Trace amounts of opioids, including fentanyl, antidepressants and other drugs have been found in freshwater fish in the Waterloo Region, a new study has found.
The study, conducted by a team of University of Waterloo researchers, found several substances that affect the central nervous system in small fish living in rivers that receive urban wastewater.
Mark Servos, a professor in the Department of Biology and Water Institute researcher, told Global News in an interview that questions had been posed by public health officials about whether these substances could be found.
“So we asked, are these compounds that we can measure in the wastewater occurring downstream, getting into the river, and what kind of impact might they have on fish?” he said. “Are they getting into the environment, and what kind of risk do they represent to ecosystems, and particularly fish?”
Using a new analysis method, the researchers, led by Diana Cárdenas-Soracá, a postdoctoral fellow at Waterloo, found male fish had higher concentrations of some substances compared to females.
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Cárdenas-Soracá noted that these substances are being found even though the water, including in the Waterloo Region, is treated. But she added that doesn’t mean treatment facilities aren’t doing a good job.
“They actually have invested a lot of effort in trying to improve their methods and they are doing a very good job on that,” she said. “They get well treated, but still sometimes very small amounts can pass.”
Servos added chemicals such as fentanyl, methadone and others are “very diverse” so they can make it through treatment plants at low concentration. He also said the plants were never designed to deal with the “complexity” of these kinds of chemicals.
He went on to tell Global News that while there is no risk to humans from the traces found on fish, it still can have an impact overall.
“The levels are extremely low, but because fish live in that environment and they essentially breathe it continuously, they could be very sensitive to it, and that could have impairments that can impact our overall well-being as humans,” Servos said. “So we should be vigilant about what we’re putting down sewers because not all of it is going to be treatable.”
Finding pharmaceuticals and other drugs in the environment is not necessarily new, but Servos said this study is different as it’s the first time this “novel group of bioactive chemicals” have been detected in fish and aquatic organisms. The findings of the study can help researchers better understand the risk and develop ways to protect these ecosystems, he said.
Previous research has shown these substances could alter fish behaviour, development and reproduction, but while Cárdenas-Soracá’s study did not specifically look at this factor, Servos said it is being investigated at Waterloo.
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