OTTAWA, Ontario — A CBC News investigation found that many Canadian cities’ drinking water is not tested for harmful contaminants, according to CBC.ca.

Out of 18 cities, only Ottawa tested for all 75 substances outlined in the country’s drinking water guidelines, noted the article. The cities were asked to provide a list of health-related contaminants tested in water.

Calgary, Edmonton and Hailfax test for all but one of the substances, stated the article, while Quebec City tests for 62, Regina 52 and Winnipeg 49. Iqaluit and St. John’s test water for 20 contaminants.

Countries like the U.S. have mandatory requirements for water testing, reported the article, and experts believe Canada’s voluntary guidelines should be made enforceable as well. Currently, each province decides the frequency of its municipalities’ testing.

"They should be testing for everything, maybe not all the time, but at least on a periodic basis, rather than never testing for them at all," said Eva Pip, a University of Winnipeg professor specializing in water quality and toxicology, in the article. "There is no such thing anymore as a pristine environment anywhere on this planet.”

The article reports that while some substances may not present an immediate threat, they do present long-term risks, even when present in low doses.

"Many of the chemicals which are of industrial origin could affect the liver, and in some cases they are carcinogens," explained Chris Metcalfe, a Trent University professor in environmental and resource studies, in the article. "They can lead to the development of cancer if we're exposed over a very long period of time."

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