Prolonged Exposure to Bisphenol A from Single Dermal Contact Events.
Level 3 - non-randomized controlled study
Non-randomized experimental crossover pharmacokinetic study in a small human cohort
PubMed 28759207 · doi:10.1021/acs.est.7b03093
What was done
Six male participants handled simulated thermal receipts containing isotope-labeled BPA (BPA-d16) for 5 minutes, followed by hand-washing 2 hours later. Urine was collected over 0-48 hours and serum over 0-7.5 hours to measure free and total BPA-d16. One week later, the same participants received an oral dietary administration of BPA-d16 with identical monitoring. One participant repeated the dermal exposure with extended monitoring (urine up to 9 days, serum up to 2 days).
What was found
After dietary exposure, total urinary BPA-d16 peaked within 5 hours and cleared within 24 hours. Following dermal exposure, cumulative urinary excretion increased linearly for 2 days, and 3 of 6 participants had detectable urinary total BPA-d16 after 1 week. In the single participant followed for 9 days, urinary BPA-d16 remained detectable for 9 days with linear cumulative excretion over 5 days, and free BPA-d16 was detectable in serum. Proportions of free BPA-d16 in urine were higher following dermal contact (0.71%-8.3% of total BPA-d16) than after dietary exposure (0.29%-1.4%).
Why it matters
Handling thermal paper exposes individuals to BPA that clears far more slowly and yields higher proportions of unconjugated BPA than dietary intake, avoiding typical rapid first-pass metabolism.
Limits
The sample size was very small (n = 6), included only male participants, and did not randomize exposure order. Extended multi-day tracking past 48 hours was conducted in only a single individual.
Cited by
- supports Thermal paper receipts commonly contain BPA as a color developer, which transfers through the skin into the bloodstream upon handling.