Melanoma - both its incidence and its mortality - has been increasing in many populations around the world recently.1 Even higher rates have been predicted as a result of the depletion of stratospheric ozone.2 Many agencies around the world are now developing programmes to prevent melanoma in the future. For example, the control of skin cancer (including melanoma) is included as one of the targets in the Health of the Nation.3

Preventing disease relies on knowing both its cause and practical and cheap ways of either avoiding the cause or blocking its effect. Most people attribute the rising incidence of melanoma to social and behavioural changes this century that have resulted in increased exposure to sunlight.4 The fashion for a suntan, associated with increasing public acceptance of decreasing proportions of the body being covered while outdoors, has led to large numbers of people being exposed to sufficient sunlight to cause sunburn during leisure hours.5

Exposures sufficient to cause sunburn, particularly in childhood, have been targeted by most educational programmes as the main changeable component in the process that leads to …