Thetford Mines was founded in 1876 after the discovery of large asbestos deposits in the area, and the city became a hub for one of the world's largest asbestos-producing regions. Over 26,000 residents live in the area, located just over 100 kilometres south of Quebec City.
The exploratory sample report, published in the International Journal of Occupational and Environmental Health, documented levels of asbestos inside and outside 26 private residences in the community that significantly exceed internationally accepted limits.
"The population at large in these towns are at an elevated risk of developing asbestos-related diseases," said William Charney, an American occupational health expert and the study's lead author.
Such diseases include lung cancer, mesothelioma — a cancer of the lining of the chest and the abdominal cavity — as well as asbestosis, a chronic breathing disorder in which the lungs become scarred with fibrous tissue.
The symptoms of these diseases do not usually appear until about 20 to 30 years after the first exposure to asbestos. Richard Rousseau, founder of the Asbestos Victims Association of Quebec (AVAQ), helped the researchers with the study. His father, Hervé Rousseau, a retired miner, suffers from pleural plaque disease, a hardening of the membrane around the lungs.
During his childhood, the younger Rousseau, now 56, recalled how dust from the mines covered the lawns, the houses and everything else around the town.
Rousseau told CBC News that he recently lost an old school friend to an asbestos-related illness, which made him worry about his own health.
"Maybe my time is coming," he said.
Another resident, Diane Lapointe, looked at the last photo taken of her mother before she died of mesothelioma last year. Her mother grew up in Thetford Mines but left when she was 23.
Lapointe said she believes the industry has made many people sick, including those like her mother who never worked in the mines themselves.
Most people in the area don't want to talk about it, she said, because too many jobs depend on asbestos.
"They say it's keeping the town alive," Lapointe said. "But I think it's killing a few people, too."
The contamination isn't as visible these days, but the asbestos residue piles still rise like mountains all around the town. Young people riding bicycles and off-road vehicles on the piles said they've been playing there since they were small children.
"For me it's sand like anywhere else," said Nicholas Daigle, 22, whose clothing was covered in residue.
The study's lead author said he believes the youngest members of the community are particularly threatened.
"Children are the population most at risk from these public health exposures because of the time it takes for asbestos disease to develop," Charney said. "So the younger you're exposed, the higher the risk."
It was in 2004, a group of American and Canadian occupational health researchers sampled air, soil and dust in dozens of homes in the community and they found more than half of the 28 air samples contained asbestos fibres exceeding U.S. government safety limits.
The study concluded that residue piles and dust blowing off trucks carrying residue appeared to be among the major sources of asbestos contamination in the homes.
A majority of the 14 soil samples taken from lawns and a playground contained far more asbestos than considered safe, the group said.
"The findings of the air, soil and dust samples lead us to conclude that the residential environment in areas near Thetford Mines are severely contaminated by asbestos," the report concluded.
The authors said they hope the study will prompt the Quebec government to conduct its own tests to confirm their conclusions and take action to protect the town's residents.
Both the Quebec and federal governments have long argued asbestos from Thetford Mines is much safer to use than other types — a view opposed by virtually every international health agency.
Canada and Quebec have spent more than $40 million in recent years to promote exports of asbestos, almost all of which goes to developing countries.
According to the World Health Organization, there is no acceptable level of asbestos dust that does not constitute a risk of cancer.
Dr. Richard Lemen, a former U.S. assistant surgeon general who has been a vocal opponent of asbestos for nearly four decades, said the people in Thetford Mines deserved immediate help.