[Baylor University press release below]
Anti-depressant ingredients found in animals downstream of sewage plant.
Geological Society of America Meeting, Seattle, November 2003
A new study adds to evidence that drugs in the waste flowing from sewage-treatment plants is ending up in fish.
Three species living downstream of a water-treatment plant in northern Texas had accumulations of the active compounds in two popular antidepressants in their brains, livers and muscles, says Bryan Brooks of Baylor University in Waco, Texas.
Brooks tested bluegill, black crappie and channel catfish for Prozac's active ingredients - fluoxetine and norfluoxetine - and for sertraline and norsertraline, found in Zoloft. "We detected all of the compounds in every tissue of the fish we tested," Brooks told the annual meeting of the Geological Society of America in Seattle, Washington, this week.
Highest levels were in the fish's brains and livers. The muscles commonly eaten in fish fillets had much lower levels. "You'd have to eat a lot of fish to get a therapeutic dose of these compounds," says Brooks.
Researchers at the University of Georgia in Athens are working on how the drugs could be affecting the fish, and those who eat them.
In the United States, at least, water-quality standards do not regulate pharmaceuticals in reclaimed waste water. With water reclamation becoming increasingly important in the country's arid western states, drug compounds could become more widespread in rivers and streams.
Brooks plans to study more fish species, more streams and more pharmaceuticals. He suspects that interactions between such drugs might be an even bigger problem. "The chance that a number of compounds are occurring as a kind of drug cocktail is more likely," he says.
source: http://www.nature.com/nsu/031103/031103-8.html 8nov03
Pharmaceutical contaminants found in tissues of fish caught downstream from urban areas in a north Texas river could cause behavioral changes in fish that impact their ability to survive, according to research by a Baylor University toxicologist.
Dr. Bryan Brooks, an assistant professor of environmental studies at Baylor's Center for Reservoir and Aquatic Systems Research, has measured fluoxetine, an ingredient in antidepressants, in fish from Pecan Creek, north of Dallas. Fluoxetine is not controlled by EPA regulations for treated wastewater.
Antidepressant accumulation in the fish can cause behavioral changes, which impact aggression, mating and other behaviors necessary for fish survival.
Although treated Texas waters may meet current federal standards, Brooks said no guidelines or federal testing standards exist for pharmaceuticals because their effects in surface waters are not well understood.
The flow of the Trinity River south of Dallas and Fort Worth is greater than 90 percent dominated by wastewater releases. Wastewater refers to water that has been treated and released downstream from urban areas.
In lab and artificial stream studies, Brooks has observed the effects on fish and invertebrates of another class of pharmaceuticals, the active ingredients in birth control medications. Male fish exposed to estrogen have been shown to develop female physical characteristics and lose the ability to reproduce.
"At critical exposure levels, some fish can't reproduce at all, and some have both male and female sexual characteristics," Brooks said.
Another concern Brooks expressed is how the substances may affect humans who eat the fish. “If substances accumulate in fish tissue, and humans ingest them through fish, we don’t know if they’ll be affected,” Brooks said. He added that exposure appears to be below therapeutic levels, but the issue calls for more research to understand the responses of aquatic organisms to pharmaceutical exposures.
Brooks will present his findings at the annual meetings of the Society of Environmental Toxicology and Chemistry (SETAC) in Austin and the Geological Society of America (GSA) in Seattle in November.
For more information, contact Bryan Brooks at (254) 710-6553 or Bryan_Brooks@baylor.edu
source: http://pr.baylor.edu/story.php?id=4646 8nov03
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