In a remarkably rare move, the U.S. Environmental Protection Agency (EPA) is proposing to withdraw its approval for all agricultural uses of a widely used pesticide, chlorpyrifos.
First approved in 1965, chlorpyrifos belongs to a class of pesticides known as organophosphates — a type of chemical developed as a nerve agent prior to World War II — that kills insects by affecting their nervous systems. It’s used on dozens of crops, including citrus, grapes, almonds, corn, apples, broccoli, onions, strawberries, walnuts, soybeans and alfalfa. Although use has decreased since the 1990s, about 6 million pounds of chlorpyrifos were used across the U.S. in 2012, about a quarter of that in California alone. Chlorpyrifos is one of the pesticides most frequently cited in pesticide poisonings of agricultural workers.
The EPA’s proposal was timed to respond to a court-ordered deadline prompted by a 2007 petition from the Natural Resources Defense Council (NRDC) and Pesticide Action Network North America asking the EPA to ban chlorpyrifos. The EPA announced its intention to issue such a proposed rule in June but wanted to do so by April 2016. The 9th Circuit court rejected this timeline and ordered the EPA to act by October 31, 2015. The EPA says it intends to issue a final rule on chlorpyrifos by December 2016. Earthjustice, which filed the advocacy groups’ petitions with the EPA, is asking the 9th Circuit court to make this deadline legally binding.
“We’ve been pushing for this for many years,” Farmworker Justice occupational and environmental health director Virginia Ruiz told In These Times. This, she said, “is definitely a big deal.”
Chlorpyrifos manufacturer Dow AgroSciences downplayed the EPA action, saying in a statement that it “disagrees” with the EPA’s proposal and that the EPA proposal “is just that: a proposal, not a final regulatory action. It has no current impact on existing uses of the product.”
The pesticide manufacturers’ trade association CropLife America said in a statement posted to its website that it is “disappointed” in the EPA’s proposal, calling it a “drastic and unnecessary step that is caused by wasteful, agenda-driven litigation.” Chlorpyrifos, says CropLife America, “is an invaluable tool for growers on a diverse array of crops.”
Highly toxic to the nervous system
But chlorpyrifos is well recognized as highly toxic to the nervous system. It can have serious, immediate adverse effects — among them headache, nausea, dizziness, vision and muscle problems. Farmworkers have been overexposed “even with all the protective clothing that could possibly required,” says Earthjustice managing attorney Patti Goldman.
Chlorpyrifos is also well documented to have long-lasting negative impacts on the neurological health and development of children whose mothers were exposed to chlorpyrifos while pregnant, including at levels below those that prompt immediate effects and below exposure levels EPA considers acceptable.
Children exposed prenatally, in California agricultural communities and in New York City where chlorpyrifos was used in indoor pest control, have been found to have lowered IQ, impaired cognitive ability and behavior problems. Researchers at the University of California-Berkeley and Columbia University have both found that the higher the chlorpyrifos exposure, the greater the children’s IQ reduction. But they also found there to be no level of chlorpyrifos exposure that did not lower IQ to some extent.
What makes this evidence particularly striking is that in children exposed prenatally, researchers at Columbia University have also seen physical alterations in parts of the brain that control working memory, language, behavior and emotion. In a paper published this September, Virginia Rauh, deputy director of children’s environmental health at Columbia University’s Mailman School of Public Health and colleagues found prenatal chlorpyrifos exposure to be associated with childhood arm tremors, a sign of the pesticide’s nervous system effects.
This “is particularly compelling evidence,” says Columbia University Mailman School of Public Health professor emeritus of environmental science Robin Whyatt, whose research has linked prenatal chlorpyrifos to lower birth weights as well as neurological impacts. “This is a chemical that has been studied extensively with a phenomenal amount of consistency in experimental and epidemiological data,” says Whyatt.
EPA cites risks from drinking water
In announcing the proposed ban on October 30, the EPA explained that while “there do not appear to be risks from exposure to chlorpyrifos in food,” when “those exposures are combined with estimated exposure from drinking water in certain watersheds, EPA cannot conclude that the risk from aggregate exposure meets the Federal Food, Drug and Cosmetic Act (FFDCA) safety standard.” Watersheds of most concern are smaller ones that are heavily farmed, explains the EPA.
In other words, according to the EPA, while residues left on food alone may not present a health concern, when combined with chlorpyrifos present in drinking water as result of drift and runoff, exposure becomes a concern. “The fact that they found high levels in drinking water, that’s what’s driving the EPA to say this [agricultural use of chlorpyrifos] isn’t doable any more,” explains NRDC senior scientist Jennifer Sass.
Adding to the concern about chlorpyrifos in drinking water is the fact that, when treated by chlorination as much drinking water is, chlorpyrifos turns into another form of the chemical that is persistent and particularly toxic. Data analyzed for the EPA’s chlorpyrifos risk assessment released in December 2014 has led the agency to determine that many uses of chlorpyrifos will result in drinking water levels that put infants and children at risk.
Concern about chloryprifos has been building for some time. In 2000, the EPA banned indoor household use of chlorpyrifos (with the exception of ant and roach bat in child-resistant packaging). While the chemical breaks down when exposed to sunlight, it can last a long time indoors and thus pose long-term exposure hazards. “Chlorpyrifos can last for years and years indoors,” explains Whyatt. “We’re still detecting it a decade after the ban” in the homes where chlorpyrifos monitoring has been done, she says.
Shortly after the EPA banned indoor use, it also reduced the amount of chloryprifos that could be legally applied to apples and grapes—due to concerns about children’s exposure — and barred its use on tomatoes. Still, in 2010, the California Department of Public Health found chlorpyrifos to be among the top ten pesticides applied within one-quarter mile of California public schools in the 15 counties studied.
Then in 2012, to address concerns about pesticide drift raised in petitions filed with the EPA by Earthjustice on behalf of NRDC, Pesticide Action Network North America and other environmental organizations, the EPA imposed buffer zones around public spaces, including parks and homes, while lowering allowable chlorpyrifos application levels. Yet according to its current analysis, the EPA said in its October 30 announcement that it “cannot conclude that the risk from aggregate exposure meets the Federal Food, Drug, and Cosmetic Act (FFDCA) safety standard.”
However, the EPA is still analyzing drinking water data, both to make sure “any final decision protects infants and children” and to determine risks for the entire country in addition to those watersheds already analyzed.
The EPA proposal — which would leave in place use on golf courses, turf and other non-agricultural applications — will be open for public comment for 60 days. Dow AgroSciences says it is “confident” that “issues relating to the continued use of chlorpyrifos can be readily resolved with a more refined analysis of data.”
Among industry groups’ hopes, says Goldman, is that EPA may limit a chlorpyrifos ban to certain watersheds. But EPA is also currently reviewing seven additional organophosphate pesticides that, like chlorpyrifos, can cause both short- and long-term adverse neurological effects to workers and the general public, including infants and children. “This is huge because it means EPA is standing behind its science on neurodevelopmental effects,” says Goldman.
And when it comes to chlorpyrifos’ toxicity says Whyatt, “Compared to many chemicals, this is one about which there appears to be no doubt in anybody’s mind.”