Radiation

Introduction Cancer and radiation are, both negatively and positively, indissolubly associated. The carcinogenic potential of ionizing radiation was recognized soon after Roentgens discovery of X-rays in 1895. In 1902 the first radiationinduced cancer was reported arising in the skin. Since the atomic bombing of Hiroshima and Nagasaki in 1945 there has been interest and concern about risks arising from this and other nuclear incidents, such as the Chernobyl accident in 1986. In the last few decades there is also concern about a possible link between cancer and transmission masts, electricity pylons, and, more recently, cell phones. In 1907, Dubreuilh published the first report of skin cancer caused by sun exposure. Ultraviolet radiation (UVR) is now recognized as the major environmental risk factor for skin cancer. Recent studies, however, have provided strong evidence that sunlight reduces the risk of other types of cancer, such as colon, breast, and prostate cancer.