Resuspension processes controll variations of [sup.137]Cs activity concentrations in the ground-level air

The [sup.137]Cs activity concentration in the surface air between 1977 and 2007 was decreasing with an ecological half-life of 3.4 years, however, during 2007-2010 the yearly averaged [sup.137]Cs activity concentrations were almost constant. The increased atmospheric [sup.137]Cs and [sup.40]K levels observed during the winter may be due to surface soil resuspension and radionuclide transport by winds, particularly from open agricultural areas, as confirmed by high correlation coefficient between [sup.137]Cs and [sup.40]K atmospheric levels (R = 0.84), and similar 7Cs/ K activity ratios in aerosols (0.07) and soils (0.05). Keywords Atmospheric radioactivity * Aerosols * Global fallout * Radionuclides * Soil resuspension