At the last EPA Science Advisory Board meeting in June, the EPA SAB was asked to partake in a consultation process in review of the EPA’s planned changes to its cancer and noncancer risk assessment guidelines. These guidelines are used by the agency to help it figure out whether chemicals pose an unacceptable risk to human health and the environment. Those types of determinations are then used in regulatory policy.
The difference between a consultation and a peer review is described on the SAB’s website: consultations are designed to give early advice to the EPA on a technical product, for which there should also be a more thorough peer review from the SAB. This is typically the order of operations at the EPA.
The EPA has been vague about its planned timeline and process for these risk assessment guidelines. The guidelines were last updated in 2005 after a rigorous process that took over a decade of internal and external peer reviews and opportunities for comment. But given this administration’s dismal track record in sticking to established processes and issuing science-based policies and technical documents, there is reason to be concerned about what these initial deliberations will feed into. Former EPA SAB members agree that this ad hoc exercise for such a complex issue is “silly.”
Process breach: Departure from consensus at SAB is a big red flag
The EPA has already broken with precedent on several process matters for its advisory committees. Just last week, a GAO report found that the EPA ditched its establish procedure in order to hand-pick science advisors. Along with that change, EPA has deemed EPA funding a conflict of interest that disqualifies service on advisory committees, which has significantly skewed the panel toward members with ties to industry.
Now, the agency is activating those members to publish scientific opinions individually rather than going through a formal review process marked by deliberations that lead to consensus. A majority of the individuals who commented on EPA’s charge (11 out of 16) have been appointed by the Trump Administration, and almost all (15 out of 16) have either former or current relationships with industry through employment (as a direct employee or consultant) or funding. Now that these viewpoints are out there, the agency can cherry-pick from these statements to support changes to its guidelines that could mean less health-protective risk assessments of hazardous chemicals. While it is possible that the EPA could be planning to ask the SAB for a more thorough peer review, failure to do so would be a dramatic deviation from normal process.
The importance of building scientific consensus
The EPA told E&E News that “the typical consensus process, which can take many months, was not deemed as necessary at this point in our effort.” Building consensus is a big part of what peer review panels, like SAB, do. Why is consensus so important? Advisory committees like SAB are composed of individuals who bring different expertise and viewpoints to the table and might come to different scientific conclusions when asked the same questions. Having a space where these experts can discuss, debate, and weigh the best available science as it relates to specific questions is crucial.
During the creation of consensus reports, the chair of the SAB works to identify areas of agreement and encourage dialogue where there is disagreement. The final consensus advisory report is a robust piece of work incorporating all of the lines of discussion and collaboration to reach a consensus, with the opportunity to note areas where there was dissent. These types of reports are a staple of advisory committees and are most useful for policymakers who are interested in the weight of the evidence. But Administrator Wheeler has made it clear that he doesn’t understand the scientific process and cares little for policies supported by evidence, so it’s hard to believe that he values consensus.
Another attack on established science
This is not the first attempt by this administration to mess with the science and assessment of hazardous pollutants, especially targeting the linear non-threshold model. The agency’s restricted science rule questioned the use of this model, it is being targeted by CASAC chair Tony Cox in the ongoing assessment of particulate matter, and now it is being challenged in EPA’s risks assessment guidelines. But historically, a broad range of models have been considered in risk assessment, and the body of evidence from animal and human studies has increasingly tended toward linear dose-response models and away from models that assume a threshold below which substances are safe. The National Academies of Sciences, Engineering, and Medicine in 2009 published a report concluding the need for such a focus and directing EPA to implement this approach. The current science on ambient air pollution exposure and health effects, for example, confirms such an approach, with little evidence for non-linearity found in concentration-response relationships for ambient particulate matter and ground-level ozone concentrations.
Concerningly, scientifically unjustified weight given to non-linear models to assess relationships between these pollutants and health in EPA policy decisions is likely to disproportionately affect the sensitive populations that EPA is charged with protecting. For ozone and particulate matter, for example, evidence suggests that health effects (including mortality, cardiovascular effects, and respiratory effects) below the current NAAQS are more pronounced for the elderly, children, low-income individuals, and African Americans. As a result, setting ambient air quality standards based on models that assume no effect or lower effects of pollutants at lower concentrations is likely to disproportionately harm these sensitive populations. Making changes to the risk assessment guidelines that do not offer a protective approach threaten to exacerbate existing inequities in people’s exposure to harmful pollutants.
Changes to established science procedure warrant rigorous, transparent review
As I told SAB at its June meeting, “…the SAB should have access to not just the proposed guidelines but the scientific justification for updating them and the committee should be given the time and platform to meaningfully contribute throughout the development process which should include peer review by the National Academy of Sciences and opportunities for public comment, as have occurred when EPA risk assessment guidelines were changed previously. Changing risk assessment guidelines on the tight timeline proposed here is functionally challenging and scientifically questionable.” The EPA should not treat this consultation as an acceptable replacement for a full peer review of changes to the guidelines and should ensure that consensus reviews continue to be employed by the agency so that advisory outputs are scientifically rigorous, objective, and independent.
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