A tiered approach for assessing children's exposure

Recently, intense attention has been given to children's health issues, par ticularly in che use of consumer products. Because of this attention, resea rchers have been planning and initiating studies specifically aimed at deve loping both toxicology data and exposure data directed to improve our under standing of industrial and consumer product chemical impacts on children's health. To ensure that this research is focused on the highest priority che micals, we present a methodology for determining and prioritizing the highe r ha Lard chemicals and scenarios for which children could be disproportion ately or highly exposed. This tiered approach includes a screening step for initial chemical selection, a hazard assessment based on no- or Lowest-obs erved-adverse-effect levels, and a margin of exposure (MOE) calculation. Th e initial chemical screen focuses on the chemical presence in specific medi a that are special to children, such as foods children regularly ear and dr ink, residential or school air, products children use, and soil and dust in and around residences. Data from the literature or from models serve as th e initial exposure estimate. This methodology would allow us to focus on th ose chemicals to which children are most exposed that are also associated w ith, potentially, the highest risk. rise of the MOE calculation allows for comparison among chemicals, prioritization of chemicals for evaluation and testing, and identification of significant data gaps.