Pot

Cigarette smoking by adults has declined from 42% to 17% while pot smoking has increased from 7% in 2013 to 12% today. Lung cancer death rates declined 45% from 1990 to 2015 among men and 19% from 2002 to 2015 among women. The link between tobacco smoke and lung cancer is well-known. Studies show that marijuana smoke has many of the same harmful substances as tobacco, and often more of them. It appears that we will have to allow for more years of pot smoking to gather data on cancer so as more states allow for pot smoking the lung cancer rates should catch up with cigarettes. Seems like a risky experiment.