The Economist just published a list of the cities with the dirtiest air in the world’s largest economies. But that’s nothing, until you look at the source database from the World Health Organization, which I managed to find for download here. Find your city and compare it to others. I was staggered to find Montreal as Canada’s most polluted city, despite being global leaders in hydro power. The USA has pretty good air quality in just about every city including the giants of NY, and LA.