Wednesday, March 25, 2009

Your Fish Dinner Contains More Than Just Omega-3s

Photo courtesy of Discovery website.

A short while ago, I did a blog on all those lovely little extras that get into our water supply. Delights such as insecticides, pesticides, prescription medications, toxins: in short everything we let enter our sewer system, flush down the toilet or allow to soak into our earth.

To the surprise of no one (who thinks anyway), researchers have announced that fish caught near wastewater treatment plants serving five major US cities had residues of prescription medications in their tissues. This included; but, was not limited to various medications used to treat high cholesterol, allergies, high blood pressure, bipolar disorder and depression. (I think my water's been looking a little cloudy lately!!)

"The average person hopefully will see this type of a study and see the importance of us thinking about water that we use every day, where does it come from, where does it go to? We need to understand this is a limited resource and we need to learn a lot more about our impacts on it," said study co-author Bryan Brooks, a Baylor University researcher and professor. He has published more than a dozen studies related to pharmaceuticals in the environment.

Brooks maintains that a person would have to eat hundreds of thousands of fish dinners to get even a single therapeutic dose. However, researchers including Brooks, have found that even extremely diluted doses of medication harm fish, frogs, and other aquatic species due to their constant exposure to the contaminated water.

Brooks and his colleague, Kevin Chambliss, tested fish caught in rivers close to the wastewater treatment plants release sites in Chicago, Dallas, Phoenix, Philadelphia and Orlando, FL., and compared them with fish taken from New Mexico’s pristine Gila River Wilderness Area, an area free from human pollution.

Much of the contamination comes from medication that the body has not metabolized and excretes; and/or, medications that have been flushed down the toilet. Earlier research has already established that fish absorb the medicines (and other pollutants) because sewage treatment plants do not remove 100% of toxic residues.

The researchers tested for 24 different pharmaceuticals as well as 12 chemicals found in personal care products. They found 7 drugs and 2 soap scent chemicals in fish from all five of the urban river sites. The amounts of chemicals found varied; but, some of the fish had many different compounds in their liver. The reference fish caught in rural New Mexico had no such chemical residues found anywhere in their bodies.

Trace concentrations of numerous pharmaceuticals have been detected in the drinking water of at least 46 million Americans. I would suspect the numbers are similar in Canada, Europe, UK and other developed countries. Limited laboratory studies have shown that human cells failed to thrive or assumed unusual shapes when exposed to combinations of some pharmaceuticals found in drinking water.

"This pilot study is one important way that EPA is increasing its scientific knowledge about the occurrence of pharmaceuticals and personal care products in the environment," said EPA spokeswoman Suzanne Rudzinski.

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