Children who are exposed to second-hand smoke are more likely than other kids to develop lung cancer later in life, according to a European study of more than 60,000 people who had never smoked.

For those who reported having been in a smoky environment for many hours daily, the risk tripled, but even exposure once a week had significant consequences. The work, published in the British Medical Journal, also found that ex-smokers are affected more by passive smoking than non-smokers.

“Passive smoking clearly increases the risk of lung cancer,” says Paolo Vineis, author of the research and an epidemiologist at Imperial College London. “People should not smoke in the presence of their children.” (www.reuters.co.uk, 28 January 2005)

“This study raises a terrifying spectre for smoking parents”, said Robert West of Cancer Research UK. “Exposing their children to cigarette smoke not only damages the child's airways at the time, but may lead to development of lung cancer in later life.” (The Guardian, UK, 28 January 2005)

Vineis is unsure whether children are more vulnerable to the effects of smoke, or whether their longer-term exposure increases their risk. However, he points to evidence indicating that young animals are more susceptible to carcinogens (http://www.abc.net.au/am/content/2005/s1291698.htm, 29 January 2005).

Simon Clark, of the UK smoker's lobby group Forest, says the effects of passive smoking are difficult to measure, most studies being based on “...imprecise recall and anecdotal evidence”. He suggests the work is “...a further attempt to demonise smokers for their habit” (http://news.bbc.co.uk/, 28 January 2005).