Bans on smoking in public places and workplaces can sharply reduce heart attacks among both smokers and nonsmokers, according to a report issued Thursday by the Institute of Medicine.
The report provides strong support for the anti-smoking laws now in place in 21 states and the District of Columbia and is likely to bolster efforts to pass such laws elsewhere.
"It's clear that smoking bans work," said Dr. Lynn R. Goldman of the Johns Hopkins Bloomberg School of Public Health, who chaired the panel that produced the report. "Bans reduce the risk of heart attacks in nonsmokers as well as smokers."
The study "confirms that eliminating smoking in workplaces, restaurants, bars and other public places is an effective way to protect Americans from the health effects of secondhand smoke," said Dr. Thomas R. Frieden, director of the federal Centers for Disease Control and Prevention, which commissioned the study.
Nearly 440,000 Americans die each year from smoking-related illnesses, more than a third of them heart disease, according to the American Heart Assn. About 38,000 of those deaths are related to secondhand smoke. The association between illness and secondhand smoke was reinforced by a 2006 surgeon general report on the consequences of exposure to environmental smoke.
But bans on smoking have remained controversial, in part because of fears that they would reduce traffic in bars and restaurants. When the CDC commissioned the study last year, some panel members were skeptical about the benefits of such bans, according to statistician Stephen E. Fienberg of Carnegie Mellon University in Pittsburgh. They quickly changed their minds when they began reviewing the evidence.
The panel examined 11 studies of heart attacks in areas where bans were implemented and found a decrease in heart attacks in every study, ranging from 6% to 47%, depending on how the study was conducted.
"Such consistent data confirms for the committee that smoking bans do, in fact, decrease the rate of heart attacks," they wrote. One study, for example, found that hospitalizations for heart attacks in Pueblo, Colo., dropped 41% in the three years after the city banned smoking in the workplace.
In most of the studies, it was difficult to isolate the benefits for nonsmokers from those for smokers, but two of the studies showed a very clear benefit for nonsmokers.
The committee also surveyed the evidence from laboratory studies in animals and concluded that these results also supported smoking bans. The studies show that particulates and other toxins in cigarette smoke can trigger heart attacks in people who have heart disease and may not know it, providing the final shove that pushes them into cardiac arrest.