The number of people being taken to hospital with heart attacks in Scotland has fallen significantly since the smoking ban was introduced, the most detailed study into the impact of the measure has revealed.

Researchers found a 17% drop in the number of people admitted for heart attacks in the year since the ban came into force, compared with an average 3% reduction a year over the previous decade. The reduction was most marked among non-smokers, with a 20% fall, compared with a 14% drop among smokers.

The finding, gleaned from an analysis of heart attack admissions at nine Scottish hospitals, was revealed yesterday at a two-day conference studying the impact of the ban on smoking in enclosed public places. Scotland introduced the ban in March 2006, with Wales and Northern Ireland following in April 2007 and England in July this year.

Other research presented at the conference in Edinburgh, Towards a Smokefree Society, and published by the British Medical Journal, found a 39% reduction in second-hand smoke exposure among primary school children in Scotland, and a 49% reduction among adult non-smokers.

Bar staff also experienced fewer respiratory problems. A separate study of the impact on nearly 400 non-smoking bar staff, based on an analysis of nicotine levels in their saliva, found their exposure had reduced by 89%.

Scotland's deputy chief medical officer, Peter Donnelly, said research showed the "significant" public health benefits the smoking ban was already having.

"It provides evidence that the legislation is improving the health of everyone in Scotland - including smokers, non-smokers, children and bar workers.

"One of the most important findings is the reduction in heart attacks. We believe that the smoking ban was a large contributory factor to this drop."

Gill Pell, of Glasgow University, who headed the research into heart attacks, said hers was the first to determine the effect of a smoking ban on non-smokers. Four previous studies, in cities in the US and in northern Italy, found a link between a smoking ban and heart attacks among smokers but did not measure the impact on non-smokers.

"The primary aim of smoking bans is to protect non-smokers from the effects of passive smoking," said Professor Pell. The study had confirmed that the legislation had been effective in helping non-smokers.

Prof Gill added that the nine hospitals, in areas including Edinburgh, Glasgow, Paisley, Dundee and Lanarkshire, accounted for 63% of heart attack admissions in Scotland. The number of all heart attack admissions at these hospitals had fallen by more than 550, from 3,235 in the year to March 2006, to 2,684 in the year to March 2007. Among non-smokers, the reduction was from 1,630 to 1,306.