Updated regulatory screening for endocrine disruptors is needed on a particular alternative to BPA (bisphenol A) because the substitute may have similar health effects as the latter chemical, and people can have significant exposure to it, some scientists are saying.
Manufacturers put BPA into plastics, and paper companies use it in the ink of heat-sensitive sales receipts. Animal studies have shown that the compound has a wide range of effects as an endocrine disruptor, which act like natural hormones and can interfere with cellular pathways.
Animal studies also have shown that BPA can cause health problems, such as obesity and mammary and prostate tumor growth. About 30 epidemiological studies have linked exposure to BPA to similar effects in people. Despite the studies, the U.S. Food and Drug Administration has not acted to ban BPA from food packaging.
Because of concerns about health effects, manufacturers have started to produce and market BPA-free products. But a new study has found that one of the compounds to replace BPA is just as prevalent in paper products and could lead to significant human exposure, reports Janet Pelley of Chemical & Engineering News. The authors of the study say that toxicology research is needed on the BPA alternative.
A co-author of the study, Kurunthachalam Kannan, an environmental chemist at the New York State Department of Health, and his team were examining BPA concentrations on thermal receipts in 2010 when they noticed that paper companies were replacing BPA with bisphenol S (BPS), which is structurally similar to BPA and also causes similar health effects, he says.
The scientists took samples of BPS from thermal receipts given in stores in the United States, Japan, South Korea, and Vietnam. Using high-performance liquid chromatography with tandem mass spectrometry, they found an average concentration of 0.181 mg of BPS per gram of paper. Some samples reached a concentration of 22 mg/g. The findings are reported in a paper in Environmental Science & Technology.
Pelley explains what the researchers did next:
The researchers then used a mathematical model to estimate a person’s daily intake of BPS. The model assumed the rate of transfer of BPS to skin was similar to that of BPA and took into account how often and how long people handled BPS-containing paper. The general population likely absorbs 291 ng of BPS per day through their skin, they concluded, while workers such as store clerks may absorb 21,804 ng/day.
The study demonstrates that people may experience significant exposure to BPS, says Frederick vom Saal, a developmental endocrinologist at the University of Missouri, Columbia, who did not participate in the study. Because manufacturers replaced a known endocrine disruptor with a compound that causes similar health effects, regulatory requirements need to be updated for screening compounds that disrupt endocrine systems, he says.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.