Pubdate: Fri, 25 Mar 2016 Source: Globe and Mail (Canada) Copyright: 2016 The Globe and Mail Company Contact: http://www.theglobeandmail.com/ Details: http://www.mapinc.org/media/168 Page: A12 Marijuana CONTROLLING THE HIGH Today's marijuana might surprise the counterculture types who smoked an occasional spliff in their misspent youth. The main psychoactive chemical - delta-9-tetrahydrocannabinol, or THC - is often present in exponentially stronger concentrations than even a decade ago. It's a result of modern horticultural techniques and careful breeding. What will be the consequences when the federal government legalizes pot? Weed advocates like to say that marijuana has no known fatal dose - unlike booze or hard drugs. But there is good evidence that a habit of elevated THC can have serious, lasting effects on teenaged brains. Canadian governments limit the amount of alcohol by volume in beer, wine and spirits. Will they cap THC levels, too? Should they? That would risk yielding a profitable niche to the black market. Leaving it up to growers could have unintended consequences. The point of legalization shouldn't be to cripple the marijuana business with regulation upon regulation. But the federal government will presumably have to enact measurement and labelling standards for recreational pot. Licensed medical cannabis producers are already obliged to show THC concentration, but the testing and measurement are mostly left to industry. ( Health Canada has issued a "guidance document" for quality assurance rather than hard rules.) It would follow that similar measures should be applied to recreational pot, but that implies costs, and recent experience in the U. S. shows a label can be inaccurate. Then there's the potency of derivatives like "edibles." In Canada, food products containing marijuana are illegal for recreational use. Presumably, that will change - bringing its fair share of headaches. Two years ago, Colorado set a limit on THC content in edibles, which are immensely popular everywhere pot is legal. It was soon discovered that uniform concentrations are tricky to achieve - which can lead to unintentional over ingestion. The maximum dosage per unit was swiftly lowered. The state also rushed stiffer childproof packaging requirements into law last fall amid reports of small kids accidentally eating marijuana-laced snacks. There is much work ahead for Ottawa. - --- MAP posted-by: Matt