Exposure to electromagnetic radiation, invisible, high-energy light waves such as sunlight and X rays, accounts for about 2 percent of all cancer deaths. Most cancer deaths from radiation are from skin cancer, which is triggered by too much sun exposure.
Sunlight that reaches the Earth’s surface contains two kinds of ultraviolet (UV) radiation. UV-A and UV-B both contribute to sunburn and skin cancer as well as to conditions such as premature wrinkling of the skin. Depletion of the ozone layer, which absorbs ultraviolet radiation in the upper atmosphere, will continue to increase skin damage and skin cancer rates in the future. Radon, a colorless, odorless, radioactive gas, seeps from the Earth in some regions of the United States. Breathing the gas over a long period has been linked to a small number of lung cancer cases. Providing adequate air circulation in a building reduces exposure to radon. Infrequently, radiation exposure associated with medical treatments, such as therapeutic radiology, leads to cancer. This type of exposure is responsible for about 1 percent of all U.S. cancer deaths.