Citation:

MELNYK, L. J. AND C. E. BERNARD. CHILDREN'S DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS. Presented at ISEA 2005 Annual Conference, Tucson, AZ, October 30 - November 03, 2005.

Impact/Purpose:

The overall objective of this research is to support NERL's human exposure measurement and exposure modeling efforts by reducing the uncertainty in the dietary measurements critically needed for improved aggregate/cumulative exposure assessment. Specifically, the research provides validation of the Children's Dietary Intake Model, information regarding the importance of dietary exposure relative to other pathways, and the tools to design and understand dietary measurements.

Description:

The Food Quality Protection Act of 1996 requires EPA to more accurately assess children's aggregate exposures to environmental contaminants. Children have unstructured eating behaviors which cause excess exposures as a result of their activities. Determining total dietary intake is an important factor in assessing children's aggregate exposures. A deterministic model was developed to more accurately estimate dietary intake 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 the activity level of the child are the dominant factors of exposure 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 for evaluating children?s dietary exposures, including factors associated with additional contamination caused by surface contacts and eating activities, will be presented.

Record Details: