Backed by agrochemical companies, the current administration and Congress are moving to curb the role of human health studies in regulation.
SALINAS, Calif. — José Camacho once worked the fields here in the Salinas Valley, known as “the Salad Bowl of the World” for its abundance of lettuce and vegetables. His wife still does.
But back in 2000, Mr. Camacho, who is 63, got an unusual phone call. He was asked if he wanted to work for a new project studying the effects of pesticides on the children of farm workers.
“This seemed really crazy,” he recalled saying at the time, since he barely spoke English. “A research study?”
The project, run by scientists from the University of California, Berkeley, and funded in part by the Environmental Protection Agency, is still going all these years later. Known as Chamacos, Spanish for “children,” it has linked pesticides sprayed on fruit and vegetable crops with respiratory complications, developmental disorders and lower I.Q.s among children of farm workers. State and federal regulators have cited its findings to help justify proposed restrictions on everything from insecticides to flame-retardant chemicals.
But the Trump administration wants to restrict how human studies like Chamacos are used in rule-making. A government proposal this year, called Strengthening Transparency in Regulatory Science, could stop them from being used to justify regulating pesticides, lead and pollutants like soot, and undermine foundational research behind national air-quality rules. The E.P.A., which has funded these kinds of studies, is now labeling many of them “secret science.”
Studying disease trends in specific groups of people — a branch of medicine known as epidemiology — started to gain currency at the E.P.A. in recent years. These studies can be difficult because they require adjusting for all the various substances people are exposed to beyond pesticides. But researchers had amassed years of data from a wave of compelling chemical studies begun in the 1990s, giving regulators a new body of research to incorporate into their decision-making.
Under the Obama administration, the E.P.A., which had long favored tests on rats and other laboratory animals in its pesticide regulation, began considering epidemiological studies more seriously. The agency leaned on this type of research in proposing to ban an insecticide called chlorpyrifos in late 2016, and has been repeatedly prodded to take action on the chemical by federal courts.
But weeks after Donald J. Trump was elected president, CropLife America, the main agrochemical trade group, petitioned the E.P.A. to “halt regulatory decisions that are highly influenced and/or determined by the results of epidemiological studies” unless universities were forced to share more of their data.
Industry leaders aggressively challenged such studies in high-level meetings and emails with E.P.A. leaders, according to thousands of pages of documents obtained through Freedom of Information Act requests. One trade group invited a top E.P.A. official to meet with its Washington lobbyist last year, complaining that “carefully controlled” animal studies were giving way to “conclusions reflected in epidemiological papers.”
Gary W. Van Sickle, executive director of the California Specialty Crops Council, wrote to the agency last September that “there have been serious flaws with E.P.A.’s conclusion to use these data.”
The council, representing growers of crops as diverse as carrots, garlic, pears and peppers, cited “inappropriate use of the epidemiology.”
The E.P.A., whose new leadership is seeded with industry veterans, has responded. In a mid-July assessment of atrazine, a widely used weed killer long banned in Europe, the agency reviewed and dismissed 12 recent epidemiological studies linking the herbicide to such ailments as childhood leukemia and Parkinson’s disease. It echoed the conclusions of research funded by Syngenta, atrazine’s manufacturer, finding the chemical unlikely to cause cancer.
Before scandals forced Scott Pruitt out last month as head of the E.P.A., he proposed the transparency regulation. It would ban many epidemiological studies, and other outside research, unless more data behind the studies was made public. In doing so, he revived a strategy advanced for years by congressional Republicans and corporate interests like tobacco companies.
“The era of secret science at E.P.A. is coming to an end,” Mr. Pruitt proclaimed at the time. The agency’s new acting administrator, Andrew R. Wheeler, says he’s moving forward with the proposal, as the agency re-evaluates a class of widely used insecticides, called organophosphates, that have been the subject of numerous epidemiological studies like Chamacos.