
[Federal Register: December 8, 2008 (Volume 73, Number 236)]
[Notices]               
[Page 74485-74486]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08de08-49]                         

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2006-0922; FRL-8748-5]

 
Final Risk and Exposure Assessment Report for Nitrogen Dioxide 
(NO2)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability of final report.

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SUMMARY: On November 21, 2008, the Office of Air Quality Planning and 
Standards (OAQPS) of EPA made available a final report titled, Risk and 
Exposure Assessment to Support the Review of the NO2 Primary National 
Ambient Air Quality Standard: Final Report. This final report has two 
primary purposes. The first is to convey the approaches taken to 
characterize human exposures and health risks associated with ambient 
NO2 and to present the results of these analyses. The second 
is to present a discussion of the NO2 scientific evidence 
and the exposure- and risk-based information specifically as it relates 
to the current and potential alternative NO2 standards.

FOR FURTHER INFORMATION CONTACT: Dr. Scott Jenkins, Office of Air 
Quality Planning and Standards (Mail Code C504-06), U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711; e-mail: 
Jenkins.scott@epa.gov; telephone: 919-541-1167; fax: 919-541-0237.

SUPPLEMENTARY INFORMATION:

General Information

A. How Can I Get Copies of This Document and Other Related Information

    1. Docket. EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2006-0922. Publicly available docket materials 
are available either electronically through http://www.regulations.gov 
or in hard copy at the EPA Docket Center (EPA/DC), EPA West, Room 3334, 
1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center 
Public

[[Page 74486]]

Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the Office 
of Air and Radiation Docket is (202) 566-1742.
    2. Electronic Access. You may access this Federal Register document 
electronically through the EPA Internet under the Federal Register 
listings at http://www.epa.gov/fedrgstr/.
    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 nitrogen oxides 
(NOX) and NAAQS have been established for nitrogen dioxide 
(NO2), an indicator for gaseous NOX. Presently, 
EPA is in the process of reviewing the NAAQS for NO2. As 
part of its review of the NAAQS, EPA prepared 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 were considered in developing 
the document titled, Risk and Exposure Assessment to Support the Review 
of the NO2 Primary National Ambient Air Quality Standard: First Draft, 
which was released for public review and comment in April 2008. This 
document was the subject of a CASAC review on May 1 and 2, 2008. 
Comments received from that review were considered in developing the 
document titled, Risk and Exposure Assessment to Support the Review of 
the NO2 Primary National Ambient Air Quality Standard: Second Draft, 
which was released for public review and comment in two parts, the 
first in August, 2008 and the second in October, 2008. This document 
was the subject of CASAC reviews on May 1 and 2, 2008 and on October 
22, 2008. In preparing the final risk and exposure assessment report, 
EPA has considered comments received from the CASAC and the public at 
those meetings.
    This final report has two primary purposes. The first is to convey 
the approaches taken to characterize human exposures and health risks 
associated with ambient NO2 and to present the results of these 
analyses. The second is to present a discussion of the NO2 scientific 
evidence and the exposure- and risk-based information specifically as 
it relates to the current and potential alternative NO2 standards. This 
final document is available online at: http://www.epa.gov/ttn/naaqs/
standards/nox/s_nox_cr_rea.html.

    Dated: December 1, 2008.
Mary E. Henigin,
Acting Director, Office of Air Quality Planning and Standards.
 [FR Doc. E8-28984 Filed 12-5-08; 8:45 am]

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