State waters contain chemicals and pharmaceuticals

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Researchers have collected more data that shows how widespread endocrine active chemicals are in Minnesota surface water. It appears these chemicals are found in most rivers and lakes in the state, even in remote locations.

Minnesota Pollution Control Agency scientists are analyzing groundwater to see if these chemicals are also found in aquifers. It will be several months before that research is completed.

Endocrine active chemicals are compounds that might come from detergents, plastics, or pharmaceuticals, just to name a few sources. They can mimic hormones in the body and potentially have a variety of effects.

Minnesota researchers are focusing primarily on fish as they look for these effects.

A recent study by a Swedish researcher found Levonorgestrel, a pharmaceutical progestin used as a contraceptive, causes sterility in frogs.

The study, done at the Department of Environmental Toxicology, Uppsala University found exposure to low levels of the progestin

"severely impaired oviduct and ovary development and fertility."

The study found that after mating, only one of 11 female frogs laid eggs, while all of the females who were not exposed to the drug laid eggs.

The Swedish researchers point out that as several progestins are commonly found in surface water, more research is needed to study the effect on wild frog populations.

Some Minnesota scientists believe the use of DNA micro array technology will offer new insights on how these drugs affect aquatic life. The micro array research lets scientists see which of thousands of genes are switched on or off by the chemicals in surface water.

Minnesota scientists have discovered hundreds of genes in fathead minnows are affected by the endocrine active chemicals in surface water. For example, genes related to the immune system and the formation of red blood cells are changed.

By knowing what functions those genes control, scientists will then be able to focus on specific physiologic systems, like the immune system, or creation of red blood cells to learn what the long term effects are.

Until now, much of the research has focused on how endocrine active chemicals affect reproductive systems. But it appears they could have much broader affects, at least on aquatic species.

Listen to my story Friday on the MPR News program Morning Edition.

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