Web edition: October 29, 2012
Print edition: December 1, 2012; Vol.182 #11 (p. 18)
Perhaps living in a “nanny state” isn’t half bad. In a Minnesota county that banned smoking in public places in 2007, the heart attack rate dropped by one-third after the ban compared with the period just before the restrictions were phased in, researchers report in the Oct. 29 Archives of Internal Medicine.
The study is the longest analysis to date to measure a smoking ordinance’s effect on community-wide heart health, says study coauthor Richard Hurt, an internist at the Mayo Clinic in Rochester, Minn.
“Our hope is that this will turn the page on this chapter, and whether secondhand smoke is associated with heart attacks,” Hurt says. “It is.”
Olmsted County prohibited smoking in restaurants on January 1, 2002, and expanded the ban to all workplaces, including bars, on October 1, 2007. Cigarette smoke inhalation increases heart attack risk, so Hurt and his colleagues calculated the rate of heart attacks during the 18 months preceding the enactment of the first ordinance and the 18 months immediately after the full ban went into effect.
The county has a population of nearly 145,000 people. Medical records show 187 heart attacks there in the 18 months before the first smoking ban and 139 in the same time frame immediately after the full prohibition began. When adjusted to account for demographic changes in the county's population between the two periods, the data revealed an annual heart attack rate of 151 per 100,000 people before and 101 per 100,000 afterward.
Olmsted County is hardly the first to enact curbs on public smoking, but the county benefits from having an exhaustive medical database of its residents to analyze. The new study and a litany of similar findings impress even those who promoted smoking bans early on. “Initially, when these ordinances were passed, I don’t think anyone really expected to see such a rapid cardiovascular effect,” says Pamela Ling, an internist at the University of California, San Francisco. “But I think the evidence now — particularly linking smoke-free policies and real medical outcomes — is really quite strong.”
The new data reflect less smoke exposure and probably also less smoking, she says. “One of the arguments was that smoke-free policies would restrict it in the workplace but that people would smoke more at home,” Ling says. “But actually, studies suggest ... that people don’t compensate.”
Hurt says he hopes the emerging antismoking ethic will now spread to automobiles. When someone smokes in a car, he says, “the concentration of secondhand smoke is just amazing.”
R.D. Hurt et al. Myocardial Infarction and Sudden Cardiac Death in Olmsted County, Minnesota, Before and After Smoke-Free Workplace Laws. Archives of Internal Medicine. Online October 29, 2012.
N. Seppa. Secondary smoke carries high price. Science News. Volume 153, Jan. 17, 1998, p. 36
R.P. Sargent et al. Reduced incidence of admissions for myocardial infarction associated with public smoking ban: before and after study. British Medical Journal. Volume 328, 2004, p. 977.