Bisphenol A (BPA) is one of many toxic chemicals that is known to be an endocrine disruptor and associated with a growing number of recognized negative health consequences. Although most of the research has focused on its estrogenic properties, a new study indicates that it can affect thyroid hormone levels in baby boys:
In addition, it was recently discovered that a metabolite of BPA (a substance produced when BPA is metabolized or processed by our body) is even more estrogenic than BPA itself:
BPA is found in many types of plastics and known to leach into foods and liquids stored in anything that contains it. One of the greatest sources of BPA is the plastic on the inner lining of canned foods and beverages that is used to prevent the contents of the cans from coming into contact with the metal that the can is composed of. Other major sources include thermal papers such as those used for cash register receipts and in fax machines. In studies where blood samples have been taken to determine the level of BPA in the blood and tissues of the subjects participating in the studies, cashiers tend to have among the highest levels because the BPA in receipts can be absorbed through our skin. Sadly, because thermal papers are included as a source of paper for recycling, paper that has post-consumer recycled content tends to have BPA as well.
BPA has been in use since the 1950s. As with so many other industrial chemicals, we have all been taking part in a continuous experiment on the toxicity of these chemicals, as have our animal and plant brothers and sisters.
This green frog (Rana clamitans), and all of the other beautiful beings that we share this planet with,
would love us to stop dumping endless amounts of toxic stuff into their (and our) environment!
It is insane that industries are allowed to use these things without adequate testing. As more research is done, we are beginning to comprehend some of their detrimental effects, but we still know virtually nothing about how all of these toxins interact in our bodies because almost all of the research is conducted on individual chemicals in isolation. Another major concern is that scientists are prone to linear thinking. That means that they assume that if a chemical seems to be safe at a particular dose, it will be even safer at a lower dose. However, recent research indicates that sometimes chemicals can be more toxic at very low doses than at higher doses:
Natural systems are incredibly complex and what we know is infinitesimally small compared to what there is to know. Things don't work in Nature the way they do in the artificial environment of a lab. There is very little in Nature that occurs in nice, neat linear patterns.
With the growing awareness of the harmful effects of BPA, many manufacturers are now offering "BPA Free" products. Well consider this: BPA has a function! If you take it out of something it must be replaced with something else. Unless these substances are added directly to foods or beverages for human consumption, there is very little regulation of them. That means that manufactures will just add some other chemical with little to no research on its potential harmful effects. And guess who are going to be the unwilling subjects in the longitudinal study on their harmful effects? That right ... all of us!
So, it turns out that in most of the "BPA Free" products out there the BPA has been replaced by a closely related substance called bisphenol S (BPS). There is considerably less research on BPS compared to BPA, but the research is starting to be done and (surprise!) it's looking like BPS might be just as bad as BPA:
Ideally, regulatory agencies should be adhering to the precautionary principle, that is, that nothing should be allowed to be implemented outside a lab until we are certain that it will not have any negative consequences on the natural world (including us!). Or, as our Native American brothers and sisters would say, until we are sure that it will not have any negative consequences for the next seven generations.
Since the regulatory agencies don't get it (and are heavily influenced by industry), we need to think (and act) for ourselves. If we learn that something is bad for us and/or the environment, it makes sense to avoid it as much as possible - or it's supposedly "safe" replacement (e.g. avoid consuming things in cans as much as possible even if they are "BPA Free" and stick to glass bottles, or better still, make it fresh or can it ourselves). On the positive side, with a little education and effort, there are a lot of unhealthy things out there that we can avoid, and there are a lot of healthy choices that we can make as well.