Introduction. River bottom sediments are a significant link in the biogeochemical cycles of water bodies and an accumulator of pollutants. The purpose of this study is to assess the level of heavy metal pollution of river sediments within the coal-mining areas of the East Donbass (Rostov Region, Russian Federation) to assess the potential risk for the population using surface water as a source of water supply. Methods. It is suggested to use the pelitic fraction for a more accurate assessment of the heavy metal pollution level of river sediments. It is proposed to use the average continental shale concentration as a baseline value for the pelitic fraction. Contamination factor (Cf), degree of contamination (Cd) and geo-accumulation index (Igeo) were used to assess the degree of heavy metal pollution of the bottom sediments in the East Donbass rivers. Results. Studies of the chemical composition and the level of bottom sediments pollution in the East Donbass rivers showed that the concentration values of heavy metals vary greatly. Assessing the degree of heavy metal pollution of the river sediments in the East Donbass allows us to classify them mainly as moderately contaminated (uncontaminated to moderately contaminated). At the same time, the level of river sediments pollution in the Seversky Donets basin is generally lower than that in the Tuzlov basin. Conclusion. The results will be used to improve the system for assessing water and bottom sediments quality in the region as well as evaluate the environmental risk to public health. Although the results showed a moderate level of heavy metal contamination of the East Donbass rivers sediments, the potential hazard of secondary pollution of the aquatic environment with metals deposited in sediments remains. Pollution of water and river bottom sediments is directly linked to the potential risk to public health because these rivers are used as sources of drinking water for towns and countryside.
A five-year study on the heavy-metal pollution of Guanabara Bay sediments (Rio de Janeiro, Brazil) and evaluation of the metal bioavailability by means of geochemical speciation
