Cigarettes marketed as light or low tar may be responsible for a significant increase in a rare form of lung cancer, the government's chief medical officer has said.

Professor Liam Donaldson said the label "light" or "low tar" was misleading as it implied that those products were less of a danger to health.

He told the House of Commons Health Select Committee that use of the description should be urgently reviewed.

Professor Donaldson said a draft European directive on smoking could be strengthened to tighten up restrictions on labelling, marketing and content of cigarettes.

Professor Donaldson said: "There is no such thing as a safe cigarette. This is an area that needs to be looked at very closely."

Smokers of low tar cigarettes puff more intensely, delivering more carcinogens and toxins to the peripheral lung area where the lung cancer adenocarcinoma develops.

Many switch to low tar

Paul Lincoln, from the Health Education Authority, told the select committee that research showed 77% of light smokers had switched from regular cigarettes largely because they saw low tar cigarettes as being less harmful than regular brands.

He said: "Almost three out of 10 smokers said that a main reason for switching was as a step towards quitting.

"The use of the term `light' is misleading the public. I would like to see the issue reviewed very quickly."

Professor Liam Donaldson warned that low tar labels mislead the public

Mr Lincoln said that up to the mid-1980s government advertising had advised smokers that if they could not quit they should at least switch to a low tar brand.

"That is no longer the case. We now tell people not to smoke at all," he said.

Dr Dawn Milner, the Department of Health's senior medical officer, said research should continue to see if it possible to find a "safer" cigarette.

"Of course all cigarettes are lethal and we should want everybody to stop smoking. But given the strength of addiction, shouldn't we also, at the same time, try to make a safer cigarette?"

Inhaling deeply

Dr Mick Peake, a consultant physician at the chest unit of Pontefract General Infirmary, said it was possible, although not proven, that low tar cigarette smoking could be linked to a rise in adenocarcinoma cases.

He said nine out of ten cases of lung cancer, and 75% of adenocarcinoma cases, were caused by smoking.

"Inhaling more deeply may draw smoke into the lower parts of the lung, and perhaps that may cause adenocarcinoma," he said.

Amanda Sandford, director of research for the anti-smoking charity Action on Smoking and Health (ASH) said low tar cigarettes were a "health con".

She said the only way people could effectively reduce the health risks of smoking was to give up.

John Carlisle, director of public affairs for the Tobacco Manufacturers Association, told News Online definitions of low and light tar cigarettes had been agreed with the government as part of its drive to cut tar levels in tobacco products.

He said: "These descriptors have been used as brand markings and customers have become used to them.

"We have never claimed they have any health connotations at all."

The draft European directive, not likely to come into force until 2003, proposes that health warnings are displayed more prominently on cigarette packets, and that the maximum tar yield of a cigarette is reduced from 12milligrams to ten.

European Union member states will be given the freedom to implement the directive as they see fit.