UV exposuie represents the most important risk factor for the development of nonmelanoma skin cancer. Additionally, assessment of sun exposure parameters has consistently shown an association between the development of malignant melanoma and short term, intense UV exposure, particularly burning in childhood. As a consequence, protection of the skin from UV exposure is an integral part of skin cancer prevention programs. However, more chronic, less intense UV exposure has not been found to be a risk factor for melanoma and in fact has been found in some studies to be protective. Moreover, 90%...