Medical scientists dispute geologists’ claims about safety of asbestos
It’s a hot issue in Quebec, where the mineral is a major export product, despite efforts to ban it.
by Daniel Drolet
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| An asbestos mine in Thetford Mines. Photo by the National Institute for Occupational Safety and Health |
An open letter by four geologists from Université Laval reignited a simmering debate about the safety of asbestos – and provoked strong responses from academics at Laval and elsewhere.
Earlier this year, in a letter published in Au fil des événements, the campus newspaper at Laval, the four geologists argued that because asbestos is not one but several mineral substances with different properties, health studies that fail to take this into account are flawed.
Chrysotile asbestos, they wrote, is not as dangerous as amphibole asbestos – a position also put forward by the Chrysotile Institute, a Montreal-based organization whose stated goal is to promote the use of chrysotile asbestos.
The geologists’ assertion was immediately rejected by two other academics at Laval the following week, who argued there is no getting around the fact that asbestos – whether chrysotile or amphibole – has negative health effects.
Asbestos is a fibrous mineral whose ability to resist fire and heat once made it popular in construction and manufacturing. It occurs in six forms, including chrysotile and amphibole. Canada is a major world producer of chrysotile asbestos, and Canada’s production is concentrated in Quebec.
Exposure to asbestos has been linked with lung diseases, notably mesothelioma (a form of cancer) and asbestosis. Because of these health concerns, dozens of countries have banned the use of asbestos. However, Canada continues to mine asbestos and export it to countries where the product is not banned. The Chrysotile Institute continues to advocate its use, arguing that chrysotile asbestos can be handled safely.
Geologists Georges Beaudoin, Josée Duchesne, Tomas Feininger and Réjean Hébert wrote the original letter describing chrysotile asbestos as much less toxic than the amphibole variety. In an interview, Dr. Beaudoin said that people continue to lump all different kinds of asbestos together; anyone who fails to distinguish between the types, he added, is a “charlatan.”
Dr. Beaudoin also said that we handle dangerous products, such as gasoline, every day; we’ve simply found ways to handle them safely. The same is true, he inferred, for asbestos.
“Geologists aren’t seeing any patients,” countered Tim Takaro, an occupational and environmental medicine specialist and associate dean for research at Simon Fraser University’s faculty of health sciences.
Dr. Takaro’s signature was the first on a letter signed by more than 100 scientists from 28 countries appealing to Quebec Premier Jean Charest to stop exporting asbestos to the developing world. The open letter was published in the International Journal of Occupational Environmental Health in April.
“The geologists are correct in saying that asbestos is a very heterogeneous material,” said Dr. Takaro. “This has allowed for a generation of different opinions about the level of toxicity in different types of asbestos. There does seem to be some variation, but there’s no doubt about the carcinogenic or inflammatory properties related to asbestos. And there’s no doubt that chrysotile asbestos is a powerful carcinogen and a cause of asbestosis.”
He added that “the notion that the material can be used safely is false,” and said that by continuing to export asbestos to developing countries, “the new burden of disease is being borne by the most vulnerable nations.”
His view is shared by Yv Bonnier-Viger, professor in the department of social and preventive medicine at Laval and one of the signatories to the open letter in the occupational health journal. He is also one of the two Laval professors who rebutted the geologists’ claims about chrysotile in the campus newspaper. In an interview, he compared asbestos advocates to people who lobby in favour of tobacco products. “A century ago, asbestos did us a great service,” he said. “But now there are alternative products.”
The issue of asbestos continues to be relevant in Quebec because the province is being asked to save jobs by helping the asbestos mining industry, said Amir Khadir, a medical doctor and member of the Quebec national assembly for Québec Solidaire, a party that opposes the continued mining of asbestos. “We’re being asked to commit money to an industry that’s on its deathbed,” he said.
Dr. Takaro of SFU said it’s not uncommon for an industry and its supporters to try to display a problem product in a good light when the industry’s survival depends on it. He said the industry may try to do that by raising doubts about the science that was used to prove there’s a problem. “Science is not often about certain-ties,” said Dr. Takaro. “There’s generally uncertainty in science, and industry tends to exploit that to its advantage.”
Laval geologist Dr. Beaudoin stated that the Chrysotile Institute has not funded his research.
