Experts also focussed on the rising number of teenage smokers and the links between poverty and addiction to tobacco.

Scottish government ministers have set ambitious targets to curb smoking which costs 13 thousand lives and the National Health Service £140m a year.

The conference, organised by the Roy Castle Foundation, also heard how rigorous enforcement of the laws governing the sale of cigarettes to under 16-year-olds and a tougher line on smuggling tobacco would help.

Teenage smoking is a concern

The foundation says the outlook for lung cancer sufferers is extremely poor, with the average time from diagnosis to death being just four months and only five in every 100 cases survives longer than five years.

Its Assistant Medical Director Dr Jesme Baird said: "A recent study in Scotland showed the number of 15-year-old girls smoking regularly has doubled in the last decade, which has worrying implicaitons for the future health of this generation.

One issue which delegates examined was why the health message does not appear to be getting through to the young.

DC Gerry McCann, of Strathclyde Police drugs squad, said parents who smoke have a part to play as well.

"A lot of parents, their children come to them and say: 'I took ecstasy at the weekend or I smoked cannabis, but you've got your drugs - you smoke cigarettes.

"The only answer the parent has is: 'My drug is legal'. It's a very hypocritical answer."

Addiction links

The conference discussed why poorer people in society are more likely to smoke and links between tobacco and addiction to other drugs.

Professor Peter Boyle: Half of all smokers will die

Professor Peter Boyle, from the Imperial Cancer Research Fund, said: "It's the people in the most poorly deprived areas who have the highest rates of smoking.

"Whether it's due to hopelessness, due to social deprivation, material deprivation, we need to understand that but that's given us a tremendous clue to go back and look at these groups."

He said half of all cigarette smokers would die, many of them between the ages of 35 and 69, cutting their life expectancy by up to 22 years.

Professor Boyle said: "That's a terrible thing. That's children losing their grannies when they are young and adolescents losing their parents."

Delegates also saw evidence of how tobacco companies plan to get round the UK ban on advertising which will be phased in at the end of this year.

It is believed they will resort to what is known as brand stretching - by introducing household goods or clothes with a name associated with makes of cigarettes.