New research analyzing mineral water held in bottles made from polyethylene terephthalate (PET) raises questions about whether contaminants might leach from PET into the water where they mimic estrogen’s effects. In the study reported online in Environmental Science and Pollution Research on March 10 (DOI 10.1007/s11356-009-0107-7), ecotoxicologists Martin Wagner and J rg Oehlmann of Johann Wolfgang Goethe University (Germany) report evidence of the bottles’ estrogenicity from multiple tests, but they have yet to pinpoint the exact source.
Billions of bottles and food containers made of PET are sold every year. The plastic is considered safer than others that contain endocrine-disrupting compounds, such as polyvinyl chloride which is made with phthalates and bisphenol A (BPA) and polycarbonate, which has been shown to release BPA into liquids at high temperatures.
For the new study, Wagner and Oehlmann used both a yeast-based assay and a reproduction test with the New Zealand mud snail Potamopyrgus antipodarum to tease out whether traces of chemicals in PET or other compounds mimic estrogen’s activity. The researchers tested 20 brands of mineral water sold in either glass or plastic bottles or both.
The yeast-based assay of different samples of mineral water showed that more than half the brands of water had “significantly elevated estrogenic activity,” the researchers note. On average, the effects seen were similar to those elicited by a dose of about 18 nanograms per liter of 17β-estradiol (a natural estrogen). For all but one brand, mineral water stored in plastic bottles had higher estrogenicity than the same water stored in glass bottles. And multiuse PET bottles meant to be refilled several times showed lower estrogenicity than the bottles meant for one-time use.
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