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Dr. Joe Schwartz on BPA

It is certain that Bisphenol A and other chemicals leach out of some of the plastics we use for drinking and eating every day. Is the amount of chemicals leached, however, as serious a hazard to our health as many news articles report? And, does the hype over these risks warrant a government ban of Bisphenol A used in plastic food related containers?

In a recent CTV News interview, Joe Schwartz discussed his point of view on the Bisphenol A (BPA) debate. Dr. Schwartz is a doctor of chemistry and professor at McGill University in Montreal, Quebec. He is the director of McGill’s Office for Science & Society which is dedicated to demystifying science for the public.

According to Dr. Schwartz, it is difficult to predict the long term health effects of Bisphenol A. “Toxins by definition are poisonous substances, so certainly are worth worrying about.  But of course as toxicologists point out, “only the dose makes the poison.”

Some rodent studies and laboratory experiments have shown that trace amounts of BPA’s can cause problems ranging from birth defects and impaired blood sugar control to breast and prostate irregularities. Whereas these studies have used rodents as subjects, BPA has also been found in our blood and urine. Dr. Schwarrtz points out that “our ability to detect trace amounts of chemicals has surpassed our ability to interpret what the numbers mean.  Hence the debate about the risks of BPA exposure”.

Producers of BPA assure us that the amounts to which we are exposed is not worrisome, while some researchers claim that even minute levels of BPA in our bodies is potentially harmful. The argument continues with studies showing that “rodents employ a different detoxication mechanism than humans, and do have more circulating BPA after exposure than we would have.” There is also the issue of type of exposure to BPA.  “Many of the rodent studies have used injected or implanted BPA, which is a different type of exposure than ingestion.”  BPA critics retort with the argument that “injecting BPA into pregnant rodents is an appropriate way to study effects on the fetus.  And, as far as humans go, while indeed detoxification reactions do swing into action, these are much less efficient in children and babies, who are therefore at greater risk.” 

Dr. Schwartz continues to outline various other natural substances in our environment that expose us to higher estrogen levels that BPA. Alfalfa sprouts, soy beans, lavender oil and milk are among these. There is also Nonylphenol, an estrogenic ingredient in numerous detergents, along with the natural estrogens and birth control pill remnants that end up in our sewage.  These substances are not removed by sewage treatment and end up in our surface and ground water.

“In other words we are awash in a sea of both natural and synthetic hormone disrupting substances and it is unrealistic to accuse a specific one of being the devil incarnate.” 

Dr. Schwartz warns us, however, that “this does not mean that we should be cavalier about hormone-like substances in the environment.”  Even though there is no hard evidence that BPA levels encountered present a risk to humans, there are potential risks that we are not sure of. It is possible that babies do not excrete BPA as efficiently as adults. We also do not know what synergistic effect BPA has when combined with other endocrine disrupting substances. Dr. Schwartz suggests that there are glass baby bottles and containers of other plastics available. He also believes that it “seems a good idea to search for viable alternatives to the epoxy lining in canned foods”.

Dr. Schwartz’ final message is that: “panic over drinking from polycarbonate bottles is unwarranted, and talk of banning polycarbonate plastics is naive.”

Quotes are taken from Dr. Joe Schwartz’ article entitled: “Bisphenol A (BPA) – The Case for Polycarbonate Water Bottles”


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