[dhs12345]

Ya, I know. And Bill Clinton didn’t inhale. Note the “...four times as much tar...” in the below.

There is ton of information the web.

For starters.

Tobacco vs. Marijuana

Like tobacco smoke, marijuana smoke contains cancer-causing chemicals. There are 33 cancer-causing chemicals contained in marijuana. Marijuana smoke also deposits tar into the lungs. In fact, when equal amounts of marijuana and tobacco are smoked, marijuana deposits four times as much tar into the lungs. This is because marijuana joints are un-filtered and often more deeply inhaled than cigarettes.

Marijuana smoke is also an irritant to the lungs, and frequent marijuana smokers can have many of the same respiratory problems experienced by people who smoke tobacco. These include coughing and phlegm production on most days, wheezing, bronchitis, and greater risk of lung infection.

http://www.lung.org/associations/states/colorado/tobacco/marijuana.html

[Tailback]

This is because marijuana joints are un-filtered and often more deeply inhaled than cigarettes.

Know any pot smokers that smoke 4 joints a day? I don't, because joints are not the preferred method of delivery these days. Bongs or vaporizers are what people use these days. Vaporizers (not e-cigarettes) heat the weed enough to extract the THC but not burn the leafy parts which means no carcinogens. Bongs filter out a large portion of the non-psychoactive substances that you would get in a joint.

I think it's so cute when people that have no idea what they're talking about chime in as an expert.