The University of Mississippi's Potency Monitoring Project, a government-sponsored program that analyzes samples of seized marijuana, reports that the average THC level in 2008 was 10.1 percent, up from 7.3 percent in 2007 and 3.2 percent in 1983. Mahmoud ElSohly, the project's director, predicts that average potency will continue to rise in the next five to 10 years, leveling off at 15 percent or so. Although it's not clear how representative the project's samples are, there's little doubt that average THC levels have risen significantly during the last two decades as growers have gotten better at producing high-quality cannabis. For consumers, this is good news: They can achieve the same effect with less exposure to combustion products, inhalation of which is the main health risk associated with marijuana use.
But drug warriors want us to believe that better pot is somehow worse. The New York Daily News, for instance, cites the fear that "inexperienced pot tokers may not moderate their intake and possibly suffer from paranoia, irritability and other negative effects." Since pot smokers feel the drug's effects immediately and can decide whether they want another puff based on how they feel, this concern seems pretty implausible. Likewise the notion that stronger pot is qualitatively different, such that we cannot rely on previous experience with the drug in assessing its hazards. That argument seems like little more than a transparent attempt to justify and amplify former pot smokers' anxieties about their offspring's pot smoking. A child psychiatrist tells the Daily News such propaganda is not likely to deter teenagers from smoking pot: "Telling them it's 10%—three times more potent than what their parents smoked—is not an argument they are likely to buy into or to even utilize in any constructive sort of way." In fact, it may come across as an endorsement.