Can you get lung cancer from smoking weed?

Ben - The data you present do NOT support the conclusion that marijuana is safer than tobacco or that it does not cause lung cancer. The major difference is that probably no one has smoked as much marijuana as the average lung cancer tobacco smoking person. Just do the math which many so-called scientists do not do as they forget to involve a statistician to determine whether the sample sizes are comparable. You cite what falsely seem to be a lot of marijuana but the 22,000 joints smoked over a lifetime amount to just a little over 3 pack-years. (22,000 divided by 20 cigarettes or joints per pack divided by 365 days per year is just a little over 3 pack years whereas cigarettes smokers commonly consume over 20 pack-years of tobacco. Marijuana seems to be safer mainly because people smoke much less marijuana in a lifetime than tobacco. Microscopically, using biopsies of the bronchial lung lining in contact with smoke, the earliest abnormal changes leading to cancer are found to be greater with marijuana than with tobacco. Of course many people smoke both. You pays your money and gets to choose your poison.