via Emmett Environmental Law & Policy Clinic blog
by Jackie Calahong
February 5, 2021 – Today, the Clinic submitted a comment letter urging the Environmental Protection Agency (EPA) to reverse its proposed registration decision for chlorpyrifos and revise the underlying Human Health Risk Assessment (HHRA). The comments were submitted on behalf of the following scientific and medical experts: Scott Belcher, David C. Bellinger, Linda S. Birnbaum, Gemma Calamandrei, Aimin Chen, Richard A. Fenske, Philippe Grandjean, Russ Hauser, Irva Hertz-Picciotto, Bruce Lanphear, Pamela J. Lein, Axel Mie, Devon Payne-Sturges, Frederica Perera, Virginia A. Rauh, Laura Ricceri, Beate Ritz, Christina Rudén, Robert Sapolsky, Theodore Slotkin, Elsie M. Sunderland, Charles V. Vorhees, and Robin M. Whyatt.
Chlorpyrifos is an organophosphorus pesticide that has been registered for use in the United States since 1965. While EPA has phased out almost all residential uses of chlorpyrifos, it has remained the most broadly used organophosphate insecticide ingredient in the United States. Numerous scientific studies have found increasing evidence that prenatal exposure to chlorpyrifos is directly correlated with significant long-term adverse neurodevelopmental impacts in children, and that these impacts persisted at least until adolescence.
In 2016, EPA proposed to ban almost all remaining agricultural uses of chlorpyrifos, but the Trump administration withdrew that proposal the following year. The proposed registration decision and HHRA were issued in late 2020 pursuant to that reversal.
The Clinic’s letter calls into question EPA’s decision to use 10% red blood cell acetyl cholinesterase (AChE) inhibition as the basis for the toxicological point of departure, and argues that the HHRA’s refusal to rely on the findings of a key epidemiological study is irrational and contrary to EPA’s longstanding commitment to rely on the best available science.
The Clinic previously submitted two amicus briefs in the 9th Circuit challenging the Environmental Protection Agency’s failure to ban agricultural uses of chlorpyrifos – one brief was filed in February 2018 and the second brief was filed in December 2019.