Technogenic and natural radionuclides in the bottom sediments of the Sea of Azov: regularities of distribution and application to the study of pollutants accumulation chronology

3rd International Conference Environment and Sustainable Development of Territories: Ecological Challenges of the 21st Century

生态环境科学;地球科学;经济学

Kuznetsov, A.N.^1 ; Fedorov, Yu A^1 ; Yaroslavtsev, V.M.^1

Southern Federal University, Bolshaya Sadovaya 105/42, Rostov-on-Don

344090, Russia^1

关键词: Anthropogenic pressures;    Atmospheric lead;    Chernobyl accident;    Natural radionuclides;    Naturally occurring;    Petroleum components;    Specific activity;    Vertical distributions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/107/1/012063/pdf
DOI  :  10.1088/1755-1315/107/1/012063

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The study of pollutants vertical distribution in seabed sediments is of high interest as they conserve the information on the chronology of pollution level in the past. In the present paper, the results of layer by layer study of Cs-137, Am-241, Pb-210 specific activities as well as concentrations of petroleum components, lead and mercury in 48 sediment cores of the Sea of Azov, the Don River and the Kuban River are examined. In most sediment cores, two peaks of Cs-137 and Am-241 are detected. The upper of them was formed due to the Chernobyl accident in 1986 and the other is related to the global nuclear fallout of 1960s. The specific activity of naturally occurring atmospheric Lead-210 decreases exponentially with the sediment core depth. However, it is influenced by fluvial run-off, coastal erosion, Radium-226 and Radon-222 decay. The data on the radionuclides distribution in the seabed sediments is used to date them. According to the results of dating, most of petroleum components, lead and mercury quantities are concentrated in the upper sediment layer formed in the last 50 to 70 years i.e. in the period of the most important anthropogenic pressure.