Change will come. And not to be all Toronto-centric but the dense big cities need the fresher air sooner... remember Toronto's most popular nickname used to be "the big smoke" and smog alerts and yellow / brown air used to be the norm throughout our muggy summers. But things in Toronto have dramatically improved in my lifetime, as we focused on reducing pollution especially from passenger vehicles.
In fact now that gasoline cars as so much more efficient (eg. my last gas car's Carbon Monoxide emissions were zero) my biggest concern for fresh air is from diesel vehicles. Plumes of diesel smoke are literally made of disgusting carcinogenic filth.