Exposure Assessment for Endocrine Disruptors: Some Considerations in the Design of Studies

In studies designed to evaluate exposure-response relationships in children's development from conception through puberty, multiple factors that affect the generation of meaningful exposure metrics must be considered. These factors include multiple routes of exposure; the timing, frequency, and duration of exposure; need for qualitative and quantitative data; sample collection and storage protocols; and the selection and documentation of analytic methods. The methods for exposure data collection and analysis must be sufficiently robust to accommodate the apriori hypotheses to be tested, as well as hypotheses generated from the data. A number of issues that must be considered in study design are summarized here.