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USE OF PBPK MODELING TO ASSESS CYPERMETHRIN EXPOSURE IN YOUNG AFTER A RESIDENTIAL APPLICATION
Citation:
TORNERO-VELEZ, R., N. S. TULVE, M. S. OKINO, AND C. C. DARY. USE OF PBPK MODELING TO ASSESS CYPERMETHRIN EXPOSURE IN YOUNG AFTER A RESIDENTIAL APPLICATION. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Impact/Purpose:
The overall goal of this work is to reduce the uncertainty in risk assessment. The chemical-specific models developed under this task highlight common methods, analyses, and data requirements for general dose modeling. Specific objectives relate directly to customer needs and contributions to the scientific field.
1)Quantify the relevant dose metrics, and associated uncertainties, under scenarios of regulatory interest.
2)Develop and evaluate methods for species-to-species, age, and route-to-route extrapolation.
3)Evaluate and identify important mechanisms of chemical interaction for cumulative risk assessment.
4)Identify data gaps, and recommend targeted experimental studies to reduce the uncertainties in the dose metric estimates.
5)Provide information on common ADME pathways to recommend enhancements of the general ERDEM dose modeling platform.
6)Develop specific chemical and chemical class PBPK/PD models to support pesticide product registration and re-registration demands through 2008 (EPA Strategic Plan Objective 4.1.1: Reduce exposure to toxic pesticides).
Description:
PBPK modeling was used to interpret exposure to cypermethrin among children in a small community of Jacksonville,FL. Sock loadings of cypermethin were used as a measure of exposure to cypermethrin. Urinary markers served as a measure of absorbed dose. In a comparison of presumptive dermal and oral exposure, a MonteCarlo sampling routine was employed with the model, and showed that the oral pathway was a far greater contributor to the absorbed dose. Additional data on residues in food comsumed by study participants (from duplicate diet assessment) indicated an apparent relationship with environmental loadings. Using the model, it was found that these residues result in urinary markers above NHANES 95% for chlorinated chrysanthemic metaboltie (DCVA) in the population suggesting that the residues are derived from home application, not from agricultural processes.