Article courtesy of Dene Moore | July 22, 2015 | | Shared as educational material
Illicit drugs, including cocaine and amphetamines from urban wastewater, could be contaminating Canadian rivers and the drinking water we draw from them, a new study finds.
A team of researchers at McGill University tested water in municipal wastewater treatment plants located along the Grand River watershed in southern Ontario. They also tested water downstream from the plant, as well as the raw and treated water from a drinking water treatment plant 19 kilometres further along the river.
These tests showed for the first time that illicit drugs are present in rivers where treated wastewater is discharged.
The researchers found cocaine, amphetamines, MDMA, ephedrine, morphine and opioids, albeit in low concentrations. The study is being published this week in the scientific journal Environmental Toxicology and Chemistry.
The levels of those drugs did not decline further downstream and many were not removed completely during standard treatments meant to clean drinking water.
“We proved what most people expected — that whatever we discharge along with the wastewater we can find in the drinking water,” says Dr. Viviane Yargeau, the lead author and a faculty member in the university’s chemical engineering department.
Previous studies led by Yargeau have shown that legal pharmaceutical drugs are also found in treated wastewater and drinking water.
While the low concentrations don’t cause concern for human consumption, they may pose a risk to aquatic life, Yargeau tells Yahoo Canada News.
“Many of the illicit drugs were not tested for their effect on fish but many pharmaceuticals have been tested,” she says.
That previous research “proved that at these low concentrations there is an effect on the endocrine system or on the behaviour of fish that might affect the fish population and the aquatic environment.”
Yargeau says there should also be concern that as the human population increases, more and more wastewater will be discharged into river systems, which means more and more pharmaceutical and illicit drugs.
“So as a way to protect drinking water sources, we propose better wastewater treatment,” she says.
“We believe that if improvements are made to wastewater treatment plants to protect the sources of drinking water, this will prove a more effective way of dealing with the problem in the long run and would also protect the aquatic environment and all the plants, insects and fish that are found there.”
The McGill team is now working on a more detailed five-year study of wastewater treatment and contamination in Canadian surface water.