摘要 : The ~(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 ~(137)Cs activity concentrations were almost cons... 展开 The ~(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 ~(137)Cs activity concentrations were almost constant. The increased atmospheric ~(137)Cs and ~(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 ~(137)Cs and ~(40)K atmospheric levels (R = 0.84), and similar ~(137)Cs/~(40) activity ratios in aerosols (0.07) and soils (0.05). 收起