An article in the Orange County register presents a smoker who is also a smog technician. Compared to the emissions from the tailpipe of a car, the smoker is "a gross polluter." In fact, while cars only emit about 200 micrograms of fine particle mass per mile driven, a smoked cigarette emits about 10,000 micrograms. What does this mean for people riding inside a car with a smoker? You can explore this issue using the simulations available on this website.