The Environmental Protection Agency has issued a new health assessment for the insecticide chlorpyrifos. The assessment finds a risk to workers who mix, load and apply chlorpyrifos and is based on a response to a petition submitted by Natural Resources Defense Council (NRDC) and Pesticide Action Network (PAN) in 2007, which called on the agency to ban all uses of the insecticide.
Chlorpyrifos is an organophosphate insecticide with neurotoxic action. It is a cholinesterase inhibitor, binding irreversibly to acetylcholine esterase (AchE), an essential enzyme for normal nerve impulse transmission in the brain, inactivating the enzyme.
Scientific studies have documented that exposure to even low levels of organophosphates like chlorpyrifos during pregnancy can impair learning, change brain function and alter thyroid levels of offspring into adulthood. A study from the University of California, Berkeley, examined families in the intensive agricultural region of Salinas Valley, California, and determined that IQ levels for children with the most organophosphate exposure were a full seven IQ points lower than those with the lowest exposure levels. The Berkeley team also found that every tenfold increase in measures of organophosphates detected during a mother’s pregnancy corresponded to a 5.5 point drop in overall IQ scores in the 7-year-olds. Researchers from Mount Sinai School of Medicine also found that prenatal exposure to organophosphates is negatively associated with cognitive development, particularly perceptual reasoning, with evidence of effects beginning at 12 months and continuing through early childhood.
Grassroot consumer organization have called for a widespread ban for a number of years citing public health concerns and toxicity specifically in children. In 2010, over 13,000 organizations and individuals submitted a letter to EPA calling for a ban. In 2012, EPA imposed “no-spray” buffer zones around public spaces, including recreational areas, schools and homes to reduce bystander exposure risks; however, chlorpyrifos still poses risks to human and environmental health as the agency refuses to step up and ban the chemical.
The revised health assessment is open for public commentary for 60 days.To view related documents and submit comments, go to docket EPA-HQ-OPP-2008-0850 at www.regulations.gov.