Calgary Sewage Probed for Drugs
Calgary city workers will measure levels of prescription and non-prescription drugs in sewage effluent after tests showed the drugs could pose threats to wildlife.
A study, paid for in part by Environment Canada, showed the presence of drugs in Canadian rivers, streams and sewage effluent near treatment plants, including Calgary. Some of the drugs scientists found were small levels of Aspirin, Tylenol, cholesterol-lowering drugs, antibiotics, anti-depressants and birth-control pills.
The levels of concentration were very low, measuring one part per billion and even one part per trillion.
Mark Servos, a research scientist at the National Water Research Institute, said scientists there have duplicated the study's results.
"Birth-control pills can have dramatic impact on reproduction in aquatic animals. (Antidepressants) can affect the spawning behavior in invertebrates."
Most of the drugs enter the sewer system through human waste -- they are flushed down the toilet.
Only recently have scientists developed the technology to measure the drugs. Now they will work toward determining the impact on wildlife and human health.
Wolf Keller, the city's manager of strategic services for Calgary wastewater, said staff has been collecting samples at the Bonnybrook and Fish Creek treatment plants.
"We're trying to determine how much is coming out of the plants," Keller said. "Then we will go from there."
The study was headed by Chris Metcalfe at Trent University in Peterborough, Ont. His research showed that drugs could alter the balance of hormones and affect cell function in fish.
It has been submitted for peer review but has not yet been published.