статья в журнале

En

Continental Shelf Research

ISSN:02784343

2025

Zhuravleva, A.A.²

10.1016/j.csr.2024.105386

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, 210Pbex, 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

Heavy metals, Mass accumulation rate, Pollution indices, Radionuclides, Sediment accumulation rate, The Kerch Strait

2025-01-16 12:21:19 (квартал- IV)