Citation:

Melnyk, L J., C E. Bernard, AND M R. Berry Jr. EVALUATING EXCESS DIETARY EXPOSURE OF YOUNG CHILDREN EATING IN CONTAMINATED ENVIRONMENTS. Presented at 5th European Pesticide Residue Workshop, Stockholm, Sweden, June 13-16, 2004.

Impact/Purpose:

The purpose of this research is to reduce uncertainties in exposure assessments of young children by improving EPA's ability to measure exposures in the context of aggregate and cumulative exposure assessments. The general objective of this research is to support FQPA children's exposure assessment efforts by improving procedures and reducing uncertainty in measurements for dietary exposure of young children, a critically needed area for improved risk assessment. Specifically, this research will evaluate a protocol and companion model for measuring or otherwise assessing the combined dietary intake of a young child as influenced by pesticides, or other environmental contaminants, which contaminate their foods during the eating process (indirect ingestion exposure). This research will continue to develop the important factors which are needed to characterize excess intake of pesticides by young children. Specifically, the research will measure pesticide surface transfer efficiencies for food contacts with surfaces and eating activity patterns of young children that define the frequency of contacts with contaminated surfaces. A series of reports/products are anticipated by the end of FY05.

Description:

The United States' Food Quality Protection Act of 1996 requires more accurate assessment of children's aggregate exposures to environmental contaminants. Since children have unstructured eating behaviors, their excess exposures, caused by eating activities, becomes an important factor in determining dietary exposures of the most highly exposed children. A deterministic model was developed to more accurately estimate dietary intakes of a chemical contaminant by young children. The sum of three terms determine total intake: the original contaminant residue on food, surface-to-food contamination, and surface-to-hand-to-food contamination. Transfer of the contaminant from surfaces (including hands) to food and activity level of the child are the dominant factors for food consumed in highly-contaminated environments. Pesticide transfer from surfaces to foods has been measured to establish relationships between different pesticide classes, surface types, and contact duration. Transfer efficiencies from hardwood flooring surfaces were 30 to 57% of applied pesticide concentrations. The corresponding transfer efficiencies from carpet were much less. Transfer to foods was greater with both increased contact force and duration. Limited data are available for assessing factors associated with children's dietary activities. Videotaping allows frequencies and durations of hand and food contacts to be recorded and translated by a computerized software program. However, video analysis is labor intensive and new approaches to define children's activity patterns are being evaluated including accelerometers, handling of a standard food, and questionnaires. Research directed at developing measurement approaches to evaluate children's dietary exposures, including factors associated with additional contamination caused by surface contacts and eating activities, will be presented.

Record Details: