Well I dont believe that the actual work out is giving me cancer but enviroment may well be.
You see I work in Midtown Manhatten and I live in Brooklyn so as Part of my Work Out I walk as far as i can until I hit water which takes a long time but is fun and gives me a great feeling of accomplishment to cover almost five miles (and Im working my way up to walking all the way home) the only problem is the smokers!!
It seems I walk down wind from every smoker on the west side. I'm usually fairly tolerant of smokers (maybe I shouldnt be but I understand addiction so...) I realize that outside is probably the best place for them to smoke if they must but its so hard to be sympathetic of such an unhealthy habit when people are blowing smoke in your face! I swear I have lost some sight in my left eye because it keeps getting smoke directly blown into it.
I realize the limited exposure I get on my walks probably isnt enough to cause cancer or even blindness and I do love my walks but I just needed to vent.
If it makes you feel any better, I just read that you are exposed to far more pollutants while riding in a car than you are walking. For what it's worth which isn't much, I know)...