US EPA

EPA announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA's decision regarding whether the current standards for CO sufficiently protect public health and the environment.

EPA has released this second draft document for review by the Clean Air Scientific Advisory Committee (CASAC) and the public (meeting date and location to be specified in a separate Federal Register notice). The draft document does not represent, and should not be construed to represent, any final EPA policy, viewpoint, or determination. EPA will consider any timely public comments submitted when revising the document.

Carbon monoxide (CO) is one of six principal (or criteria) pollutants for which EPA has established NAAQS. Periodically, EPA 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 the current NAAQS and the appropriateness of possible alternative standards. The Clean Air Scientific Advisory Committee (CASAC), an independent science advisory committee whose existence and whose review and advisory functions are mandated by Section 109 (d) (2) of the Clean Air Act, is charged (among other things) with independent scientific review of EPA's air quality criteria.

Section 108(a) of the Clean Air Act directs the EPA Administrator to identify certain pollutants that “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or 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 such pollutant in the ambient air….” Under section 109 of the Act, EPA is to establish national ambient air quality standards (NAAQS) for each pollutant for which EPA has issued criteria. Section 109(d) of the Act requires 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 or welfare. EPA is also to revise the NAAQS, if appropriate, based on the revised air quality criteria.

The second external review draft ISA for CO will be discussed at a public meeting for review by CASAC, and public comments received will be provided to the CASAC review panel. 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 ISA is scheduled for release in January 2010.

U.S. EPA. Integrated Science Assessment (ISA) for Carbon Monoxide (Second External Review Draft, Sep 2009). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/019B, 2009.

Included for public review is the draft Integrated Science Assessment for Carbon Monoxide (SecondExternal 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-2007-0925 (for the docket ID) to comment on this report.

The deadline for comments is Nov. 13, 2009.