TORONTO -- The tracking of dangerous radioactive substances in the Great Lakes basin is woefully inadequate given the intensive nuclear activity in the area, environmental and health groups say.

In a letter to the Canadian and U.S. governments on Wednesday, more than 100 organizations called for such substances to be designated as "chemicals of mutual concern."

Such a designation -- recognition that radionuclides are potentially harmful to human health or the environment -- would require governments to develop a strategy for dealing with them with a view to keeping them out of the lakes.

"Radionuclides can have very serious immediate, long-term and intergenerational effects on human and non-human health," the letter states. "There is no level of radionuclides below which exposure can be defined as 'safe'."

Chemicals such as uranium or plutonium -- which can remain toxic for eons -- can cause cancer, birth defects and genetic mutations in both people and animals. Yet despite a surprising amount of activity involving the substances on or near the Great Lakes, a report commissioned by the Canadian Environmental Law Association in support of the designation finds monitoring of the radioactivity is patchy at best.

Study author John Jackson, who notes the lakes are a source of drinking water for millions of Canadians and Americans, said it's high time for the long-standing deficiency to be rectified given that the basin is a "hotbed" for nuclear-related activity.

"With the exception of Lake Superior, our lakes are surrounded by nuclear facilities," Jackson said in an interview Wednesday from Kitchener, Ont. "This isn't something small scale; this is something ringing the basin."

Those facilities -- dozens of nuclear generating stations, fuel-processing facilities, waste-disposal, and uranium mine-tailing sites among them -- all use, store and dispose of radionuclides. At the moment, however, little hard, consistent data is available as to how much radioactive toxins they discharge annually into the lakes.

An International Joint Commission study in 1997 found that keeping tabs on radioactive substances was essentially left to users, resulting in a fragmented approach that included differences in reporting and off-site monitoring.

"This situation has not improved," Jackson writes.

Recent changes under the Great Lakes water quality agreement have allowed the public to nominate "chemicals of mutual concern" to help address gaps in stemming contaminants in the lakes. The environmental law association says the submission around radionuclides is the first attempt by any group to use the process.

The designation would lead to development of a strategy to deal with the substances involving all affected parties.

"For the first time, we could have a real basin-wide discussion," Jackson said.

The issue is taking on increased urgency with a plan by Ontario Power Generation to bury tonnes of contaminated materials deep underground near the shore of Lake Huron -- a proposal currently before the federal environment minister -- as well as an ongoing search for a permanent storage site for highly radioactive spent fuel rods.

"The large number of facilities around the Great Lakes Basin, usually near the shoreline, result in ongoing regular discharges into the lakes as well as a high probability of accidents that release higher amounts of radionuclides," the letter states.

Even though some levels of radioactivity occur naturally, Jackson said every effort needs to be made to minimize any increase.

Signatories to the letter include groups such as the Canadian Association of Physicians for the Environment, Greenpeace, the Council of Canadians and Sierra Club.