Enviros worry EPA will dismiss science showing pyrethroids’ risk to kids

On the heels of EPA Administrator Scott Pruitt’s eleventh-hour reversal last March of an Obama-era ban on chlorpyrifos — an insecticide that can permanently damage a child’s developing brain, according to the EPA’s own scientists — the agency is evaluating yet another family of controversial pesticides possibly linked to attention deficit disorders, cognitive problems, and autism.

The Environmental Working Group, a nonprofit health research and public advocacy organization, is concerned that crucial scientific research about that class of chemicals, pyrethrins and pyrethroids, is being omitted from the evaluation and putting industry interests above public health.

Pyrethrins and pyrethroids are insecticides based on a natural neurotoxin found in the pyrethrum genus of plants, which includes chrysanthemums. Pyrethrin insecticides are natural while pyrethroids are manmade. Present in more than 3,500 commercial products, the insecticides are found in shampoos used to treat kids’ head lice, flea and tick medicines for pets, garden pesticides, and mosquito repellants. Farmers apply them to a variety of crops, from apples, peaches, and potatoes to tomatoes, spinach, cauliflower, and corn.

The EPA reviews pesticides at least every 15 years to determine whether they continue to meet scientific and regulatory standards; if they do, they are re-registered for commercial use. The class of pyrethroids and pyrethrins, which includes about 20 individual chemicals, is currently undergoing a safety analysis as part of that re-registration process, which is open to public comment.  

Comments submitted last week by the Environmental Working Group charge that the EPA safety analysis is flawed because it has failed to consider six new studies from the United States, France, and Canada indicating that everyday exposures — through food residues, residential uses, and by living near or working in agricultural fields — may cause subtle but lasting damage to childhood brain development and behavior.

In one study of more than 600 American children between the ages of 8 and 15, kids with detectable pyrethroid residues were twice as likely to be diagnosed with attention deficit hyperactivity disorder as other children. A California study found a link between a mother’s proximity to agricultural fields treated with pyrethroids and neurodevelopmental disorders, including autism. Meanwhile, a study of 6-year-old children in France, where exposure levels to pyrethroids are measurably lower than in the United States, showed an association with behavioral changes. Similarly, Canadian children with high exposures were more likely to have parent-reported behavioral problems than children with lower exposures.

Sonya Lunder, a senior analyst with the Environmental Working Group, said the EPA is basing its safety assessment on short-term neurotoxicity tests in laboratory animals. These latest studies, she said, show children are much more sensitive than rodents.

“The whole point of the regulatory process is to prevent harmful exposures to children,” she told FERN’s Ag Insider. “That system is failing. The great length to which we go to protect our kids from harm is out of sync with the regulatory process. What’s profound about this early period of life is that you only have one chance to get it right. The brain forms, these critical systems are put in place, and that sets your child up for susceptibility for later life problems.”

The EPA did not respond to requests for comment.

The main concern for public health and environmental advocates is whether the agency will follow the example set by Pruitt’s announcement postponing the EPA’s final safety assessment of chlorpyrifos until at least 2022.

“There are a lot of questions about where the EPA is headed on pesticides after Pruitt reversed the [chlorpyrifos] ban even over the heads of his rank and file, who had spent several years developing a risk assessment that showed low levels of chlorpyrifos residues in the diet were unsafe for kids,” Lunder said.

“Between now and 2022, 20 million American pregnancies will come to term. Those kids will be exposed to a chemical that the EPA deemed to be harmful. Science is showing us ways of gauging the effects of very low levels of exposure, and the EPA needs to consider all the science. That effort was thwarted with chlorpyrifos, and kids are paying the price.” It will soon be evident if the EPA will take a similar approach with pyrethrins and pyrethroids.

Rene Ebersole, a contributor to FERN’s Ag Insider, writes and edits articles about science, health, and the environment for such publications as Outside, Modern Farmer, Popular Science, and Audubon.