Bisphenol A-free (BPA-free) plastics aren't as safe as you think. Researchers found that Bisphenol S (BPS), which replaced BPA in many plastic products, can speed up embryonic growth and disturb the reproductive system.
Manufacturing companies stopped using BPA to strengthen plastic products after studies associated it with the increase in prostate and breast cancers and early puberty. A research team from the University of California, Los Angeles (UCLA) found that BPS is not safe either.
The study is the first to analyze the effects of both BPA and BPS on growth-related genes, vital brain cells and reproductive organ functions. The findings were published in the journal Endocrinology.
Senior author Nancy Wayne and her team used a zebrafish model to see the effects of low BPA and BPS exposure. The team chose the zebrafish because their transparent embryos make it easy to see the cell growth.
The amount of BPA and BPS they used in the study is equivalent to the chemicals traces in polluted waters. In as fast as 25 hours, the chemicals changed the embryonic stage physiology of the zebrafish.
The team also used fluorescent protein tags to track the development of endocrine brain cells, which are responsible for controlling fertility and puberty. They found that the presence of chemicals raised the numbers of endocrine neurons, suggesting that BPA sends the reproductive system into overdrive.
The exposure to tiny amounts of BPA also revealed a substantial impact on the genes that regulates reproduction in adulthood. The team found that both BPS and BPA act through the estrogen and thyroid hormone systems.
"We saw many of these same effects with BPS found in BPA-free products. BPS is not harmless," added Wayne is UCLA's David Geffen School of Medicine's physiology professor and reproductive endocrinologist. Her lab plans to investigate how overstimulated reproductive neurons could result in premature puberty and an altered reproductive system.
BPA can leak into food front the lining of cans, especially under heat. Consumer products that may contain BPA include baby bottles, food containers, plastic tableware, water bottles, contact lenses, compact discs, eyeglass lenses, ATM receipts and dental sealants.