Smoking bans in offices, restaurants, airports and other public places reduce the risk of heart attacks and heart disease, a federally-commissioned panel of US experts found Thursday.
Exposure to secondhand smoke increase the risk of heart problems for both smokers and non-smokers, the US Institute of Medicine study concluded, citing "compelling" indirect evidence that even brief exposure to smoke can lead to a heart attack.
"It's clear that smoking bans work," said Lynn Goldman, who chaired the panel of scientists and is professor of environmental health sciences at Johns Hopkins Bloomberg School of Public Health.
"Bans reduce the risks of heart attack in non-smokers as well as smokers... There is no question that smoking bans have a positive health effect."
But Goldman cautioned that further research could provide more detail into how great an impact the bans have on both smokers and non-smokers, and how secondhand smoke produces its effects.
The report, sponsored by the Centers for Disease Control and Prevention, was based on a review of published and unpublished data on the links between secondhand smoke and heart problems, focusing on 11 key studies on the effects of smoking bans on heart attack rates.
The level of heart attack reduction varied greatly in those studies, from six percent to 47 percent, but all showed a drop in heart attacks after smoking bans were implemented.
That repeated finding "conclusively demonstrates that smoke-free policies help protect people from the cardiovascular effects of tobacco smoke," the committee of scientists said.
But because of the variations in how the studies were conducted and what they measured, the committee said it could not determine the exact impact of the bans on specific types of heart disease or to heart attacks.
Despite important decreases in recent years on people's exposure to environmental tobacco smoke in the United States, some 126 million non-smokers were still breathing smoke in 2000, the report said, citing public health data.
And around 43 percent of non-smoking children (under the age of 18) and 37 percent of non-smoking adults are exposed to secondhand smoke, which the CDC says kills 46,000 Americans each year.
The report was also unable to determine the exact degree of increased heart disease risk presented by breathing environmental tobacco smoke, although the committee noted that studies consistently show that the risks grow by 25 to 30 percent.
Smoking bans currently affect about 40 percent of the US population through laws in 22 of the 50 states that make tobacco use illegal in public places.