug scenario is 
likely to be exceeding small. Similar to the manner in which 
residential exposure was incorporated in the aggregate exposure 
assessment, if EPA had information showing meaningful exposure to 
children as a result of living close to agricultural areas, those 
exposures would receive full consideration in assessing aggregate 
exposure to the existing children's subgroups. Thus, the fact that EPA 
has not labeled farm children as a major identifiable subgroup has not 
in any way affected EPA's consideration of exposures that are unique to 
farm children. For the reasons discussed in the Units VII.A. and 
VII.D.4, however, EPA concludes that its exposure assessment has 
adequately considered any potentially greater exposures to children in 
agricultural areas.
    That being said, EPA does not believe that NRDC has made an 
adequate case that the group of children NRDC designates as ``farm 
children'' are an identifiable group. Many of the commenters protested 
NRDC's designation of ``farm children'' as a major identifiable 
subgroup, noting the heterogeneous nature of the group and NRDC's lack 
of precision in defining the group. To be sure, NRDC's suggested 
subgroup is constructed differently than EPA's historical practice with 
regard to population subgroups. That practice has focused on 
categorizing individuals by age, ethnicity, and region of the country. 
Similarly, NRDC is, in fact, far from precise in defining the limits of 
the suggested subgroup. For example, NRDC does not clarify whether 
urban or suburban children on the borders of areas that exist side-by-
side with agricultural areas should be included in the alleged 
subgroup, or whether it would include in the subgroup children in 
agricultural areas who might live no closer to application sites than 
some urban or suburban children.
    Moreover, several of the reports submitted by NRDC undermined its 
contention that farm children are an identifiable subgroup based on 
exposure. The CFPR Report, for example, in a number of places 
highlights the degree to which, not only farm-area residents, but also 
urban and suburban residents are exposed to pesticides. The asserted 
exposures suffered by urban dwellers, moreover, include spray drift not 
only from urban area applications (e.g., from home and garden 
applications, as well as other structural applications), but long-range 
spray drift from agricultural area applications. These aspects of the 
report run counter to NRDC's suggestions that: (1) farm children are a 
major subgroup that receives greater exposure than non-farm children; 
and (2) farm children are a major identifiable subgroup, in that the 
lines in the report between farm area children and non-farm-area 
children exposed to agricultural spray drift are blurred.
    In addition, although in places the CFPR Report cites to studies 
purportedly showing that farm children suffer more exposure to 
pesticides than other children, on account of spray drift, it largely 
relies on the Washington State studies discussed above. For reasons 
already mentioned, the Agency does not believe that those studies 
support the designation of farm children as a major identifiable 
subgroup.
    The Ranking Study, for its part, also emphasized that ``an 
increasing number of children live along the nation's agricultural-
urban edge.'' As discussed above, this phenomenon clouds the potential 
for a distinction between farm and non-farm children. Moreover, the 
authors of the study identified ``[n]otable uncertainties'' in their 
risk assessment, and would go only so far as to suggest that 
``farmworker/farm children'' constitute a subgroup ``potentially at 
higher risk.'' Thus, it, too, fails to support the identification of 
farm children as a major identifiable subgroup, as distinguished from 
children generally.
    NRDC also alleges that farm children have ``unique . . 
.sensitivities to exposure'' that must be considered by EPA. 
Imidacloprid Objections at 11-12. NRDC, however, cites no unique 
toxicological sensitivities of farm children but rather focuses on the 
allegedly unique exposure patterns of farm children. At most, NRDC 
points to the fact that children generally may be more toxicologically 
sensitive than adults because their internal organs and bodily 
processes are still developing. Id. at 13. But the fact that children 
may have different toxicological sensitivities than adults does not 
support any claim regarding differences in sensitivities between 
children generally and farm children.
    In sum, the above studies and information, whether concerning 
children in agricultural areas and non-agricultural areas or children 
in agricultural areas alone, and whether concerning environmental 
levels, biological levels, or both, provide no sufficient basis for 
designating ``farm children'' as a major identifiable subgroup. It thus 
was reasonable for EPA to assess aggregate exposure to the challenged 
pesticide tolerances without identifying farm children as an additional 
major identifiable subgroup of consumers. EPA's approach, described 
above, of examining the range of exposures in each of the age-based 
subgroups of children is adequately protective of children to the 
extent they experience higher exposures from proximity to agricultural 
areas.
    3. NRDC's 1998 petition on farm children. As previously mentioned, 
NRDC petitioned EPA in 1998 to designate farm children as a major 
identifiable subgroup under section 408 and take several other various 
steps regarding farm children's exposure to pesticides. For the reasons 
stated above, EPA does not believe it is appropriate to designate farm 
children as a major identifiable subgroup although, as indicated, EPA 
will consider reliable data on the range of pesticide exposures 
received by children, including data pertaining to such issues as spray 
drift, volatilization, and farmworker take-home exposures that were 
raised by the 1998 petition.
    The 1998 petition also requested that EPA: (1) retain the 
additional 10X safety factor for the protection of children where EPA 
lacks data on farm children exposure; (2) make specific determinations 
as to the exposure of farm children from all pathways; (3) require data 
from registrants where data is lacking on farm children's exposure and 
not issue a tolerance until such data is submitted; (4) refuse to 
register a new pesticide unless a validated scientific method is 
available to detect residues of the pesticide in food; (5) increase 
research into exposures and health status of farm children; and (6) 
honor the Executive Order on environmental justice.
    As explained above, EPA has initiated a myriad of different 
research and outreach programs concerned with pesticide exposure to 
farmworkers and their families. The most important of these include, on 
the research front, EPA work with the National Agricultural Workers 
Survey (NAWS), and the Agricultural Health Survey (AHS). In terms of 
outreach, EPA has many ongoing programs, but would like to highlight 
two projects in particular. The Agency's work with the Association of 
Farmworker Opportunity Programs (AFOP), and its work on the National 
Strategies for Health Care Providers: Pesticide Initiative.
    Through the Agency's cooperative agreement with the Association of 
Farmworker Opportunity Programs (AFOP), EPA funds the National 
Pesticide Safety Education Program for agricultural workers and farm 
worker children. Working with Americorps

[[Page 30070]]

members, AFOP trains 25,000 farm workers and farm worker children every 
year about pesticide safety using Americorps members in over 50 sites 
in 16 states. AFOP conducts pesticide safety training for children at 
childcare centers, schools, churches, and community centers, and has 
developed a handbook in Spanish. The National Strategies for Health 
Care Providers: Pesticide Initiative is an initiative created by the 
EPA and the National Environmental Education and Training Foundation 
(NEETF) in collaboration with the U.S. Departments of Health and Human 
Services, Agriculture and Labor. It is aimed at incorporating pesticide 
information into the education and practice of health care providers. 
The goal is to improve the recognition, diagnosis, management, and 
prevention of adverse health effects from pesticide exposures. This 
initiative also serves as a model for broader efforts to educate health 
care providers about the spectrum of environmental health issues. Seven 
federal agencies and 16 professional associations of health care 
providers were involved in launching this initiative. These actions 
address the Petition's request regarding increased research and 
fidelity to the Executive Order on Environmental Justice.
    EPA agrees that where additional data are needed to characterize 
farm children's exposure to a specific pesticide it will retain the 
additional 10X safety factor unless reliable data exist that support 
selection of a different safety factor. Further, EPA will seek 
additional data on farm children exposure where necessary. Any decision 
on whether to approve a tolerance where additional data has been 
required will have to be a case-by-case determination considering other 
data that is available on the pesticide and the ability of use of 
additional safety factors to address any uncertainty raised by the 
requested data. As to making specific findings on all possible pathways 
of exposure to farm children, EPA will follow a pesticide-specific 
approach which considers both the generic information and pesticide-
specific information in regards to whether a particular pathway has the 
potential for significant exposure. Finally, EPA agrees that it should 
not register a new pesticide for use on food unless it has approved an 
analytical method for detecting the level of pesticide residues in food 
or found that such a method is unnecessary.
    4. Adequacy of EPA's assessment of the aggregate exposure of 
children, including children in agricultural areas. EPA believes that 
it has adequately assessed the aggregate exposure of children to 
imidacloprid generally (including both farm children and non-farm 
children), through its assessment of exposure through food, drinking 
water and residential use pathways. In support of its objection to this 
assessment, NRDC cites numerous studies for the proposition that other 
pathways (e.g., track-in) increase farm children's exposures, and it 
also cites information purportedly suggesting that volatilization and 
spray drift lead to higher exposures among farm children. For reasons 
discussed above, however (see Unit VII.A.), EPA does not believe that 
this information demonstrates that the pathways asserted, to the extent 
they exist, lead to farm children experiencing imidacloprid exposure 
levels higher than those experienced by other children. Rather, these 
studies are inconclusive, and suggest that farm children and non-farm 
children generally receive similar levels of exposure. Nor does the 
information bearing on volatilization and spray drift demonstrate that 
farm children receive greater imidacloprid exposures through these two 
additional pathways. For example, as stressed above, imidacloprid 
exposures due to residential and pet uses common to farm and non-farm 
areas would dwarf any exposures that might be attributable to either 
volatilization or spray drift in agricultural areas.
    5. Residential exposure as a result of use requiring a tolerance. 
NRDC also argues that EPA has erred in not including the added 
residential exposure that occurs in the home when an additional 
agricultural use is added. The reasons explained above as to why any 
additional exposure to children as a result of their proximity to 
farming operations is expected to be insignificant as regards 
imidacloprid apply with equal or more force as to this contention.
    6. Population percentile used in aggregate exposure estimates--a. 
In general. NRDC contends that EPA in making the reasonable certainty 
of no harm finding must make such a finding as to ``all children'' - 
that is, EPA must find that ``no children will be harmed'' by exposure 
to the pesticide. Although EPA is somewhat uncertain as to precisely 
what approach to risk assessment and safety findings NRDC is 
advocating, EPA believes that its approach to implementing the 
reasonable certainty of no harm standard is consistent with the 
statutory framework. As specified in the statute, EPA focuses its risk 
assessment and safety findings on major identifiable population 
subgroups. 21 U.S.C. 346a(b)(2)(D)(vi). For children EPA has identified 
the following subgroups: nursing infants (0-6 months); non-nursing 
infants (6 months - year); 1-2 year-olds; etc. EPA evaluates each of 
these subgroups to determine if it can be determined that there is a 
reasonable certainty of no harm for individuals in these subgroups. 
(See Ref. 48 at 46 and Ref. 51 at 14)
    b. Choice of population percentile. NRDC asserts that EPA erred by 
allegedly making its safety decision as to the acute risk posed by 
imidacloprid based on only a portion of the population, leaving the 
rest of the population unprotected. According to NRDC, EPA only 
considered 95% of the affected population. EPA admits using the 
population percentage cited by NRDC in estimating acute exposure for 
imidacloprid. EPA most definitely was not, however, acting in a manner 
designed to only protect 95% of the population. To the contrary, EPA's 
exposure estimates were designed to capture the full range of exposures 
in each population subgroup.
    As explained in its science policy paper on this subject, EPA, in 
estimating acute exposure for population subgroups, generally considers 
various population percentiles of exposure between 95 and 99.9, 
depending on the extent of overestimation in the residue data used in 
the assessment.(See Ref. 52) In each exposure assessment EPA is 
attempting to reasonably estimate the full range of exposures in a 
subgroup. The use of a particular percentile of exposure is a tool to 
estimate exposures for the entire population and population subgroups 
and not a means to eliminate protection for a certain segment of a 
subgroup. When inputs for pesticide residue values in the exposure 
estimate are high end (e.g., assuming all food contains tolerance level 
residues), a lower percentile of exposure (e.g., 95%) is thought to be 
representative of exposure to the overall population as well as 
subgroups. As increasingly realistic residue values are used (e.g., 
information from pesticide residue monitoring), a higher percentile of 
exposure (e.g., 99.9%) is generally necessary to be protective of the 
overall population and its subgroups.
    This issue was the subject of some attention when EPA began 
performing probabilistic acute exposure (risk) assessments using 
monitoring data for residue values and increasingly used a population 
percentile of 99.9 to estimate exposure. Some affected parties became 
concerned that EPA was determining that only 99.9% of the population 
were entitled to protection from potentially unsafe pesticide residues. 
EPA

[[Page 30071]]

addressed this issue in a policy paper, noting that:
    just as when OPP uses the 95th percentile with non-probabilistic 
exposure assessments OPP is not suggesting that OPP is leaving 5% of 
the population unprotected, OPP is not by choosing the 99.9th 
percentile for probabilistic exposure assessments concluding that 
only 99.9% of the population deserves protection. Rather, it is 
OPP's view that, with probabilistic assessments, the use of the 
99.9th percentile generally produces a reasonable high-end exposure 
such that if that exposure does not exceed the safe level, OPP can 
conclude there is a reasonable certainty of no harm to the general 
population and all significant population groups.
Id. at 31.
    Other parties had the opposite concern - namely, that by using the 
99.9 percentile EPA was grossly overstating exposure to the population. 
Interestingly for the purpose of the NRDC's claims regarding 
imidacloprid, EPA's analysis of the reasonableness of its exposure 
assessments demonstrated that exposure estimates using high end residue 
values and the 95th percentile of exposure were significantly greater 
than exposure estimates for the same pesticide relying on monitoring 
data and 99.9th percentile. Id. at 16-17 (citing an example showing 
exposure estimates over an order of magnitude lower when using 99.9th 
percentile with monitoring data rather than 95th percentile assuming 
tolerance level residues).
    For imidacloprid, EPA estimated acute exposure using the gross 
overestimate of all crops covered by the tolerance containing residues 
at tolerance levels. Thus, EPA believes it acted reasonably in using 
the 95th percentile of exposure in estimating imidacloprid exposure to 
the overall population and major identifiable subgroups in making its 
reasonable certainty of no harm finding as to the acute risks posed by 
imidacloprid.
    7. Lack of residential exposure assessment for adults. NRDC objects 
to EPA's decision not to conduct residential exposure assessments for 
adults despite the fact that imidacloprid has numerous residential 
uses. Imidacloprid Objections at 16. As explained in Unit VII.B.5. 
above, EPA has now determined that residential exposure assessments are 
appropriate as to short-term dermal and inhalation exposures but that 
other types of residential exposure are unlikely to occur (e.g., short-
term adult oral exposure and intermediate-term exposure).
    8. Percent crop treated. NRDC asserts that EPA's use of percent 
crop treated data pertaining to blueberries in calculating aggregate 
exposure for imidacloprid is in violation of the requirements specified 
in section 408(b)(2)(F). That section imposes certain conditions upon 
EPA's use of percent crop treated data when assessing chronic dietary 
risk. Among the specified conditions are the requirements that EPA find 
that ``the data are reliable and provide a valid basis to show what 
percentage of the food derived from such crop is likely to contain such 
pesticide chemical residue . . . [and] the exposure estimate does not 
understate exposure for any significant subpopulation group . . . .'' 
21 U.S.C. 346a(b)(2)(F). NRDC claims that, because EPA used national 
percent crop treated data on blueberries even though imidacloprid use 
on blueberries is only permitted in Michigan and New Jersey, EPA had no 
``valid basis'' for projecting the percent crop treated in those two 
states. Additionally, NRDC argues that use of national percent crop 
treated data on blueberries will ``understate exposure'' for the 
significant population group of blueberry consumers in Michigan and New 
Jersey.
    NRDC's argument here is without merit because EPA assumed that 100% 
of the blueberries consumed in the United States would be treated with 
imidacloprid in conducting the imidacloprid risk assessment. Although 
the Federal Register notice explaining the basis for the imidacloprid 
blueberry tolerance does note that ``percent crop treated data [was] 
used of selected commodities,'' 64 FR 56225, 56228 (November 7, 2001), 
those commodities did not include blueberries. (Ref. 58; see also Ref. 
44 at 43-44)

E. Lack of Emergency

    In comments filed on its own objections, NRDC advances a new 
challenge to the imidacloprid tolerance on blueberries. This challenge 
is unrelated to the safety issues raised in its objections; rather, it 
is instead tied to the fact that this imidacloprid tolerance was 
established in conjunction with EPA's approval of the use of 
imidacloprid under section 18 of FIFRA to address an emergency 
situation in the state of Michigan. Section 18 of FIFRA gives EPA the 
authority to exempt States and Federal agencies from the requirements 
of FIFRA in emergencies. NRDC claims that the ``alleged'' emergency 
justifying the approval of imidacloprid on blueberries, and 
correspondingly the blueberry tolerance, does not meet the criteria for 
an emergency in EPA regulations.
    Under EPA regulations, EPA may authorize an emergency exemption if 
it determines, among other things, that an ``emergency condition 
exists.'' 40 CFR 166.25(b)(1)(i). An ``emergency condition'' is defined 
as ``an urgent, non-routine situation . . . .'' 40 CFR 166.3(d). The 
regulations deem an emergency condition to exist when (1) no effective, 
registered pesticides are available to address the conditions; (2) ``no 
economically or environmentally feasible alternative practices which 
provide adequate control are available;'' and (3) the situation will 
cause ``significant economic loss . . . .'' Id. Applicants for 
emergency exemptions are required to submit information to EPA 
addressing these issues. 40 CFR 166.20. EPA may ``discontinue 
processing'' of incomplete applications, 40 CFR 166.30(a)(1), and deny 
an application for a information gap but must reconsider the 
application when the information gap is filled. 40 CFR 166.30(a)(2).
    EPA first approved the State of Michigan's request for an emergency 
exemption for the use of imidacloprid on blueberries in July, 2001. The 
problem faced by growers in Michigan was that the Japanese beetle (an 
invasive pest introduced to the United States in 1916) was increasingly 
contaminating shipments of harvested blueberries. Although the beetle 
does not reduce the production of blueberries in the field, the 
presence of the beetle mixed in with harvested blueberries has resulted 
in wholesale rejection by fruit buyers of shipped blueberries. 
Purchasers, according to Michigan, follow a ``one beetle is too many'' 
approach. Michigan cited one instance in the prior year (2000) in which 
two shipments of blueberries totaling 1.7 million pounds of blueberries 
were rejected at the point of delivery. Looking to the future, Michigan 
noted that ``the three largest buyers of Michigan blueberries for 
yogurt production have chosen not to purchase blueberries from Michigan 
in 2002, because of Japanese beetle contamination in previous years.'' 
These buyers alone purchased 5 million pounds of the 65 million pound 
Michigan blueberry crop. Michigan stated that this contamination had 
occurred despite the addition of more workers on packing lines and 
investment in expensive color sorting technologies. No pesticides were 
then registered for control of Japanese beetle grubs in blueberries and 
the two products registered for control of adult Japanese beetles in 
blueberries are of limited effectiveness.
    The basis for NRDC's challenge to EPA's conclusion that an 
emergency condition existed in Michigan is (1) that Michigan did not 
demonstrate that the ``alternative solutions [of using

[[Page 30072]]

additional workers or color sorting technologies] are economically or 
environmentally infeasible;'' and (2) that Michigan has failed to 
provide economic data on estimated net and gross revenues with and 
without the pesticide. As to whether Michigan adequately demonstrated 
the infeasibility of addressing the Japanese beetle problem by using 
additional workers or sorting technology, EPA believes that Michigan's 
reliance on the fact that use of these practices has in the past failed 
to solve the problem is an adequate demonstration. Regarding data on 
potential economic losses, Michigan's data was not as detailed as EPA 
would have preferred, but in the context of an emergency situation, 
providing information indicating that close to 10% of the Michigan 
blueberry crop had already been threatened by the lack of control of 
Japanese beetles (the loss of purchasers for 5 million pounds out of 
Michigan's 65 million pound crop) is sufficient to show a ``significant 
economic loss.''
    In any event, this issue has no relevance to the action being taken 
today to establish a permanent tolerance for imidacloprid on 
blueberries because it is not being done in connection with an 
emergency exemption under FIFRA.

VIII. Response to Comments on NRDC's Objections

    EPA has responded to the comments submitted that pertained 
specifically to imidacloprid to the extent the comments were relevant 
above. The only remaining comments that EPA believes are appropriate to 
address are the comments filed by the IWG raising legal objections to 
EPA's consideration of data bearing on exposure to pesticides other 
than through pesticide residues in food. EPA has also included a short 
response to the comments received from citizens and IR-4.

A. IWG Comments

    To recap, the IWG's argument is based on the presence of the 
defined term ``pesticide chemical residue'' in the critical statutory 
injunctive that a pesticide tolerance is safe only if ``there is 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all dietary exposures and 
all other exposures for which there is reliable information.'' 21 
U.S.C. 346a(b)(2)(A)(ii). The term ``pesticide chemical residue'' is 
defined to mean a residue of the pesticide, or any substance present as 
a result of metabolism or degradation of the pesticide, ``in or on raw 
agricultural commodities or processed food.'' 21 U.S.C. 321(q)(2). The 
IWG argues that, because aggregate exposure is described only in terms 
of exposure to the ``pesticide chemical residue'' and a pesticide 
chemical residue is defined as only including residues in food, 
aggregate exposure must be limited to exposure to pesticide residues in 
food. Under this interpretation, EPA may not consider exposures from 
non-food sources such as residues in drinking water, or residues in or 
around the home from residential uses of a pesticide in making the 
safety determination under section 408.
    In its initial construction of the FQPA, and consistently 
thereafter, EPA has taken a distinctly different approach to section 
408's safety finding. EPA's interpretation has been that the statute 
requires EPA, in making a section 408 safety finding, to consider all 
exposures to the pesticide and related substances, whether the exposure 
is from food, water, or other sources, with the exception that 
occupational exposures are excluded. See, e.g., 61 FR 48843, 48844 
(September 17, 1996) (Aggregate exposure ``includes exposure through 
drinking water, but does not include occupational exposure.''); 62 FR 
17096, 17097 (April 9, 1997) (``In examining aggregate exposure, FQPA 
directs EPA to consider available information concerning exposures from 
pesticide residue in food, including water, and all other non-
occupational exposures. The aggregate sources of exposure the Agency 
looks at includes food, drinking water or ground water, and exposure 
from pesticide use in gardens, lawns, or buildings (residential and 
other indoor uses).''); (Ref. 62) (``EPA must now consider other non-
occupational sources of pesticide exposure when performing risk 
assessments and setting tolerances. This includes dietary exposure from 
drinking water, non-occupational exposure, exposure from like 
pesticides that share a common mechanism of toxicity as well as other 
exposure scenarios.''). (Ref. 48 at 36 and Ref. 49 at 8). Since August 
3, 1996, the date of the passage of the FQPA, EPA has promulgated 
hundreds of tolerance rulemakings and conducted thousands of tolerance 
reassessments based on this interpretation of the statute.
    EPA's interpretation that it must consider all non-occupational 
exposures to pesticides and related substances under section 408 rests 
on the plain language of the FQPA, its statutory structure, and its 
legislative history. Section 408, by its very terms, in some places 
dictates that pesticide chemical residues being referred to are 
residues ``in or on food'', see, e.g., 21 U.S.C. 346a(a)(1), and yet, 
in other places omits this ``in or on food'' modifying language. Most 
notably, the ``in or on food'' qualification is omitted from the 
aggregate exposure provisions. See 21 U.S.C. 346a(b)(2)(A)(ii); 
346a(b)(2)(C)(ii)(I); 346a(b)(2)(D)(vi). Because Congress at times 
paired the term ``pesticide chemical residue'' with the phrase ``in or 
on food'' and other times (such as in describing aggregate exposure) 
did not, EPA believes that Congress' usage of the term ``pesticide 
chemical residue'' should not be interpreted as restricted to residues 
in or on food unless Congress explicitly directed in its specific usage 
of the term ``pesticide chemical residue'' that the residue must be in 
or on food. Admittedly, the definition in section 201 of ``pesticide 
chemical residue'' as being a residue in or on food creates ambiguity 
as to Congress' precise intent with regard to its use of the term 
``pesticide chemical residue'' in section 408. As explained below, 
however, EPA's interpretation is the only reasonable interpretation 
considering the language, structure, and history of section 408.
    First, other plain language in the statute confirms the 
reasonableness of EPA's interpretation. On two occasions, Congress 
explicitly referenced other ``sources'' of exposure as being relevant 
to section 408's safety standard. First, in the provision addressing 
aggregate exposure, Congress directed that EPA consider aggregate 
exposure ``to the pesticide chemical residue and to other related 
substances, including dietary exposure under the tolerance and all 
other tolerances in effect for the pesticide chemical residue, and 
exposure from other non-occupational sources.'' 21 U.S.C. 
346a(b)(2)(D)(vi) 346a(b)(2)(C) (emphasis added). Second, in expanding 
the protection for infants and children, Congress specified that, for 
the purposes of making a safety finding as to infants and children, 
``an additional tenfold margin of safety for the pesticide chemical 
residue and other sources of exposures shall be applied . . . .'' 21 
U.S.C. 346a(b)(2)(C)(emphasis added). Thus, Congress could not have 
intended that residues in food would be the only ``source'' considered 
in calculating aggregate exposure. The legislative history is quite 
clear on this point, explicitly noting that aggregate exposure includes 
both exposure under all tolerances for the pesticide and exposure from 
other sources:
    The Committee understands ``aggregate exposure'' to the 
pesticide chemical residue to include dietary exposures under all 
tolerances for the pesticide chemical residue, and exposure from 
other non-occupational sources.

[[Page 30073]]

H. Rept.104-669, Part 2, 40 (July 23, 1996)
    Second, the structure of the statute confirms that considering 
other ``sources'' of pesticide exposure in section 408's safety 
determination is the only reasonable interpretation of this section. 
Congress required consideration of aggregate exposure not just to 
pesticide chemical residues but also to ``other related substances.'' 
21 U.S.C. 346a(b)(2)(D)(vi). In including ``other related substances,'' 
however, Congress imposed no limitation that aggregate exposure to 
these ``other related substances'' was confined only to aggregate 
exposure to these substances in food. It would be unusual indeed to 
suggest that Congress intended that the section 408 safety 
determination on a pesticide tolerance be constrained in the type of 
pesticide exposures that could be considered (i.e., only pesticide 
exposures in food but not exposures from other sources such as drinking 
water or residential uses) but that no such limitations applied to 
exposures to substances related to pesticides (i.e., consider exposures 
to related substances from all sources including food, drinking water, 
and residential uses).
    In contrast to the reasonable coherence between EPA's approach to 
interpreting what pesticide residues should be considered in making the 
section 408 safety determination and the language, structure, and 
history of the FQPA, the IWG's construction is frequently at odds with 
these guides to interpretation and, in the end, even if accepted fails 
to achieve the IWG's goal of excluding EPA's consideration of pesticide 
residue sources other than food.
    The IWG's narrow approach to aggregate exposure cannot explain both 
the statute's and legislative history's references to other ``sources'' 
of exposure. The IWG's position is that Congress' reference to ``other 
non-occupational sources'' is a reference to dermal exposure to 
pesticides from handling of food containing pesticide residues during 
food preparation. Yet, exposure to pesticides from food handling does 
not constitute a different source of pesticide exposure than 
consumption of food bearing pesticide residues. In either case, the 
source is the food. Further, strictly following the definition of the 
term ``pesticide chemical residue'' introduces numerous redundancies, 
see, e.g., 21 U.S.C. 346a(a) (defining when a ``pesticide chemical 
residue in or on a food'' is unsafe); 21 U.S.C. 321(s) (where the 
definition of the term ``food additive'' states that it excludes ``a 
pesticide chemical residue in or on a raw agricultural commodity or 
processed food''); 21 U.S.C. 346a(o)(2) (requiring EPA to provide 
information to retail grocers concerning actions taken ``that may 
result in pesticide chemical residues in or on food . . . .''), and 
even anomalies into the statute. For example, if each reference in the 
FFDCA to ``pesticide chemical residue'' must be to a pesticide residue 
in a food, then under section 402(a)(2)(B), a food is only rendered 
adulterated by the presence of a pesticide if it is a pesticide residue 
that is already in a food, since to be adulterated a food must ``bear[] 
or contain[] a pesticide chemical residue [in or on a raw agricultural 
commodity or processed food] . . . .'' 21 U.S.C. 342(a)(2)(B) 
(bracketed language inserted from the definition of pesticides chemical 
residues in 21 U.S.C. 321(q)(2)). Although such an approach might be 
understandable as concerns prepared foods which are a mixture of 
different commodities, it makes no sense as to raw agricultural 
commodities which are, and have been, the focus of FDA monitoring 
efforts regarding pesticide residues in food (Ref. 20 at 3 and 
Appendices A and B) (``Emphasis is on the raw agricultural product, 
which is analyzed unwashed and whole (unpeeled).'').
    Finally, the reasonableness of the IWG argument is called into 
question because, even if followed, it seems to make no difference in 
what substances are to be considered in making section 408 safety 
determinations. In other words, IWG's construction does not accomplish 
the IWG objective of limiting the safety determination under section 
408 to consideration of pesticide residues in food. This is due to the 
fact that EPA is required to consider both exposures to ``pesticide 
chemical residues'' and exposures to ``other related substances.'' If 
pesticide residues in water, in the air, and on surfaces in and around 
the home or public spaces are not ``pesticide chemical residues'', they 
certainly would qualify under the plain meaning of the term ``other 
related substances.'' For if the IWG position is accepted that every 
substance that would qualify under the dictionary definition of a 
pesticide chemical residue does not actually fall within the FFDCA 
definition of pesticide chemical residue, it follows necessarily that 
non-FFDCA-qualifying pesticide chemical residues have to be some other 
type of substance. Further, such other substances are clearly related 
to FFDCA-defined pesticide chemical residues given that it is only the 
limiting nature of the statutory definition that keeps them from being 
considered the same substance. Notably, there is no language in the 
statute suggesting that ``other related substances'' only pertains to 
such substances in or on food.
    EPA cannot accept the argument that, because the term ``related 
substances'' appears in the pre-FQPA version of FFDCA section 408 and 
EPA allegedly has never stated that ``related substances'' extends to 
substances residing in exposure sources other than food, Congress's 
repetition of the term ``related substances'' in the FQPA enacted EPA's 
supposed sub silentio interpretation of the term ``related substances'' 
as meaning ``related substances in food.'' Courts have found 
reenactment of administratively-interpreted language to be a 
ratification of the administrative interpretation but only in 
circumstances where a longstanding administrative interpretation has 
been affirmatively brought to Congress' attention and Congress has 
clearly expressed its approval. AFL-CIO v. Brock, 835 F.2d 912, 915 
(D.C. Cir. 1987); accord, Micron Technology, Inc. v. U.S., 243 F.3d 
1301, 1310-1311 (Fed. Cir. 2001). These circumstances are completely 
absent here. EPA had not affirmatively interpreted ``related 
substances'' in the manner suggested by IWG in an administrative 
proceeding prior to FQPA's enactment, and Congress never explicitly 
addressed the issue of interpretation of the term.
    For all of these reasons, EPA reaffirms its contemporaneous and 
consistent interpretation of FFDCA section 408 as requiring 
consideration of all exposures to pesticide residues and other related 
substances other than those exposures occurring in the occupational 
setting. Relevant exposures include pesticide residues in food and 
water and exposures to pesticides around the home or in public from 
sources other than food and water.
    Alternatively, the IWG argues that the requirement that data on 
``all other exposures'' be based on ``reliable data'' precludes the 
consideration of exposure information regarding pesticides in drinking 
water and pesticides used around the home or in public spaces. EPA has 
repeatedly rejected this argument in the past in issuing policy 
statements regarding implementation of the FQPA. (See Ref. 47 at 135-
155). After reviewing the IWG's latest reiteration of the argument, EPA 
finds no reason to differ from its earlier conclusions.

B. Citizen Comments

    As mentioned above, EPA received several thousand comments from 
private citizens in support of NRDC's

[[Page 30074]]

objections. These comments, for the most part, use identical language. 
NRDC has urged EPA not to dismiss the citizen comments because they 
``raise a wide range of issues reflecting the different ways that 
people are personally affected by EPA's tolerance decisions.'' (Ref. 37 
at 4). EPA has considered the citizen comments but finds their 
significance to be limited because they contain only unsubstantiated 
claims regarding the harms of pesticides or general policy arguments as 
to why fewer pesticides should be used instead of providing reliable 
information pertaining to the safety standard in section 408(b)(2).

C. IR-4 Comments

    EPA appreciates that, as IR-4 mentioned, imidacloprid is critical 
for minor crop growers and has an important role as an organophosphate 
replacement. Consideration of information on pesticidal benefits, 
however, that is often relevant under FIFRA, see 7 U.S.C. 136(bb), 
plays a very limited role under section 408, see 21 U.S.C. 
346a(b)(2)(B), and is not applicable to pesticides such as imidacloprid 
which only poses threshold-type risks. 21 U.S.C. 346a(b)(2)(B)(i)(I).

IX. Regulatory Assessment Requirements

    As indicated previously, this action announces the Agency's final 
order regarding an objection filed under section 408 of FFDCA. As such, 
this action is an adjudication and not a rule. The regulatory 
assessment requirements imposed on rulemakings do not, therefore, apply 
to this action.

X. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, does not 
apply because this action is not a rule for purposes of 5 U.S.C. 
804(3).

XI. Time and Date of Entry of Order

    For the purposes of 28 U.S.C. 2112(a), the date of issuance of this 
order shall be May 26, 2004.

XII. References

    1. Acetochlor Registration Partnership, Surface drinking water 
monitoring program for acetochlor and other corn herbicides: Fifth year 
sampling and analytical results (August 28, 2000).
    2. Acetochlor Registration Partnership, Surface drinking water 
monitoring program for acetochlor and other corn herbicides: Seventh 
year sampling and analytical results (June 27, 2002).
    3. Bayer CropScience, Comments to the March 19, 2002 NRDC Letter on 
Objections to the Establishment of Tolerances for Imidacloprid (October 
16, 2002).
    4. Bird, Sandra L., Perry, Steven G., Ray, Scott L., and Teske, 
Milton E., Evaluation of the AgDISP Aerial Spray Algorithms in the 
AgDRIFT Model, Environmental Toxicology and Chemistry, Vol. 21, No.3, 
pp. 672-681 (2002).
    5. Bradman, M., Harnly, M., Draper, W., Seidel, S., Pesticide 
Exposures to Children from California's Central Valley: Results of a 
Pilot Study, 7 Journal of Exposure Analysis and. Environmental 
Epidemiology 217 (1997).
    6. Burns, Lawrence, Probabilistic Aquatic Exposure Assessment for 
Pesticides EPA/600/R-01/071 (September, 2001).
    7. Californians for Pesticide Reform, Secondhand Pesticides: 
Airborne Pesticide Drift in California (2003).
    8. Camann, D.E., J.S. Colt, S.L. Teitelbaum, R.A. Rudel, R.M., 
Hart, M.D Gammon, Pesticide and PAH Distributions in house Dust from 
Seven Areas of USA, Society of Environmental Toxicology and Chemistry 
21st Annual Meeting. Nashville , TN (2000).
    9. Camann, D. E., Akland, G. G., Buckley, J. D., Bond, A. E., Mage, 
D. T., Carpet Dust and Pesticide Exposure of Farm Children, 
International Society of Exposure Analysis Annual Meeting, Research 
Triangle Park, N.C. (November 5, 1997).
    10. Camann, D.E., Geno, P.W., Harding, H., Jac, Giardino, N.J. and 
Bond, A.E., Measurements to assess exposure of the farmer and family to 
agricultural pesticides,U.S. EPA (Contract 68D10150). pp. 712 - 717 
(1993).
    11. Curl, C. L., Fenske, R., Kissel, J. C., Shirai, J. H., Moate, 
T. F., Griffith, W., Coronado, G., Thompson, B., Evaluation of Take-
Home Organophosphorus Pesticide Exposure among Agricultural Workers and 
Their Children, 110 Environmental Health Perspectives A 787 (December 
2002).
    12. Dourson, M., Felter, S., and Robinson, D.,Evolution of Science-
based Uncertainty Factors in Noncancer Risk Assessment 24 Regulatory 
Toxicology and Pharmacology 108 (1996).
    13. Fenske 2002: Fenske, R. A., Lu, C., Barr, D., Needham, L., 
Children's Exposure to Chlorpyrifos and Parathion in an Agricultural 
Community in Central Washington State, 110 Environmental Health 
Perspectives 549 (May 2002).
    14. Fenske, R. A., Lu., C, Simcox, N.J., Loewenherz, C., 
Touchstone, J., Moate, T. F., Allen, E. H., Kissel, J. C., Strategies 
for Assessing Children's Organophosphorus Pesticide Exposures in 
Agricultural Communities, 10(6Pt 2) Journal of Exposure Analysis and 
Environmental Epidemiology 662 (2000a).
    15. Fenske, R. A., Kissel, J. C., Lu., C., Kalman, D. A., Simcox, 
N. J., Allen, E. H., Keifer, M. C., Biologically Based Pesticide Dose 
Estimates for Children in an Agricultural Community, 108 Environmental 
Health Perspectives 515 (June 2000b).
    16. FIFRA Scientific Advisory Panel, Session III - A Set of 
Scientific Issues Being Considered by the Agency Regarding Use of 
Watershed-derived Percent Crop Areas as a Refinement Tool in FQPA 
Drinking Water Exposure Assessments for Tolerance Reassessment (May 27, 
1999) (available at http://www.epa.gov/ gov/ oscpmont /sap /1999 /may /
final. pdf).
    17. FIFRA Scientific Advisory Panel, A Set of Scientific Issues 
Being Considered by the Agency in Connection with Proposed Methods for 
Basin-scale Estimation of Pesticide Concentrations in Flowing Water and 
Reservoirs for Tolerance Reassessment, (September 2, 1998)(available at 
http://www.epa.gov/ gov/ oscpmont / sap / 1998 / july / final1. pdf).
    18. FIFRA Scientific Advisory Panel, A Set of Scientific Issues 
Being Considered by the Agency in Connection with Estimating Drinking 
Water Exposure as a Component of Dietary Risk Assessment(1997) 
(available at http://www.epa.gov/ gov/ oscpmont / sap / 1997 / december / 
finaldec .pdf).
    19. FIFRA Scientific Advisory Panel, Transmittal of the Final 
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    20. Food and Drug Administration, Residue Monitoring 2001 (2001) 
(available at http://www.cfsan.fda.gov/acrobat/pes01rep.pdf).
    21. FQPA Implementation Working Group, Response to Objections of 
the Natural Resources Defense Council to Regulations Establishing 
Tolerances for Residues of Various Pesticide Chemicals In or On Food 
Items (October 16, 2002).
    22. Gordon, S. M.., Callahan, P. J., Nishioka, M. G., Brinkman, M. 
C., O'Rourke, M. K., Lebowitz, M. D., Moschandreas, D. J., Residential 
Environmental Measurements in the National Human Exposure Assessment 
Survey (NHEXAS) Pilot Study in Arizona: Preliminary Results for 
Pesticides and VOCs, 9 Journal of

[[Page 30075]]

Exposure Analysis and Environmental Epidemiology 456 (1999).
    23. Hertl, P., Phelps, W. et al., A Comparison of US EPA's Tier 1 
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    24. Hewitt, Andrew J., Johnson, David R., Fish John D., Hermansky, 
Clarence G., and Valcore, David L., Development of the Spray Drift Task 
Force Database for Aerial Applications, 21(3) Environmental Toxicology 
and Chemistry, . 648-658 (2002).
    25. Higgins, G. M., Munz, J. F., McCauley, L. A.,Monitoring 
Acetylcholinesterase Levels in Migrant Agricultural Workers and Their 
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(2001).
    26. Holden, Patrick W., Pesticides and groundwater quality: Issues 
and Problems in Four states. National Academy Press. (1986).
    27. Inter-Regional Research Project Number 4, Response to Natural 
Resources Defense Council Objection to Tolerances Established for 
Certain Pesticide Chemicals (October 15, 2002).
    28. Jones, R.L. and Russell, M.H., FIFRA Environmental Model 
Validation Task Force: Final Report (April 27, 2001).
    29. Lee, S., McLaughlin, R., Harnly, M., Gunier, R., Kreutzer, R., 
Community Exposures to Airborne Agricultural Pesticides in California: 
Ranking of Inhalation Risks, 110 Environmental Health Perspectives 1175 
(December 2002).
    30. Leonard, R.A., ``Movement of Pesticides in Water,'' Pesticides 
in the Soil Environment, SSSA Book Series No. 2, Chap. 9, pp. 303-349 
(1990).
    31. Loewenherz, C., Fenske R. A., Simcox N. J., Bellamy G., Kalman 
D., Biological Monitoring of Organophosphorus Pesticide Exposure among 
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    32. Lu, C., Knutson, D. E., Fisker-Andersen, J, Fenske, R. 
A.,Biological Monitoring Survey of Organophosphorus Pesticide Exposure 
among Pre-school Children in the Seattle Metropolitan Area, 109 
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    33. Lu, C., Fenske, R. A., Simcox, N. J., Kalman, D., Pesticide 
Exposure of Children in an Agricultural Community: Evidence of 
Household Proximity to Farmland and Take Home Exposure Pathways, 
Environmental Research Section A 84, 290 (2000).
    34. Mills, P. K., Zahm, S. H., Organophosphate Pesticide Residues 
in Urine of Farmworkers and Their Children in Fresno County, 
California, 40(5) American Journal of Indistrial Medicine 571 (2001).
    35. National Center for Environmental Assessment, U.S. EPA, 
Exposure Factors Handbook, Vol. 1 (1997).
    36. Natural Resources Defense Council et al., Petition For A 
Directive That the Agency Designate Farm Children as a Major 
Identifiable Subgroup and Population at Special Risk to Be Protected 
under the Food Quality Protection Act (October 22, 1998).
    37. Natural Resources Defense Council, Letter from Aaron Colangelo, 
NRDC, to Office of Pesticide Programs, EPA,OPP-2002-0057 - Additional 
Data on Exposure from Pesticide Drift, and Summary of Citizen Comments 
(June 19, 2003).
    38. Nishioka, M.G., Burkholder, H.M, Brinkman, M.C., and Lewis, 
R.G., Distribution of 2,4-Dichlorophenoxyacetic Acid in Floor Dust 
Throughout Homes Following Homeowner and Commercial Lawn Applications: 
Quantitative Effect of Children, Pets, and Shoes, 33 Environ. Sci. 
Technol. 1359-1365 (1999).
    39. Office of Pesticide Programs, US EPA, Memorandum, Jeffrey Evans 
to Betty Shackleford,Spray Drift Estimates for Imidacloprid (April 30, 
2004).
    40. Office of Pesticide Programs, US EPA, Memorandum from Jeffrey 
Evans to Betty Shackleford, Review of Data on Farm Children Exposure 
(April 29, 2004).
    41. Office of Pesticide Programs, US EPA, Memorandum from Ronald 
Parker to Betty Shackleford, Comparison of EFED Surface Water Model 
Estimates with USGS NAWQA Monitoring Values (April 8, 2004).
    42. Office of Pesticide Programs, US EPA, Memorandum from Michael 
R. Barrett to Betty Shackleford, Comparison of Ground Water Model 
Estimates and NAWQA Monitoring Values (April 30, 2004).
    43. Office of Pesticide Programs, US EPA, Memorandum from Michael 
R. Barrett to Betty Shackleford, Review of Imidacloprid Ground Water 
Residue Data from Prospective Ground Water Studies and Long Island 
Monitoring Studies (April X, 2004).
    44. Office of Pesticide Programs, US EPA, Memorandum, from Jennifer 
R. Tyler to Robert Forrest, Imidacloprid in/on Cranberry; Okra; Pop 
corn; Watercress; Guava, Papaya, Lychee, Avocado and Related 
Commodities; Root and Tuber Vegetables (Except Sugar Beets); Leaves of 
Root and Tuber Vegetables; Artichoke; Bushberry; Lingonberry; 
Juneberry; Salal; Legume Vegetables (Except Soybeans); Strawberry and 
Stonefruit. Health Effects Division (HED) Risk Assessment. PC Code: 
129099. DP Barcodes: D286101, D284746, D282414, D280766, D278760, 
D286722, D280447, and D285741, (March 4, 2003).
    45. Office of Pesticide Programs, US EPA, Memorandum from Michael 
R. Barrett to Jennifer Tyler, Imidacloprid: Tier I Drinking Water EEDs 
for Use in the Human Health Risk Assessment (February 25, 2003).
    46. Office of Pesticide Programs, US EPA, Memorandum, Imidacloprid 
- Report of the Hazard Identification Assessment Review Committee (TXR 
 0051292) (October 31, 2002).
    47. Office of Pesticide Programs, US EPA, Office of Pesticide 
Programs' Policy on the Determination of the Appropriate FQPA Safety 
Factor(s) For Use in the Tolerance Setting Process: Response to 
Comments (February 28, 2002) (available at http://www.epa.gov/ gov/ 
oppfead1 / trac / science / fqpa--resp .pdf).
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Appropriate FQPA Safety Factor(s) in Tolerance Assessment (January 31, 
2002) (available at http://www.epa.gov/ gov/ oppfead1 / trac / science / 
determ .pdf).
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Performing Aggregate Exposure and Risk Assessments (November 28, 2001) 
(available at http://www.epa.gov/ gov/ pesticides / trac / science / 
aggregate. pdf).
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Cholinesterase Inhibition for Risk Assessments of Organophosphorous and 
Carbamate Pesticides (August 18, 2000)(available at http://www.epa.gov/ gov/ pesticides / trac / science / cholin. pdf).
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on Assessing Pesticide Exposure From Food: A User's Guide (June 21, 
2000) (available at http://www.epa.gov/ gov/ fedrgstr / EPA-PEST / 2000 / 
July / Day-12/ 6061. pdf).
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Acute Dietary Exposure as a Threshold of Regulatory Concern (March 16, 
2000) (available at http://www.epa.gov/ gov/ pesticides / trac / science / 
trac2b054 .pdf).
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Level Assessment Part B(PublicComment Draft 2000) (available at http://www.epa.gov/oppfead1/trac/science/reservoir.pdf).
    54. Office of Pesticide Programs, US EPA, Estimating the Drinking 
Water Component of a Dietary Exposure

[[Page 30076]]

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Related to The Standard Operating Procedures For Residential Exposure 
Assessment, Health Effects Division of the Office of Pesticide Programs 
(August 5, 1999)(available at http://www.epa.gov/oscpmont/sap/1999/september/resid.pdf).
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- Report of the FQPA Safety Factor Committee (HED DOC. NO. 013581) 
(July 21, 1999).
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Determining Watershed-derived Percent Crop Areas and Considerations for 
Applying Crop Area Adjustments to Surface Water Screening Models (May 
27, 1999) (available at http://www.epa.gov/oscpmont/sap/1999/may/pca_sap.pdf).
    58. Office of Pesticide Programs, US EPA, Memorandum from William 
Cutchin to Yan Donovan,Dietary Exposure Analysis for Imidacloprid in/on 
Cranberries and Blueberries, Attachment 1 (April 27, 1999).
    59. Office of Pesticide Programs, US EPA, Memorandum from Jim 
Carleton to William Wassell, Drinking water assessment for Imidacloprid 
(July 15, 1998).
    60. Office of Pesticide Programs, US EPA, Proposed Methods for 
Basin-scale Estimation of Pesticide Concentrations in Flowing Water and 
Reservoirs for Tolerance Reassessment (1998) (paper presented to FIFRA 
Scientific Advisory Panel)(available at http://www.epa.gov/oscpmont/sap/1998/index.htm).
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Procedures for Residential Exposure Assessment (1997)(available at 
http://www.epa.gov/oscpmont/sap/1997/september/sopindex.htm).
    62. Pesticide Registration Notice 97-1, Agency Actions Under the 
Requirements of the Food Quality Protection Act Sec. IV (January 31, 
1997) .
    63. Simcox, N.J, Fenske, R.A., Wolz, S.A., Lee, I.-C. and Kalman, 
Pesticides in Household Dust and Soil: Exposure Pathways for Children 
of Agricultural Pathways, 103(12) Environ Hlth Perspect 1126-34 (1995).
    64. Solomon, K.R., Harris, S.A. and Stephenson, G.R., Applicator 
and Bystander Exposure to Home Garden and Landscape Pesticides, 
American Chemical Society, Pesticides in Urban Environments, Chapter 
22, pp. 262-274 (Eds. Racke and Leslie) (1993).
    65. Teske, Milton E., Bird, Sandra L., Esterly, David M., 
Curbishley, Thomas B., Ray, Scott L., and Perry, Steven G., AgDRIFT: A 
Model for Estimating Near-field Spray Drift from Aerial Applications, 
21 Environmental Toxicology and Chemistry 659-671 (2002).
    66. Thompson, B., Coronado, G.D., Grossman, J.E., Puschel K., 
Solomon, C.C., Islas, I, Curl, C.L., Shirai, J.H., Kissel, J.C., and 
Fenske, R.A., Pesticide Take-Home Pathway among Children of 
Agricultural Workers: Study Design, Methods, and Baseline Findings, 45 
Journal of Occupational and Environmental Medicine. 2003, 42-53 (2003).
    67.US EPA, Pesticide Exposure and Potential Health Effects in Young 
Children Along the U.S.-Mexico Border, 600/R-02/085 (November, 2002).
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Program, Report 94-70 (1994).
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from agricultural fields: A review, 7 Journal of Environmental Quality 
459-472 (1978).

List of Subjects

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Recordkeeping and 
requirements.

    Dated: May 14, 2004.
James Jones,
Director, Office of Pesticide Programs.

[FR Doc. 04-11779 Filed 5-25-04; 8:45 am]
BILLING CODE 6560-50-S