Marijuana doesn’t increase risk of lung cancer, mental illness or death
Dr. Donald Tashkin, professor of medicine at University of California, Los Angeles, is among the foremost researchers studying the effects of marijuana on the lungs. His 2006 study, one of the largest to look at marijuana use and lung and upper-airway cancers, found that the “association of these cancers with marijuana, even long-term or heavy use, is not strong and may be below practically detectable limits.”
A larger, longer-term study published in 2012 by a separate group of researchers showed that marijuana had no detrimental effect on lung function. Tashkin, who was not involved in the study, called it “well conducted” and said the results confirmed his own findings."