SCIENTISTS in Southampton might soon be able to explain why some smokers live to a ripe old age, while others die prematurely of lung disease.

A team of researchers at Southampton General Hospital have launched a unique study into how different people's lungs react to cigarette smoke.

The study focuses on the threat posed by emphysema - one of the biggest killers in the western world.

Dr Ratko Djukanovic, who is leading the project, said: "It's probably the fourth biggest cause of death in the developed world.

"Heart failure and pneumonia are often directly connected to emphysema. And it's the main cause of the winter crisis that hits the NHS every year, responsible for more than 50 per cent of emergency hospital admissions.

"Currently there are no effective treatments for the condition.

"If we can understand why some smokers do not develop emphysema we might be able to find ways of helping those who do."

Around 50 volunteers have already been recruited to take part in the £750,000 study, but a further 20 are still needed.

Researcher Rory O'Donnell said: "Everyone knows a relative who smoked until they were 90.

"The majority of smokers do not develop emphysema - although there are plenty of other smoking-related diseases.

"No one knows why some smokers avoid the disease.

"We are looking for three types of volunteers - smokers who have developed emphysema, smokers who haven't developed the disease and healthy non-smokers.

"They must be aged between 40 and 65. All volunteers will be given a detailed lung examination using the latest scanning technology."

Anyone wishing to take part in the study should call Meredith O'Donnell on 023 8079 4343.