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Critics pan EPA plan for evaluating studies of toxic chemicals

U.S. regulators are reviewing the safety of asbestos, which is still used to make fire-resistant fabrics.

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By Vanessa Zainzinger

Academic scientists and advocacy groups are urging the Environmental Protection Agency (EPA) to withdraw and rewrite proposed guidelines for determining which scientific findings to use when evaluating the safety of toxic chemicals. Critics say that if adopted, the guidance will allow regulators to exclude high-quality health and risk studies for “ridiculous” reasons, favor industry-backed research, and prevent EPA from considering academic studies that rest on innovative methods.

EPA’s guidance “is less about evaluating the quality of evidence, and more about eliminating it altogether,” the Natural Resources Defense Council (NRDC) of Washington, D.C., wrote this week to EPA in comments blasting the “flawed” proposal, which it says “describes a head-in-sand approach to any evidence that a toxic chemical is toxic.” EPA, however, says the guidelines are likely to evolve and that it is aiming for an “efficient systematic review process that generates high-quality, fit-for-purpose risk evaluations that rely on the best available science.”

The controversy, which mirrors a debate over a proposal EPA released earlier this year that critics say would allow the agency to ignore certain human health studies, has its roots in a 2016 overhaul of the nation’s premier chemical safety law, the Toxic Substances Control Act (TSCA). The revised law aims to make it easier for EPA to complete safety reviews of new chemicals before they reach the market and to more quickly restrict the use of existing chemicals if new evidence of risks emerges. It also orders EPA to develop new guidelines for the “systematic review” of the quality of the scientific evidence used in risk assessments.

In response, EPA released a 248-page draft in May describing the review process it is using for its first major round of chemical assessments under the new TSCA. The agency is focusing on 10 compounds already in use, including asbestos (which is still used in the production of chlorine), carbon tetrachloride (often used to make refrigerants), and Violet 29, a common pigment. EPA notes the document offers only “general expectations” and that regulators can depart from the guidance. But it does appear to allow a publication to be excluded if it does not include detailed methods, for instance, or if specific information about study subjects or data sources is withheld because of privacy, business, or other concerns.

A key industry group, the American Chemistry Council in Washington, D.C., said in a statement that the guidelines have “many positive attributes,” but would “benefit from additional explicit guidance,” for example on how to make EPA’s process for integrating evidence into the rulemaking process more transparent.

Critics worry that President Donald Trump’s appointees at EPA will use the guidance—which they note has not been independently reviewed—to put a pro-industry spin on evidence reviews, and perhaps make it easier for companies to keep dangerous chemicals on the market. And they say it could make it easier for EPA to ignore data from certain kinds of health studies. “The things that they are excluding [studies] on are ridiculous,” says Tracey Woodruff, director of the Program on Reproductive Health and the Environment at the University of California, San Francisco (UCSF), one of 25 academics and advocacy group officials who signed a letter to EPA criticizing the guidance. In particular, they say it places too much emphasis on how a study is described—or reported—in the scientific literature.

Detailed information on methods and subjects is often left out of journal publications, the critics note, and has “nothing to do with the quality of the study,” Woodruff says. The approach, NRDC adds, mirrors the so-called transparency rule proposed this past April by former EPA Administrator Scott Pruitt; researchers argue it would bar the agency from using major epidemiological studies based on confidential health records.

In contrast, the critics note, the TSCA guidance fails to mention financial conflicts of interest as a reason for excluding a study. And they argue it inappropriately implies that studies done in industry-funded laboratories that adhere to specific standards, known as Good Laboratory Practices (GLP), are more trustworthy than studies done in academic laboratories that don’t follow GLP—often because they are pioneering innovative methods.

Critics want EPA to scrap the draft guidance and replace it with an established method for systematic review, such as one developed by the National Toxicology Program, which has already been peer reviewed. “I have not seen an explanation of why EPA’s approach is so far outside of the scientific mainstream on systematic reviews,” says Veena Singla, an associate director of UCSF’s health and environment program.

EPA is now deciding how to proceed. The deadline for public comment on the draft was 16 August. The guidelines would need to be revised soon, as the agency has said it wants to complete its 10 initial chemical assessments by late next year. 

Source: Science Mag

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