Globe and Mail
October 21, 2002
A study currently being looked at by the federal government shows Canadian rivers and streams are contaminated with a range of pharmaceutical drugs that present unknown dangers to people and wildlife. Tests of water samples taken near sewage-treatment plants in 14 different cities as well as in open water at various points along the Great Lakes found traces of a number of drugs.
Last week, at a conference of the State of the Lakes Ecosystem in Cleveland, participants assessed the Great Lakes ecosystem using biological indicators. The flow of pharmaceuticals such as painkillers and birth-control pills into the water is becoming an area of "increasing concern" to SOLEC, said John Mills, regional director-general for Environment Canada.
"There are still fairly small trace levels of these pharmaceuticals but it's becoming a bit troublesome. At this point," Mr. Mills said, "it's one of research — of looking at what are those impacts, what are the potentials there, and what are some of the options we can do to address them."
A nationwide study said recently that painkillers, anti-inflammatory drugs and prescription drugs used to treat epilepsy and blood cholesterol were found in waters near sewage-treatment plants across the country.
The study, paid for part by Environment Canada and obtained under the Access to Information Act, confirms suspicions held by some Canadian scientists for many years.
Although European and U.S. research has documented the problem in those jurisdictions, this is the first study to verify its existence in Canada and determine its extent.
"It is an issue. It's mostly through the sewer systems that it's entering the lakes ... and through agricultural runoff. Because we use a lot of pharmaceuticals in our agricultural practices," Mr. Mills said.
The Great Lakes have a larger problem with chemicals flowing into water than other Canadian lakes, because they are surrounded by cities, he said.
"When you have a third of the population in this area, obviously you're getting some concentrations, particularly in some areas."
The contribution of substances into the Great Lakes from the United States to Canada can be as high a ratio as 3 to 1 or 5 to 1, relative to the population, he said.
Pharmaceutical contamination is an area of emerging concern to scientists, Mr. Mills said. In the coming years, they will continue to compile research on the issue, he said. At this point, however, it is not a critical concern because the levels found have been low, in some cases one part per billion and one part per trillion.
Scientists at the SOLEC conference found that the quality of drinking water from the Great Lakes has steadily improved.
"The Great Lakes continue to be one of the greatest sources of drinking water in the world. That's treated drinking water of course," said John Mills.
Scientists at last week's conference also found while the level of toxins have decreased in fish tissue, they have not dropped enough that all fish can be safely eaten.
The scientists also discussed concerns with the cutting down of trees near the Great Lakes.
With fewer trees surrounding the lakes, at times of intense rainfall, sewage treatment plants overflow and bacteria enter the lake directly.
The increasing number of beach closings in the Great Lakes each summer from high levels of bacteria is an issue the scientists want to address.
Mr. Mills said they are looking at ways to better inform the public of the state of the water, so if someone were to go to the beach in the morning they would have an accurate idea of how many bacteria were present in the water.
With reports from CTV's Mark Stevenson
