The health of Scotland's bar staff has improved dramatically since the introduction of a smoking ban, a medical study has found.
Bar worker Shelagh Matthews has felt benefits from the ban
Researchers at Dundee University found significant health improvements in the first two months after the March ban.
The results have led to calls for the UK Government to speed the introduction of a similar ban south of the border.
But smokers' rights group Forest said the link between passive smoking and ill health had not been proven.
The team from the university's asthma and allergy research group began testing bar workers in and around Dundee in February, a month before the ban came into force.
Using a series of indicators, they established symptoms attributable to passive smoking, measuring lung function and inflammation in the bloodstream.
Testing volunteers a month later and then again in May, the researchers were not only able to back up anecdotal evidence of a general feeling of wellbeing but scientifically establish significant improvements in people's health.
Daniel Menzies, from the research group, said that in the two months following the introduction of the ban, the number who showed smoke-related symptoms fell from more than 80% to fewer than half.
The team also recorded reductions in levels of nicotine in the bloodstream and breathing tests showed improvement in lung function of as much as 10%.
The researchers measured the lung function of bar staff
"Our study shows that, across a number of health indicators, positive changes were evident even in the first two months following the introduction of the smoking ban, which is a very rapid change," said Dr Menzies.
Shelagh Matthews, an asthmatic who works as the bar manager at Dundee city centre pub The Phoenix, said she had used her inhaler less frequently since the ban.
"The smoke was something that definitely did have an effect, though perhaps we didn't realise how much of an effect until it was gone," she said.
"I do actually feel the difference."
Neil Rafferty, from the Freedom Organisation for the Right to Enjoy Smoking Tobacco (Forest), questioned the medical basis for the research.
Mr Rafferty said it diverted attention from the issue of people's right to choose under a system of smoking and non-smoking venues.
He said: "Many people who work in pubs are smokers, many of whom like to have a cigarette during their shift and many of whom aren't really concerned about the issue of passive smoking.
"The science on passive smoking is still very inconclusive, the anti-smoking lobby are still making exaggerated claims about passive smoking, meanwhile people are being denied choice."
Following the results of the study, which have been published in the Journal of the American Medical Association, the British Heart Foundation called on Prime Minister Tony Blair to name a precise date for the introduction of an English ban.
Chief executive Peter Hollins said: "This study provides compelling evidence that making workplaces smoke free can have a significant and speedy impact on people's health."