Exposure to BPA in Children—Media-Based and Biomonitoring-Based Approaches

Bisphenol A (BPA) is used in numerous industrial and consumer product applications resulting in ubiquitous exposure. Children’s exposure is of particular concern because of evidence of developmental effects. Childhood exposure is estimated for different age groups in two ways. The ―forward‖ approach uses information on BPA concentrations in food and other environmental media (air, water, etc.) combined with average contact rates for each medium. The ―backward‖ approach relies on urinary biomonitoring, extrapolating backward to the intake which would have led to the observed biomarker level. The forward analysis shows that BPA intakes are dominated by canned food consumption, and that intakes are higher for younger ages. Mean intake estimates ranged from ~125 ng/kg-day for 1 year-olds to ~73 ng/kg-day among 16–20 years olds. Biomonitoring-based intakes show the same trend of lower intakes for older children, with an estimate of 121 (median) to 153 (mean) ng/kg-day for 2–6 years, compared with 33 (median) to 53–66 (mean) ng/kg-day for 16–20 years. Infant intakes were estimated to range from ~46 to 137 ng/kg-day. Recognizing uncertainties and limitations, this analysis suggests that the ―forward‖ and ―backward‖ methods provide comparable results and identify canned foods as a potentially important source of BPA exposure for children.