Evaluation of ecological risk, source, and spatial distribution of some heavy metals in marine sediments in the Middle and Eastern Black Sea region, Turkey.

Aylin Apaydın,Engin Tıraşoğlu,Erhan Cengiz,Gökhan Apaydın,Hasan Baltaş,Murat Şirin,Oğuz Kağan Köksal,Hatice Kabaoğlu

doi:10.1007/s11356-021-16017-4

Abstract

In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling locations in the Middle and Eastern Black Sea regions, Turkey, were measured using energy dispersive X-ray fluorescence spectroscopy (EDXRF). Various pollution parameters and methods, such as the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), ecological risk index (RI), and geo-spatial distribution patterns, were used to assess the pollution status, ecological risks, and sources of metals in sediment in detail. The mean concentrations of Mn, Fe, Ni, Cu, Zn, Cr, and Pb were found to be 565.38, 46,000, 34.38, 104.06, 109.88, 87.31, and 32.31 mg/kg, respectively. Results showed that the mean concentrations of Cu, Zn, and Pb exceeded the crustal shale value, with the exception of Mn, Fe, Ni, and Cr. According to the calculated pollution parameters, although minimal or moderate pollution was detected in the area investigated, it was determined that there was a very low ecological risk. Multivariate statistical analysis results showed that Cu, Zn, and Pb levels in the investigated region were slightly influenced by anthropogenic inputs such as mining and agricultural practices. In addition, the geo-spatial distributions of Cu, Zn, Fe, and Pb were found to be higher in this region due to the mining activities carried out in the Eastern Black Sea region.

Highlights

49 Human activities and the processes of rocks such as fragmentation, transportation and sedimentation are increasing the accumulation of heavy metals in sea bottoms
Average metal concentrations were found in the order of Fe > Mn > Zn > Cu > Cr > Ni > Pb. In the ase of Mn, Fe, Ni and Cr, the concentration in all sampling locations is lower than the average shale value reported by Krauskopf (1985) while the mean concentration of Cu, Zn, and Pb is greater than the average shale value due to pedogenic process and human–origin inputs such as mining activities, agricultural runoffs, and traffic emissions
In order to test the normality of the data, the Kolmogorov–Smirnov test (K–S) was applied to the data obtained and the distribution of the data was considered normal if the p value was above 0.05 (Kelepertzis 2014; Cai et al 2015)

Summary

Introduction

49 Human activities and the processes of rocks such as fragmentation, transportation and sedimentation are increasing the accumulation of heavy metals in sea bottoms. Sediment is an important accumulation place for heavy metals It is very often used in the determination of metal contamination of the aquatic environment. Agricultural surface water and inadequate treatment of urban sewage effluents are the main sources of metal pollution in the Black Sea coast of Turkey (Topcuoglu et al 2003). The Black Sea region has a very rich potential in terms of Cu, Zn and Pb mineral reserves. For this reason, the wastes of the mentioned mines are transported to the marine environment by means of surface waters, as well as rivers and streams of various sizes (Çevik et al 2008; Baltas et al 2017a). The sediments in the Black Sea have been negatively suffered by the anthropogenic contaminations (Yiğiterhan and Murray 2008; Mülayim and Balkıs 2015)

Methods

Results

Conclusion