No smoking areas in restaurants and bars fail to protect people from second-hand smoke, a study suggests.
Exposure to second-hand smoke can cause lung cancer
Public health doctors in Australia carried out tests in 17 venues with both smoking and non-smoking areas.
While levels of nicotine and other chemicals were lower in non-smoking areas, they were still relatively high.
Writing in the journal Tobacco Control, the doctors from the Sydney Public Health Unit said only smoke free venues offered people complete protection.
'Millions at risk'
Millions of people around the world are exposed to second-hand smoke at work.
In the UK, passive smoking is estimated to be responsible for 1,000 deaths each year.
Many bars and restaurants have introduced non-smoking areas as a way of protecting staff and customers.
Doctors tested the air quality in each of the 17 clubs. They carried out tests in both smoking and non-smoking areas.
They found that non-smoking areas offer little protection from second-hand smoke.
At the very most, they reduced smoke levels by 50%.
The doctors said separate non-smoking rooms rated only slightly better. They too had relatively high levels of cancer-causing chemicals.
"No-smoking areas may provide some reduction in the level of exposure of individuals to environmental tobacco smoke. However, the reduction may be marginal or trivial," the researchers said.
The anti-smoking group ASH welcomed the study.
"This important new research confirms that 'no-smoking' areas in the hospitality trade just don't work," said Deborah Arnott, its director.
"They don't properly protect the public because smoke drifts. And they don't protect employees at all because they still have to work in areas where smoking is allowed.
"The scientific evidence is now clear. We need clear legislation which prevents smoking in the workplace and in enclosed public places. The time for excuses and half measures is gone."
Dame Helena Shovelton, chief executive of the British Lung Foundation, said:
"Today's research that non-smoking areas do not protect the public from
second-hand smoke is a significant finding.
"It adds to the argument that smoking should be banned in public places."
The UK government has so far resisted calls to introduce a ban on smoking in public places.
Ireland will become the first country in Europe to introduce such a ban in March.