Relationship between activity concentrations of ⁴⁰K, ²³²Th and ²²⁶Ra in soil and soil properties within Vi Thanh town (Hau Giang province)

In this research, activity concentrations of radionuclides ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs in soil and plant samples in Vi Thanh city were analyzed by gamma spectrometer using HPGe detector and FSA method. The properties, physico-chemical composition (soil pH, electrical conductivity, density and structural properties) of the soil samples were also determined by appropriate methods. Transfer factor (TF) of the radionuclides from soil to plant were also determined and evaluated. Analytical results showed that radioactivity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs were the highest in the Gleysols. In some soil samples the radioactivity concentrations of the radionuclides exceeded the average value of UNSCEAR 2000. The radioactive concentration of ¹³⁷Cs in soil samples found to be lower compared to those found elsewhere in the world. The TF appeared to be increased by an order ⁴⁰K > ²²⁶Ra > ²³²Th. Radioactivity concentrations of the radionuclides well correlated with soil pH, electrical conductivity, organic carbon content and cation exchange capacity. (author)