Characteristics of natural radionuclides and 137Cs in surface soil in Phonsavan, Xiengkhouang, Laos

Abstract

Assessment of the characteristics of natural radionuclides and 137Cs in soil in Phonsavan district, Xiengkhouang province, Laos has been conducted using a standard electrode coaxial Ge (SEGe) detector. Soil samples were collected at 20 locations close to the populated and agricultural area in Phonsavan district. The average activity concentrations of 226Ra, 238U, 232Th, 40K and 137Cs are 54.0 ± 2.5, 65.1 ± 4.4, 96.9 ± 3.7, 433.2 ± 20.7, and 1.54 ± 0.13 Bqkg-1, respectively. The average radium equivalent activity Raeq is 225.9 ± 7.8 Bqkg-1. The highest Raeq of 269.9 Bqkg-1 is still lower than the safety limit of 370 Bqkg-1. Associated radiological hazard indices, such as absorbed gamma dose rate, outdoor annual effective dose equivalent, excess lifetime cancer risk, external and internal hazard indices, and gamma index, were also calculated and presented.

Keywords

• natural radionuclide
• 137cs
• soil sample
• activity concentration