[Skin cancers and environmental factors]

In the fair skinned populations of the industrialised nations, the number of cutaneous melanoma doubles every ten to twenty years. Currently, each year in Belgium, about 1,000 new cases of cutaneous melanoma and 15 to 20,000 basal cell or spinal cell epitheliomas are diagnosed. In Europe and in North America, the increase is essentially attributable to the considerable changes in sun exposure habits that took place after World War II. The type of ultraviolet radiation implicated in skin cancers is not known yet, but both the ultraviolet A and the ultraviolet B radiation could be involved in their occurrence. The impact of the stratospheric ozone depletion on skin cancer incidence remains uncertain. The impact of the stratospheric ozone depletion on skin cancer incidence remains uncertain. The sunbed tanning fashion represents another potential source of hazards for skin cancers. Their use must be discouraged. Some European countries have now adopted regulations about their commercialisation and utilisation. Current sun protection messages insist on the physical sun protection (wearing of clothes, staying in the shade), rather than on the use of a sunscreen. In fact, nearly all epidemiological studies done so far have found sunscreen use to be associated with a higher risk of melanoma or non-melanoma skin cancer. Because of their ability to delay sunburns, sunscreens could encourage excessive sun exposure. Sunscreen users should be told to voluntarily limit their sun exposure. New sun protection methods include the measurement of the individual exposure to ultraviolet radiation, with the emission of a signal when a critical level of exposure has been reached.