Urban geochemical changes and pollution with potentially harmful elements in seven Russian cities

Abstract

This paper presents results of an analysis of potentially harmful elements (PHEs, Pb, Zn and Cu) and conservative element (CE, Fe) concentrations in urban surface deposited sediment (USDS). The study was conducted in seven large Russian cities located in different geographic and climatic zones, and in territories with different geology and anthropogenic pressures: Chelyabinsk, Magnitogorsk, Nizhniy Novgorod, Nizhniy Tagil, Rostov-on-Don, Tyumen, and Ufa. The initial geochemical baseline relationships between PHEs and CE concentrations in the USDS were reconstructed for each city applying an approach based on linear weighted fitting of PHE as a function of CE with lower weights assigned to more polluted samples. The reconstructed average initial baseline Pb, Cu, and Zn concentrations varied between 17-52, 25-196, and 91-413 mg kg −1 , respectively. Several new criteria for assessing the degree of geochemical transformation and pollution of the urban environment, such as the percentage of polluted samples, average pollutant concentration in polluted samples, and weighting degree index δ, were suggested and compared with common criteria, such as the PHE concentration and the geo-accumulation index. The environmental rank of a city significantly differed depending on whether the criterion for ranking was total pHe pollution or changes in comparison with the initial geochemical baseline. An urban landscape is an environment formed as an upper geological strata of the Anthropocene 1,2. The content of elements in environmental compartments in an urban area changes as a result of anthropogenic activities during landscape forming. The transformation of geochemical conditions in an urban area is a permanent environmental process governed by natural and artificial components. The content of elements in compartments of the urban environment at some initial moment, that either existed in reality or is assumed, before artificial and natural components of the environment were subject to any anthropogenic impact after creation of the landscape, is considered as initial geochemical baseline (IGB) conditions. Geochemical transformation and change of the IGB is a complex process affecting all components of the urban environment 3. The primary driving forces of the geochemical transformation include pollution of the environmental compartments by point and nonpoint sources 4 and erosion and degradation of the environmental compartments as a result of natural and anthropogenic impacts 5. Geochemical transformation in the urban environment consists of altering mineral and elemental composition, modification of physicochemical properties of the urban soil 6 , urban surface deposited sediment (USDS) formation, in particular road deposited sediment 4,5,7 , changes in volume of the surface stormwater runoff 8,9 , redistribution of pollutants 3,10 , and forming geochemical barriers 7 among others. USDS is an environmental compartment that is involved with the majority of geochemical transformation processes. In the urban environment, the ra...

Daily Variations In Wet Deposition And Washout Rates Of Potentially Toxic Elements In Moscow During Spring Season

“…This indicates the significant role of wet deposition processes for the PTEs input into terrestrial landscapes. The main sources of most of these PTEs are vehicle emissions, fuel combustion, tires and brake pads wear, road surface abrasion, roadside soil particles blowing, industrial enterprises emissions, as well as macroregional long-distance transport of pollutants (Demetriades and Birke 2015;Grigoratos and Martini 2015;Grivas et al 2018;Konstantinova et al 2020;Liyandeniya et al 2020;Logiewa et al 2020;Orlović-Leko et al 2020;Ramírez et al 2020;Seleznev et al 2020;Tian et al 2020), which is confirmed by the previously identified sources of snow cover pollution in the western part of Moscow (Vlasov et al 2020). The remaining PTEs on the territory of the MO MSU were apparently of mixed anthropogenic-terrigenous sources (P 38 , Ba 31 , As 30 , W 22 , Mn 20 , Sn 19 , Na 16 , Co 14 , Ni 12 , Be 11 , K 11 ) and terrigenous origin (Rb 6 , Cr 4 , Fe 3 ), which indicates the influence of solid particles blown out from the Earth's surface and included in the atmospheric precipitation.…”

Coarse Technogenic Material in Urban Surface Deposited Sediments (USDS)

“…The city of Rostov-on-Don is the most southern of the surveyed cities. According to previous studies, the city has the highest accumulation of dust and USDS due to the arid climate and bad cleaning and management of the urban environment [1,22]. The lower amount of the anthropogenic coarse material was found in Perm and Tyumen.…”

“…Each sample was taken from the local depressions of the microrelief from 3-5 localizations on the territory of the courtyard space of the quarter. The sample collection procedure was described in detail in previously published papers [22,25,46]. The sample mass was 1-1.5 kg.…”

“…While the environmental role of the USDS in modern cities had been demonstrated in the previous studies involving such characteristics as pollution with the heavy metals [22,24,25,46] and the contribution of the dust fraction [23], this study has been focused on the technogenic particles in the urban environment. The objectives of the study were: (1) the identification of particles of the anthropogenic origin found in the urban environment compartments; (2) the classification and characterization of the morphological features of technogenic particles; (3) the assessment of the amount of technogenic material in urban surface deposited sediments; and (4) in an urban environment; and (5) the characterization of cities according to the amount of technogenic material in the contemporary urban surface sediments.…”

“…USDS (urban surface-deposited sediments) is a common term characterizing the various types of loose sediment formed as a result of weathering, erosion, and destruction of soils, pavements, and construction in the urban environment, which is deposited in depressed areas as a result of surface runoff of relief [22][23][24]. The solid material of the USDS is composed of the particles of soil, sand, peat, dust, and small debris [25].…”