Article by: ANDREW MONSERUD , St. Paul Academy
Updated: July 4, 2011 – 11:32 PM
Minnesotans are pretty confident about their water. After all, we have the source of the Mighty Mississippi and more than 14,000 lakes. Why should we worry about water?
But some Minnesotans are worried, and for good reason. Scientists are increasingly aware of pollutants that were unknown or immeasurable just a few years ago. One documented effect has been the “feminization” of fish in the Mississippi River because of estrogen-like chemicals in the water.
Just how worried should we be? The presence of these contaminants in Minnesota’s rivers and lakes is a source of “concern, not alarm,” says Heiko Schoenfuss, one of the leading researchers in the field.
These “contaminants of emerging concern,” or CECs, are getting the attention of scientists and environmentalists because of what we do know, but also because of what we don’t know.
These contaminants are widespread in our rivers and lakes at relatively low concentrations, says Mark Ferrey, an environmental scientist at the Minnesota Pollution Control Agency (PCA). They can cause observable changes in the reproductive organs of some fish.
Schoenfuss, director of the Aquatic Toxicology Laboratory at St. Cloud State University, says we don’t yet know what long-term effects they could have on populations of fish, other organisms, ecosystems and even humans.
Of greatest concern to researchers is a group of contaminants known as “endocrine disruptors,” notably the female hormone estrogen and a variety of man-made chemicals that mimic it.
Naturally occurring estrogen, produced mainly by the ovaries, is the primary influence on the female reproductive system’s development, maturation and function. It is excreted in the urine of humans, all mammals, and many other species. However, it is the widespread use of synthetic, or man-made, estrogen and other estrogen-like chemicals that is triggering scientific concern.
Estrogenic substances can be found in things we use every day, such as detergents, prescription drugs, fragrances, birth control pills and patches, and personal care products such as body wash and shampoo. Hormones are also used in animal food.
These chemicals can get into surface water — rivers, streams and even relatively remote lakes — through the effluent from sewage treatment plants, agricultural runoff, leaching from landfills, and drainage from rural septic systems.