I'm sure I read somewhere that living in london the air pollution is equivalent to smoking 150 cigarettes a year.
Ffp3 masks if it gets bad.
My first trip to Bangkok years ago I thought it was a good idea to walk in the first heavy down poor of the year and couldnt work out why I was getting odd looks. Turns out that the first rains bring down alot of pollution and in the past people have had bad skin and eye irritations.
Live and learn.