Air Quality Standards and Sound Science: What Role for CASAC?

Publication Date: January 2007

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Environment

Type:

Abstract:

As the Environmental Protection Agency (EPA) completes its reviews of the ozone and particulate matter (PM) air quality standards -- the PM review was completed in September 2006, and the ozone review is due for completion in early 2008 -- the Clean Air Scientific Advisory Committee (CASAC), an independent committee of scientists that advises the agency's Administrator, has received some notable attention as a result of its disagreements with EPA's decisions.

CASAC was established by statute in 1977. Its members, largely from academia and from private research institutes, are appointed by the EPA Administrator. They review the agency's work in setting National Ambient Air Quality Standards (NAAQS), relying on panels of the nation's leading experts on the health and environmental effects of the specific pollutants. CASAC panels have a nearly 30year history of working quietly in the background, issuing what were called "closure letters" on agency documents that summarize the science and the policy options behind the NAAQS. The science and policy documents, written by EPA staff, generally have gone through several iterations before the scientists were satisfied, but, with the issuance of a closure letter, CASAC has in past years removed itself from the process, leaving the final choice of standards to the Administrator.

In 2006, however, CASAC and its 22-member PM Review Panel forcefully objected to the Administrator's decisions regarding revision of the particulate NAAQS. The committee took the unprecedented steps of writing to the Administrator both after he proposed the standards in January, and after he promulgated them in September. In the latter communication, CASAC stated unanimously that the Administrator's action "does not provide an `adequate margin of safety ... requisite to protect the public health' (as required by the Clean Air Act) ...." (Italics in original)

Within a month of CASAC's September 2006 letter, the committee's ozone review panel approved EPA's policy options Staff Paper, the next-to-last formal step before the Administrator proposes to retain or revise the ozone NAAQS. In doing so, the panel drew a firm line ("There is no scientific justification for retaining the current primary 8-hr NAAQS"), and recommended a range far more stringent than the current standard. The Administrator has until May 2007 to propose a decision.

At the same time that CASAC panels were speaking out, EPA was conducting a review of CASAC's role and other aspects of the NAAQS-revision process. A December 7, 2006 EPA memorandum makes a number of changes in that process that many argue will diminish the role of CASAC and agency scientists. CASAC has not formally opposed these changes. However, a number of Senators have written the EPA Administrator to express their opposition to the changes, and Congress is expected to take up these issues through oversight hearings. This report discusses these issues, focusing on the statutory and historical role of CASAC and various proposals for change.