RESUMEN
Complex studies of soil cover within the urbanized areas represent one of the main research directions in environmental geochemistry. Urban soil geochemistry depends on a combination of natural and urbanization factors unique to each urban environment. Although Tyumen, in Western Siberia, is an intensively developing urban city, a detailed geochemical survey of its soils has never been performed. In this study, we conducted a systematic geochemical soil survey across the urbanized area of Tyumen, Russian Federation. Surface soil samples (0-10â¯cm) were collected from 241 sampling sites: 1â¯×â¯1â¯km regular grid for highly urbanized areas, and 4â¯×â¯4â¯km grid for peripheral parts of the city. The contents of V, Cr, Co, Ni, Cu, Zn, As, Sr, and Pb were determined using XRF analysis. Data were interpreted using GIS and multivariate statistical analyses, including hierarchical cluster analysis and principal components analysis. The results showed a non-uniform spatial distribution of individual metals, associated with natural soil-lithological conditions and urban environment characteristics. Our data showed that variation in soil element content was origin dependent: V, Cr, and Co contents were related to their natural origin; As and Pb to their anthropogenic origin; and Ni, Cu, and Zn to their mixed origin. Elevated V, Cr, Co, Ni, Cu, and Zn contents correlated with proximity to motorway networks and machinery. Strong As and Pb anomalies were associated with the activity of battery enterprises. The spatial distribution of Sr was significantly different from other studied elements - anomalous content of this metal was confined to hydromorphic boggy landscapes of the city's northern part. In general, Tyumen territory was slightly polluted with metals. Zn and Pb contents were slightly lower than in most cities with similar population levels, while those of V and Co were higher. Other metal contents were comparable to those in large cities, with a long history of industrial development. Elevated Cr, Ni, Zn, Cu, As, Pb, and Co contents were observed in areas that developed during mid last century.
Asunto(s)
Contaminantes del Suelo/análisis , Suelo/química , Ciudades , Monitoreo del Ambiente/métodos , Metales Pesados/análisis , Federación de RusiaRESUMEN
Understanding urban soil geochemistry is a challenging task because of the complicated layering of the urban landscape and the profound impact of large cities on the chemical dispersion of harmful trace elements. A systematic geochemical soil survey was performed across Greater Athens and Piraeus, Greece. Surface soil samples (0-10cm) were collected from 238 sampling sites on a regular 1×1km grid and were digested by a HNO3-HCl-HClO4-HF mixture. A combination of multivariate statistics and Geographical Information System approaches was applied for discriminating natural from anthropogenic sources using 4 major elements, 9 trace metals, and 2 metalloids. Based on these analyses the lack of heavy industry in Athens was demonstrated by the influence of geology on the local soil chemistry with this accounting for 49% of the variability in the major elements, as well as Cr, Ni, Co, and possibly As (median values of 102, 141, 16 and 24mg kg(-1) respectively). The contribution to soil chemistry of classical urban contaminants including Pb, Cu, Zn, Sn, Sb, and Cd (medians of 45, 39, 98, 3.6, 1.7 and 0.3mg kg(-1) respectively) was also observed; significant correlations were identified between concentrations and urbanization indicators, including vehicular traffic, urban land use, population density, and timing of urbanization. Analysis of soil heterogeneity and spatial variability of soil composition in the Greater Athens and Piraeus area provided a representation of the extent of anthropogenic modifications on natural element loadings. The concentrations of Ni, Cr, and As were relatively high compared to those in other cities around the world, and further investigation should characterize and evaluate their geochemical reactivity.