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Human Health Risk Assessment
Additional Information
Current Research Tasks
Exposure Assessment Methods for Perfluorinated Compounds (PFCs)
Research in this task will provide basic methods and data to characterize environmental distributions of perfluorinated chemicals (PFCs), the transport and transformation of these compounds in the environment, and the disposition of the PFCs in animal models used in the risk assessment process. Many of the most widely used PFCs are volatile and subject to metabolism/degradation that leads to the formation of the persistent sulfonate and carboxylic acid forms of these materials. The most fundamental aspects of this issue remain largely undescribed at this time. To understand the global transport of the PFCs and their distribution in the environment, it is crucial to understand these basic metabolic/physical processes and to be able to measure selected degredates. Multi-compound methods for the collection, extraction, and analysis of PFCs in raw and finished water and soil will be developed and applied. Methods for analysis of PFCs in house dust and human blood serum will be developed. Methods and data will be provided to the Office of Pollution Prevention and Toxics to help estimate concentrations of PFCs in the environment, to characterize human and ecological exposures, and to establish the risks associated with these exposures. Research will also be performed to develop and apply analytical methods to support toxicology studies that will inform the risk assessment process. Details of Exposure Assessment Methods for Perfluorinated Compounds (PFCs)
Exposure and Dose Modeling for Pyrethroids
The goal of this task is to develop state-of-the-art exposure and dose modeling tools to support the Office of Pesticide Program’s cumulative risk assessment of pyrethroid insecticides. Measurement data will be developed and analyzed both to provide inputs to and to evaluate the models. Combined exposure and dose models will permit an evaluation of the simultaneous exposures of pyrethroid pesticides that lead to cumulative risk. Models that will be applied include the Stochastic Human Exposure and Dose Simulation model and the Exposure Related Dose Estimating Model. Measurement studies, data analysis, and exposure modeling will be used to identify and quantify critical routes and pathways of exposure for the pyrethroid pesticides, and to assess population estimates of aggregate and cumulative pyrethroids exposure. This work will also identify the mixtures of pyrethroid pesticides that individuals are exposed to in real world situations. To understand the relationship between exposure and internal dose, investigators are working closely with scientists in the National Health and Ecological Research Laboratory to develop human physiologically based pharmacokinetic models of pyrethroids. These models will be used to interpret the exposure data and compute integrated dose metrics related to toxic outcome for multiple routes of exposures to pyrethroid mixtures. Details of Exposure and Dose Modeling for Pyrethroids