Secondhand Smoke More Dangerous Than Believed

June 29, 2004 -- The harmful effects of secondhand smoke may be much greater than previously thought, according to a new study released today.

The research, published in the British Medical Journal, suggests that inhaling someone else's tobacco smoke may increase your risk of heart disease by up to 60 percent.

Some U.S. cities have banned smoking in bars and restaurants. But in most of the country, it's still legal.

Many communities insist there's not enough evidence that breathing in someone else's smoke does any harm, though this study is likely to change that.

"For the first time, we have hard evidence, physical evidence, of secondhand smoking getting into the bodies of nonsmokers and putting their health at risk," said Dr. Michael Fiore, professor of medicine at the University of Wisconsin Medical School.

"The important thing for the public is to get across the message that passive smoking really is a health hazard," said study author Martin Jarvis, a professor of epidemiology and public health at University College London in England.

"The scientific evidence is strong. The notion that it is still a 'controversy' is put about by the tobacco industry and its defenders in the face of clear evidence," he added.

The study followed more than 2,000 nonsmokers for 20 years.

Instead of simply asking study participants how much secondhand smoke they were exposed to both at home and at work, this study measured how much smoke they were actually breathing.

Researchers checked their blood for levels of cotinine, a byproduct of nicotine found only in tobacco smoke.

"What they found is that those individuals who had cotinine in their blood stream, but who were not smokers, had a much greater risk of heart attacks," Fiore said.