you're forgetting about the accelerated cellular death and regrowth.

yeah, smoking pot excessively would totally damage your lungs, like tobacco, but if you're not over doing it, you wont cause more damage than your body can quickly repair.
Stoner Shadow Wolf Reviewed by Stoner Shadow Wolf on . Pot not a major cancer risk NEW YORK (Reuters Health) - Although both marijuana and tobacco smoke are packed with cancer-causing chemicals, other qualities of marijuana seem to keep it from promoting lung cancer, according to a new report. The difference rests in the often opposing actions of the nicotine in tobacco and the active ingredient, THC, in marijuana, says Dr. Robert Melamede of the University of Colorado in Colorado Springs. He reviewed the scientific evidence supporting this contention in a recent Rating: 5