Radioactivity and its effects. Consequences on the environment and bio-concentration in mushrooms

The Tchernobyl accident which took place on April 26, 1986, has revealed the risks linked with the use of nuclear energy and in particular its consequences on the environment and on the populations' health (thyroid cancers, acute childhood morbidity etc..). Radionuclides are excellent tracers which can be followed in all ecosystems, atmospheric, aquatic and terrestrial. Their migration through food chains is characterized by different concentration factors for each species. Mushrooms, like lichens, are excellent bio-indicators and reflect perfectly the favorable conditions of radionuclides bio-concentration and also the long-term evolution of radio-contamination. Despite the establishment of international radioprotection standards and tolerance levels for the importation of food products from foreign countries, mushroom samples taken in France and near Tchernobyl show cesium radioactivity levels much higher than the 600 Bq/kg threshold. Promoting the development of renewable energies is one solution to reduce the contamination risks linked with the domination of nuclear energy. (J.S.)