Irradiation and Hormesis

Since the discovery of radioactivity more than a century ago, there are mountains of data about the effects of radiation on health. There is consensus that large doses cause harm. However, intense controversy exists regarding the health effects of low-level radiation.

At the end of the 19th century and early in 20th century, it was generally believed that ionizing radiation has numerous beneficial effects. The low doses of radiation, mostly radium and X-rays, were considered to be medical marvels. It was claimed, for example, that blindness might be cured by X-rays. People went to spas to drink radioactive water or stayed for hours in caves to be irradiated by ionizing radiation. The “mild radium therapy” was widely used. This therapy involved the oral or parenteral administration of microgram quantities of radium and its daughter isotopes, often as cures for rheumatic diseases, hypertension, and metabolic disorders. Between 1925 and 1930 over 400,000 bottles of distilled water containing radium-226 and radium-228 were sold. It was advertised that some mixtures could treat over 150 diseases, especially lassitude and sexually impotence. The death of the Pittsburgh millionaire Eben M. Byers by radium poisoning in 1932 brought to an end to the era of “mild radium therapy” and alerted the public, and much of the medical profession, of the harmful effects of this therapy (for reviews see, e.g., Macklis 1990; Wolff 1992).