According to Irish researchers, a smoking ban which began March 2004, has worked on many counts-not only has there been a drastic cut in air pollution, the health of bar workers has improved considerably.
Putting it in figures, the researchers gave an 83 percent reduction in air pollution and an 80 percent cut in cancer-causing agents. In addition, the report, which was published in the American Journal of Respiratory and Critical Care Medicine, states that the lung function of bar workers has also improved.
The team from the Research Institute for a Tobacco Free Society in Dublin, studied environmental tobacco smoke exposure in 42 Dublin pubs and tested 73 bar workers who volunteered to take part in the study.
The workers were all given lung function tests before the ban came in and then, a year later.
Asked about their workplace exposure to tobacco, the bar-workers said they were exposed to around 40 hours per week before the ban came in while this fell to 25 minutes afterwards - a 99 percent decrease in exposure.
It was also seen that lung function tests improved dramatically in non-smoking barmen after the ban. They also demonstrated significant reductions in cough and phlegm production.
A significant observation was that smokers' health was not found to improve.
Smoking bans are already in place in Wales and Scotland. Northern Ireland will follow suit on 30 April, while England's ban comes into force on 1 July.
Says lead researcher Dr Luke Clancy: "These results confirm that the approach of a total ban on smoking in the workplace is successful in reducing the exposure of workers to particles."
Martin Dockrell, of Action on Smoking and Health (ASH) says: "Tobacco interests have continued to suggest that there is no evidence that other people's smoke is harmful.
"Dr Clancy's study shows not only how direct the harm is but - most importantly - it shows how comprehensive smoke-free public places can reverse the harm."
Yet, according to Simon Clark, director of the smokers' lobby group Forest, self-reporting of exposure and symptoms cannot be taken seriously.
"It's hardly rocket science to conclude that smoking bans reduce exposure to airborne carcinogens", he says.
"However, it's the dose that makes the poison and although second-hand smoke may increase people's exposure to carcinogens, the concentration of particles is usually very small.
"A good ventilation system can reduce it even further. A lot of people may find a smoky environment unpleasant but that doesn't justify a ban on smoking in every pub, club and bar in the country.
"This feeble report won't change our opinion", he was quoted.