Bottled water may contain ‘hormones’: Glass

Researchers in Frankfurt, Germany, have just reported evidence suggesting that estrogen-mimicking chemicals can leach out of certain plastic bottles. Disturbing as that is, their data indicate that the mineral water dispensed in some glass bottles may also contain such hormonelike pollution — and not because it leached out of the glass.

This would mean the water was polluted prior to bottling. Several scientists now suspect one source might be the plumbing used to move water from natural reservoirs to — and/or through — processing equipment in a bottling plant.

Polyvinyl chloride tubing, for instance, is widely used by industry. So if mineral water were pumped through PVC piping it could pick up bisphenol-A, organotin and phthalates — “because [PVC] is a source of all those,” notes Shanna Swan, an environmental epidemiologist at the University of Rochester School of Medicine and Dentistry. And, she adds, all of these materials that have been found in PVC have an estrogenic alter ego.

Polycarbonate plastic is also used for industrial tubes and piping, notes endocrinologist Ana Soto of the Tufts University School of Medicine in Boston. The basic building blocks of that plastic are molecules of bisphenol A, a compound that her team has established to be a potent estrogen mimic.

Soto recalls an anecdote from a few years back, when she was just beginning to collaborate with someone new in scouting for potential hormonelike pollutants in Massachusetts Bay. “I recommended that the guy send the water out for extraction to an EPA-certified lab,” she says. “But he told me no. I’m a chemist. I can do this.” So she suggested processing a few clean samples first. She’d then screen them for contamination.

Sure enough, she recalls, the first few samples he sent were laced with “stratospheric estrogens.” Chagrinned, the researcher substituted a plastic filter and the next samples came back estrogenfree. Soto says she’s found out the hard way that unless a liquid is kept in glass or ceramic containers, it risks coming into contact with some estrogenic mimic as it travels through pipes, is filtered or heated.

Phthalates, a widely used class of volatile industrial solvents and plasticizers, also can taint water or any other material — outdoors or in a bottling plant, Soto notes. Another potential source of waterborne “hormones”: excreted drugs. Many of the ones that are known to taint water supplies can turn on estrogen receptors in the body.

Concludes Soto, “We live in a soup of ‘estrogens,’ if you will, which we can acquire from almost anywhere.” This complicates our food choices, she says, because people seldom know what upstream contaminants have contacted our foods and beverages before we’re given the choice: Plastic or something else?

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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