You have a good point, Trapper. I spend very little time driving or near highways, so hopefully that exposure is limited. However, it does not excuse or let off the hook any cigarette smoker who exposes me to their carcinogens. At least let me make my own decisions as to what and how much I am exposed to. I can count seven family members and friends who have died from lung cancer. Six had smoked for most of their lives. The seventh was a club musician who spent his evenings breathing someone else's cigarette smoke.