Evaluation of Bisphenol A Dermal Exposure and Toxicokinetics among Cashiers: Final Project Report.

摘要

The expanding service industry in the U.S. carries with it unique exposures and risks. A case in point is cashiers' exposure to BPA that coats receipt tape as thermal developer. Such exposures are of particular concern among cashiers because the workforce is dominated by women of childbearing age and there is evidence to suggest that BPA may act as an endocrine disruptor. A critical data gap to evaluating this risk is the level and extent of exposure associated with handling receipt tape. To address this gap, we conducted two related experiments. The first was a 6-person controlled exposure study where subjects handled receipts in a prescribed fashion and exposure was evaluated based on transfer (receipt tape and hands) and pre- and post-exposure (~21 hours) urinary biomarker measurements. The second study was observational where pre- and post-shift urinary BPA and BPS were measured for 25 cashiers. Our results are preliminary. In the controlled exposure experiment, blood collection was abandoned due to unavoidable contamination from collection supplies. In both experiments, BPA and BPS were successfully measured in environmental and biological media; however, a clear exposure signal was not evident. Among cashiers, on average the post-shift concentration exceeded pre-shift by 30% but that difference was not significant (p>0.05). The levels of BPA detected in cashiers was within the 50 - 75% NHANES observed range, despite a protocol aimed at minimizing the dominant source of exposure, diet. Taken together, preliminary results suggest that the exposure signal associated with receipt handling may be indistinguishable from intrapersonal variability given the limitations of this study design. However, we cannot conclude that cashier exposure to receipt tape is unimportant, since uncertainty remains about the long-term effects of low-level chronic exposure to endocrine disrupting compounds like BPA and BPS. Future research should focus primarily on BPS exposure and other alternative thermal developers that arrive on the market, since much less is known about their potential adverse health effects and exposure sources and levels in the general population.