Human health risk assessment of endosulfan. Part III: Occupational handler exposure and risk

The United States Environmental Protection Agency (USEPA) and the California Department of Pesticide Regulation (CDPR) have authority to regulate pesticides, respectively, within the United States and within the state of California. Both agencies are obligated to protect human and environmental health within the geographical boundaries where they have authority. Risk assessment of pesticidal active ingredients is conducted by both USEPA and CDPR, yet the agencies have different legal mandates that influence how they conduct assessments. Exposure estimates are key inputs into the risk assessment. Both agencies released draft risk assessments for endosulfan in the same time frame, and while some exposure estimates were similar, many differed considerably. This paper focuses on the differences in exposure estimates for individuals involved in endosulfan applications (handler exposures). Although CDPR and USEPA relied on the same data sets for their exposure estimates for most handler scenarios, CDPR estimates were in some cases more than an order of magnitude higher than estimates from USEPA. Reasons underlying these disparities, and their effects on risk estimates and resulting regulatory decisions, are discussed in this paper. Additionally, because of differences in legal mandates, CDPR estimated exposures for scenarios lacking data, whereas USEPA did not.