Every year, hundreds of people in the UK die from lung cancer believed to have been caused from exposure to secondhand smoke.

One reason why secondhand smoke is dangerous is that it contains cancer causing chemicals in higher concentrations than are inhaled by the smoker.

Studies have found that living with a smoker can increase your risk of getting lung cancer by 20 to 30 per cent. And one study estimates that passive smoking may kill more than 11,000 people every year in the UK.

These people do not just die from cancer, but from other illnesses such as heart disease and strokes.

Because of this, many people have welcomed the ban on smoking in enclosed public places in England which came into force in July.

Richard Raczynski- Floyd, who manages Coolings bar in Gandy Street, Exeter, said: "The smoking ban has definitely made working easier and better. I have had no complaints from my customers either but we have had lots of nice positive comments."

"Customers say they can actually taste the food and wine. Before, we used to get complaints about smoke in the food."

Will Williams, the Royal Devon & Exeter Hospital's specialist no-smoking adviser, who helps patients to quit, said passive smoking is more dangerous than people realise.

"The dangers of passive smoking are that you get secondhand smoke rather than mainstream smoke," he said.

"And what comes off the end of the cigarette is unfiltered. The chemical risk of inhaling toxic fumes is underestimated."

"People who worked in bars also had a high level of cotinine, which is a by product created when your body metabolises certain chemicals from cigarettes.

"Their levels were the same as people who smoked 40 a day. Afterwards, they dropped substantially."

Will said that another good reason for the ban was that smoking in public had a bad influence on people trying to give up.

"It is almost like a visual impact. If people are trying to quit and see other people smoking near them it has an effect."

He added that it was important to raise awareness of the issue through initiatives such as Lung Cancer Awareness Month.

"Not everyone is aware of the risks of smoking but it is one of the massive contributing factors to do with lung cancer," he said.

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