“People who occasionally smoke marijuana do not suffer long-term lung damage the way cigarette smokers do, and may actually experience a slight improvement, a 20-year US study has revealed.”
“Since the research included more than 5,000 people over a long time span, the authors said it should help clear up some of the confusion about the risks of marijuana smoking, which is increasingly common in the United States.”
Read more: http://health.msn.co.nz/healthnews/8401956/no-lung-damage-from-marijuana-study