In my view, a big stumbling point to legalizing marijuana is the lack of a 'legal limit' of THC for permissible driving or performing a hazardous activity. Enforcement of driving laws, for alcohol consumption, is much easier with a legal limit in place, and it likely dissuades drivers from imbibing. The use of marijuana has been implicated in as many as 11-33% of fatal accidents among 15-30-year-olds. (1) Brookoff, D, Cook, CS, Williams, C, Mann, CS. Testing reckless drivers for cocaine and marijuana. N Engl J Med 1994; 331:518. (2) Sutton, LR. The effects of alcohol, marihuana and their combination on driving ability. J Stud Alcohol 1983; 44:438. However, given the prolonged storage of marijuana in fat and the brain, long term effects are more likely compared to other inebriants.