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January 29, 2015

NRC Report Reviews DPR

Lisa R. Burchi

An ad hoc committee of the National Research Council (NRC) released a report, Review of California’s Risk-Assessment Process for Pesticides, following its scientific and technical evaluation of the California Environmental Protection Agency’s (EPA) risk assessment process for pesticides.

The NRC committee review, which commenced in October 2013, examined documents provided by the California EPA’s Department of Pesticide Regulation (DPR) regarding the processes it uses for hazard identification, exposure assessment, dose-response analysis, and risk characterization. The Report discusses the following issues:

                  ■ Setting Priorities Among Pesticides: The NRC committee generally supported DPR’s process under which pesticides are reviewed as candidates for risk assessment, but made recommendations for DPR to: (1) update and provide more details regarding its documentation of the priority setting process; (2) provide more explicit documentation and support for how pesticides are categorized into groups of high, medium, and low priority; and (3) develop a more objective and structured approach for ranking high-priority pesticides.

                  ■ Risk Assessment Methods and Practices: The NRC committee reviewed DPR’s risk assessment guidance documents as well as three recently completed risk assessments for chloropicrin, carbaryl, and methyl iodide. The NRC committee found DPR’s documents to be comprehensive but questioned “whether the extensive effort needed to conduct a comprehensive risk assessment independently of EPA is justified in light of DPR’s resources.” The Committee recommended that DPR: (1) determine whether an independent and comprehensive evaluation of pesticides is required in every case where a risk assessment is performed; (2) incorporate problem formulation and other relevant elements recommended in the 2009 NRC report Science and Decisions: Advancing Risk Assessment into its risk assessment process; and (3) update its guidance documents “regularly and perhaps develop additional reference materials to reflect the most current risk-assessment practices.”

                 ■ California Data to Inform Priority-Setting and Risk Assessment: The NRC committee found DPR’s practice of supplementing its exposure assessments with California-specific information to be “among the most valuable contribution to DPR’s risk-assessment process.” The committee suggests expanding DPR’s current Pesticide Use Reporting (PUR) program to include all licensed pesticide applicators and, if resources allow, “PUR data should be reviewed in relation to air-monitoring data and pesticide-illness surveillance data to determine whether any patterns are evident and to judge the accuracy of exposure assumptions or models.” The committee also had recommendations to improve the reporting of pesticide-related illnesses, including, for example, improving the training of physicians and searching electronic health records.