Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
Risk Assessment
Contact Us

Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (Second External Review Draft, 2015)

On this page:

  • Overview
  • History
  • Downloads

Alert
Alert Notice - This site contains archived material(s)

Archive disclaimer
Archived files are provided for reference purposes only. The file was current when produced, but is no longer maintained and may now be outdated. Persons with disabilities having difficulty accessing archived files may contact the Risk Webmaster for assistance. Please use the contact us form if you need additional support.

Abstract

This draft document provides EPA’s evaluation and synthesis of the most policy-relevant science related to the health effects of oxides of nitrogen. When final, it will provide a critical part of the scientific foundation for EPA’s decision regarding the adequacy of the current primary (health-based) national ambient air quality standards for nitrogen dioxide.

The references considered for inclusion in or cited in the first and second external review drafts of the ISA are available at https://hero.epa.gov/oxides-of-nitrogen.
Oxides of nitrogen are one of six principal (or criteria) pollutants for which EPA has established national ambient air quality standards (NAAQS). For oxides of nitrogen, the NAAQS are specified in terms of nitrogen dioxide (NO2). The Clean Air Act requires EPA to periodically review the scientific basis for these standards by preparing an Integrated Science Assessment. These reviews play a significant role in EPA’s commitment to ensuring a clean and healthy environment for the public.

The second draft ISA is part of the Agency’s periodic review of the primary (health-based) NAAQS for NO2. Overall, findings from recent studies strengthen the conclusions from the previous NAAQS review, which was completed in 2010. Results from recent studies strengthen the body of evidence indicating that short-term exposure to NO2 can cause respiratory effects, in particular, effects related to asthma exacerbation. Recent results also strengthen the evidence that the respiratory effects of short-term NO2 exposure are independent of the effects of many other traffic-related pollutants. There is now stronger evidence for a relationship between long-term exposure to NO2 and respiratory effects, particularly the development of asthma in children. Results suggest that short-term exposure to NO2 may be associated with cardiovascular effects and related metabolic effects and premature mortality and that long-term exposure may be associated with cardiovascular and related metabolic effects, poorer birth outcomes, premature mortality, and cancer; however, it is uncertain whether these effects of NO2 exposure are independent from the effects of other traffic-related pollutants.

Impact/Purpose

The Clean Air Act (CAA) requires EPA to periodically review and revise, as appropriate, existing air quality criteria and NAAQS. The CAA also requires an independent scientific committee to review the criteria and to advise the Administrator regarding any recommended revisions to the existing criteria and standards, as may be appropriate. The Clean Air Scientific Advisory Committee (CASAC) of EPA’s Science Advisory Board serves as this independent scientific committee. The ISA is one of the four major elements of the NAAQS review process that will inform the Agency’s final decisions; other components of the process are an integrated plan highlighting the key policy-relevant issues; a risk/exposure assessment if warranted; and an advance notice of proposed rulemaking (ANPRM) reflecting the Agency’s views regarding options to retain or revise the NO2 NAAQS based on the evaluation of key information contained in the ISA and Risk/Exposure Assessment, as well as additional appropriate technical analysis.

Status

This draft will be reviewed by the Clean Air Scientific Advisory Committee (CASAC) at a public meeting announced in the Federal Register. A future Federal Register notice will inform the public of the exact date and time of that CASAC meeting. In revising and finalizing the ISA, EPA will take into account CASAC advice and recommendations as well as public comments. The final assessment, will be posted on EPA’s website, and will provide a critical part of the scientific foundation for the primary NAAQS for nitrogen dioxide.

Citation

U.S. EPA. Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (Second External Review Draft, 2015). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-14/006, 2015.

History/Chronology

Date Description
01- Jul 2008 EPA released the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Final Report) (EPA/600/R-08/071). [Federal Register Notice Jul 11, 2008]
02- Mar 2012 EPA held a workshop entitled "Kickoff Workshop to Inform EPA's Review of the Primary NO2 NAAQS'" co-organized by EPA/ORD/NCEA and the EPA/OAQPS Staff to help with the development of future products on this subject matter. The workshop was held February 29 - March 1, 2012, in Research Triangle Park, North Carolina. [Federal Register Notice Feb 10, 2012]
03- May 2013 EPA released the Draft Plan for the Development of the Integrated Science Assessment for Oxides of Nitrogen - Health Criteria. [Federal Register Notice May 3, 2013]
04- Jun 2013 EPA's Science Advisory Board's CASAC announces a June 2013 consultation by the Oxides of Nitrogen Review Panel on the draft plan. [Federal Register Notice May 9, 2013]
05- Jun 2013 EPA held a public workshop to review initial draft materials to inform the development of the upcoming development of the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria. [Federal Register Notice May 10, 2013]
06- Nov 2013 EPA released the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (First External Review Draft) for public review and comment. [Federal Register Notice Nov 22, 2013]
07- Mar 2014 EPA's Science Advisory Board's CASAC announced a meeting for the Oxides of Nitrogen Review Panel regarding the review of the first external review draft. [Federal Register Notice Feb 13, 2014]
08- Jan 2015 EPA released the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Second External Review Draft) for public review and comment. [Federal Register Notice Jan 30, 2015]
09- Mar 2015 EPA announced an extension of the public comment period until April 30, 2015. [Federal Register Notice Mar 20, 2015 ]

Additional Information

Included for public review is the draft Integrated Science Assessment for Oxides of Nitrogen - Health Criteria (Second External Review Draft). Comments on this document may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select Environmental Protection Agency and the keyword EPA-HQ-ORD-2013-0232 (for the docket ID) to comment on this report.

Download(s)

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

  • Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Second External Review Draft) (PDF)  (1135  pp, 14.7 MB, about PDF)
  • CASAC REVIEW OF THE EPA’S INTEGRATED SCIENCE ASSESSMENT FOR OXIDES OF NITROGEN – HEALTH CRITERIA (SECOND EXTERNAL REVIEW DRAFT
  • CHARGE QUESTIONS - CASAC REVIEW OF THE SECOND EXTERNAL REVIEW DRAFT INTEGRATED SCIENCE
  • AGENCY RESPONSE

Related Link(s)

  • CASAC PEER REVIEW REPORT (1st ERD - Nov 2013)
  • AGENCY RESPONSE TO CASAC REVIEW OF THE EPA’S INTEGRATED SCIENCE ASSESSMENT FOR OXIDES OF NITROGEN – HEALTH CRITERIA (1st ERD – Nov 2013)
  • Draft Plan for Development of the Integrated Science Assessment for Nitrogen Oxides Health Criteria
  • Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (First External Review Draft, 2013)

Federal Register Notices

  • FR Notice Mar 20, 2015
  • FR Notice: Jan 30, 2015
  • Risk Assessment Home
  • About Risk Assessment
  • Risk Recent Additions
  • Human Health Risk Assessment
  • Ecological Risk Assessment
  • Risk Advanced Search
    • Risk Publications
  • Risk Assessment Guidance
  • Risk Tools and Databases
  • Superfund Risk Assessment
  • Where you live
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 04, 2017
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshots
  • Grants
  • No FEAR Act Data
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.