Comparison of Measured and Predicted Dietary Intakes of Pesticides: Implications for Probabilistic Exposure and Risk Assessment. David L. MacIntosh, Kelly Scanlon, Karen Hammerstrom, and P. Barry Ryan, University of Georgia, Athens, GA; Emory University, Atlanta, GA; U.S.E.P.A., Washington, DC
Numerous methods for assessing dietary intakes of pesticides have been developed and include (1) direct measures such as duplicate diet studies, and (2) indirect measures such as market basket surveys that combine information on residue levels in specific foods and food consumption data to estimate pesticide intake. Here we present the results of a duplicate diet and market basket approach and evaluate the comparability of data generated from these different dietary exposure assessment methods. A four-day composite, solid food, duplicate diet sample was collected from 57-70 individuals in metropolitan Baltimore, MD during each of 6 cycles approximately equally spaced over 1 year. Participants also recorded the number of servings consumed of 154 foods on each of those days. Each participant supplied a duplicate diet sample and diet check list in 1 to 6 of the cycles. Duplicate diet samples were analyzed for malathion and chlorpyrifos by the U.S. Food and Drug Administration (FDA); analysis of samples collected through Cycle 3 is currently complete. The food check list data will be combined with pesticide residue data from the FDA Total Diet Study to predict concentrations in the corresponding duplicate diet samples. Concordance between the measured and predicted pesticide concentrations will be assessed.