Ok, another reason to vaporize your weed people! 
Another marijuana study has been done, this time suggesting that a single joint blocks as much airflow as 5 tobacco cigarettes. It also suggests that 1 joint causes as much lung damage as 2.5 to 5 cigarettes. See, the damage which occurs is from smoking the actual plant itself. Vaporizing only lets through 0-5% of the harmful toxins.
This study also found that chronic lung emphysema was uncommon among marijuana smokers. The disease was found in 18.9 percent of cigarette smokers, and only 1.3% of marijuana-only smokers. They also found that longtime pot smokers can develop symptoms of asthma and bronchitis.
