MONTREAL - A federal government plan to transform mountains of asbestos mining waste in Quebec into lush greenery could pose a risk to citizens living nearby, according to internal documents.

Ottawa is digging into tailings in the heart of Canada's asbestos country to see if they could one day yield plants, and even sprout biofuel crops.

The Natural Resources Canada project in Thetford Mines also aims to determine if it's worthwhile to extract minerals buried in the community's waste sites.

But stirring up these mounds, which contain the mineral's carcinogenic fibres, could be hazardous to people in the area, according to internal government documents.

And massive amounts of the waste sit in the middle of Thetford Mines.

"There is the risk of remobilizing chrysotile asbestos fibres during the rehabilitation of the site," said a project document prepared for the Natural Resources Department.

"This could pose a risk to people in the area and the ecosystem."

The documents were obtained by The Canadian Press under the Access to Information Act.

Towering mountains of tailings have long shadowed Thetford Mines, which has been an international leader in asbestos production for decades.

The town proudly called itself the "asbestos capital of the world" before science discovered that the substance poses serious health risks to humans.

In recent months, Canada's controversial asbestos industry has become the target of a mounting, international anti-asbestos campaign.

Health professionals and anti-asbestos activists from around the world have spoken out against Canadian asbestos exports -- the majority of which are shipped to developing countries.

The World Health Organization blames asbestos-related diseases for 90,000 deaths annually around the globe.

But in Canada the Conservative government has stood by the dying industry, insisting that asbestos is safe when handled properly.

Through the Thetford Mines studies, Natural Resources Minister Christian Paradis is trying to paint the piles of grey asbestos tailings a shade of green.

Paradis, whose riding encompasses Thetford Mines, announced two feasibility studies last summer -- at a total cost of $600,000.

The projects are funded by Ottawa's $8-million green mining initiative, which aims to improve the sector's environmental performance and create green economic opportunities.

In Thetford Mines, one study will assess the fertility of the mounds, while the other will identify minerals of "economic interest" still locked inside.

Briefing documents addressed to Paradis show the government is mulling a third project to convert the waste sites into agricultural land for biofuel crops.

But the internal lab report stresses that more scientific information is needed before any vegetation projects can proceed.

"At this point there appears to be minimal ecological risk associated with the site as it currently exists," the document said of the piles of tailings.

"However, it is unclear at this stage to what extent the site has been studied from an ecological perspective."

The province has already made unsuccessful efforts to grow plants on the hills of tailings in Thetford Mines, the town's mayor says.

But Luc Berthold hopes Ottawa will succeed.

"I think that would be a nice project," said Berthold, who estimates the total amount of tailings around Thetford Mines to be in the hundreds of millions of tons.

Still, Berthold sees benefits in the town's mounds, which he says have become tourist attractions.

"It's charming for some visitors," he said.

"I find it's what sets us apart. We're always looking for ways to be different."

Berthold is more interested in the value of the minerals, such as magnesium and nickel, believed to be stored inside the mining waste.

Mining in Thetford Mines has suffered significant decline over the decades. It was home to 5,000 miners when the asbestos industry peaked in the 1970s, but today there are only 450, he said.

"We see this (mining) waste as a bank account," said Berthold, adding it has become a regional priority to mine the mounds.

"It could give our mining sector a second life."

Berthold has no concerns about disturbing asbestos fibres in the mounds, a process he said would be handled with care to protect workers and citizens.

People in town are no more at risk to asbestos exposure than anyone else, he said.

One vocal opponent of Canada's asbestos industry, which is now confined to operations in Thetford Mines and the nearby town of Asbestos, said extraction could be an option as long as precautions are taken to protect workers.

Yv Bonnier-Viger also believes that planting vegetation on the mountains is a good idea.

He estimates that asbestos fibres make up at least 10 per cent of the tailings sites.

"(Vegetation) would stabilize the piles," said Bonnier-Viger, a physician and community health expert from Universite Laval.

"That would prevent erosion and the dispersion of asbestos residue . . . because there's a lot of it."