Probabilistic Analysis of Fieldworker Exposure to AzinphosmethylEPA Grant Number: U915309
Title: Probabilistic Analysis of Fieldworker Exposure to Azinphosmethyl
Investigators: Doran, Ed
Institution: University of Washington - Seattle
EPA Project Officer: Michaud, Jayne
Project Period: September 1, 1998 through September 1, 2000
Project Amount: $58,277
RFA: STAR Graduate Fellowships (1998) RFA Text | Recipients Lists
Research Category: Fellowship - Health Risk Assessment , Health Effects , Academic Fellowships
The objective of this research project is to critically analyze the tools that are available to predict absorbed dose following dermal exposure to pesticide residues.
The models used in these analyses were originally developed to estimate the dermal exposure of row crop workers to pesticide residues. We subsequently validated the models using data collected from a University of Washington field study of apple thinners. The following study expands our analyses by characterizing the accuracy, uncertainty, and variability of the model predictions. The distributions used in these analyses were drawn from comprehensive field studies of orchard worker exposures sponsored by either the University of Washington or the California Environmental Protection Agency. For these analyses, absorbed dose was calculated by coupling the concentration of pesticides on foliage with a transfer factor, a dermal absorption factor, the time exposed, and the personal characteristics of the workers. These parameters were entered into a standard exposure assessment model to estimate the absorbed daily dose. However, if absorption occurs until the materials are completely removed from the worker’s skin, a cumulative model may be used to calculate dermal uptake during and after the work shift. Both the standard and cumulative models were analyzed using a two-dimensional Monte Carlo protocol to determine the variability and uncertainty of the predictions. The predictions generated by the models were validated by comparing the estimated body burden to the dose represented by urinary metabolites.