Republicans on the House Science Committee are accusing Linda Birnbaum, director of the National Institute of Environmental Health Sciences, of lobbying. In letters sent to the Inspector General and acting secretary of the Department of Health and Human Services, Reps. Lamar Smith and Andy Biggs wrote that they were “conducting oversight” of Birnbaum’s activity in response to a editorial she wrote in a scientific journal.

Birnbaum’s editorial, which the journal PLOS Biology published in December, addressed the gaps in the regulation of toxic chemicals. Though there are more than 85,000 chemicals approved for use in commerce, she noted in the piece, “U.S. policy has not accounted for evidence that chemicals in widespread use can cause cancer and other chronic diseases, damage reproductive systems, and harm developing brains at low levels of exposure once believed to be harmless.”

Birnbaum called for more research on the risks posed by chemicals and, in the sentence that the representatives appear to consider lobbying, noted that “closing the gap between evidence and policy will require that engaged citizens — both scientists and non-scientists — work to ensure that our government officials pass health-protective policies based on the best available scientific evidence.”

A toxicologist who has headed NIEHS and the National Toxicology Program since 2009, Birnbaum received no funding for writing the editorial, as she notes in the piece, nor does she recommend any specific policy, piece of legislation, or action in it beyond being engaged citizens.

Nevertheless, Biggs and Smith, who have both received money from Koch Industries, Exxon Mobil, and other companies that have a financial interest in limiting research on the environmental effects of chemicals, noted that their “committee suspects this activity may be a violation of the anti-lobbying act.” The two Republican members of Congress also called on the DHHS Inspector General to analyze their concerns so that he might “launch a full-scale review of the situation.”

The Union of Concerned Scientists’s Andrew Rosenberg dismissed the representatives’ letters as “codswallop.”

“I don’t see how in any sense it is lobbying,” Rosenberg said of Birnbaum’s editorial. “Science itself is not lobbying. It is reporting on evidence.” A spokesperson for the NIEHS, which is part of the National Institutes of Health, said that Birnbaum was unavailable for comment because of the government shutdown.

This isn’t the first time the House Science Committee has gone after Birnbaum for bringing attention to environmental science that raises the need for increased regulation. In 2013, then-committee Chairs Larry Bucshon and Paul Broun, expressed outrage about a 2012 article, in which she described the harms of endocrine-disrupting chemicals.

“The proliferation of inadequately tested chemicals in commerce may be contributing to the skyrocketing rates of disease,” Birnbaum wrote in that paper. The idea that low doses of chemicals are causing widespread health effects was by then already widely accepted by independent scientists and has since been echoed by the United Nations Environmental Program and the European Commission.

But industry groups and manufacturers of chemicals have continually challenged endocrine disruption and other science showing the danger of chemicals. And Smith, who became chair of the House Science Committee in 2013, has taken their side in the fight. The Texas representative, who has also aggressively attacked climate science and climate scientists, has promoted legislation that would essentially replace independent scientists with industry representatives on Environmental Protection Agency advisory boards; the EPA has since implemented that policy. In November, Smith wrote another letter to DHHS, this one questioning the International Agency for Research on Cancer’s 2015 evaluation of glyphosate as a probable carcinogen. (IARC responded to his charges earlier this month.)

Smith’s committee has also taken aim at a program at the heart of EPA’s ability to regulate chemicals – holding a hearing in September about the Integrated Risk Information System, or IRIS, a division of the EPA that evaluates the toxicity of substances. The 2018 Senate Appropriations Bill has since proposed eliminating IRIS and giving its workload to another division of the EPA, a move that some environmental scientists fear would weaken seriously undermine the program.

Republicans on the Science Committee invited chemical industry consultants Kenneth Mundt and James Bus to testify at the IRIS hearing. Although the hearing was supposed to be on the overall integrity of IRIS, Mundt, a consultant who has worked for Philip Morris and the chemical industry, used his time before the committee to criticize the program’s evaluation of a particular chemical, chloroprene. The hearing came less than three months after residents of a Louisiana community beset by both illness and chloroprene emissions sued DuPont and another company, Denka. Mundt, who has been paid to work on chloroprene by both companies, argued that the safety threshold IRIS set for chloroprene was 156 times too high.

Smith and Bigg’s attack on Birnbaum seems less designed to exonerate a particular chemical. In the editorial that caused the most recent stir in the House committee, Birnbaum introduced an issue of the journal that covered a broad range of environmental science problems from the challenges of setting drinking water limits for PFOA to the need clarify the relationship between the dose and response of certain chemicals.

Even the best scientific evidence doesn’t necessarily result in regulation, as another piece about the failure to ban chlorpyrifos made clear. That article traced the evidence that low levels of the pesticide can cause developmental harm in children — and Scott Pruitt’s decision decision last year to nevertheless reverse a proposed ban on it. Scientists have a responsibility to speak up in such cases, the author, Leonardo Trasande, argued. But his encouragement to his colleagues came with a warning: “Scientists who raise their voices should be prepared to face criticism from those who have substantial vested interests.”