Bans on smoking in restaurants and other public places don’t just make nonsmokers’ working and dining experiences more enjoyable, they also protect our health. Reducing exposure to secondhand tobacco smoke reduces the risk of heart attacks – and the places that have enacted bans are finding that the health improvements are significant. Two new studies that pool results from several communities that enacted such bans found that a year after the bans took effect, heart attack rates were at least 17% lower.

The Wall Street Journal’s Ron Winslow describes the studies and their limitations, and he also highlights one particularly noteworthy case study:

One physician who has seen first-hand the effects of second-hand smoke on heart attack rates is Richard P. Sargent, a family doctor in Helena. He and some colleagues noticed a sharp drop in heart-attack admissions at the city’s main hospital about three months after a ban against smoking in bars, restaurants and casinos went into effect in June 2002. Then in December of that year, opponents succeeded in getting the ban revoked.

“We performed an ideal experiment,” Dr. Sargent recalls. “We turned [the ban] on, and we watched the heart-attack rate go down. We turned it off and watched it go back up.” The reduction was 40% in absolute terms—102 heart attacks per 100,000 person years after the ban, compared to 170 before the ban. Heart-attack rates rose sharply again after the ban was revoked, he says.

A Montana law has now led to the prohibition of smoking in restaurants throughout the state, and smoking will be banned from the state’s bars later this year. Seventeen states, plus DC and more than 350 other US jurisdictions, ban smoking in restaurants, bars, and other workplaces. Perhaps the accumulating evidence of the public health benefits of such bans will spur prohibitions in more locations, or even in the country as a whole.