Canada should ban asbestos inside its borders and lobby aggressively to have the chrysotile form of the carcinogenic mineral added to the hazardous substances list of a United Nations treaty, according to a commentary published Monday in the Canadian Medical Association Journal.
The editorial comes as the parties to the Rotterdam Convention prepare to meet in Geneva next week to consider adding products to the treaty, which compels countries that export hazardous substances to clearly label those products as risks to human health.
"We would really like [Canada] to play an advocacy role and actually stand up and say, 'This should be on the list,' rather than just sit back and let others discuss it," said Trevor Dummer, an associate professor in the Cancer Prevention Centre at the University of British Columbia's School of Population and Public Health.
Federal Natural Resources Minister Greg Rickford told the House of Commons last summer that Canada would not fight chrysotile's inclusion in the treaty. The office of Environment Minister Leona Aglukkaq confirmed that position in a statement on Monday.
But the Conservative government is not expected to speak out in favour of listing chrysotile as a hazardous substance.
Canada used to have a robust asbestos industry. As recently as five years ago, Quebec produced about 100,000 tonnes of chrysotile asbestos, but the province's last mine shut down at the end of 2011, after which Canada dropped its opposition to listing the fibrous mineral under the Rotterdam Convention.
When the parties to the treaty last met in 2013, Canada neither opposed nor supported adding chrysotile to the list.
Russia, on the other hand, led the charge to keep it off, something the world's largest asbestos exporter is expected to do again when the parties to the treaty meet May 12, 13 and 14. Substances are added to the list by consensus, so Russia and a handful of other asbestos exporters can block the addition if they choose.
The World Health Organization's International Agency for Research on Cancer classifies asbestos as a serious carcinogen that causes mesothelioma and other cancers, especially in the lungs. Because these diseases have a long latency period – meaning cancer often does not develop until decades after a person inhales asbestos fibres – the deleterious effects of Canada's once widespread asbestos use are expected to be felt for decades to come.
"[Asbestos exposure] has been extremely well studied in dozens and dozens of very long-term studies that allow us to make statements like were made in the [CMAJ] article that there's at least two lung cancers for every case of mesothelioma," said Paul Demers, director of the Occupational Cancer Research Centre at Cancer Care Ontario.
"That's very clear from the literature. There aren't really a lot of areas that are poorly understood about asbestos any more. It is just a matter of moving on to prevention."
A Globe and Mail investigation last year found that asbestos exposure is by far the top on-the-job killer in Canada, with nearly 5000 approved death claims since 1996.
Despite robust evidence that the flame-retardant mineral causes cancer, Canada still allows asbestos-related products into the country, mostly in the form of automobile brake linings, brake pads and some construction materials.
Last year, Canada imported $6-million worth of asbestos products, up from $4.9-million the previous year.
Dr. Dummer said that as those products deteriorate they could release asbestos fibres into the air, posing a risk to the mechanics, construction workers or home renovators who might one day inhale them.
The solution is for Canada to follow the lead of Australia and the European Union and institute a time-specific ban on asbestos-containing products, he said.
"I think we need to acknowledge that there's no safe use," Dr. Dummer said. "A safe and controlled use of asbestos is difficult to achieve. So we would like a policy where we acknowledge that and then we move towards a complete ban of asbestos-related products. I think that's very simple."