When I went to the Jeffrey Mine in Asbestos on assignment seven years ago, it was operating sporadically, with a skeleton staff. (During my visit, the owner of the mine proudly pointed out that most materials used in its office building, including the wall boards, were made from asbestos.) While seemingly on life support, the mine still had enough political sway to get a $58 million loan guarantee from the province. But a plan to finish construction of an underground mine to replace Jeffrey’s vast open pit didn’t work out, and asbestos mining ended in Canada in 2012.

Canada’s new ban has some exceptions. Companies will still be allowed to process the mountains of tailings from Quebec’s mines to extract magnesium, even though about 40 percent of those leftovers contain asbestos. And some highly specialized products containing asbestos, including fittings for nuclear power plants, will remain on the market. Ms. de Leon would like to see those phased out promptly.

More broadly, she said, much work remains to ensure that the asbestos Canadians remove from schools, hospitals, offices, factories and houses is properly disposed of. Ms. de Leon, along with the Canadian Cancer Society, wants Canada to create a national registry of buildings containing asbestos — and an agency to deal with the deadly legacy.

Devastation from last month’s tornadoes in Ontario and Quebec hinted at the challenge ahead. Beyond the destruction of property, there was another concern: possible asbestos exposure from the damaged homes and apartments.

Marijuana in the Mainstream

As readers of this newsletter who live in Canada know well, Wednesday was the first day of legal recreational marijuana sales in the country. We put together a special edition of the Canada Letter to gather up our coverage to that point. Here’s a link in case you missed it:

[Read: The Legal Cannabis Experiment Begins: The Canada Letter]

More in-depth looks at issues surrounding legalization will appear over the next few days. Until then, be sure to watch our short video about Day 1.