[Federal Register Volume 73, Number 240 (Friday, December 12, 2008)]
[Pages 75716-75717]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-29347]




Integrated Science Assessment for Oxides of Nitrogen and Sulfur--
Environmental Criteria

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Availability.


SUMMARY: The U.S. Environmental Protection Agency is announcing the 
availability of a final document entitled, ``Integrated Science 
Assessment for Oxides of Nitrogen and Sulfur--Ecological Criteria,'' 
and the supplementary annexes (EPA/600/R-08/082F). The document was 
prepared by the National Center for Environmental Assessment (NCEA) 
within EPA's Office of Research and Development as part of the review 
of the secondary National Ambient Air Quality Standards (NAAQS) for 
oxides of nitrogen and sulfur. EPA's secondary NAAQS are based on 
ecological and welfare effects.

DATES: The document will be available on or about December 12, 2008.

ADDRESSES: The ``Integrated Science Assessment for Oxides of Nitrogen 
and Sulfur--Environmental Criteria'' will be available primarily via 
the Internet on the National Center for Environmental Assessment's home 
page under the Recent Additions and Publications menus at http://www.epa.gov/ncea. A limited number of CD-ROM or paper copies will be 
available. Contact Ms. Ellen Lorang by phone (919-541-2771), fax (919-
541-5078), or e-mail ([email protected]) to request either of these, 
and please provide your name, your mailing address, and the document 
title, ``Integrated Science Assessment for Oxides of Nitrogen and 
Sulfur--Environmental Criteria'' (EPA/600/R-08/082F), to facilitate 
processing of your request.

FOR FURTHER INFORMATION CONTACT: For technical information, contact 
Tara Greaver, Ph.D., NCEA [telephone: 919-541-2435; facsimile: 919-541-
5078; or e-mail: [email protected]].

SUPPLEMENTARY INFORMATION: Section 108(a) of the Clean Air Act directs 
the Administrator to identify certain pollutants that ``may reasonably 
be anticipated to endanger public health and welfare'' and to issue air 
quality criteria for them. These 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. * * *'' Under section 109 of the Act, EPA 
is then to establish NAAQS for each pollutant for which EPA has issued 
criteria. Section 109(d) of the Act requires subsequent periodic review 
and, if appropriate, revision of existing air quality criteria to 
reflect advances in scientific knowledge on the effects of the 
pollutant on public health and welfare. EPA is also to revise the 
NAAQS, if appropriate, based on the revised air quality criteria.
    Oxides of nitrogen and sulfur are two of six principal (or 
``criteria'') pollutants for which EPA has established air quality 
criteria and NAAQS. EPA periodically reviews the scientific basis for 
these standards by preparing an Integrated Science Assessment (ISA) 
(formerly called an Air Quality Criteria Document). The ISA and 
supplementary annexes, in conjunction with additional technical and 
policy assessments, provide the scientific basis for EPA decisions on 
the adequacy of a current NAAQS and the appropriateness of new or 
revised standards. The Clean Air Scientific Advisory Committee

[[Page 75717]]

(CASAC), an independent science advisory committee established pursuant 
to section 109 of the Clean Air Act and part of the EPA's Science 
Advisory Board (SAB), provides independent scientific advice on NAAQS 
matters, including advice on EPA's draft ISAs.
    EPA formally initiated its current review of the criteria for 
oxides of nitrogen and sulfur in December 2005 (70 FR 73236) and May 
2006 (71 FR 28023) respectively, requesting the submission of recent 
scientific information on specified topics. In the initial stages of 
the criteria reviews, EPA recognized the merit of integrating the 
science assessment for these two pollutants due to their combined 
effects on atmospheric chemistry, deposition processes, and 
environment-related public welfare effects. In July 2007 (72 FR 34004), 
EPA held a workshop to discuss, with invited scientific experts, 
initial draft materials prepared in the development of the ISA and 
supplementary annexes for oxides of nitrogen and sulfur. EPA's ``Draft 
Plan for Review of the Secondary National Ambient Air Quality Standards 
for Nitrogen Dioxide and Sulfur Dioxide'' was made available in 
September 2007 for public comment and was discussed by the Clean Air 
Scientific Advisory Committee (CASAC) via a publicly accessible 
teleconference consultation on October 30, 2007 (72 FR 57568). EPA made 
its Draft Plan available on EPA's Web site: http://www.epa.gov/ttn/naaqs/standards/no2so2sec/cr_pd.html. The draft ``Integrated Science 
Assessment for Oxides of Nitrogen and Sulfur--Environmental Criteria; 
First External Review Draft'' was released for review on December 21, 
2007 (72 FR 72719). The CASAC reviewed the first draft document at a 
public peer review meeting on April 2-3, 2008. EPA addressed comments 
from the CASAC and the public in the second external review draft 
document, ``Integrated Science Assessment for Oxides of Nitrogen and 
Sulfur--Environmental Criteria; Second External Review Draft,'' which 
was released for public comment on August 12, 2008 (72 FR 46908). The 
second draft was reviewed by the CASAC at a public meeting on October 
2-3, 2008. EPA has considered comments by CASAC and by the public in 
preparing this final ISA.

    Dated: December 4, 2008.
Rebecca Clark,
Acting Director, National Center for Environmental Assessment.
 [FR Doc. E8-29347 Filed 12-11-08; 8:45 am]