US EPA

A major issue facing the Agency is how to consistently consider age-related changes in behavior and physiology when assessing early lifestage exposure and potential dose. Key to this issue is how to capture these changes in an assessment of risks from exposure to environmental contaminants. This document is intended to provide guidance to EPA scientists on the appropriate age groups to consider when assessing childhood exposure and potential dose to environmental contaminants. A consistent set of childhood age groups, supported by an underlying scientific rationale, will improve Agency exposure and risk assessments for children and will assist the Agency in implementing various regulatory initiatives. In addition, these age groups will guide future analyses of exposure factors data as well as new research and data collection efforts.