Regulating ozone became much more confusing yesterday, as the EPA’s Clean Air Scientific Advisory Committee (CASAC) leaned on a muddled mandate from the D.C. Circuit Court to introduce even more uncertainty into the standard setting process.
Under the Clean Air Act, EPA must establish, and periodically review, a national standard for ambient air concentrations of ground-level ozone at a level “requisite to protect public health” with an “adequate margin of safety.” And in 1977, the Congress established CASAC to provide “independent” advice to EPA on the setting of national standards for pollutants like ozone. CASAC’s seven member board is nominated annually, primarily from the ranks of epidemiologists and public health officials.
Setting an ozone standard at a level that protects public health with a margin of error sounds simple enough, but in practice it is an impossible task. There is, in fact, no threshold at which ambient air concentrations of ozone ceases to have an effect on human health. To be sure, we’re not talking about mortality (at least, not in the U.S.). Instead, there’s evidence that ozone can be a non-mortal irritant to sensitive populations in rough proportion to air concentrations.
Because there’s no threshold below which there is zero impact, it’s absurd to require, as does the Clean Air Act, EPA to choose a specific level of ozone that is “requisite to protect public health” with an “adequate margin of safety.” Such levels simply don’t exist. In light of this inherent contradiction between the directives of the Clean Air Act and the physical realities of ozone pollution, courts are put in an unenviable position when they try to determine whether the agency’s ozone NAAQS adheres to the statute. The D.C. Circuit Court of Appeals has exclusive jurisdiction to hear a challenge to an ozone NAAQS promulgated by EPA, and the Court’s current approach to such a review can be located in a ruling that was delivered last summer, in Mississippi et al. v. EPA.
The Mississippi ruling introduced a dichotomy between “science” considerations and “policy” considerations. The former (science considerations) is construed as pertaining to the component of the ozone NAAQS that is “requisite to protect public health.” The latter (policy considerations) is the component of the NAAQS that represents an “adequate margin of safety.”
For “science” considerations, the Court reasoned that CASAC’s recommendations are basically controlling. I’ve written before about the troubling ramifications of giving such a broad power to an unelected group of technocrats.
For “policy” considerations, the Court determined that EPA has a much greater degree of discretion. So, for these considerations, which pertain to establishing a margin of error beyond an ozone standard that is “requisite” to protect public health, CASAC’s advice is not controlling.
As I explained at the time, the difference between “science” and “policy” considerations was less than clear cut as articulated by the Court. To my eyes, it looked like a “judgment call.”
Yesterday morning, CASAC convened to decide upon its first ozone NAAQS recommendation since Mississippi et al. v. EPA. Currently the ozone standard is set at 75 parts per billion (ppb). At the outset of yesterday’s meeting, all CASAC members agreed that the standard should be set at least as stringent as 70 ppb. However, the panel was divided on how stringent an ozone standard to recommend. Some members supportted a standard near 60 ppb, while others supported a standard closer to the upper limit (i.e., 70 ppb).
In order to achieve a compromise and attain consensus, CASAC panelists agreed to get lawyerly. According to InsideEPA’s Lea Radick, they will recommend an upper limit of 70, “given that the [the recommendation] to [EPA Administrator Gina] McCarthy is modified to indicate [that] 70 ppb has a “limited” or “inadequate” margin of safety.” Also, BNA’s Patrick Ambrosio reported that CASAC will identify a “policy preference” for an ozone standard set between 60 to 65 ppb.
These qualifications explicitly refer to “policy” considerations in the context of determining an “adequate margin of safety,” which, as I’ve explained above, is a component of NAAQS-setting that affords EPA a great deal of discretion. Until this matter is litigated, it is impossible to tell whether or not the D.C. Circuit interprets CASAC’s “policy preference” as proscribing EPA’s discretion. At the very least, CASAC is needlessly complicating matters; at worst, it is infringing on EPA’s right, as a government agency with an electoral mandate (sometimes), to set policy.
Much more troubling is the following, as reported by InsideEPA’s Radick:
Panelists supported a proposal made by CASAC member Ana Diez Roux, professor of epidemiology and dean of the Drexel School of Public Health, that CASAC include language stating that there are “clearly incremental gains at population level by reducing” the standard from 70 to 65, and from 65 to 60 ppb, based on information in EPA’s Risk Exposure Analysis (REA) and estimates of what percent of the population are protected under various standards.
I’m not sure what this language gets at, because the final recommendation has not yet been issued. The term “incremental gains” seems to be operative. If these gains are health related, than this imprecise language could easily be construed as mandating an ozone NAAQS whose stringency exceeds 70 ppb. The stakes are tremendous. I’ll update this post when the letter is released.