Distribution of heavy metals and radionuclides in the sediments and their environmental impacts in Nansha Sea area, South China Sea

• Published in: Marine pollution bulletin Vol. 166; p. 112192
• Main Authors: Liu, Jing, Peng, Anguo, Deng, Shuang, Liu, Min, Liu, Guangshan, Li, Chao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2021; Elsevier BV
• Subjects: Analytical methods; atomic absorption spectrometry; Cadmium; China; Chromium; Cobalt; Contamination assessment; Copper; Cores; Correlation analysis; Ecological risk assessment; Emission analysis; Environment; environmental assessment; Environmental impact; Environmental Monitoring; Geologic Sediments; Germanium; Heavy metal; Heavy metals; Humans; Inductively coupled plasma; Lead; marine pollution; Metal concentrations; Metals; Metals, Heavy - analysis; Nansha Sea area; Nickel; Pollutant load; Pollution index; Pollution load; Radioisotopes; Radionuclide; Radionuclide kinetics; Radium 226; Radium isotopes; Radium radioisotopes; risk; Risk Assessment; Sediment; Sediment samples; Sediments; South China Sea; Spectrometry; Spectroscopy; Statistical analysis; Water Pollutants, Chemical - analysis; Zinc; China; South China Sea; Nansha Sea area; Radionuclide; Sediment; Contamination assessment; Heavy metal
• ISSN: 0025-326X; 1879-3363; 1879-3363
• DOI: 10.1016/j.marpolbul.2021.112192

Activity concentrations of radionuclides (238U, 226Ra, 232Th, and 40K) in the sediments of eight sampling stations and heavy metal concentrations (Cr, Co, Ni, Cu, Zn, As, Cd, and Pb) in the sediments of two long cores from Nansha Sea area were obtained by high-purity germanium spectroscopy and inductively coupled plasma atomic emission spectrometry. In a correlation analysis between the radionuclides and heavy metals, 232Th was positively correlated with As and Pb. 238U demonstrated a significant positive correlation with Co, Ni, Cu, Zn, and Cd. 40K was positively correlated with Co, Ni, and Cu. The geo-accumulation index, pollution load index, potential ecological risk index, and multivariate statistical techniques were used to evaluate the pollution degree and possible sources of heavy metals in the sediments. An ecological risk assessment suggested that Cr, Co, Ni, Cu, Zn, Cd, and Pb were primarily derived from natural processes, while the source of As may be related to natural processes and human activities. The geo-accumulation index (Igeo) of heavy metals in the sediment profiles was used to study the quantitative index of heavy metal pollution in sediments. [Display omitted] •A total of 121 samples from two long sediment cores with depths of 773 cm and 420 cm were analyzed.•Four radionuclides and eight heavy metals in sediments were studied at the same time.•232Th was positively correlated with Pb. 238U showed significant positive correlation with Co, Ni, Cu, Zn and Cd.•The high concentration of As in the core was related to the environment and climate change of the Last Glacial Period.