all secondary smoke is harmful but this stray smoke may be quite diluted. get this idiot to smoke further away from your home. where no one will smell it or by forced to tolerate it. better yet. encourage him to stop smoking or take it somewhere else.
smoking on the porch? . my friend smokes on the porch and my porch has a big roof over it i open the upstairs window with a fan in the window blowing outwards. will it come near the upstairs window and come inside and be harmful? . i'm never near him when he smokes.