Print edition: 
Numerous health problems, including heart and lung disease, result from exposure to secondhand smoke in indoor public places and workplaces. This is an important public health concern.
Because of our interest in the impact of indoor smoking bans on the prevention of heart attacks, my colleagues David Meyers and Jinghua He and I at the University of Kansas School of Medicine in Kansas City, Kan., conducted a systematic review of 11 studies in 10 areas in 2008 and 2009. The studies were all published in peer-reviewed journals. The areas studied included Helena, Mont.; Pueblo, Colo.; New York state; Monroe County, Ind.; Bowling Green, Ohio; Saskatoon, Canada; Scotland; and Piedmont, Rome and Naples-Trieste in Italy. The studies included 24 million people and observed 215,524 cardiac events.
Some of the studies measured secondhand smoke exposure. Some provided smoking prevalence information. And some provided information on ban compliance. We measured changes in heart-attack incidence rates before and after the bans took effect. We also performed a meta-analysis of all studies and incorporated statistical techniques to evaluate the impact of post-ban duration, population size and region (United States or non-United States).
After bans were introduced in these studies, we found a significant reduction in the incidence of heart attacks. The longer the ban duration, the greater the reduction. There was a greater impact among nonsmokers than smokers in two studies that looked at this issue.
The beneficial effect of smoking bans would appear to be rapid. Secondhand smoke can cause changes in heart rate, lipid metabolism, vascular elasticity, platelet activity and oxygen delivery to the tissues.
The studies we reviewed were of ecological design and covered a relatively short time period. Nonetheless, if the reduction in the incidence of heart attacks that we found represents a cause-and-effect relationship, and we apply it to about 920,000 incident cases in the United States per year, a nationwide ban on smoking in indoor public places and workplaces could prevent thousands of new heart attacks yearly. This includes benefits to active smokers who desire to quit.
Clean-indoor-air ordinances that ban smoking in indoor public places and workplaces, with minimal or no exemptions, will help prevent heart attacks and other health problems.
