Assessment of soil radioactivity levels and radiation hazards in Guangyao Village, South China

Soil samples were collected at 30 sampling points distributed evenly in Guangyao Village, South China to determine the radioactivity level around a monazite tailings pond via gamma spectrometry with an HPGe detector. The result of mean radioactivity concentration ± standard deviation of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil were 26.84 ± 4.36,8.87 ± 0.93 and 453.81 ± 99.95 Bq kg^-1, respectively. Shapiro-Wilk normality test results show ²²⁶Ra and ²³²Th radioactivity concentrations consistent with normal distributions. The natural radioactivity level in the soil was evaluated by Radium equivalent activity (Ra_eq), Absorbed dose rate (D_r), Annual effective dose equivalent (AEDE), Gamma level index (Iγ), Annual gonadal dose equivalent (AGDE), Internal Hazard Index (H_in) and External hazard index (H_ex). The radionuclides and radioactive hazard parameters were also statistically analyzed. A spatial distribution map of radionuclides was generated with a geographic information system and subjected to correlation analysis, principal component analysis and cluster analysis of radionuclides and radioactive hazard parameters. The results show that the radioactivity level in the soil of Guangyao Village is lower than the world average and recommended value, suggesting that it poses no significant threat to local residents. This work may provide baseline data for future soil radioactive environmental monitoring. (author)