Non-smokers benefit most from smoking bans

American researchers have found that heart attacks decrease after a smoking ban was imposed but only applied among non-smokers. Their study suggests that the major benefit of the ban on smoking in public places is being seen in nonsmokers.

According to the study, even people with no obvious risk factors for heart disease still have heart attacks. However, after a countywide smoking ban was implemented, hospital admissions for such heart attacks dropped 70% for non-smokers, but not for smokers.

The researchers conducted the study in order to investigate whether smoking bans led to any changes in hospital admissions for heart attackes.

They compared hospital admissions for heart attacks in Monroe County, Indiana, which has had a public smoking ban in place since August 2003, with those in Delaware County, also in Indiana, which has much in common with Monroe Country but does not have a smoking ban.

Dong-Chul Seo, lead author, says 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.

The study is 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 looking at non-smokers who had no risk factors for heart disease, such as high blood pressure, high cholesterol or previous heart surgery.

Experts say 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 because the smoke, which contains carbon monoxide, causes blood vessels to constrict and reduces the amount of oxygen that can be transported in the blood.

The researchers say it is of concern 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.

The study also compared the hospital admissions in Monroe county before and after the smoking ban was adopted and found there was a 70% drop in the number of hospital admissions for AMI among non-smoking patients with no history of heart disease.