Baylor University researchers have found the residue of three new human medications in fish living in the Pecan Creek in North Texas.
The pharmaceuticals, which have not been previously identified in fish, include diphenhydramine, an over-the-counter antihistamine also commonly used as a sedative in non-prescription sleep aids and motion sickness; diltiazem, a drug for high blood pressure; and carbamazepine, a treatment for epilepsy and bipolar disorder. Residue of norfluoxetine, the active metabolite of the antidepressant fluoxetine, was also detected in this study, confirming results of a previous project by the researchers.
“These results demonstrate the increasing need to consider bioaccumulation of emerging contaminants in the environment,” said Dr. Kevin Chambliss, an assistant professor of chemistry at Baylor, who is a co-lead investigator on the project. “This research proves fish are being exposed to multiple compounds in our waterways.”
Like many rivers across the country, most of the water in Pecan Creek is effluent from an upstream wastewater treatment facility. While fish are typically seen as early warning signals for larger environmental issues, even human health, the data suggests there is not a human health concern. However, exposure to the compounds may produce adverse effects in fish. For example, high levels of antidepressants, like fluoxetine, in fish are known to cause behavioral changes, which impact aggression, feeding rate and other behaviors necessary for fish survival.
“The effects of these three new compounds on fish are still not well understood, but it could be important to an emerging area of science,” said Dr. Bryan Brooks, an assistant professor of environmental and biomedical studies at Baylor who is an environmental toxicologist and a co-lead investigator on the project. “The pharmacological properties of these compounds in humans will likely provide an indication of their specific effects in fish.”
Although treated wastewater may meet current federal testing standards, no guidelines or federal water quality criteria exist for pharmaceuticals, Brooks said.