Changes in soil and sediment properties due the impact of the urban environment

Abstract

During our investigation, we analyzed the urban soils from stream banks and sediment of Rák Creek in the area of Sopron, Hungary. The aim of this work was the determination of the anthropogenic influence on a given stream that flows through an urban area (in this case through the city). The assumption was that the streamflow becomes increasingly polluted with toxic elements as it passes through Sopron; we tried to determine the extent to which the stream is polluted. We had 72 urban soil samples at 36 points at 0-10 and 10-20 cm depths on 6 subcatchments for analyzing the background pollution of Rák Creek. In addition, 6 soil samples from the bank and 12 sediment average samples were taken from the dead region and from the thalweg as well. We analyzed the physical and chemical parameters as well as the heavy metals (e.g., Cd, Co, Cu, Pb, Zn and Ni) in all of the samples. Two element fractions, the total (HNO 3 ?H 2 O 2 -extractable) and the available (NH 4 -acetate?EDTA-extractable) were used for element determination. Toxic elements were measured by ICP-OES in the urban soils and the sediments as well. Urban soils of sub-catchments confirmed the following tendency. On the investigated creek points, the Co and Ni values were below the natural background limits (Co total 4.90-14.53 mg kg -1 , Co available 0.64-3.12 mg kg -1 ; Ni total 10.77-24.61 mg kg -1 , Ni available 0.75-3.21 mg kg -1 ).Cu total content was low except in the case of GYORI point. Pb total were under the pollution limit, but Pb available were higher than the suggested pollution limit ([25 mg kg) in the sediment of thalweg and in the soil of the creek bank at the GYORI site. Summarized, GYORI point was the most polluted; this is also confirmed by the enrichment factor (EF). EF for Pb and Zn increased as we moved toward the city. Based on the investigated properties, there were significant differences in heavy metals between the urbanized and non-urbanized areas. The concentrations of heavy metals were higher in the dead region than in the thalweg except for the GYORI samples. According to our results, the city affects the stream and its influence appears in the values: as soon as the stream reaches the city, most of results increase. Therefore, the degree of heavy metal contamination depends mainly on land use.

A Complex Soil Ecological Approach in a Sustainable Urban Environment: Soil Properties and Soil Biological Quality

“…The effects of urbanization on the natural environment were the focus in the three western Hungarian cities (Sopron, Szombathely, and Székesfehérvár) selected as case study regions in 2010. The results of Sopron and Szombathely have already been published [37,43,44]. In addition, water quality analyses were carried out for the watercourses of Székesfehérvár [38].…”

Urban gardens in Antiquity

“…Urban soils generally have higher bulk density, lower microbial biomass and activity, higher nitrification rates, higher pH, lower CEC, an external or ex-situ component, and in some cases enhanced development as compared to natural and less impacted soil systems (Pereira et al, 2016;Amossé et al, 2015;Yang and Zhang, 2015;Scharenbroch et al, 2005). One of the main characteristics of modern urban soils is contamination or pollution with heavy metals, in particular, Cu, Pb, and Zn, and organic pollutants including polycyclic aromatic hydrocarbons, which accumulates in urban soils, as well as in soils and sediments in city hinterlands (Horváth et al, 2016;Lehmann and Stahr, 2007;Pereira et al, 2016;Yang and Zhang, 2015).…”

A Roman provincial city and its contamination legacy from artisanal and daily-life activities

“…One of the markers of modern industrial and urban environmental impacts is heavy metal contamination in soils, sediments, air and water at local, regional and global scales [ 1 ]. However, modern contamination is not the only source with a global traceable impact.…”