People have been ingesting cannabis since long, long, long before they smoked it from a pipe. It would surprise me if there are dire health effects that are entirely undiscovered.
This is, of course, shitty compared to actually providing a study.
This is, of course, shitty compared to actually providing a study.
The same held true for tobacco for quite a long time, do keep in mind.
[1] http://www.mayoclinic.org/healthy-lifestyle/quit-smoking/in-...
[2] http://www.cancer.org/cancer/cancercauses/tobaccocancer/smok...
The likely carcinogens in question: https://en.wikipedia.org/wiki/Tobacco-specific_nitrosamines
In fact, there are also problems for smkers who cough up and then swallow phlegm - this increases risk of bladder and penile cancers.