Should Air Pollution Rules Be Based on Politics?

Published Aug 1, 2008

Update: On May 21, 2009, EPA Administrator Lisa Jackson announced the agency is reversing the controversial changes to how science is used to set air pollution standards. Under the Bush administration, the process for setting standards was changed (described below) eliminating the independent assessment by scientific experts and injecting political determinations much earlier in the decision-making process. Now the EPA once again will fully utilize its scientists in setting air pollution standards. Click here to read the UCS statement on the announcement.


An Environmental Protection Agency (EPA) policy could significantly minimize the role of independent science in determining acceptable levels of air pollution.

The Clean Air Act requires the Environmental Protection Agency to create National Ambient Air Quality Standards (NAAQS) for harmful pollutants using the best available science. For decades, EPA staff scientists have worked with the independent Clean Air Science Advisory Committee (CASAC) to review the latest studies and recommend appropriate standards. Under these old rules, staff scientists worked with CASAC to create a scientific assessment of risks and recommend appropriate standards. Only after the scientific review was complete would the Administrator create the final policy. NAAQS have been set for six principal pollutants: carbon monoxide, lead, nitrogen dioxide, particulate matter, ozone, and sulfur oxides.¹ 

Despite this process, the recommendations of scientists have not always been heeded. In 2005, EPA Administrator Stephen Johnson overruled a nearly-unanimous recommendation from scientific advisors that the NAAQS for fine particulate matter be strengthened; Johnson instead chose to maintain a standard that does not adequately protect public health. In an unprecedented move, CASAC wrote a letter to Administrator Johnson to re-explain the science behind their recommendations and to urge him to reconsider the proposed standards. The CASAC members alleged that the EPA had "twisted" or "misrepresented" the panel's recommendations on a number of issues related to the proposed standards. For more information on this abuse of science, click here.

In December 2006, EPA Deputy Administrator Marcus Peacock announced a streamlined policy for setting the NAAQS which removed the independent assessment by scientific experts and injects political determinations much earlier in the decision-making process.² Under the new rules, high-level political appointees are involved right from the start, working with staff scientists to create a document containing "policy-relevant science" that "reflects the agency's views" instead of the independent scientific paper that staff scientists have put together in the past. CASAC is entirely cut out of the process until after the EPA has announced its proposed standard, when they are allowed to comment just like any other member of the public. The new rules closely followed recent recommendations from the American Petroleum Institute.

While recognizing that the NAAQS process is often too slow and in need of revision, CASAC criticized the new process as "no less time-consuming and likely more resource-intensive."³ CASAC made several suggestions to improve the NAAQS review process, including:

  • Streamlining scientific assessment documents
  • The convening of a transparent meeting of expert scientists as the first step in the NAAQS review process
  • The creation of a document, based on the findings of the science workshop, that would represent and defend the staff interpretation of the best available science, and which would lead into a combined science and policy document
  • The development of a public electronic database of policy-relevant publications.

The policy drew criticism from scientists, clean-air advocates and others. The American Lung Association urged the EPA to reconsider its decision.5 Several newspapers, including the New York Times6 and the Los Angeles Times,7 editorialized against the decision.

For more information about the new policy, visit the EPA NAAQS website and view comments from the Clean Air Science Advisory Committee (pdf) on the proposal.


1. Environmental Protection Agency, “National Ambient Air Quality Standards (NAAQS)," accessed December 19, 2006.
2. Memo from EPA Deputy Administrator Marcus Peacock, “Process for Reviewing National Ambient Air Quality Standards,” December 7, 2006, accessed December 19, 2006.
3. CASAC Comment Letter on the EPA National Ambient Air Quality Standards Process Review, May 12, 2006, accessed December 19, 2006.
4. CASAC Input on the Agency's Process for Reviewing National Ambient Air Quality Standards (NAAQS), Final Letter, July 18, 2006, accessed December 19, 2006.
5. American Lung Association, “EPA Erodes Scientific Process for NAAQS Reviews,” December 7, 2006, accessed December 19, 2006.
6. “Muzzling Those Pesky Scientists,” New York Times, December 11, 2006, accessed December 19, 2006.
7. “More Politicized Science at the EPA,” Los Angeles Times, December 12, 2006, accessed December 19, 2006.