Photo by University of Exeter.

Imagine if your body could tell you where and when a certain chemical is impacting your health. Scientists at the University of Exeter have done just that — with green-glowing zebrafish, that is.

Researchers genetically engineered young zebrafish to produce a fluorescent glow in the presence of hormone-disrupting chemicals like bisphenol-A. By exposing fish to endocrine disruptors and observing when individual body parts light up, researchers can learn exactly how and at what concentrations these chemicals impact various organs and tissues. They can then make certain inferences on how endocrine disruptors impact human health.

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For instance, observing the glowing fish confirmed previous findings, such as a link between bisphenol A and heart problems.

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“We do see in this fish that the heart glows particularly in response to bisphenol A,” Charles Tyler, the study’s leader, said. “So we can target the heart and try to look at the mechanics of what is happening.”

They’re already finding out new things, too: It’s generally assumed that endocrine disruptors impact specific organs like the liver, ovaries, and testes. But University of Exeter scientists say they’ve observed endocrine disruptors in a variety of tissues, including the eyes and brain.

It’s an important study because endocrine disruptors are quite literally everywhere, from plastics to credit card receipts to household cleaners to the water we drink. It was long assumed that only high levels of exposure to endocrine disruptors would harm humans, but increasing evidence suggests that even low levels of exposure can cause cancer, obesity, diabetes, and other health problems.

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Now if only human body parts could give off a glow whenever something was amiss inside …