Any citations on the numbers? I assume those aren't just the number of smokers who died from lung cancer or something as silly as that. Did you factor in the fact that air pollution kills a lot of people and is also caused by people (and cars as in your example) in different ways, for example by being one of the causes for Cardiovascular diseases(so is smoking, yes) which are the most frequent cause of death? Does pollution kill less people than tobacco? I mean you are saying that it isn't even close so you probably have, but I would not take such statements at face value without more data.