November 26, 2010

scientists comment on EU ban on bisphenol A in plastic baby bottles

The European Commission announced a ban on the chemical bisphenol A in plastic baby bottles, which will come into force in 2011

Prof Warren Foster, Department of Obstetrics & Gynecology, McMaster University, Canada, said:

“BPA is recognized as a weak estrogenic chemical that is present in many consumer products with the result that there is widespread low level exposure to this chemical in the human population. There are reports in the literature that demonstrate adverse effects of BPA on meiotic resumption in oocytes in mice, protstatic hypertrophy in a strain of mice, altered mammary gland development and carcinogenesis in rodents, and reproductive effects in rodents (advanced reproductive development). However, these reports are conflicted as other competent laboratories have been unable to replicate these findings.

“Although several epidemiological studies have appeared in the recent literature from one group that show adverse effects on libido in men and decreased semen quality in men working in the manufacture of plastics employing BPA, there is no compelling evidence that BPA exposure representative of the concentrations measured in the general population has any impact on human health.

“Consequently, it appears that regulators have reviewed the evidence of:
1.,almost universal exposure to BPA in the human population
2.,the potential for these exposures in a population sensitive to exposure to estrogenic chemicals to adversely affect estrogen-sensitive target tissue development, and
3.,the potential that if the animal studies were to accurately predict effects in the human population then there could be serious long-term health consequences for infants exposed to BPA.

“Hence, I assume that regulators have elected to act with extreme caution and to ban BPA in baby bottles. I emphasize that the decision is likely not to be because BPA will cause health problems, but because it might; and if it did cause a health problem, then because of wide-spread human exposure it could have serious long-term health consequences. From the evidence and the conclusions of EFSA and other regulatory bodies, there is no reason for concern amongst the adult population concerning exposure to BPA.”

Prof Tony Dayan, Emeritus Professor of Toxicology, University of London, said:

“This is sad news for the sciences of toxicology and risk assessment. The EC ban on bisphenol A is a political action that has allowed emotion and unreasoned concerns to overweigh scientific evidence. It denies the value of much toxicological research in part funded by the European Commission itself.”

Prof Tamara Galloway, Professor of Ecotoxicology at the University of Exeter, said:

“The precautionary approach now being adopted by the EU to protect vulnerable groups from exposure to BPA brings Europe in line with Canada and many US states. This emphasises the continued need for independent research into the safety of BPA and alternative compounds suspected of causing endocrine disruption.”

Prof Richard Sharpe, MRC Human Reproductive Sciences Unit at the University of Edinburgh, said:

“I would be happy for a baby of mine to be bottle fed from a polycarbonate bottle containing bisphenol A. I can only presume this has been done on precautionary grounds as I do not know of any convincing evidence that bisphenol A exposure, in the amounts used in polycarbonate bottles, can cause any harm to babies, as not only are the amounts so minuscule but they are rapidly broken down in the gut and liver. 95% of our exposure comes from our diet and when ingested it is rapidly metabolised and the exposure is absolutely tiny. Babies have the necessary enzymes and are able to metabolise bisphenol A just as effectively as adults.

“There are other endocrine disruptors which are of greater interests to scientists, including phthalates which are ingested from our diet. With both phthalates and bisphenol A there are levels of uncertainty but there are also differences. Whilst the relatively high levels of phthalates that we’re exposed to cause definite problems in animal studies, in contrast, studies of bisphenol A at the levels of human exposure show no consistent effects.

“Personally I think the ban is an overreaction but if satisfactory replacement chemicals are available then it can be put in place to placate those calling for action, but scientifically it’s a retrograde step.

“Parents may ask why, if there’s nothing to worry about, bisphenol A is being banned. That questions needs to be asked of a politician rather than a scientist as the ban is not based on science.”