River Bottom Sediments of Technogenic Disturbed Geosystems of the Eastern Donbas: Comparative Assessment of Pollution Level with Heavy Metals by Russian and International Criteria

Abstract

The content distribution of heavy metals in river sediments within the technogenic disturbed geosystems of the Eastern Donbas (in the Seversky Donets and Tuzlov river basins) is studied. The content of heavy metals varies widely. At the same time, the highest concentrations are characteristic of iron and manganese and the lowest concentrations—of lead and cobalt. To assess the level of bottom sediments contamination with heavy metals we used the fraction <0.01 mm (pelitic fraction) extracted from gross samples. This fraction not only>dominates most of sediments’ samples but concentrates a major part of heavy metals, and has the best indicator properties when characterizing the pollution of river ecosystems. The work used generally accepted Russian and international indices such as total pollution index (Z_c), contamination factor (C_f), degree of contamination (C_d), geoaccumulation index (I_geo); in addition average continental shale values were used as a baseline concentration for the fraction <0.01 mm. The heavy metal pollution level of river bottom sediments in>the Seversky Donets and Tuzlov river basins is classified as “moderate” by the degree of contamination index and “uncontaminated” or “uncontaminated to moderately contaminated” by the geoaccumulation index, and “low” by total pollution index. In general metal contamination of river sediments is lower in the Seversky Donets basin than in the Tuzlov basin, which is associated with a more intense anthropogenic load. The results of using different indices seem to be comparable. Generally, the pollution level of river bottom sediments within the technogenic disturbed geosystems of the Eastern Donbas can be described as relatively low.