Health groups sue EPA over insecticide that causes testicular damage in rats

Public health groups are suing the Environmental Protection Agency (EPA) over its approval of a Pfas “forever chemical” insecticide that industry research found likely reduces testicle size, lowers sperm count and harms the liver in rats.

The pesticide, isocycloseram, is used on food crops and could especially threaten children and developing fetuses, but the EPA did not factor those risks into its safety assessment, said Nathan Donley, environmental health science director with the Center for Biological Diversity, a plaintiff in the suit.

The lawsuit marks the latest flare-up in an ongoing controversy over the use of forever chemicals in pesticides, which public health advocates discovered under the Biden administration, and has accelerated under Trump.

The pesticide program has also caused friction between the Robert F Kennedy Jr.-aligned Make America Healthy Again (Maha) movement, which broadly opposes pesticide use, and Maga elements atop the Trump administration aligned with pesticide and chemical industries.

Environmental groups pin blame for the decision to greenlight the pesticide on leadership in the EPA’s chemical safety office, which is now includes former industry lobbyists. Donley said the groups are “going to fight like hell to make sure these forever pesticides aren’t allowed to poison our grandchildren’s grandchildren”.

“Approval of this dangerous pesticide spotlights how the industry puppet masters running the EPA chemicals office are making a mockery of chemical oversight,” Donley said.

Pfas are a class of about 16,000 chemicals typically used to make products that resist water, stains and heat. They are called “forever chemicals” because they do not naturally break down; they accumulate and are linked to cancer, kidney disease, liver problems, immune disorders, birth defects and other serious health problems.

The pesticide is used on crops such as apples, oranges, lettuce, spinach, tomatoes, broccoli, bell peppers, cucumbers, peaches, almonds, wheat and oats, as well as on lawns and golf courses.

An EPA spokesperson said in a statement to the Guardian that the agency does not comment on current litigation, but “is committed to tackling Pfas and protecting children’s health”.

“Armed with gold-standard science, we are Making America Healthy Again, carrying out our core mission of protecting human health and the environment,” the spokesperson said.

Kelly Ryerson, a Maha advocate who has discussed similar issues with EPA officials, lambasted the agency for approving another Pfas pesticide, and suggesting it wasn’t aligned with Maha values.

“It’s another example the chemical industry lobbyists running the EPA prioritizing corporate profits and deregulation over the very fertility of men in our country, and it’s yet another pesticide that affects our ability to procreate, and our grandchildren’s children’s ability to procreate,” Ryerson said.

The EPA wrote in its human health risk assessment for the substance that long-term dietary exposure in rats appeared to lead to “reduced testes size, increased incidence and severity of tubular degeneration in the testes, reduced sperm and cellular debris in the epididymis”.

The EPA also approved the pesticide despite the fact that Australian regulators found it induced skeletal malformations in fetal rats, and other research showed the chemical may be carcinogenic.

At least 60% of active ingredients approved for use in common pesticides at the federal level over the last 10 years fit the most widely accepted definition of Pfas, a 2023 analysis of EPA data found.

While isocycloseram itself lasts in the environment for at least hundreds of years, it is also known to degrade into 40 smaller Pfas chemicals, some of which are even more highly persistent.

That also creates risks to wildlife. Donley noted that the EPA’s own science predicts the pesticide would have significant adverse effects on more than 1,000 threatened and endangered species. It is also highly toxic to pollinators, which could be exposed to 1,500 times the lethal level of the pesticide just by collecting nectar and pollen near treated fields.

The substance was still approved because the risk assessment process “is like Swiss cheese” and full of bad assumptions about risk, Donley said. He alleged the EPA did not follow a Food Quality Protection Act mandate to factor in child safety, which requires it to lower the health risk threshold tenfold.

The mandate includes an exception to the child safety rule, if scientific evidence shows it is unnecessary, Donley said. But the EPA largely relied on industry science, and there is a dearth of independent review, which, Donley said, means the EPA does not know the risk to children. The EPA also did not factor Australian study that found skeletal deformation in rats.

Meanwhile, the agency does not consider the cumulative effects of exposures. People are exposed to potentially dozens of dangerous substances, including Pfas, that are sprayed on food crops or other uses.

“There’s this assumption that everyone is exposed in a vacuum to this chemical when in real life we’re all exposed to a soup of this stuff and that can substantially increase the risk,” Donley said.

All pesticide decisions run through the top four positions at the EPA’s chemical safety and pollution prevention office, Donley said. Kyle Kunkler, a former lobbyist for the pro-pesticide American Soybean Association, runs the pesticide office. He works under two former lobbyists for the American Chemistry Council, an industry trade group. They are overseen by a fourth industry lobbyist, Douglas Troutman, who was recently confirmed to lead the chemicals office after an endorsement by the American Chemistry Council.

Ryerson said EPA leadership is “out of touch” with what most Republicans want, and she still suspected that Trump was not aware of the day-to-day decision-making at the agency.

“I worry that he’s only hearing from the pesticide lobby,” Ryerson said. “I feel like if this was laid out in front of him, then he would say: ‘Why would you allow anything that impacts Americans’ testicles?’”