Pubdate: Thu, 05 Sep 2002 Source: Globe and Mail (Canada) Copyright: 2002, The Globe and Mail Company Contact: http://www.globeandmail.ca/ Details: http://www.mapinc.org/media/168 Author: Raju Hajela Referenced: http://www.mapinc.org/drugnews/v02/n1636/a04.html WHERE THERE'S SMOKE Kingston, Ont. -- I read The Flin Flon Flip-Flop by Spider Robinson (Sept. 2) with interest, notwithstanding his potshots at the medical profession, Anne McLellan and me. For those interested, marijuana smoke produces 50 per cent more tar and contains 70 per cent more benzopyrene than the same weight of tobacco. Marijuana smokers generally take a two-thirds larger puff volume, one-third greater depth of inhalation, and a fourfold longer breath-holding time than tobacco smokers. So it is easy to see how researchers arrive at the estimate of joint/cigarette harm of about 1:10 when one looks at acute and chronic respiratory symptoms of smoking, in addition to the risk of cancers. Chemically, tetrahydrocannabinol (THC) in marijuana is a hallucinogen that interferes with perception and is addictive. I have many patients who turned to marijuana for comfort but ended up with destruction of various aspects of their lives. Marijuana has been around for millenniums, but it has not become popular as good medicine precisely because its safety and efficacy are not established. As a science-fiction writer, Mr. Robinson can invent ideas that sound scientific; but he must remember that science related to our daily lives needs to be grounded in reality. Raju Hajela MD, past president, Canadian Society of Addiction Medicine - --- MAP posted-by: Alex