Drugs in fish: Pharmaceuticals found in fish caught near North Side sewage treatment plant in Chicago area
Thu 26 Mar 2009 04:33
By Michael Hawthorne
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Prescription drugs used to treat depression, high blood pressure, seizures and other ailments are turning up in fish caught downstream from a Chicago sewage treatment plant, according to a new study that highlights some unintended consequences of our medicated lives.
Little is known about the potential effects of drugs in the water on people and wildlife. But scientists and regulators increasingly are concerned about long-term exposure, even at very low levels.
In the largest project of its kind, researchers from Baylor University in Waco, Texas, found trace amounts of seven different pharmaceutical drugs in fish caught near the North Side Treatment Plant at Howard Street and McCormick Boulevard in Skokie. They recorded similar results near sewage plants in Dallas, Orlando, suburban Philadelphia and Phoenix.
The findings echo earlier testing by the Tribune and scientific researchers that found small amounts of pharmaceuticals in the drinking water of Chicago and dozens of other cities. Federal environmental regulators have ordered a sweeping expansion of their own assessments of pollution contaminating rivers.
"There are a lot of unanswered questions out there," Kevin Chambliss, one of the Baylor researchers, said Wednesday. "We just don't know what it means yet ecologically, but this shows there's a need to know more."
Pharmaceuticals end up in drinking water—and in fish—when people take medications and residue passes through their bodies into the sewers. Conventional sewage and drinking water treatment filters out some substances, or at least reduces the concentrations, but multiple studies have found that small amounts get through.
Earlier studies by Chambliss and others found that medicines are absorbed by fish and accumulate in livers and other tissue. The new peer-reviewed study, published online Wednesday by the journal Environmental Toxicology and Chemistry, is the first to report such findings across a broad swath of the nation.
Among the medicines that the researchers discovered in fish are norfluoxetine, an anti-depressant; diltiazem, a medicine prescribed to control high blood pressure, and carbamazepine, an anti-seizure drug. They also found medication used to control high cholesterol and allergies, along with an anti-bacterial chemical and two fragrances found in soaps.
Treated sewage from the Chicago area is pumped into the Chicago River, which was reversed during the last century to flow away from Lake Michigan, the source of most of the region's drinking water. The river isn't a major draw for anglers, but recreational fishing is not uncommon.
Testing by the Tribune last year turned up small amounts of pharmaceuticals in the region's treated drinking water, a sign that drug residue is commonly found in the lake too.
As more studies have found pharmaceuticals in drinking water and in wildlife, regulators are reversing their long-held advice that people should flush unused or old drugs down toilets.
The Metropolitan Water Reclamation District has begun monitoring for pharmaceuticals.