Profiles of urinary bisphenol A in human panel during an exposure intervention

Abstract

Bisphenol A (BPA) is a chemical commonly used in consumer products of polycarbonate plastics, epoxy resin cans and thermal ingredient of receipt paper such as food or beverage containers, thermal receipts, and medical devices, etc. Several researches in toxicology and epidemiology have been indicated that exposure to BPA may be associated with a variety of adverse outcomes, although the evidence for low dose effects is less certain. Some of recent studies reported use of polycarbonated containers, canned drinks or thermal paper could contribute to increase of body burden with estimated exposure amounts, but there were limitations of uncertainty coming from application of limited pharmacokinetic (PK) information (i.e. urinary excretion fraction from few subjects) or exposure models. The aim of the present study was to measure contribution by exposure source in daily life and provide another PK-based approach to exposure amounts. Four adult males were exposed to BPA via use of polycarbonated container, commercial canned drinks and thermal paper and three matched volunteers participated with avoidance of the exposure sources of interest at the same place as in the exposed. All urine samples were collected and combined to monitor. 5 hours before the exposure as well as at 0.5, 1, 2, 4, 6, 8, 12 and 24 hr. Urinary BPA were measured with liquid chromatography coupled with tandem mass spectrometry and the intake amounts of BPA were estimated with a human two-compartment PK model for oral consumption of BPA, which emulated about 70% of first exposed amounts in 6 hours after exposure with 3.42 hours for the biological half-time. Cumulative amounts of BPA until 6 hours, were significantly higher in users of polycarbonate bottle compared to the control (p = 0.029)

however, those for drinking of canned beverage and paper crafts of thermal paper did not make significant contribution. Based on urinary amounts of BPA, single drinking 200 mL of purified water with polycarbonated cup, single drinking of 200 mL canned beverage and paper craft with thermal paper (9 X 15 cm2 for 15 min) contributed to about 0.7~2.6 µg, 0.3~2.1 µg and 0.1~1.5 µg of intake amounts of BPA, respectively. Although the exposure experiment was performed in a confined and planned design, there was a relatively wide inter-personal variability in the urinary BPA measures and intake amounts. Considering uncontrolled spontaneous exposure to BPA in daily life, further studies are required to explore the variability in the environmental exposure and personal kinetics, but the present study showed single use of consumer products of BPA could cause distinguishable contribution to body burden.