Heavy metals in urban soil: Contamination levels, spatial distribution and human health risk assessment (the case of Ufa city, Russia).

The article examines the concentration of 9 heavy metals (Hg, Pb, Zn, Cr, Co, Ni, Cu, Ba and V) and As in the soil cover of the urban area in one of the largest cities in Russia, Ufa (the Republic of Bashkortostan). It is compared with aggregated data of concentrations on urbanized areas in surface soils throughout the world. For elements exceeding the average background values in soils of the urban area (Cr, Ni, Cu and Co), the average concentrations in the city soils were 346, 101, 51 and 18 ppm, respectively. Using enrichment factor (EF), geoaccumulation index (Igeo), and concentration coefficients (CC), Cr and Ni were identified as elements entering the soil cover as a result of anthropogenic pollution. Although the level of their enrichment and contamination of soils in the most territory of the city corresponds to the moderate class, there are sites with critical threshold values. Spatial analysis of heavy metals distribution was carried out based on the results of pollution load index (PLI) and ecological risk factor (Er) calculations with the use of graphical presentation of results, which allowed specific and detailed description of sites calling for special attention. The use of cluster analysis allowed dividing the sample of chemical elements into groups with probably similar sources of entry into the environment. Monte Carlo modeling of risk calculation showed negligible non-cancer risks for both adult and child populations in most of the city. While children's exposure to Cr was of concern in the more residential part of the city, free of large industrial plants, As posed a threat with respect to cancer risks in the southern part of the city, with elevated concentrations and other HMs in vicinity of the oil refineries.

Influence of local geological data and geographical parameters to assess regional health impact in LCA. Tomsk oblast', Russian Federation application case.

The research paper is aimed to modify the human health impact assessment of Cr in soils. The current article presents the input of several critical parameters for the human health Impact Score (IShum) assessment in soils. The modification of the IShum is derived using geological data - results of neutron activation analysis of soils are used in the IShum calculation; research area is divided using the watersheds and population size and density. Watersheds reflect the local environmental conditions of the territory unlike the administrative units (geographical areas of the studied region) due to their geological independence. The calculations of the characterization factor value underestimate the influence of the population size and density on the final result. Default characterization factor values cannot be considered during the assessment of the potential human health impact for the big sparsely inhabited areas. In case of very low population density, the result will be overrated and underestimated in the opposite case. The current approach demonstrates that the geographical separation in the USEtox model should be specified. The same approach can be utilized for other geo zones due to the accessibility of this information (area size, population size, and density, geological, and landscape features).

Influences of geological factors on the distribution of uranium in drinking water limescale in the junction zone of the East European Platform and the Southern Urals.

An assessment of uranium contents and distribution in drinking water limescale has been conducted in the Republic of Bashkortostan (RB), Russia. A total of 515 limescale samples from 262 settlements of the RB were analyzed. The spread of U concentration values in limescale samples ranged from 0.01 to 61.0 µg/g. Elevated U concentrations in the West of the RB corresponded with the horsts of the granite-gneiss crystalline basement of the South-Tatar Dome and their Eastern slopes, the areas with the Lower Permian red beds and the oil and gas fields. The U migration from the granite-gneiss basement is attributed to the tectonic factor and hydrocarbons movement. Elevated concentrations of U within the South of the RB are associated primarily with the deposits of the Southern Ural brown coal basin. The Bashkir Trans-Urals anomalies are mainly associated with Lower Paleozoic eclogite complex, Devonian and Carboniferous volcanic-sedimentary, carbonate, intrusive formations, as well as the Jurassic cover of terrigenous marine sediments. The negative anomalies of the spatial distribution of U are located in the area of the Ufimian Plateau mainly composed of limestone.