THE EFFECT OF DIETARY LEVELS SELENIUM ON RADIATION-RESISTANCE AND RADIATION-INDUCED CARCINOGENESIS

Combined (internal plus external) radiation exposure of the population and emergency workers, as a result of the Chernobyl accident, increas ed the oncogenic risk, and to reduce it is a problem of the utmost imp ortance. A long-term experiment in 400 rats exposed to radiation follo wing the Chernobyl pattern showed that a selenium-enriched diet starte d after exposure caused a longer average lifespan and a 1.5 - 3.5 fold decrease of leukaemias and other malignancies, e.g. breast, thyroid a nd lung cancers, etc., at late times. Selenium was first demonstrated to provide protection against late effects which is equivalent to a wh ole-body dose reduction by 1.4 Sv (140 rem) The dietary levels of sele nium used were above those accepted as physiological but considerably below toxic ones (10, 30 and 100 mu g Se/day per capita).