Finnish experts say UVA radiation more harmful than previously thought

Sunscreens often protect only against UVB

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With the summer approaching, Finns are being warned again about the dangers of excessive exposure to the rays of the sun. New research indicates that UVA radiation, long considered to be far less harmful than the UVB radiation that causes sunburns, is a greater skin cancer hazard than previously thought. UVA is the part of the ultraviolet spectrum that tans the skin.
      "UVA radiation has been seen as a kind of harmless little brother, even though its carcinogenic effects have been known for a long time", says researcher Riikka Pastila.
     
UVA does not burn the skin, but it penetrates deeper, reaching into the basal cells, where they can cause permanent cellular changes.
      UVA rays have also been found to weaken the skin’s immune defences, which also increases the risk of skin cancer. When there is exposure to both UVA and UVB at the same time, the two types of radiation reinforce each other.
     
Pastila sees no need for panic: she says that normal protection is enough. However, she warns against relying on sunscreens alone.
      Sunscreens provide good protection against the UVB rays, but their protection against UVA radiation is often weaker than advertised. As the UVB protection prevents the skin from burning, sunbathers are easily lulled into a false sense of security, and feel that they can safely spend hours with their skins exposed to the sun.
     
Matti Rautalahti, head physician of the Finnish Cancer Organisations, says that it is all right for Finns to enjoy the sun in moderation. However, he is concerned about the hard-core tanners who prepare holidays to warm climates by taking a series of sessions in tanning beds, and then spending the whole holiday lying on the beach.
      Last winter there was much talk about a Finnish study suggesting that vitamin D might help prevent the onset of cancer. Rautalahti urges moderation in this.
      "To get enough vitamin D, it is sufficient to spend a normal amount of time out-of-doors. Scientific evidence of the effectiveness of vitamin D in the prevention of cancer is still weak", he says.


Links:
  Medical College of Wisconsin Healthlink: Sunscreen, Skin Cancer, and UVA

Helsingin Sanomat