Canada’s political parties need to put the issue of toxic waste from the country’s mining industry on their agendas for the federal election campaign, an Ottawa-based environmental group said Monday.

Mining Watch Canada said many Canadian mines and quarries do not disclose the full extent of toxins found in the millions of tonnes of tailings and waste rock they produce.

In 2007, three environmental organizations — including Mining Watch — went to court to try to make federal environmental regulators force full disclosure of toxic substances found in tailings and waste rock.

The Mining Association of Canada (MAC), which represents the industry, said mines do disclose all toxic material discharged into the environment by their processing. The association said the issue of releasing information about tailings is being complicated by the court case.

"It’s their legal action that has prevented resolution of this issue," said Justyna Laurie-Lean of the MAC. "There has been a process going on to resolve this."

Environment Canada changed the rules on reporting pollution discharges from mines in 2006, but the change hasn’t resulted in full disclosure of potential toxins found in tailings and waste rock from mines, according to Catherine Coumans of Mining Watch.

Now, in the run-up to the Oct. 14 election, is the time for political parties to start highlighting the issue, she said.

"The Green Party has picked this up on its website, but we don’t see much else happening," Coumans told CBC News.

Rock from quarries, gravel pits included: MAC

She said that if Canadians knew how much poisonous material was found in mine tailings and waste rock, they would be shocked.

"If it was [fully] reported, it would immediately be the large single source of toxins in Canada," Coumans said. "It would dwarf the amount of toxins produced by municipal waste and all other industries put together."

But Laurie-Lean of the Mining Association said it’s misleading to lump together tailings from all of Canada’s extractive industries, including gravel pits and quarries.

"These are extractive industries for which there is no processing on site," she said. "They produce large quantities of rock and some may have elevated levels of [substances] of concern, some may not."

Since 1998, U.S. regulations have required mines to disclose all potentially harmful substances released by the extraction process, including harmful substances in tailings.

Concern for the environment emerged as the second-most important issue to Canadians in a recent CBC-Environics opinion poll, behind health care.

Federal Environment Minister John Baird said he won’t comment on the specifics of the toxins disclosure issue but he’s happy with the regulations in place now.

"I believe in tough environmental law, aggressive enforcement and public participation and knowledge," Baird said. "Some of that’s done federally and some of that’s done provincially. I think that’s a good thing."

Mining contributes nearly four per cent of Canada’s gross domestic product, and mined natural resources are among the country’s most important exports.