E8-7882. Draft Risk and Exposure Assessment Reports for Nitrogen Dioxide (NO2

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of draft reports for public review and comment.

SUMMARY:

On April 4, 2008, the Office of Air Quality Planning and Standards (OAQPS) of EPA is making available for public review and comment two draft documents. The first document is titled “Risk and Exposure Assessment to Support the Review of the NO₂ Primary National Ambient Air Quality Standard: First Draft.” The title of the second document is “Risk and Exposure Assessment to Support the Review of the NO₂ Primary National Ambient Air Quality Standard: Draft Technical Support Document (TSD).” The purpose of these draft documents is to convey the approach taken to assess exposures to ambient NO₂ and to characterize associated health risks, as well as to present the results of those assessments.

DATES:

Comments on the above reports must be received on or before May 1, 2008.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2006-0922, 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 [e-mail], Attention Docket ID No. EPA-HQ-OAR-2006-0922.
• Fax: Fax your comments to 202-566-9744, Attention Docket ID. No. EPA-HQ-OAR-2006-0922.
• 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-2006-0922.
• 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-2006-0922. 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 [phone].

FOR FURTHER INFORMATION CONTACT:

Dr. Scott Jenkins, Office of Air Quality Planning and Standards (Mailcode C504-06), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711; e-mail: [e-mail]; telephone: [phone]; fax: [phone].

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 reproduced.
• 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 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 nitrogen oxides (NO_X) and NAAQS have been established for nitrogen dioxide (NO₂), an indicator for NO_X. Presently, EPA is reviewing the air quality criteria for NO_X and the NAAQS for NO₂. As part of its review of the NAAQS, EPA is preparing an assessment of exposures and health risks associated with ambient NO₂. A draft plan describing the proposed approaches to assessing exposures and risks is described in the draft document, Nitrogen Dioxide Health Assessment Plan: Scope and Methods for Exposure and Risk Assessment. This document was released for public review and comment in September, 2007 and was the subject of a consultation with the Clean Air Scientific Advisory Committee (CASAC) on October 24 and 25, 2007. Comments received from that consultation have been considered in developing the draft risk and exposure assessment documents being released at this time.

The draft documents convey the approach taken to assess exposures to ambient NO₂ and to characterize associated health risks, as well as to present the results of those assessments. These draft documents will be available online at: http://www.epa.gov/​ttn/​naaqs/​standards/​nox/​s_​nox_​cr_​rea.html.

The EPA is soliciting advice and recommendations from the CASAC by means of a review on the draft documents at an upcoming public meeting of the CASAC. A Federal Register notice will inform the public of the date and location of that meeting. Following the CASAC meeting, EPA will consider comments received from the CASAC and the public in preparing a second draft risk and exposure assessment report. The release of the second draft report will be followed by another CASAC meeting and ultimately by a final risk and exposure assessment report.

Dated: April 4, 2008.

Mary E. Henigin,

Acting Director, Office of Air Quality Planning and Standards.