[Federal Register Volume 74, Number 77 (Thursday, April 23, 2009)]
[Pages 18573-18575]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-9336]



[EPA-HQ-OAR-2007-0352; FRL8786-5]

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of second draft report for public review and comment.


SUMMARY: On or about March 19, 2009, the Office of Air Quality Planning 
and Standards (OAQPS) of EPA is making available for public review and 
comment a draft document titled ``Risk and Exposure Assessment to 
Support the Review of the SO2 Primary National Ambient Air 
Quality Standards: Second Draft.'' The purpose of this draft document 
is to convey 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.

DATES: Comments on the above report must be received on or before May 
20, 2009.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-0352, by one of the following methods:

[[Page 18574]]

     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 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.
    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.

    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

[[Page 18575]]

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 document being released at this time 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 (ISA) 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 will be available online at: http://www.epa.gov/ttn/naaqs/standards/so2/s_so2_cr_rea.html.
    The EPA is soliciting advice and recommendations from the CASAC by 
means of a review of the draft document at an upcoming public meeting 
of the CASAC scheduled for April 16-17, 2009 in Chapel Hill, NC. 
Information about this public meeting will be published as a separate 
notice in the Federal Register. Following the CASAC meeting, EPA will 
consider comments received from the CASAC and the public in preparing a 
final risk and exposure assessment report.

    Dated: March 18, 2009.
Stephen D. Page,
Director, Office of Air Quality Planning and Standards.
[FR Doc. E9-9336 Filed 4-22-09; 8:45 am]