January 12, 2012 by Karen Boruff 
 
 A study published earlier this week in the Journal of the American Medical Association reveals that smoking small amounts of marijuana may not do the kind of damage tobacco does.  The 20-year study finds that smoking marijuana once a week, or slightly more, does not appear to harm lung function, although heavier use might have negative effects.  The new findings may give fuel to the ongoing debate over the legalization of marijuana, which is legal in California only for medical use.    
 
The study, funded by the National Institute on Drug Abuse, randomly enrolled over 5,000 men and women aged 18 to 30 in four cities – Birmingham, Chicago, Oakland, and Minneapolis.  Participants periodically answered questions about recent marijuana or cigarette use and were given lung functions tests throughout the study.  About 37 percent reported occasional marijuana use, with most also reporting cigarette use, and 17 percent said they smoked cigarettes but not marijuana.  The analyses found that pot didn’t appear to affect lung function, while cigarettes did.  The study did not focus on other affects, such as deep throat irritation and cough, which seems to affect both marijuana and cigarette smokers.  It also did not look at lung cancer, although other studies have found no definitive link between smoking marijuana and lung cancer.