The Cancer Risk from Low Level Radiation

Abstract

There have been many situations in which large numbers of people have been exposed to high levels of radiation, and through studies of them^1,2 the health effects of high level radiation are rather well known. Among the survivors of the atomic bomb attacks on Japan, there were 24,000 people who received an average exposure of 130 rem, and about 120 extra cancers developed among them up to 1972. There were 15,000 British patients treated with X-rays for ankylosing spondylitis (arthritis of the spine) with doses averaging 370 rem, and they had about 115 extra cancers. Over 900 Germans were treated for that same disease with injections of radium-224 giving an average dose to the bone of 4400 rem*, and 45 of them got bone cancer (vs 0.1 expected). About 1700 U.S. women employed during the 1920s in painting radium on clock and watch dial numerals to make them self-luminous used their tongues to put a fine tip on the brush, getting radium into their bodies; their average bone dose was 17,000 rem and 48 of them died of bone cancer (vs 0.4 expected). Among 4100 U.S. uranium miners exposed to excess levels of radon gas due to poor mine ventilation, the average exposure to bronchial surfaces was 4700 rem and up to 1972 there were 135 lung cancer deaths among them vs 16 expected. There have been several other miner groups which have experienced excess lung cancers, like a group of 800 Canadian fluorspar miners whose average bronchial exposure was 2800 rem, resulting in 51 lung cancer deaths vs 2.8 expected.