Fish near treatment sites have drug taint

Fish caught near wastewater treatment plants serving five major U.S. cities had residues of pharmaceuticals in them, including medicines used to treat high cholesterol, allergies, high blood pressure, bipolar disorder and depression, researchers reported Wednesday.

Findings from this first nationwide study of human drugs in fish tissue have prompted the Environmental Protection Agency to expand similar research to more than 150 locations.

“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?” said study coauthor Bryan Brooks, a Baylor University researcher.

A person would have to eat hundreds of thousands of fish dinners to get even a single therapeutic dose, Brooks said. But researchers have found that even extremely diluted concentrations of pharmaceutical residues can harm fish, frogs and other aquatic species because of their constant exposure to contaminated water.

The research was published online by the journal Environmental Toxicology and Chemistry and presented at a meeting of the American Chemical Society in Salt Lake City.

Brooks and his colleague Kevin Chambliss tested fish caught in rivers where wastewater treatment plants release treated sewage in Chicago, Dallas, Phoenix, Philadelphia and Orlando, Fla. Research has confirmed that fish absorb medicines because the rivers they live in are contaminated with traces of drugs that are not removed in sewage treatment. Much of the contamination comes from the residues of pharmaceuticals that people have taken and excreted; unused medications dumped down toilets also contribute to the problem.

They found trace concentrations of seven drugs and two soap scent chemicals in fish at all five of the urban river sites studied.