The correlation of soil properties, climate factors, and 137Cs activity in soils

The entry of ¹³⁷Cs into the soil can lead to its presence in food and water. Understanding how ¹³⁷Cs behaves in soil is important for predicting its environmental fate. Thirteen agricultural and one pasture soil sample were collected from various locations. A comprehensive analysis of the soil's physicochemical properties and climate and geographical factors was conducted. ¹³⁷Cs activity and clay mineralogy were determined using γ-spectrometer and x-ray diffraction. Correlation analysis between measured factors with ¹³⁷Cs activity revealed that the presence of carbonate minerals played a significant role in the negative correlation between pH and ¹³⁷Cs activity (r = −0.43). While a weak negative correlation was observed between clay mineral content and ¹³⁷Cs activity (r = −0.12), the type of clay minerals presents proved to be more influential on ¹³⁷Cs adsorption. Smectite minerals exhibited a positive correlation with ¹³⁷Cs activity (r = 0.46), aligning with the correlation between ¹³⁷Cs activity and precipitation (r = 0.49). The strong positive correlation between longitude and ¹³⁷Cs activity (r = 0.66, p < 0.01) was not directly indicative of longitude's influence on nuclear fallout distribution. Instead, this correlation was attributed to the interplay of other factors, including precipitation, smectite, calcium carbonate, and chlorite minerals. The possible effect of soil erosion, land use, and human activity on ¹³⁷Cs activity was discussed in provinces with similar soil and climate characteristics. This research explored the potential influence of various factors on ¹³⁷Cs activity, highlighting the complexity of environmental factors in accurately estimating ¹³⁷Cs levels in soil.