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Several recent studies now confirm what had been feared so far — the toxicity of a chemical present in feeding bottles and other plastic products. As reports by  P. Hari

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Bisphenol A or BPA is a compound that is found in many plastic products around the world. It has been in use since 1891, and known to be toxic since 1930. Regulatory authorities all over the globe, however, had pushed the issue under the carpet, citing the absence of solid evidence of the material’s toxicity.

Now, at least one organisation — the US Food and Drug Administration (FDA) — seems ready to revise its opinion. Two weeks ago, the FDA issued a statement that read: “… recent studies provide reason for some concern about the potential effects of BPA on the brain, behaviour and prostate gland of foetuses, infants and children.”

In the last one year, a spate of studies has pointed to the serious toxicity of BPA. Children born to women exposed to BPA during pregnancy may show serious reproductive and neurological defects in adulthood. Even adults who are exposed periodically may develop heart disease, diabetes and liver ailments. Earlier studies in the US had shown that 93 per cent of the population is exposed to BPA. “Toxicologists proceed on the assumption that there is a safe level of BPA exposure,” says Frederick vom Saal, professor of biological sciences at the University of Missouri. “That assumption is ludicrous.”

BPA is a common constituent of many feeding bottles. It could be present in plastic water pitchers, or any clear and stiff plastic. It is widely used to stiffen a type of plastic called polycarbonates. This is often present in food cans, beverage bottles, dental fillings and many other items. So common is BPA now in our world that it is one of most widely manufactured chemicals in the world. But so far, only a handful of people thought exposure to this chemical was dangerous. As evidence mounts, the minority voice is becoming louder.

Consider, for example, these studies. Two weeks ago, scientists at the University of Exeter in the UK published the result of a study that found a clear association between heart disease and BPA levels in the urine of adults. A month and a half ago, scientists at the University of Sherbrooke Hospital Centre in Quebec, Canada, published research that found that BPA can kill foetal cells at low doses. Another study — which is yet to be published — at the California-based Kaiser Foundation Research Institute and some Chinese institutions found that high levels of exposure can lead to sexual dysfunction and other reproductive problems. “We found several reproductive problems in adults exposed to BPA,” confirms Harvey Checkoway, professor of environmental health and epidemiology, University of Washington, a co-author of the study.

The Sherbrooke University study came up with an interesting, as well as troubling, finding. Placental cells exposed to BPA did not follow the normal patterns of toxicity that have been known so far. In other words, it was seen that the lower the dose, the more toxic is the effect. The university scientists isolated placenta cells and exposed them to low doses of BPA, at levels found in the blood of pregnant women. The compound damaged cell membranes and also produced a protein associated with cell death. This suggests that BPA in the blood can affect foetal development, lead to premature birth or even loss of pregnancy. This provides further evidence that BPA can affect reproductive health in low doses.

The science behind this association is not too difficult to understand. BPA is similar to the hormone oestrogen. Therefore, the human body recognises the molecule as oestrogen and acts as such. But the human body already has very high levels of oestrogen for there to be a “safe level” of BPA exposure. “Concepts of threshold levels (of BPA) have no meaning when the body already has high levels (of oestrogen),” says vom Saal. The body is very sensitive to this chemical and cells can detect even one molecule of BPA.

Higher than normal levels of oestrogen has been implicated in many diseases such as breast cancer in women and prostate cancer in men. Many endocrinologists now think that BPA could be responsible for the increase in the rate of breast cancer in the last few decades. The chemical could also be the reason for the rising incidence of many diseases in men, as everybody in the world is exposed to it at some level. It is now present everywhere — in the oceans, sewage, drinking water. And it is already disrupting the reproductive systems of many marine animals.

Two weeks ago, almost at the same time the FDA issued its notice, the US Department of Health came up with a set of guidelines for parents. According to these, one should not heat feeding bottles or put them in a microwave, as heat is known to release BPA. Also, they shouldn’t be put in dishwashers. And finally, scratched bottles must be discarded immediately.

Such measures, say scientists, will not eliminate the infant’s exposure to BPA, but will at least reduce it to some extent.

You may click to see:->PLASTIC BOTTLED WATER DANGERS

Source: The Telegraph (Kolkata, India)

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