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METHOD DEVELOPMENT, EVALUATION, REFINEMENT, AND ANALYSIS FOR FIELD STUDIES
Impact/Purpose:
The goal of this task is to contribute to a better understanding of human exposure to pesticides, especially for small children. We will develop, evaluate, and refine methods to characterize sources and pathways in and around the residential environment. Specific methods of interest include those using gauze wipes as sampling media (hands, floors, surfaces, etc.) for compounds such as permethrin, cyfluthrin, diazinon, chlorpyrifos, and allethrin. We will support the science behind FQPA and assist the Office of Pesticide Programs (OPP) in the development of guidelines for the assessment of residential exposure and risk to pesticides. Specific research objectives include: (i) to apply analytical methods for the field measurement efforts of the Exposure Measurement and Analysis Branch (EMAB); (ii) to evaluate developed methods in support of the National Exposure Research Laboratory's (NERL) Human Exposure Measurement Project; (iii) to develop a plan for chiral research and method development; (iv) to develop multi-residue analytical methods in support of regional projects.
Description:
Manufacturers routinely introduce new pesticides into the marketplace and discontinue manufacturing older pesticides that may be more toxic to humans. Analytical methods and environmental data are needed for current use residential pesticides (e.g., pyrethrins, synthetic pyrethroids, fipronil, hydramethylnon), many of which are chiral. Existing methods need to be refined, evaluated, and validated for a large number of pyrethroids and other current use residential pesticides. Validated methods are needed for application to all of the different types of media used for human exposure studies (e.g., floor wipes, press sampler media, house dust) which can be used to estimate respiratory, dermal and nondietary oral exposures. Methods research and analysis under this task will support the Food Quality Protection Act (FQPA) and enhance the understanding of children's exposures and risk. In addition to human exposure applications, these new methods and technologies can be transferred to EPA Regional laboratories to advance sampling and measurement protocols. We will focus on the reduction of extraction time and waste, new analytes such as pyrethroids, and multi-residue methods of interest. Environmental concentrations in conjunction with chiral residue data improve our understanding of exposure pathways, transformation of pesticides, and will improve the uncertainty of human risk assessments. Risk assessments can benefit from the understanding of enantiomeric selectivity in environmental degradation, human metabolism, route of movement, potential human exposure, and (or) toxicity.