deaths attributable to marijuana overdose versus deaths related to tobacco

http://www.huffingtonpost.com/entry/marijuana-deaths-2014_56816417e4b06fa68880a217?ncid=fcbklnkushpmg00000021§ion=crime&te=Newser OK, it's somewhat confusing as to how the CDC can say that there is zero overdose deaths, and at the same time http://www.cdc.gov/tobacco/data_statistics/fact_sheets/health_effects/tobacco_related_mortality/index.htm. I guess there may also technically zero overdose deaths from Tobacco as well. E-cigarettes are supposedly popular, but there could be some popcorn lung related incidence of death there, who knows for sure. I guess technically, popcorn lung is, strictly speaking, not an overdose. It may be good that the numbers of new smokers may actually be declining. Of course, the organized crime element may play a part in some of the MJ distribution. Perhaps the Tobacco Lobby could claim that there are zero overdose deaths from tobacco. My grandmother died with Emphasema (I guess now they might refer to it as COPD - chronic obstructive pulmonary disease) largely caused by smoking. Possibly from pneumonia, or some other infection which was more difficult to fight with a weakened system, from what I understand.