Accumulation and ecotoxicological risk assessment of heavy metals in surface sediments of the Olt River, Romania

Abstract

Heavy metal pollution of river freshwater environments currently raises significant concerns due to the toxic effects and the fact that heavy metal behavior is not fully understood. This study assessed the contamination level of eight heavy metals and trace elements (Cr, Ni, Cu, Zn, As, Pb, Cd, and Hg) in the surface sediments of 19 sites in 2018 during four periods (March, May, June, and October) in Olt River sediments. Multivariate statistical techniques were used, namely, one-way ANOVA, person product-moment correlation analysis, principal component analysis, hierarchical cluster analysis, and sediment quality indicators such as the contamination factor and pollution load index. The results demonstrated higher contents of Ni, Cu, Zn, As, Pb, Cd, and Hg, with values that were over 2.46, 4.40, 1.15, 8.28, 1.10, 1.53, and 3.71 times more, respectively, compared with the national quality standards for sediments. We observed a positive significant statistical correlation (p < 0.001) in March between elevation and Pb, Ni, Cu, Cr, and Zn and a negative correlation between Pb and elevation (p = 0.08). Intermetal associations were observed only in March, indicating a relationship with river discharge from spring. The PCA sustained mainly anthropogenic sources of heavy metals, which were also identified through correlation and cluster analyses. We noted significant differences between the Cr and Pb population means and variances (p < 0.001) for the data measured in March, May, June, and October. The contamination factor indicated that the pollution level of heavy metals was high and significant for As at 15 of the 19 sites. The pollution load index showed that over 89% of the sites were polluted by metals to various degrees during the four periods investigated. Our results improve the knowledge of anthropogenic versus natural origins of heavy metals in river surface sediments, which is extremely important in assessing environmental and human health risks and beneficial for decision-maker outcomes for national freshwater management plans.

A functionally-oriented approach to digitalization of the activities of competence centers in the field of agricultural cooperation

“…To do this, it is proposed to conduct analytical work to identify groups of agricultural producers whose objective performance indicators can lead to their unification with the support of a center of competencies. Various methods of cluster data analysis are used in various fields of scientific research -agricultural breeding [8], medicine [9], ecology [10], archeology [11], in this study, a practical implementation of the hierarchical clustering method in the software product [7] is undertaken.…”

Distribution of Heavy Metals and Organic Compounds: Contamination and Associated Risk Assessment in the Han River Watershed, South Korea

“…However, am substances, Cr showed the most prominent environmental impact with RQ season, demonstrating the potential risk of Cr on the ecological environme the risk level for each substance was high during the wet season, except Changes in the RQ values of all substances in the wet and dry seasons fo trends, with some substances (Hg, molinate, carbofuran, quinoline) havin ues, however, posing amplified risks at higher tropical levels, on bioacc assessment should, therefore, not be neglected as a factor in gauging the impacts of potential pollutants [2]. The results demonstrated the internal relationships between the metals and indicated that untreated industrial and municipal waste, as well as other geogenic activities, could be the possible sources of these elements [56], thus highlighting the role of anthropogenic and natural activities on heavy metal accumulation in the environment [31,57,58].…”

Past Metal(loid) Pollution Records Inferred from the Sediments of Bukit Merah Reservoir Perak, Malaysia

“…Substantial excess 210 Pb activity at the base of the recovered core showed a high sedimentation rate (Table 1). Indeed, the average sedimentation rate determined in BMR was higher compared to other reservoirs in Southeast Asia [47,48]. The reservoir, which has been undergoing serious sedimentation problems since 1984, was still highly degraded until 2018, showing severe erosion and siltation [49].…”