2009:24 UV-radiation induced disease – roles of UVA and UVB

There is a large uncertainty concerning the impact of UVA and UVB radiation on the skin and eye. For example, UVA radiation used to be considered low risk since it was believed that DNA damage could only be caused by UVB radiation. However, recent studies show that UVA and UVB can give rise to similar DNA damages in human skin. Because of the potentially greater exposure to UVA while using sunbeds or UVB-blocking sunscreens, further information on the role of UVA is crucial. It constitutes a necessary foundation for the authority for its recommendations for prevention as well as regulations. In particular, the new findings may have a vast impact on the risk estimation and regulations of sunbeds.

Exposure to ultraviolet (UV) radiation is a dominating risk factor underlying skin cancer, but major uncertainties remain concerning its biological effects and cellular defence mechanisms, hindering implementation of effective preventive measures. A conference sponsored by the Swedish Radiation Protection Authority and the Swedish Cancer Society and held at Karolinska Institutet, Stockholm in October, 2007, brought together scientists studying different aspects of the biological impact of UV-radiation to present and discuss current knowledge of this area of research with special attention to the relative importance of short (UVB) and long (UVA) wavelength UV-radiation. This report is based on the evidence presented at that meeting.