Pubdate: Wed, 26 Nov 2014 Source: San Francisco Chronicle (CA) Copyright: 2014 Hearst Communications Inc. Contact: http://www.sfgate.com/chronicle/submissions/#1 Website: http://www.sfgate.com/chronicle/ Details: http://www.mapinc.org/media/388 Author: Greta Kaul SECONDHAND POT SMOKE ALSO BAD FOR BLOOD VESSELS Breathing secondhand cigarette smoke damages blood and heart vessels - - and so does marijuana smoke, UCSF scientists have found. When researchers exposed lab rats to 30 minutes of secondhand marijuana smoke, they saw a 70 percent decline in the function of the animals' blood vessels. Blood vessel function was still subpar when there was no tetrahydrocannabinol (THC), which gives pot its intoxicating qualities, in the marijuana. Studies have shown that blood vessels regain their normal function 30 minutes after exposure to tobacco smoke. In the new study, blood vessels hadn't returned to normal 40 minutes after exposure to marijuana smoke. The research is important because many people know secondhand cigarette smoke is bad - it causes about 34,000 premature deaths due to heart disease in the United States annually - but do not know that secondhand marijuana smoke has health consequences, too, said Dr. Matthew Springer, the study's senior author and an associate professor of medicine at UCSF. With more states legalizing marijuana, it could become a health concern, he said. The study was presented Nov. 16 at the American Heart Association's Scientific Sessions. - --- MAP posted-by: Jay Bergstrom