Experts say a one-time exposure to asbestos, such as that experienced in the area around the Sunrise Propane blast, is unlikely to raise an individual's cancer risk.
"People need to know if they inhale a little, it's not game over," said Mark Smith, a senior consultant with GTA Environmental. "It's not like a poison gas."
The Ministry of Labour and the Ministry of the Environment both identify low levels of asbestos exposure, which they deem acceptable, he said.
"I've heard some of the crap on TV, 'one fibre will kill, two fibres oh, we don't know ...' " said Paul Bozek, a professor from the University of Toronto's school of public health. "[But, in fact,] you are allowed to breathe in tens of thousands if not hundreds of thousands of fibres a day and your chances of getting cancer are next to none."
Even if Toronto experts find that there were very high asbestos levels in the air for a few hours after the explosion, he said, there is no data to say that a one-time intense exposure to asbestos will cause cancer or asbestosis in 20 to 40 years.
"Nobody really knows if that kind of exposure would lead to cancer," he said.
Prof. Bozek said that in his view, a more real risk would come from weeks' or months' exposure to asbestos that's still lying around, getting ground up underfoot, and thus becoming airborne and dangerous.
"If [residents] were exposed to that over the next couple of months, then there would be slight elevations in cancer rates around there," he said.