Radionuclides and heavy metals in the Kerch Strait sediments: Spatial distribution, fluxes and pollution loads

IF 2.1 3区地球科学 Q2 OCEANOGRAPHY

Continental Shelf Research Pub Date : 2025-02-01 DOI:10.1016/j.csr.2024.105386

Konstantin I. Gurov , Ekaterina А. Kotelyanets , Anna A. Zhuravleva , Dmitrii A. Kremenchutskii

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引用次数: 0

Abstract

The Kerch Strait is a shipping artery connecting the Black Sea and the Sea of Azov and plays an essential role in the transportation of chemicals between the seas, fishing, socio-economic and tourism activities. The primary factors affecting the strait's ecosystem are construction in the coastal zone (e.g., Crimean Bridge), dredging and soil dumping, port enterprises' operations and shipping. It is known that high concentrations of radionuclides and heavy metals (HMs) are harmful to aquatic organisms and human health due to their persistence, bioaccumulation, acute and chronic toxicity. The study aims to reveal the peculiarities of the spatial distribution of radionuclides (¹³⁷Cs, ⁴⁰K, ²¹⁰Pb_ex, ²²⁶Ra, ²³²Th) and HMs concentration (Cu, Fe, Cr, Pb, Ni, V, Zn, As, Mn, Ti) in the sediments of the Kerch Strait, assess their sedimentation fluxes, radiological hazard parameters and pollution indices. For this purpose, 12 samples of the surface sediments and four cores were collected in the strait in 2020. The concentration of most radionuclides and HMs in the surface sediments directly correlated with the percentage of mud fraction (r = 0.28–0.90) and TOC (r = 0.41–0.95). The results of Hierarchical cluster analysis and Principal component analysis indicated the presence of two sources of HMs in the surface sediments: geogenic and combined (geogenic + anthropogenic). From the mid-90s to 2020 the sediment and mass accumulation rates increased by a factor of 1.9 and 1.4, respectively. The temporal variability of radionuclides and HMs fluxes into sediments was reconstructed. The sedimentation flux of ¹³⁷Cs during 1980–1987 was nine times higher than that in 2014–2020. The average sedimentation fluxes of Fe, Zn and Pb during 2014–2020 additionally increased by 31, 21 and 25%, respectively. The radiological hazard parameters indicated no significant health risk to humans from radionuclides and no enrichment/pollution for most HMs. The main exceptions were Cr, Pb and As, for which the geoaccumulation index reached unpolluted to moderately polluted levels while the enrichment factor reached strong, minor and moderate levels, respectively.

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来源期刊

Continental Shelf Research 地学-海洋学

CiteScore

4.30

自引率

4.30%

发文量

136

审稿时长

6.1 months

期刊介绍： Continental Shelf Research publishes articles dealing with the biological, chemical, geological and physical oceanography of the shallow marine environment, from coastal and estuarine waters out to the shelf break. The continental shelf is a critical environment within the land-ocean continuum, and many processes, functions and problems in the continental shelf are driven by terrestrial inputs transported through the rivers and estuaries to the coastal and continental shelf areas. Manuscripts that deal with these topics must make a clear link to the continental shelf. Examples of research areas include: Physical sedimentology and geomorphology Geochemistry of the coastal ocean (inorganic and organic) Marine environment and anthropogenic effects Interaction of physical dynamics with natural and manmade shoreline features Benthic, phytoplankton and zooplankton ecology Coastal water and sediment quality, and ecosystem health Benthic-pelagic coupling (physical and biogeochemical) Interactions between physical dynamics (waves, currents, mixing, etc.) and biogeochemical cycles Estuarine, coastal and shelf sea modelling and process studies.