Persistent contamination of water and food by Chernobyl: reversibility of 137Cs fixation

Radiocaesium (137Cs) from the 1986 Chernobyl accident has persisted in freshwater fish in a Scandinavian lake for much longer than was expected1. On the basis of new data generalizing this observation, we propose that the continuing mobility of 137Cs in the environment is due to the so-called fixation process of radiocaesium in the soil tending towards a reversible steady state. Our results enable the contamination of foodstuffs by Chernobyl fallout to be predicted over the coming decades. Restrictions in the United Kingdom, for example, may need to be retained for a further 10-15 years, more than 100 times longer than originally estimated.