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STUDY TO IDENTIFY IMPORTANT PARAMETERS FOR CHARACTERIZING PESTICIDE RESIDUE TRANSFER EFFICIENCIES
Citation:
CohenHubal, E A., L S. Sheldon, AND J C. Suggs. STUDY TO IDENTIFY IMPORTANT PARAMETERS FOR CHARACTERIZING PESTICIDE RESIDUE TRANSFER EFFICIENCIES. Presented at ISEA 2000 Exposure Analysis in the 21st Century: Integrating Science, Policy and Quality of Life, Monterey Peninsula, CA, October 24-27, 2000.
Impact/Purpose:
1. To identify those pesticides, pathways, and activities that represent the highest potential exposures to children;
2. To determine the factors that influence pesticide exposures to children;
3. To develop methods for measuring multimedia exposures to children, including methods that account for important activities that take place in home, school, and day care settings;
4. To generate data on multimedia pesticide concentrations, pesticide biomarkers, and exposure factors that can be used as inputs to aggregate exposure models for children.
Description:
To reduce the uncertainty associated with current estimates of children's exposure to pesticides by dermal contact and non-dietary ingestion, residue transfer data are required. Prior to conducting exhaustive studies, a screening study to identify the important parameters for characterizing these transfers was conducted.
In this study, parameters that affect residue transfer from surface-to-skin, skin-to-other objects, skin-to-mouth, and object-to-mouth, were evaluated using a fluorescent tracer as a surrogate for pesticide residues. A fluorescent tracer was applied as a residue at levels typical of residential pesticide applications to surfaces of interest. Controlled transfer experiments were conducted by varying contact parameters with each trial. The mass of a tracer transferred was measured and the contact surface area estimated using video imaging techniques. In addition, laboratory evaluations were conducted to relate transfer of a tracer to transfer of pesticides.
Parameters evaluated included: surface type, surface loading, contact motion, pressure, duration, and skin condition. Both transfers onto, and off of, the hand were measured. To efficiently identify parameter changes resulting in significant effects, the Youden ruggedness test was used to select the combination of parameters varied in each contact trial. In this way, more than one parameter could be varied at a time and the number of trials required was minimized.
Results of this study showed that surface type and skin condition are among the important parameters for characterizing residue transfers. Data from this study will reduce uncertainty associated with estimating dermal and non-dietary ingestion exposure. This data will also determine what additional residue transfer data should be collected and what type of microactivity data are needed to estimate dermal and non-dietary ingestion exposure. Finally, these data are required as inputs to the residential pesticide exposure models currently under development.
This work has been funded wholly or in part by the United States Environmental Protection Agency under contract no. 68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication.