“It is not a problem of PM 2.5 dust at all, but a natural phenomenon in the summer which is about to change into the rainy season."
PM 2.5 is not a problem for those that don't breathe often. Oh, and don't worry because in a few months it will all blow off somewhere else. Meanwhile it's perfectly fine to go outside and bike a few km or maybe run a marathon.
OK folks, there's nothing to see here - keep moving along...