Half of a group of homes in Thetford Mines, Que., had levels of asbestos high enough that, if the same concentrations were detected in U.S. schools, students wouldn't be allowed inside the buildings, says a study published today in the International Journal of Occupational and Environmental Health.
The Quebec community is the center of Canada's asbestos mining industry, and the study concluded that the cancer-causing mineral is drifting into homes from the large piles of mine waste that dot the area.
The majority of the houses with high readings were either downwind of a mine-tailing pile or close to one. The testing also found elevated asbestos readings on a windowsill and in soil around homes.
"If these houses were schools in the United States, they would be shut down until effective corrective measures were taken to bring dust levels below [standards]," the study said.
The testing was conducted by a Montreal-based activist group, the Asbestos Victims Association of Quebec.
The group took air samples from 26 homes in 2003 and 2004, and submitted them for evaluation at an accredited U.S. laboratory.
Thetford Mines has a population of about 26,000, so the testing represented a relatively small percentage of homes in the community, located in south-central Quebec. But one of the study authors said he suspects asbestos exposure is widespread.
"The mining towns are completely contaminated because they have mountains of pilings that are totally and constantly off-gassing asbestos dust," said William Charney, an industrial hygienist in Vermont. Mr. Charney said he believes residents face "a huge public health crisis" from asbestos exposures.
The Quebec Ministry of Environment referred questions to the Institute national de santé publique du Québec. A 2004 report the public health agency commissioned concluded that ambient asbestos levels in mining areas were "generally very low," based on industry testing.
But Mr. Charney said measurements should be done by an independent third party not related to the mining industry or the Quebec government, which promotes asbestos use.
Asbestos, a wool-like mineral, is a hazard when its microscopic fibers are inhaled. It causes lung cancer, a debilitating breathing difficulty known as asbestosis, and mesothelioma, a rare cancer in the lining of the chest wall. Quebec has some of the highest rates of mesothelioma in the world, according to the Institute national: Among men, it is 30 per cent higher than the Canadian average and, among women, 90 per cent higher.
The World Health Organization says there is no known safe exposure level to the material. Several dozen countries have completely banned its use; others tightly regulate it.
The dangers of asbestos have led to strict limits on workplace exposures, but legal standards for homes don't exist, so the study used the U.S. figure for school asbestos remediation. The most contaminated house had a level nine times the school safety limit, and 13 of the 26 houses were over the limit.
A U.S. Environmental Protection Agency official, who has seen the new study and is involved in a major asbestos cleanup, said he was alarmed by the findings.
"I know one thing. If I lived in that community, I'd move," said Mike Cirian, EPA remediation project manager in Libby, Mont., where about 900 homes and other properties are being cleaned up in a $200-million (U.S.) effort to reduce asbestos contamination from a now-closed mine.
Mr. Charney said that, based on the study results, Thetford Mines "without any question" should also be considered for a cleanup.