Secondhand smoke - even a wisp - found dangerous
|BY DELTHIA RICKS - STAFF WRITER - May 24, 2005|
Secondhand smoke may be more dangerous than previously thought, amplifying blood clotting and damaging the walls of blood vessels within minutes of exposure, researchers reported yesterday.
Scientists in California found that exposure to small doses of smoke, equivalent to the amount encountered when several people gather to puff in smokers' zones, delivers enough punch to change blood chemistry.
"We asked a lot of questions: What does secondhand smoke do to platelet function or to arterial walls?" said Dr. Stanley Glantz, a professor of medicine at the University of California, San Francisco, who has produced one of the largest studies to date on the effects of secondhand smoke exposure. He also asked questions about cholesterol chemistry and heart rhythms.
"We found that exposure to secondhand smoke is about 80 percent as bad as being a smoker," he said. The study examined 29 previous medical investigations on secondhand smoke.
One long-held notion, he said, is that researchers have believed bystanders needed to inhale large doses of smoke for extended periods of time, the equivalent of being "in a smoky bar for a very long time." But the new study shows much larger cardiovascular effects with much less exposure.
"In five minutes of exposure your aorta gets stiffer and in 20 minutes the smoke affects your platelets," Glantz said of the sticky cells that cause blood to clot. "Smoke has the opposite effect of aspirin and Plavix and other anti-platelet medications. It causes more clotting." He added that about 20 minutes of exposure spurs changes in cholesterol chemistry. And in two hours of exposure changes occur in the heart's rate.
Dr. Joaquin Barnoya, co-author of the new analysis, said, "Even a little secondhand smoke is dangerous. The effects on blood, blood vessels and heart rhythm occur quickly, often within minutes."
Copyright 2005 Newsday Inc.