Inventory and vertical migration of 137Cs in Spanish mainland soils

► Measured the 137Cs activity in Spanish mainland, being within a range of [251, 6074] Bq/m2, with a mean value of 1726 Bq/m2. ► Establishment of the 137Cs background by means of a 137Cs inventory map showing its distribution in the Spanish mainland. ► 137Cs shows two different behaviour tendencies in soil depending on it. ► The parameters which govern the applied model have been obtained for the analysed profiles. ► Analysed those parameters, the two tendencies have been reflected in the obtained values.