Chlorpyrifos: Who Paid and Who Profited?

Chlorpyrifos is an organophosphate pesticide that has been widely used in agricultural and residential contexts since its introduction in 1965. Policies surrounding chlorpyrifos use changed dramatically over the past two decades. In 2021, the U.S. Environmental Protection Agency (EPA) limited applications to nonfood uses. The EPA's recent policy implementation was catalyzed by research findings published over a decade ago, citing the impacts of chlorpyrifos exposure on the developing nervous system. In this historical essay, we briefly outline the uses and hazards of chlorpyrifos and the factors influencing regulatory guidelines and policy implementation. Using an environmental justice framework, we present the story of chlorpyrifos as a case study of broader trends in the history of environmental hazards and pollution regulation, where regulatory interference allows companies to profit while those outside of the market pay the price. In the case of chlorpyrifos, corporate-funded research on the safety of the pesticide formed the basis for its continued usage. Meanwhile, people who are poor, belong to a racial and ethnic minority, and/or who work in agriculture face disproportionate rates of exposure, giving rise to disparate neurodevelopmental outcomes. In this way, the story of chlorpyrifos regulation is an example of how health inequities can remain entrenched in disenfranchised communities across the United States.