Although not conclusive, this research does seem to suggest that smoking tobacco may be even more dangerous for women than men.

Why that may be will be the focus of many discussions over the next few years. Speculation will centre on two things: the biological differences between the sexes, and secondly the type of tobacco smoked and the way its inhaled.

Clearly there are major hormonal and genetic differences between men and women, but that may not completely explain why more women in Britain are being diagnosed with Small Cell Lung Cancer.

Some experts believe the reason may lie in the cigarettes themselves. Women in the UK are more likely to smoke low tar cigarettes.

One theory is that to get a strong "hit" of nicotine from such tobacco, a person needs to inhale more deeply and more often increasing the number of particulates in the lung.

Low tar threat

Teenage girls who smoke are putting themselves at risk

Anti-tobacco campaigners have long criticised low tar cigarettes, claiming their name implies they're less dangerous than normal tobacco.

Part of their construction involves little holes in the filter which allows some of the smoke to escape before it enters the mouth.

However, campaigners say many women block these holes up to get more of the smoke and a strong intake of nicotine.

This research will alarm many. Its known that the numbers of teenage girls smoking has recently increased.

Now around one in three of all women smoke. And the future is grim. Recent research suggested that at least a third of all smokers will get some form of cancer.

With those sorts of statistics doctors say serious measures need to be taken to avoid a major epidemic in the future.