Argument: The health risks of smoking marijuana are relatively minor
Lester Grinspoon, M.D., Emeritus Professor of Psychiatry, Harvard Medical School. "Puffing Is the Best Medicine," Los Angeles Times. May 5, 2006. - "[T]here is very little evidence that smoking marijuana as a means of taking it represents a significant health risk. Although cannabis has been smoked widely in Western countries for more than four decades, there have been no reported cases of lung cancer or emphysema attributed to marijuana. I suspect that a day's breathing in any city with poor air quality poses more of a threat than inhaling a day's dose -- which for many ailments is just a portion of a joint -- of marijuana."