Zombies, Ahoy! Endocrine-Disrupting Pollutants, Broken Up By Sunlight, Can Reform Themselves

Hormone-disrupting chemicals may be far more prevalent in lakes and rivers than previously thought. Environmental scientists have discovered that although these compounds are often broken down by sunlight, they can regenerate at night, returning to life like zombies.

“The assumption is that if it’s gone, we don’t have to worry about it,” says environmental engineer Edward Kolodziej of the University of Nevada in Reno, joint leader of the study. “But we’re under-predicting their environmental persistence.”

“Risk assessments have been built on the basis that light exposure is enough to break down these products,” adds Laura Vandenberg, an endocrinologist at the University of Massachusetts in Amherst who was not involved in the study. “This work undermines that idea completely.”

Endocrine disruptors — pollutants that unbalance hormone systems — are known to harm fish, and there is growing evidence linking them to health problems in humans, including infertility and various cancers1. But pinpointing specific culprits from the vast array of trace chemicals in the environment has proved difficult. Indeed, concentrations of known endocrine disruptors in rivers often seem to be too low to explain harmful effects in aquatic wildlife, says Kolodziej.

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http://www.nature.com/news/hormone-disruptors-rise-from-the-dead-1.13831