ENVIRONMENT REPORTER
Researchers in Germany have found traces of an unknown estrogen-mimicking chemical leaching into mineral water from a widely used type of plastic bottle.
The bottles are made from polyethylene terephthalate, or PET, and the scientists detected estrogenic activity in 78 per cent of samples, according to a study published online in Environmental Science and Pollution Research.
The testing, conducted at Johann Wolfgang Goethe University in Frankfurt, is the first to find consistent contamination of bottled water with a hormonally active substance leaching from PET, one of the world's most popular packaging materials. The plastic is also used for soft-drink bottles and a host of other food and beverage containers and is identified by the recycling-industry symbol of the numeral "1" encased in a triangle.
The research is part of an effort by scientists to investigate and understand the biological activity of consumer food and beverage packaging, a topic that has been highlighted by the controversy over bisphenol A, another plastic-making compound able to act like a female hormone.
The discovery that PET containers are also capable of leaching a synthetic estrogen worries one of the study authors because of the widespread use of the plastic.
The finding "might be a bigger problem. ... If you go to the supermarket, everything is packed in plastic," said Martin Wagner, a PhD student in aquatic toxicology at the university.
The health risk, if any, from the mineral water, is currently unknown. But researchers found that when they raised mud snails, an animal sensitive to female hormones, in the plastic mineral-water bottles, it prompted an increase in embryo production in the mollusks.
Mr. Wagner said the researchers haven't been able to identify the substance or substances causing the hormonal activity. PET isn't thought to contain bisphenol A or phthalates, another item often found in plastics that is able to disrupt hormones. The plastic does contain small amounts of antimony, which has estrogenic activity.
Not all the bottles tested positive for estrogen, suggesting that even though PET is considered a single type of plastic, it has slight differences in chemical composition, depending on the manufacturer.
Frederick vom Saal, a biologist at the University of Missouri who is considered an authority on the health effects of bisphenol A, said he worries about exposures to synthetic estrogens because they add to the natural female hormones already in people.
