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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