The average smoker uses a pack a day. 20 cigarettes. Even back in high school when I knew some of the biggest stoners, smoking 4 joints would have had them sleeping. Bongs filter out a lot of the tars and other carcinogens. Unless you’re superman, You’re not going to smoke 20 bowls of weed a day in a bong.
Haven’t touched the stuff in over 20 years. Won’t touch it for at least another 15. The day I retire is the day I quit alcohol and switch to weed. I’ll get my Medical (green card) cert and never look back. God willing I live that long of ocurse...
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