Occupational exposure to Bisphenol S via thermal paper. Preliminary results

Introduction
Bisphenol A (BPA) is widely used in the production of diverse industrial and consumer products. BPA also has been shown to occur in the paper industry as color developer in thermal paper. Human exposure to BPA is widespread and has been associated with an array of adverse health outcomes. However, controversial discussions around the effects of BPA are still ongoing. Given the societal pressure and the regulation put forward to limit its applications, BPA is gradually being replaced by alternative chemicals to produce “BPA-free” products. In thermal paper, Bisphenol S (BPS) is the primarily replacement for BPA. Limited information on the hazards of BPS is available. Moreover, data on the occurrence of BPS in human specimens are scarce. In this study, we investigated the urinary BPS levels of cashiers and controls from 2 hypermarkets.
Methods
Total (unconjugated and conjugated forms) BPS was measured urine samples, using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spot urine samples, including pre-shift and post-sift samples and first morning void were collected from each participant. BPS concentration in thermal paper was also measured from each hypermarket and the number of receipts handled by cashiers was estimated.
Results
Urine samples were collected from 17 cashiers and 15 controls. The estimated number of receipts handled was highly variable among cashiers, ranging from 10 to 400 for a working day. The mean concentration of BPS in thermal paper was 13 mg/g. Total BPS was detected in 95 % of samples in the control group and a significant increase was found in urinary total BPS concentration for cashiers compared to controls.
Conclusion
The detectable levels of BPS in urine of controls would suggest the exposure of general population to BPS. More, frequent contact with thermal paper would be associated with an increase in urinary total BPS concentration in cashiers.