Level, distribution and sources of plutonium in the northeast and north China

Concentrations of 239 Pu and 240 in 163 surface soil samples five cores collected from the northeast north China were analyzed using radiochemical separation combined with inductively coupled plasma mass spectrometry measurement. The average Pu/ atomic ratios (0.185 ± 0.018) for all indicated that global fallout is major source plutonium studied region. 239,240 concentrations ranged 0.002 mBq/g to 4.82 mBq/g, lying range reported results areas similar latitude, except a few samples. distribution this region controlled by deposition atmosphere its preservation soil, which affects multi-factors such as topography, climate, utilization land vegetation coverage. analytical could be used baseline data assessment impact nuclear activities past future. • Global Northeast China. topography precipitation are key factor Pu. westerlies monsoon important Land use reservation soil.