Experts warn people not to expose themselves to secondhand smoke, since it will induce potentially lethal damage to hearts, lungs and arteries.

Experts warn people not to expose themselves to secondhand smoke, since it will induce potentially lethal damage to hearts, lungs and arteries.

"In terms of lung cancer, secondhand smoke is thought to cause the deaths of 3,000 Americans every year, and the number for cardiovascular deaths is even higher, between 37,000 to 50,000 deaths per year," said Dr. Norman Edelman, consultant for scientific affairs at the American Lung Association.

The tars, nicotine and carbon monoxide in cigarette smoke pose a triple threat to lung tissue and blood vessels, upping cancer risk, constricting airways and arteries and robbing blood of precious oxygen.

"By speeding up the heart and squeezing down the vessels, it just puts a big burden on your heart," Edelman said. In fact, a British study published in June 2004 in the journal Thorax found that men exposed to secondhand smoke over long periods of time faced a 50 percent higher risk of coronary heart disease than men without such exposures.

One recent study tracking risk for heart attacks in both smokers and nonsmokers found that heart attack risks for individuals at the highest level of secondhand smoke exposure were "two and a half times higher than those in the low range.

Some experts even wonder if passive smoking might be worse than dragging directly off a cigarette.

Whatever its potency, tobacco smoke remains extremely harmful even when sourced secondhand.

Based on the accumulated evidence, three major health groups -- the American Cancer Society, the American Heart Association and the American Lung Association -- have long called for bans on smoking in workplaces, including bars and restaurants.

Public smoking bans are not about simply trying to make it tougher for smokers so that they have to give up smoking, this is a legitimate health issue, in terms of protecting the air quality for everybody, said Dr. Richard Stein, a spokesman for the American Heart Association and a cardiologist at Beth Israel Hospital in New York City.

Editor: Catherine