Yes, and I believe that's a limit of the concept. If you smoke 2 cigarettes on one day, chances are that you are actually a smoker and therefore you fall in th

Yes, and I believe that's a limit of the concept. If you smoke 2 cigarettes on one day, chances are that you are actually a smoker and therefore you fall in the category of people that are more likely to die from cancer. The actual impact of the cigarettes you have smoked isn't really taken into account here, it is the fact that you are likely be a smoker that increases the number of microdeath.