31 Oct Sales Receipts May Lead to High Levels of BPA Absorption
Medical Research: What is the background for this study? What are the main findings?
Dr. Taylor: Bisphenol A (BPA) is an industrial chemical present in a large number of consumer products, including polycarbonate plastics, food can linings, resins and thermal paper. A 2008 study of BPA levels in human urine concluded that over 90% of the U.S. population is exposed to BPA. BPA is an endocrine disrupter; its estrogenic properties were first described long before its commercial use, but today it is known that it not only acts like an estrogen but also interferes with thyroid hormone, androgen and insulin action. In population-based studies, higher urinary levels of BPA have been linked to a number of human health issues. For example, higher BPA concentrations have been associated with obesity and aggressive and hyperactive behaviors in children, and with cardiovascular disease and diabetes, altered liver and kidney function, and immune and reproductive disorders in adults.
It was at one time thought that almost all human exposure occurs via food and drink, but calculations of exposure from these sources do not adequately account for the sometimes high amounts measured in urine, and the fact that BPA concentrations in population-based studies are not lower with increasing fasting time suggests that some other form of ongoing exposure. Our interest here was in thermal paper. BPA has been used as a color developer in thermal paper for many years and can be present in milligram amounts in the paper coating. Because thermal printing is widely used for items such as sales and ATM receipts, airline tickets and luggage labels, thermal paper may represent an important high-concentration source of exposure.
We screened thermal paper receipts from 50 in-state vendors and found that 44% used BPA as the color developer, but 52% used another chemical called BPS (bisphenol S) which was present in similar quantities to BPA. Two receipts contained neither BPA nor BPS, and so presumably used an alternative (unidentified) chemical.
In preliminary work we measured the transfer of BPA from thermal paper to the hands, and found much higher transfer to hands that were pre-wet using hand sanitizer. We also determined that BPA transferred to hands could then be transferred to food. In our study we asked men and women to first wet their hands with sanitizer before holding the receipts for a few minutes, and then with the same hands pick up french fries and hold them briefly before eating them. We then cleaned one hand but allowed the other to remain “contaminated”. We took blood samples over the next 90 minutes, either from the arm linked to the clean hand or the arm linked to the dirty hand, and collected a urine sample at the end.
We found that for the subjects who held a thermal receipt paper immediately after using hand sanitizer, significant amounts of free BPA were transferred to the hands and then to the french fries they ate. The combination of skin and food exposure led to a rapid increase in serum free (bioactive) BPA, and a high concentration in the urine within 90 minutes. We also found that blood levels of BPA were higher when taken from the arm linked to the “contaminated” hand than if taken from the clean side. Because the vein sampled collects blood draining from the hand, this suggested to us that there was continuing absorption of BPA through the skin. This study thus demonstrates the potential for BPA exposure via two routes, oral and dermal, from thermal paper. The use of hand sanitizer, which contains chemicals used as skin penetration enhancers, may augment the dermal absorption of BPA and similar chemicals.
Medical Research: What should clinicians and patients take away from your report?
Dr. Taylor: As already stated, exposure to higher levels of BPA, as indicated by urine concentrations, has been associated with a variety of health or behavior issues. The urine levels measured in this study are equivalent to those associated with a significant increase in the likelihood of developing cardiovascular disease and type 2 diabetes, and although we do not fully understand all of the links between BPA and many of the health issues, it seems prudent to limit exposure to this and similar chemicals. A common-sense approach suggests limiting handling of sales receipts, having a designated container for the ones needed, and washing one’s hands – with soap and water, not sanitizer! – after handling these products.
It should also be noted that the actions of hormones and their disrupters may be more pronounced in the very young, when hormone actions may still be activational and effects may be permanent. Since obesity, as one example, is often programmed early in life, attention should be paid to children’s exposure to BPA and similar chemicals.
Finally, if a thermal paper product is labeled as “BPA-free”, it is not necessarily inert. BPS, which we detected in 55% of the receipts we screened, has estrogenic potency only slightly lower than that of BPA. It is less well characterized, but may also be more persistent in the environment. It is likely that BPS represents the main alternative in thermal paper receipts today, and BPS has been detected in human urine in several countries.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Taylor: The impact of the use of dermal penetration enhancing chemicals in skin care products on transdermal absorption of environmental contaminants should be taken into consideration in risk assessments and should be a priority for future research.
Holding Thermal Receipt Paper and Eating Food after Using Hand Sanitizer Results in High Serum Bioactive and Urine Total Levels of Bisphenol A (BPA)
- Annette M. Hormann, Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America Annette M. Hormann, Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, UnitedFrederick S. vom Saal, Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America X Susan C. Nagel, Affiliation: Department of Obstetrics, Gynecology and Women’s Health, University of Missouri, Columbia,Richard W. Stahlhut, Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States oCarol L. Moyer, Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of AmericaMark R. Ellersieck, Affiliation: Department of Statistics, University of Missouri, Columbia, Missouri, United States of Americ Wade V. Welshons, Affiliation: Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States of America X Pierre-Louis Toutain, Affiliations: Université de Toulouse, INPT, ENVT, UPS, UMR1331, F- 31062 Toulouse, France, INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, F-31027 Toulouse, France X Julia A. TaylorE-mail: TaylorJA@missouri.edu Affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America X
Published: October 22, 2014