SOIL-FUNGI RADIOCESIUM TRANSFER IN FOREST ECOSYSTEMS IN MEXICO

Eight different species of fungi were collected at the Nuclear Center of Mexico (NCM) together with soil samples from mushroom growing spots , during 1993. The samples were analysed for Cs-137 and K-40 using gam ma spectrometry. To quantify the transport of Cs-137 from the soil int o the mushrooms, the Aggregated Transfer Coefficient (ATC) was determi ned. The results indicate that radiocesium absorption varies over a wi de range among several fungi species as a function of factors such as mycelium deepness, and fungi symbiotic or saprophytic features. Two lo cal species were found to have the highest ATC for Cs-137. The K-40 co ntent was found to be lower for mycorrhyzal species. (C) 1996 Elsevier Science Ltd.