ExpoKids: An R-Based Tool for Characterizing Aggregate Environmental Exposure During Childhood

Abstract

Aggregate exposure, the combined exposures to a single chemical from all pathways, is a critical children’s health issue. To illustrate potential differences in aggregate exposure at various childhood lifestages and the adult lifestage, we developed ExpoKids (an R-based tool) using oral exposure estimates across lifestages generated by US EPA’s Exposure Factors Interactive Resource for Scenarios Tool (ExpoFIRST). ExpoKids is applied to illustrate aggregate oral exposure, for 10 media, as average daily doses (ADD) and lifetime average daily doses (LADD) in 5 graphs organized across 7 different postnatal childhood lifestages and the adult lifestage. This data visualization tool conveys ExpoFIRST findings, from available exposure data, to highlight the relative contributions of media and lifestages to chemical exposures. To evaluate the effectiveness of ExpoKids, three chemical case examples (di[2-ethylhexyl] phthalate [DEHP], manganese, and endosulfan) were explored. Research questions regarding media and lifestage contributions to aggregate exposure across lifestages were asked and data available in the published literature and databases for each case example were used. These illustrative case examples demonstrate ExpoKids’ versatile application to explore a diverse set of children’s health risk assessment and management questions by visually depicting specific media and lifestage contributions to aggregate exposure.