Epidemiology of Chronic Disease Risks in Relations to Ultraviolet Radiation Exposure (invited paper)

Epidemiological study of the possible effects of ultraviolet radiation (UVR) exposure in man has concentrated primarily on ill-effects to the skin and eyes. There is evidence for a causal relation of UVR exposure to lip cancer, non-melanoma skin cancer, cutaneous melanoma, squamous cell carcinoma of the conjunctiva, and cortical cataract, but the type of exposure thought to be of importance varies between these outcomes. Much the most serious of these conditions in terms of mortality is cutaneous melanoma. Evidence on whether uveal melanoma is caused by UVR is equivocal. Issues of importance with regard to UVR-related epidemiology that remain uncertain or contentious and require further investigation include: the relationships of different types of skin cancer to the pattern of sun exposure; the degree of importance of childhood exposure to risk of cutaneous melanoma; the relationship of cutaneous melanoma to use of sunbeds; the possibility that PUVA may be aetiological for melanoma as well as for non-melanoma skin cancer; the effects of protective measures on skin cancer risks; the role of naevi in UVR-related risks of melanoma; and the genetic factors influencing UVR-related risks. There is also a need for development of better markers of solar UV exposure history and of phenotype. (author)