"Estimation of Daily Bisphenol A Intake of Japanese Individuals with Emphasis on Uncertainty and Variability"
Kenichi Miyamoto, Mari Kotake
National Institute of Advanced Industrial Science and Technology
Environmental Sciences, Vol.13 No.1 pp. 15- 29 (2006/6)
The purpose of this study was to comprehensively assess the exposure of Japanese individuals to BPA with emphasis on uncertainty and variability in the available information. The uncertainty and variability in parameters were numerically analyzed using Monte Carlo simulation. The uncertainty in the functional relationship between sources and exposure was treated by comparing 2 types of approaches: one was to aggregate ingestion and inhalation through all possible exposure pathways and the other was to estimate the intake from urinary excretion by a backward calculation. For individuals aged 6 months or above, food was the most significant source of intake. Alteration of the method used to inactivate the inside surface of drink cans slightly contributed to the decrease in the daily intake. By the backward calculation approach based on urinary excretion, 95% confidence intervals about the daily intake for high-exposure populations were estimated to be 0.037–0.064 µg/kg/day for males and 0.043–0.075 µg/kg/day for females. Even conservatively estimated daily intakes were lower than the EUís temporary TDI of 10 µg/kg/day as well as the US EPAís RfD of 50 µg/kg/day. Thus, it is unlikely that humans, including infants and young children, are at risk from possible BPA exposure.