History of radiation research, discovery, and progress, including the first uses of radiation as cancer therapy.
1800s People, particularly upper-class women, are disciplined in avoiding sun overexposure. Brimmed hats, veils and parasols are used for sun protection and become fashionable. Some women even wear collapsible hoods to shade their faces.
1890s Niels Finsen, a Danish physician, reports the first successful use of UV radiation in treating tuberculosis. The treatment, known as phototherapy, becomes a major physical therapy in the early 20th century.
1894 Dermatologist Paul Gerson Unna publishes a textbook on the histopathology of skin diseases and is credited with being the first to associate long-term exposure to the elements and precancerous changes in the skin. However, clinical reports linking skin cancer and sun overexposure do not receive coverage in the press, and the findings receive little attention from physicians outside the dermatology field.
1895 Wilhelm Conrad Roentgen discovers X-rays.
1898 Marie and Pierre Curie report the discovery of radium.
1904 In his initial work with X-rays, Clarence Madison Dally (Thomas Edison’s assistant) is believed to be the first person to die from a radiation-induced malignancy.
1920s Sunbathing and use of UV lamps become widely popular. Warnings from dermatologists in advertisements are unable to overshadow cartoons and articles in the press that call sunshine “good medicine” and “the finest tonic and health-builder in the world.”
1925 to 1930 400,000 bottles of Radiothor, a potion containing radium that was said to cure various health issues, including stomach ulcers and impotence, are sold in the United States.
1930s UV radiation becomes recognized as a human carcinogen. The American Medical Association establishes guidelines for UV lamps, and the U.S. Public Health Service begins to issue warnings about the risks of sunbathing.
1945 United States drops atomic bombs on Hiroshima and Nagasaki. The Life Span Study of 94,000 survivors reports in 1997 that of approximately 9,300 cancer deaths, an estimated 5 percent are attributable to radiation exposure.
1950s Use of Thorotrast (thorium dioxide, a radioactive material), employed as a contrast agent in medical radiology, was discontinued after it was found to cause various types of cancer.
1950s to 1960s Nuclear testing dusts cancer-causing radioactive iodine across Nevada, Utah, Arizona and Idaho. Most residents who later get cancer as a result of the fallout receive federal compensation through the Radiation Exposure Compensation Act.
1979 NASA collects its first satellite data on ozone levels.
1987 Montreal Protocol begins banning ozone-depleting substances known as CFCs; the 1990 Clean Air Act sets a schedule for ending CFC production.
1994 NTP lists radon as a known human carcinogen (a decade later, NTP lists ionizing radiation as a known human carcinogen).
2000 The ozone hole reaches a record size of 11.4 million square miles. Gradual recovery of the ozone resulting from the ban of CFCs leads to the hole decreasing to 9.4 million square miles in September 2004.
2005 WHO recommends that no one under 18 should use a sunbed.