People with different hair colours are being sought

Experts at Edinburgh University are looking for 400 volunteers aged between 18 and 30 to take part in the three-year research project.

They are appealing for blondes, brunettes and redheads to come forward.

Dermatologist Dr Terence Wong said people varied considerably in their sensitivity to sunshine.

"Understanding these differences is important because sunshine is the main cause of skin cancers," he said.

Skin cancer

"Nowadays, there is also greater scientific interest in understanding why humans vary so much in terms of hair, eye and skin colour.

"These wide variations in pigmentation have developed during the past 10,000 to 15,000 years and we want to find out more."

The study, funded by the Medical Research Council, has been described as one of the most extensive to be carried out in the UK into skin cancer.

The research programme aims to explore the link between the disease and exposure to the sun.

The study will investigate the links between the sun and skin cancer

Dermatologists will measure volunteers' skin, hair and eye colour and will take small samples of their hair, skin and blood.

The skin's tanning rate will then be measured after ultraviolet light is shined onto small areas of skin.

The study will take into account all different eye, skin and hair colours.

People aged between 18 and 30 are being sought because they are most likely to have their original hair colour.

However, those who are balding or have dyed hair will not be excluded from the test.

Dr Wong said malignant melanoma of the skin killed 132 people in 2002.