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

Abstract The entry of 137 Cs into the soil can lead to its presence in food and water. Understanding how 137 Cs 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. 137 Cs activity and clay mineralogy were determined using γ‐spectrometer and x‐ray diffraction. Correlation analysis between measured factors with 137 Cs activity revealed that the presence of carbonate minerals played a significant role in the negative correlation between pH and 137 Cs activity ( r = −0.43). While a weak negative correlation was observed between clay mineral content and 137 Cs activity ( r = −0.12), the type of clay minerals presents proved to be more influential on 137 Cs adsorption. Smectite minerals exhibited a positive correlation with 137 Cs activity ( r = 0.46), aligning with the correlation between 137 Cs activity and precipitation ( r = 0.49). The strong positive correlation between longitude and 137 Cs 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 137 Cs activity was discussed in provinces with similar soil and climate characteristics. This research explored the potential influence of various factors on 137 Cs activity, highlighting the complexity of environmental factors in accurately estimating 137 Cs levels in soil.