When Scott Pruitt, administrator of the U.S. Environmental Protection Agency (EPA) in Washington, D.C., announced last week that the agency plans to bar regulators from considering studies that have not made their underlying data public, he said it was to ensure the quality of the research used to shape new rules. “The era of secret science at EPA is coming to an end,” Pruitt said at a 24 April event (which was closed to the press) unveiling the proposed “transparency” rule.
But longtime observers of EPA, including former senior agency officials, see a more troubling and targeted goal: undermining key studies that have helped justify stricter limits on air pollution. In particular, they say, the new policy is aimed at blocking EPA consideration of large epidemiological studies that have highlighted the health dangers of tiny particles of soot and other chemicals less than 2.5 microns in diameter. Those studies, which rest in part on confidential health information that is difficult to make public, have been under attack for decades from some industry groups and Republican lawmakers in Congress, who argue that the confidentiality masks flaws in the studies. The same interests lobbied heavily for the new EPA rule, and critics of the policy say it is just new clothing for an old—and largely discredited—argument.
“It just keeps coming back in different forms. … It’s like malaria. Or maybe herpes would be a better analogy,” says toxicologist Dan Costa of Chapel Hill, North Carolina, who recently retired after leading EPA’s air research program for 14 years.
At the heart of the fight is a type of pollution scientists believe is particularly lethal, but relatively costly to control: tiny particles of soot and other chemicals produced by burning oil, coal, gasoline, wood, and other fuels, which can lodge deep in the lungs. In the mid-1990s, two major epidemiological studies—known as the Harvard Six Cities and American Cancer Society (ACS) studies—tracked the medical histories of thousands of people exposed to different levels of air pollution. The studies found that exposure to even relatively low particulate levels increased premature deaths. Further studies have linked the pollution to other problems including asthma, heart disease, and heart attacks.
In response, EPA began tightening clean air regulations—and affected industries began to attack the findings. Industry representatives also urged Congress to pass legislation that would bar EPA from using nonpublic data in crafting regulations. In recent years that legislation, championed by Representative Lamar Smith (R–TX), head of the House of Representatives’s science committee, failed to gain approval. But after the election of President Donald Trump, Smith and his allies found a receptive audience in Pruitt, who agreed to implement similar policies as an EPA rule.
In the meantime, an array of studies, including a government-sponsored reanalysis of the original particulate data, has generally validated the findings. “The bottom line is the results don’t go away. They’re real,” says C. Arden Pope III, one of the lead researchers on the Six Cities and ACS studies and now an epidemiologist at Brigham Young University in Provo, Utah.
In 2013, that scientific consensus prompted EPA to reduce allowable particulate levels to 12 micrograms per cubic meter of air, down from an earlier standard of 15 micrograms. At the same time, the agency calculated that the benefits of even tighter standards would outweigh the costs. Lowering the standard to 11 micrograms would increase pollution-control costs by as much as $1.35 billion in 2020, analysts estimated, but the health gains and lives saved would be worth as much as $20 billion a year.
That cost-benefit ratio is “an inconvenient fact if you’re someone who doesn’t like air pollution regulations,” says Gretchen Goldman, an analyst and former pollution scientist in the Washington, D.C., office of the Union of Concerned Scientists, which opposes the new EPA rule.
The timing of the rule—which observers expect EPA to adopt once a public comment period closes—is no coincidence, Goldman and others believe. The agency is about to embark on a periodic review of key air pollution limits, including those governing particulates. Even seemingly modest changes in how the agency evaluates the science could lead to lower estimates of the health benefits of tighter standards.
“If stakeholders can change the ground rules so that the EPA can’t look at that [health] data, that kind of takes away the foundation on which to quantify the adverse effects of exposure,” says environmental engineer Chris Frey of North Carolina State University in Raleigh. Frey previously chaired EPA’s Clean Air Scientific Advisory Committee (CASAC) and now serves on an agency panel that reviews particulate pollution science.
The current head of EPA’s CASAC, however, says the agency will still have good science to draw on. Anthony Cox, a statistician and risk analyst based in Denver, whom Pruitt appointed to lead the panel last year, says there are ways to analyze confidential health data without disclosing identities. He’s confident that the agency and his committee will “act with integrity and intelligence in using the best available science” when reviewing air pollution standards. (EPA did not respond to a request for comment.)
A first test could come later this year, when EPA researchers expect to finalize a report on the latest particulate science. Cox’s committee would then review the report, which would underpin any agency decision about where to set new pollution thresholds.
In the meantime, Frey questions whether the new rule, which would apply only to “significant” regulations judged to cost $100 million or more, will survive an expected court challenge. In particular, he wonders how EPA will meet its legal obligation, spelled out by Congress, to base regulations on the “best available science” if it tries to disregard a large body of accepted research. “I don’t see how,” he says, “EPA could defend that in court.”