An Indiana University study found that after a countywide smoking ban was implemented, hospital admissions for such heart attacks dropped 70 percent for non-smokers -- but not for smokers.
"Heart attack admissions for smokers saw no similar decline during the study, so the benefits of the ban appear to come more from the reduced exposure to second-hand smoke among non-smokers than from reduced consumption of tobacco among smokers," said Dong-Chul Seo, lead author and an assistant professor in IU Bloomington's Department of Applied Health Science.
The study, published in the latest Journal of Drug Education , was the first to examine the effect of public smoking bans on heart attacks in non-smokers. Previous studies did not distinguish between non-smokers and smokers when examining the effect of the bans or specifically look at non-smokers who had no risk factors for heart disease, such as high blood pressure, high cholesterol or previous heart surgery.
Exposure to second-hand smoke for just 30 minutes can rapidly increase a person's risk for heart attack, even if they have no risk factors. The smoke, which contains carbon monoxide, causes blood vessels to constrict and reduces the amount of oxygen that can be transported in the blood.
"What concerns us is the fact that about half of all non-smoking Americans are regularly exposed to second-hand smoke, even though more than 500 municipalities nationwide have adopted some form of a smoking ban in public places," said Seo, whose research interests include smoking and obesity prevention.