(NaturalNews) Fish from 5 effluent-heavy rivers in various parts of the U.S. have been found to be tainted with residues from human medications and common chemicals, according to the results of a study by the U.S. Environmental Protection Agency (EPA) and Baylor University. The study's findings were presented on March 25 at the National Meeting of the American Chemical Society in Salt Lake City, and are part of a federal strategy to address the effects of pharmaceuticals and personal care products (PPCPs) on the environment and wildlife.
"While this study found the residue of several pharmaceuticals and personal care products in fish tissue, it also demonstrated for the first time that fish from several different locations across the country are exposed to multiple PPCPs in effluent-dominated waterways," said Dr. Bryan Brooks, associate professor of environmental sciences at Baylor, one of the lead investigators on the study.
The fish collected for the study were retrieved from discharge areas of wastewater treatment plants in Chicago, Dallas, Orlando, Fla., Phoenix, and West Chester, near Philadelphia. The Gila River Wilderness Area in New Mexico was used as a reference site for the study because it is does not contain pollution from human sources.
36 different medications and chemicals were tested - 24 different human medications and 12 common chemicals - on fish fillets and liver tissue. Residue from seven pharmaceuticals and two personal care products was detected in fish from all five rivers, and in many cases, multiple residual doses were found in the same fish. Significantly, the cholesterol drug gemfibrozil (Lopid) was for the first time detected in wild fish.
Other substances that tested positive in the study included diphenhydramine (a common antihistamine and sedative), diltiazem (Cardizem, a blood pressure medication), carbamazepine (Tegretolan, an epilepsy and bipolar drug), norfluoxetine (an active ingredient in Prozac), the antidepressant sertraline (Zoloft), and two odor-enhancing ingredients in soap and hygiene products.
In contrast to the 5 rivers where the drug and chemical residues were found, no residues were detected in any of the fish collected at the reference location in New Mexico.
"We found the highest concentrations and frequencies of compounds in the fish livers but considering that the liver is the primary site of metabolism for xenobiotics in fish, as in humans, this result is logical," explained Dr. Kevin Chambliss, a Baylor co-lead investigator with Brooks.
In addition to the Salt Lake City presentation, the findings are set to be published in a special on-line edition of Environmental Toxicology and Chemistry dedicated to PPCPs found in the environment.
The results echo earlier tests done by the Chicago Tribune and scientific researchers in 2008. In those studies, small amounts of pharmaceuticals were found in the drinking water of Chicago and dozens of other cities. Chambliss noted that the far-reaching effects, if any, are unknown. "We just don't know what it means yet ecologically, but this shows there's a need to know more."
The results are part of a pilot study funded by a contract from the EPA with Tetra Tech, a leading provider of consulting, engineering and technical services. According to their website, Tetra Tech provides "scientific, consulting, engineering, and project management services for water resources, groundwater, watershed management, mining, geotechnical, environmental management, and information technology projects."
Fish collection for the study began in 2008 and continues in 2009.