My personal take on this is that it is less of a problem in Tokyo and the other places in the Pacific side. But I would like to here direct feedback from those who live along the Japan Sea coast.

I have been to Amano Hashi Date, where some people said they get a bit of junk in the sea. As for the smoke, it is mostly seen in Western Japan (Osaka can have a bit, too). Since we hear that China too is taking the problem seriously, let's hope that things will improve.

I don't think there is anything to worry about. I guess you would likely want to ask someone who have professional work/experience with the issue. I am not even sure how they rate pollution these days.