Can smoking weed once a week give you lung cancer and/or emphysema?

Perhaps: Currently, there is no link between marijuana and lung cancer or emphysema. There has been no conclusive research linking marijuana to lung cancer or emphysema. However, marijuana has been linked to a multitude of other health problems, and just because there is no research demonstrating a link to lung cancer or emphysema does not mean that a link does not exist. More research must be done.

Probably not: Moderate cannabis smoking has not been associated with developing emphysema or lung cancer. Heavy users can develop chronic bronchitis.

Perhaps.: While risk varies for different people, the main risk factor for lung cancer is tobacco use, especially cigarette smoking. Smoking other things, like weed does not appear to have a strong link to increased risk for lung cancer, but is not a good idea, because if you smoke that, you may also smoke cigarettes. See your doctor to be sure.

Data lacking: Since the exact cause of the oncogenic (cancer-causing) effects of tobacco is not entirely clear, and the simple role of a chronic irritant has not been clearly delineated, any opinions are pretty much guess work, and as stated earlier, more data is needed.

YES: Recent studies have found links of lung cancer to smoking marijuana. Marijuana is a risk factor. Its impact is dependent on intensity of exposure and duration. The best information to date is that it is a carcinogen linked to developing lung cancer. Emphysema changes are demonstrated in lung tissue of mj smokers.