By Gordon Chan
Surely, you’ve seen or heard about Bisphenol A by now. More commonly known as BPA, it’s a form of clear plastics called polycarbonates which are used in the linings of food and drink cans. It can also be found in everyday products such as infant feeding bottles, paper receipts, and food storage containers. BPA commonly ranks amongst one of the highest-volume chemicals manufactured with an estimated “8 billion pounds of BPA are produced annually”. Yet studies have shown that even low-doses of BPA exposure is associated with obesity, increased risk of breast and prostate cancer, and reproductive defects. This could have significant implications on BPA regulations and drastic economic consequences on BPA production.
On May 11th 2015, BPA was unanimously added to California’s Proposition 65 list of harmful chemicals. Although California has officially acknowledged the toxic properties of BPA, the federal government still hasn’t reached a conclusive decision on BPA safety levels. Without any proper guidelines, how do families determine which cans to buy or discard?
First appearing in products as early as the 1950s, BPA has become the unofficial poster child for this group of hormone disrupting chemicals. For decades, scientists have debated over the safety of BPA. In April 2008, the National Toxicology Program (NTP), which is a part of the NIH, raised concerns about BPA’s relationship to breast cancer and prostate defects. Yet just a few months later, the FDA concluded that “BPA exposure for adults and children are well below toxic doses”. How could two of our national health organizations come to such polar conclusions? Are we intentionally being scared by the NTP? Or is the FDA hiding some greater truth from the public eye?
According to the Environmental Working Group, a non-profit organization dedicated to protecting human health and the environment, early studies on BPA indicated that it does not leach, or leaches in very small quantities, from plastic products into our bodies. However, many of these studies have a potential conflict of interest with those within the chemical industry, such as the American Plastics Council, who have a strong desire to maintain using BPA in plastics production. There are only five companies in the United States that make BPA: Bayer, Dow, Hexion Specialty Chemicals, SABIC, Sunoco. Yet all together they brought in over $15.6 billion in 2015; and its projected that their value will reach a projected $22 billion by 2022. The growing global consumption of BPA is likely bolstered by the lack of consensus among federal agencies about it’s safety. And if you’re just finding out about BPA for the first time, it might be confusing to digest all the information out there.
Since 1999, many studies have shown that BPA exposure is associated with adverse health effects. But critics have pointed out that these studies generally used doses that were much lower than the doses humans are normally exposed to, thus invalidating their results. Now, based on traditional knowledge of toxicology, it holds that “the dose makes the poison”. But this is not the case with BPA, in fact quite the opposite. A study measuring low-dose BPA exposure and breast cancer found that, even at low doses of exposure, BPA could cause significant, irreparable harm.
However, despite numerous studies, there are still critics who claim that the effects of BPA are often exaggerated, stressing that the toxic effects of BPA are only experienced at very high concentrations. Surprisingly, the FDA is in favor of this position and has maintained that the current levels of BPA exposure through food packaging do not pose a health risk for children or adults.
In a recent study published in The Lancet Diabetes & Endocrinology Journal, researchers employed a new method that more accurately evaluates exposure to BPA. It provides evidence that current regulations, like the FDA, are relying on measurements that are underestimating true BPA exposure by as much as 44 times. Patricia Hunt, a molecular biosciences professor at Washington State University and a corresponding author on the paper, emphasized that the measurement tools we’ve been using for chemicals are highly inaccurate. But with this new method, we can make more accurate estimates of human BPA exposures. Thus, there is a clear need for regulatory agencies to review the health literature on BPA and prompt BPA manufacturers to reconsider their use of this chemical in their products.
But BPA is far from the only modern-day substance that we don’t fully understand. There is a whole list of other synthetic BPA alternatives that the chemical industry has begun manufacturing. And in fact, one of them, BPS, may be even worse than BPA. In the meantime, what is the consumer supposed to do? Continue to trust that federal administrations have their best interests at heart or take active measures against BPA themselves? For now, it seems important the we educate ourselves as much as possible.
References Darbre, P. D. (2015, April 3). What Are Endocrine Disrupters and Where Are They Found? doi.org/10.1016/B978-0-12-801139-3.00001-6  Wang, Z., Liu, H., & Liu, S. (2016). Low-Dose Bisphenol A Exposure: A Seemingly Instigating Carcinogenic Effect on Breast Cancer. Advanced science (Weinheim, Baden-Wurttemberg, Germany), 4(2), 1600248.
doi: 10.1002/advs.201600248  Rochester JR, Bolden AL. 2015. Bisphenol S and F: a systematic review and comparison of the hormonal activity of bisphenol A substitutes. Environ Health Perspect 123(7):643–650. doi.org/10.1289/ehp.1408989