The influence of Brazilian soils properties in Americium sorption

Although some radioecological studies have been accomplished in Brazilian soils supplying useful information to optimization of emergency planning actions in rural areas and to the management of soils contaminated by Cs-137, Co-60 and Sr-90, few studies were made with transuranic elements in tropical agricultural areas. The different scenarios found in Brazilian agricultural environments enhance the importance of studying the biogeochemical behavior of radionuclides in representative soils. The objective of this work was to determine the mobility of Am-241 in 3 different Brazilian agricultural soils evaluating migration with depth and Kd values for Am-241 and the effect of organic amendments on this behavior. A strong effect of organic amendments on mobility of americium could be observed. The values of Kd obtained in all studied tropical soils were however smaller than those found in European soils and from those recommended by IAEA to be used as default values in the absence of regional data. This result reinforces the vulnerability of some tropical soils to a contamination, emphasizing the need to use of regional values.