Study on the relationship between soil properties and activity concentrations of radioisotopes in some environmental samples

In this work, activity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs in soil and plant samples in Vi Thanh City were analyzed by laboratory gamma spectrometer with HPGe detector based on the Full Spectrum Analysis (FSA) method. The analytical results showed that the radioactivity values of ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs reach the highest values in the Gleysols. The radioactivity contents of ²²⁶Ra, ²³²Th and ¹³⁷Cs in some soil samples exceeded the average value reported by UNSCEAR (Sources and effects of ionizing radiation. Report of the United Nations Scientific Committee on the Effects of Atomic Radiation to the General Assembly, United Nations Scientific Committee on the Effects of Atomic Radiation, New York, 2000). Among many considered soil properties, the pH, electrical conductivity, organic carbon content and cation absorbance are correlated with the radioactivity content in the soil samples. The analysis of soil-to-plant transfer factors showed the general absorption trend in plants with the orders of transfer factors ⁴⁰K > ¹³⁷Cs > ²²⁶Ra > ²³²Th. (author)