Distributions of environmental radionuclides in a marine core from the eastern continental shelf of Hainan Island, South China Sea and risk assessment

Several long half-life natural and anthropogenic radionuclides, including 137 Cs, 226 Ra, 232 Th, and 40 K, in a 45 cm-long sediment core collected from the east continental shelf of Hainan Island, South China Sea, have been analyzed. The results showed that mean activity of 137 Cs, 226 Ra, 232 Th, and 40 K were 2.03 ± 1.2, 20.4 ± 1.8, 45.7 ± 3.0, and 520.0 ± 20.0 Bq/kg, respectively. Radium equivalent activity and External hazard index imply a low radiation, and the study area could serve as a background reference value for environmental radionuclides in east continental shelf of Hainan Island, South China Sea.