[Federal Register Volume 74, Number 97 (Thursday, May 21, 2009)]
[Pages 23858-23859]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-11917]



[EPA-HQ-OAR-2007-0352; FRL-8908-6]

Second Draft Risk and Exposure Assessment Report for Sulfur 
Dioxide (SO2)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of extension of comment period.


SUMMARY: The EPA is announcing an extension of the public comment 
period for the draft document titled ``Risk and Exposure Assessment to 
Support the Review of the SO2 Primary National Ambient Air 
Quality Standards: Second Draft'' (74 FR 18573). The EPA is extending 
the comment period that originally ends on May 20, 2009. The extended 
comment period will close on June 11, 2009. The EPA is extending the 
comment period to provide stakeholders and the public with adequate 
time to conduct appropriate analysis and prepare meaningful comments.

DATES: Comments on the above report must be received on or before June 
11, 2009.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-0352, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: Comments may be sent by electronic mail (e-mail) 
to [email protected], Attention Docket ID No. EPA-HQ-OAR-2007-
     Fax: Fax your comments to 202-566-9744, Attention Docket 
ID. No. EPA-HQ-OAR-2007-0352.
     Mail: Send your comments to: Air and Radiation Docket and 
Information Center, Environmental Protection Agency, Mailcode: 2822T, 
1200 Pennsylvania Ave., NW., Washington, DC 20460, Attention Docket ID 
No. EPA-HQ-OAR-2007-0352.
     Hand Delivery or Courier: Deliver your comments to: EPA 
Docket Center, 1301 Constitution Ave., NW., Room 3334, Washington, DC. 
Such deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2007-0352. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at http://www.regulations.gov, including any personal 
information provided, unless the comment includes information claimed 
to be Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. Do not submit information 
that you consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Air Docket in the 
EPA Docket Center, EPA West, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 
p.m. Monday through Friday, excluding legal holidays. The Docket 
telephone number is 202-566-1742; fax 202-566-9744.

FOR FURTHER INFORMATION CONTACT: Dr. Michael Stewart, Office of Air 
Quality Planning and Standards (Mailcode C504-06), U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711; e-mail: 
[email protected]; telephone: 919-541-7524; fax: 919-541-0237.

General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM 
as CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that

[[Page 23859]]

includes information claimed as CBI, a copy of the comment that does 
not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. Information so marked will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

SUPPLEMENTARY INFORMATION: Under section 108(a) of the Clean Air Act 
(CAA), the Administrator identifies and lists certain pollutants which 
``cause or contribute to air pollution which may reasonably be 
anticipated to endanger public health or welfare.'' The EPA then issues 
air quality criteria for listed pollutants, which are commonly referred 
to as ``criteria pollutants.'' The air quality criteria are to 
``accurately reflect the latest scientific knowledge useful in 
indicating the kind and extent of all identifiable effects on public 
health or welfare which may be expected from the presence of [a] 
pollutant in the ambient air, in varying quantities.'' Under section 
109 of the CAA, EPA establishes National Ambient Air Quality Standards 
(NAAQS) for each listed pollutant, with the NAAQS based on the air 
quality criteria. Section 109(d) of the CAA requires periodic review 
and, if appropriate, revision of existing air quality criteria. The 
revised air quality criteria reflect advances in scientific knowledge 
on the effects of the pollutant on public health or welfare. The EPA is 
also required to periodically review and revise the NAAQS, if 
appropriate, based on the revised criteria.
    Air quality criteria have been established for the sulfur oxides 
(SOX) and NAAQS have been established for sulfur dioxide 
(SO2), an indicator for SOX. Presently, EPA is 
reviewing the air quality criteria for SOX and the NAAQS for 
SO2. As part of its review of the NAAQS, EPA has prepared an 
assessment of exposures and characterization of health risks associated 
with ambient SO2. Planned approaches to assessing exposures 
and characterizing risks were described in the document, Sulfur Dioxide 
Health Assessment Plan: Scope and Methods for Exposure and Risk 
Assessment. This planning document was released for public review and 
comment in November 2007 and was the subject of a consultation with the 
Clean Air Scientific Advisory Committee (CASAC) on December 5 and 6, 
2007. Comments received from that consultation were considered in 
developing the ``Risk and Exposure Assessment to Support the Review of 
the SO2 Primary National Ambient Air Quality Standards: 
First Draft,'' which was released in July 2008.
    The second draft of this document was released in March 2009 and 
conveys the approach taken to assess exposures to ambient 
SO2 and to characterize associated health risks, as well as 
to present the results of those assessments. In addition, this document 
also contains a staff policy assessment that considers the evidence 
presented in the final Integrated Science Assessment and the exposure 
and risk characterization results presented in this second draft 
document, as they relate to the adequacy of the current SO2 
NAAQS and any potential alternative primary SO2 standards. 
This draft document is available online at: http://www.epa.gov/ttn/naaqs/standards/so2/s_so2_cr_rea.html.

    Dated: May 14, 2009.
Jenny Noonan Edwards,
Acting Director, Office of Air Quality Planning and Standards.
[FR Doc. E9-11917 Filed 5-20-09; 8:45 am]