UVA rays, emitted by the sun and tanning beds, are more dangerous than previously thought, according to new research.
Although associated with premature ageing, UVA light was previously regarded as relatively harmless. However, a new study has revealed that it causes harm deeper down, increasing the risk of cancer.
Researcher, Professor Antony Young, of King’s College, London, compared the effects of both UVA and UVB rays on the skin of 12 healthy, young Britons.
He dismissed tanning salon claims that UVA is safe as “nonsense” warning that they “may be more carcinogenic than previously thought.”
Young, an expert in the effect of sunlight on the skin, also warned that it is not just the midday sun that is dangerous, as UVA levels are still high in the morning and in the late afternoon.
He revealed that even motorists are at risk as UVA penetrates glass.
After shining UV light on the skin of the volunteers, Professor Young took samples and studied them for potentially cancerous damage. The results showed that UVB, usually blamed for skin tumours, mainly damages the top layer of skin.
However, the outer cells are renewed and replaced every four weeks or so.
Conversely, UVA, which is associated with ageing but often dismissed as harmless, caused damage deeper down. What’s more, cells damaged by UVA grow and divide very quickly, increasing the risk of cancer.
“UVB is still the most important ultraviolet light in terms of damage to DNA, but UVA has a significant contribution,” he told the Journal of Investigative Dermatology.
Unlike UVB light, UVA rarely burns the skin so people are unaware when the damage is happening.
Professor Mark Birch-Machin, a skin scientist from Newcastle University said: “This is a sound piece of science from an excellent team of researchers.
"Although UVB causes more types of DNA damage than UVA for the same sunburn dose, the effects of UVA go deeper into the skin."
He added: "My advice remains the same: make sure you're putting enough sun cream on. Most people only apply a third to a half of the amount they need – make sure you're not one of them, especially if we have another autumn heatwave."