[wideawake]

There has never been a single person with bodily damage from cannabis.

So it's magic smoke then? That leaves no trace on the lungs?

[varyouga]

If you do smoke it, it will reduce lung capacity temporarily. However, it has never been separately linked to chronic lung disease or cancer like tobacco smoke. There has never been a single recorded case of a smoker with lung disease only from smoking cannabis – the ones with lung disease all also smoked tobacco. Tobacco itself is radioactive (look it up) and the particles enter deeper into the finer passages of the lungs.

The most recent study:

Study Finds Periodic Pot Smoking Doesn't Harm Lungs(Journal of the American Medical Association)
http://copd.about.com/b/2012/01/11/study-finds-periodic-pot-smoking-doesnt-harm-lungs.htm

Also, it doesn’t have to be smoked. It can be vaporized with a device barely larger than a lighter. Or can be easily made into a tincture or pills using only kitchen utensils. All the products are 100% non-toxic even at impossible doses.

With tobacco, you can actually die from spilling nicotine extract on your skin. “A person can overdose on nicotine through a combination of nicotine patches, nicotine gum, nicotine inhaler cartridges and/or tobacco smoking at the same time. Spilling an extremely high concentration of nicotine onto the skin can result in intoxication or even death since nicotine readily passes into the bloodstream from dermal contact.” - http://en.wikipedia.org/wiki/Nicotine_poisoning