December 14th, 2009 
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Media attention in the last couple of years has turned the public largely against the use of hard plastic water bottles and many such bottles have instead been replaced with metal ones. The reason for this is that production of these hard plastic bottles involves a chemical called Bisphenol A or BPA for short and BPA has been associated with a number of problems to human health. Unfortunately, it seems, getting rid of these bottles does not eliminate our exposure to the chemical.
BPA is an organic chemical used during the production of what are called polycarbonate plastics; the high impact kind that you would recognize used in toys, CDs, safety glasses and of course, water bottles. While the chemical has been around for more than 100 years, it is only within the last 10 years or so that the negative health effects from the current exposure levels have been identified.
We are typically exposed to the chemical as a result of consuming food and liquids that have been stored in containers made from the material.
Based on various research activities, the chemical BPA has been found to cause a wide variety of problems in the human body. This is not unexpected when we consider that it mimics the hormone estrogen and that hormones are typically responsible for controlling many aspects of our bodily operation. Unfortunately, based on a collection of studies using urine samples, it is estimated that more than 90% of the US population had detectable levels of the chemical in their urine.
Among the effects seen in the research, BPA has been found to cause insulin resistance that can ultimately lead to obesity and Type 2 diabetes. Similarly, scientists from Tufts University School of Medicine have found that BPA increases the number of fat cells in the developing fetus. Such an increase means that it is easier for an individual to put on weight later in life. Given the severe obesity epidemic in the US, such findings indicate that the chemical could be contributing to a very costly health problem that is currently endangering the lives of many people.
In research into other areas of BPA health impact, scientists have found other effects on the developing fetus. Researchers from the University of Missouri-Columbia found that in mice, BPA exposure resulted in the development of a permanently enlarged prostate. Other research at both The Rockefeller University and the Yale School of Medicine has found that even low-level BPA exposure of the fetus in pregnant monkeys resulted in the development of mood disorders and effects on the ability to think in the newborn monkeys. Obviously, this implies that pregnant women should avoid exposure.
As for the effects in adults who were not exposed before birth, researchers at the University Department of Growth and Reproduction, Rigshospitalet, Denmark have found that the BPA can disrupt operation of the thyroid, another hormone sensitive and hormone regulating gland in the body. Thyroid disruption can lead to high blood pressure, irregularities in heart beat and weight loss to name only a few issues.
Other effects of BPA in adults are an increased risk of breast cancer. Research performed at Fox Chase Cancer Center has found that the chemical can induce the transformation of certain cells in the breast to become cancerous. Such effects undoubtedly add to the concern over the use of the chemical.
Given all of these known effects, it is good to see that some governments in a number of countries have imposed various restrictions on the use of the chemical. However, most restrictions are limited. Canada, as one of the first to rule on the chemical, has declared the chemical toxic, but banned its use only in baby bottles while other countries have stated there is no risk to its use.
Unfortunately, these governments appear to be erring on the side of industry rather than public health. The public is being exposed to BPA from a number of sources and assessing the cumulative effects of this exposure should be a higher priority.
As for the sources of BPA exposure, Health Canada found the chemical in 69 of 72 soft drinks or sodas. Though the governmental body indicates that the levels are low, it is important to keep in mind that many different sources can lead to an accumulated level that exceeds the safe limits. It is also important to understand that the safe level is subject to change given ongoing research into the effects of the chemical.
With BPA used in so many plastics, it is not surprising to find it in the replacement for our metal fillings. Here again, Health Canada has said that levels of exposure are low, but given the persistent nature of fillings, we may very well be receiving a daily dose from our fillings long after they have been put in.
In other research into dietary sources of BPA, an assessment conducted by Consumer Reports in the US and only recently published found that “almost all” of the canned foods tested contained BPA and even those labeled as “BPA-free” contained the chemical. In some cases, a single serving was sufficient to put an individual over the recommended limit of daily exposure. While the research conducted by Consumer Reports was not comprehensive, it does indicate, at a minimum, the need for more research.
Given both the amount of industry that is dependent on BPA for its livelihood and the increasing number of research findings with respect to health effects of the chemical, it will take some time before a final decision is communicated from our governments relating to how bad this chemical really is. Even with the head of the US federal agency, the National Institute of Environmental Health Sciences and the National Toxicology Program, indicating that people should avoid exposure if at all possible, we cannot expect quick action. However, that does not stop each of us from taking preventative action for the sake of our health.
We can use bottles and containers made of metal, glass, ceramic or the BPA-free plastics PETE and HDPE that have the added benefit of being fully recyclable. We can also write to our food producers and ask them to remove BPA sources from their food production. Given that there are many types of plastic that do not contain Bisphenol A, we do have options for limiting our exposure and when we have such options, why wouldn’t we exercise them?
Are you concerned about BPA or do you think alarmists are propagaing fear? If you have concerns or comments about BPA, why not share them in the health forums?
Related Links:
http://www.scientificamerican.com/article.cfm?id=just-how-harmful-are-bisphenol-a-plastics
http://www.cdc.gov/exposurereport/executive_summary.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1332699/
http://dx.doi.org/10.1016/j.mce.2009.02.023
http://ehp.niehs.nih.gov/docs/2007/9804/abstract.html
http://www.pnas.org/content/105/37/14187
http://www.washingtonpost.com/wp-dyn/content/article/2008/09/03/AR2008090303397.html?hpid=topnews
http://www.ncbi.nlm.nih.gov/pubmed/19625957
http://tpx.sagepub.com/cgi/content/abstract/0192623309354108v1
http://www.canada.com/vancouversun/news/story.html?id=9f043e28-3d09-4480-8f03-edac6b0964b9&k=96037
http://www.hc-sc.gc.ca/fn-an/securit/packag-emball/bpa/bpa_survey-enquete-can-eng.php
http://www.theglobeandmail.com/life/article681175.ece
http://www.consumerreports.org/cro/magazine-archive/december-2009/food/bpa/overview/bisphenol-a-ov.htm
http://www.jsonline.com/watchdog/watchdogreports/79111742.html
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