US EPA

EPA announced the availability of the final report, Integrated Science Assessment (ISA) for Carbon Monoxide (CO). This report is EPA’s latest evaluation of the scientific literature on the potential human health and welfare effects associated with ambient exposures to CO. The development of this document is part of the Agency's periodic review of the national ambient air quality standards (NAAQS) for CO. The recently completed CO ISA and supplementary annexes, in conjunction with additional technical and policy assessments developed by EPA’s Office of Air and Radiation, will provide the scientific basis to inform EPA decisions related to the review of the current CO NAAQS.

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.

The first and second drafts of the CO ISA were reviewed at public meetings of the CASAC CO Review Panel on May 12-13, 2009 and November 16-17, 2009, respectively. This final CO ISA has benefited from the expert comments received at the CASAC meetings and from public comments, and it has been revised accordingly.

The integrated Plan for Review of the National Ambient Air Quality Standards for Carbon Monoxide (U.S. EPA, 2008, 193995) identifies key policy-relevant questions that provide a framework for this assessment of the scientific evidence. These questions frame the entire review of the NAAQS for CO and thus are informed by both science and policy considerations. The ISA organizes, presents, and integrates the scientific evidence which is considered along with findings from risk analyses and policy considerations to help the U.S. Environmental Protection Agency (EPA) address these questions during the NAAQS review.

This is the final document. Additional technical and policy assessment documents for this review are available from the Office of Air Quality Planning and Standards (http://www.epa.gov/ttn/naaqs/standards/co/s_co_index.html).

U.S. EPA. Integrated Science Assessment (ISA) for Carbon Monoxide (Final Report, Jan 2010). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/019F, 2010.