The influence of anthropogenic pollution, particularly with polycyclic aromatic hydrocarbons (PAHs) on soil toxicity and spread of antibiotic resistance genes (ARGs) is extremely important nowadays. ...We studied 20 soil samples from a technogenically polluted site, municipal solid wastes (MSW) landfills, and rural settlements in the southwestern part of the Rostov Region of Russia. A close correlation was established between the results of biosensor testing for integral toxicity, the content of genes for the biodegradation of hydrocarbons, and the concentration of PAHs in soils. The relation between the quantitative content of ARGs and the qualitative and quantitative composition of PAHs has not been registered. Soils subjected to different types of the anthropogenic pressure differed in PAHs composition. The technogenic soils are the most polluted ones. These soils are enriched with 5 ring PAHs and carry the maximum variety of assayed ARGs, despite the fact that they do not receive household or medical waste.
•At biotesting soils contaminated with industrial PAHs are more toxic than landfills.•Technogenically polluted soils are enriched with 5 ringPAHs compared to landfills.•Technogenically polluted soils contain more diverse ARGs.
•The high content of pollutants negatively affects bacterial biodiversity.•The structure of soil microbiome depends on the pollutant type.•Pollutants have diverse effects on different bacterial taxa.
...Metagenomic studies of soil microbocenoses are extremely relevant nowadays. The study of pollution impact on soil microbiomes is of particular interest. The structure of microbial communities in soils with different levels of pollution by polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) was studied. High bacterial biodiversity was found in all the studied soil samples, but its lowest values are found in soil samples taken on the territory of technogenically polluted Lake Atamanskoye. Assessment of soil pollution showed the highest content of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) for the soils Lake Atamanskoye. The high content of pollutants negatively affects the abundance of representatives of the phyla Actinobacteria, Planctomycetes, Verrucomicrobia, and Nitrospirae. Such phyla as Proteobacteria, Candidate Divisions TM7, OD1, WPS-2, Chlamydiae, Cyanobacteria are characterized by positive direct correlation with the content of pollutants, especially with PAHs. A cooperative effect of decrease in the number of Actinobacteria and Proteobacteria with an increase in Armatimonadetes probably corresponds to PTEs contamination. The proportion of Candidate Division OD1, Chlamydiae, Cyanobacteria, and Candidate Division WPS-2 was increased in the soil microbiome under the influence of severe combined pollution. Pollutants negatively affect the abundance of dominant unclassified_o__Gaiellales and unclassified_o__WD2101 genera. Iamia, Salinibacterium, Arthrobacter, Kaistobacter, Thiobacillus genera are characterized by a low abundance, but they are presumably the most resistant to soil pollution. It was revealed that the level of soil pollution largely determines the composition and diversity of bacterial communities in the soils of the studied territories. Operating taxonomic units have been established that have prognostic value for assessing the state, level of soil pollution, and their biological safety.
Total concentrations of Ti, Cr, Mn, Ni, Cu, Zn, Rb, Sr, and Pb as well as soil granulometric texture were studied for three plot sites representing different geomorphologic units of the southwestern ...part of Western Siberia: periphery of the upland Tobolsky Mainland, Ishim plain, Turinskaya plain. Interregional difference in the relationship by and among the content of trace elements and particle size distribution of soil horizons is established. Thus, for the soils of Turinskaya plain such interrelations are not observed. For the soils of Ishim Plain moderate negative correlation between Pb concentrations and medium silt, as well as average positive correlations between Zn and fine sand, coarse sand and Pb are found. For the soils of the high terraces of the Irtish and periphery of Tobolsky Mainland interface zone moderate positive correlations between contents of Ti, Zn, Sr and fine sand, weak positive ones between Rb and medium sand, moderate negative ones between Zn and clay, Ti, Ni, Cu, Zn, Rb, Sr, and fine dust, Ti, Cu, Zn, Rb, Sr and medium silt are observed. Consequently, properties and genesis of local parent rocks are significant factors for distribution and accumulation of trace elements in the soils of the southern taiga; at the same time, the processes of bioaccumulation in thick humus horizons of dark gray soils and chernozems apparently play an important part in accumulation and migration of trace elements in forest-steppe soils of Ishim and Turinskaya plains.
Studies of polycyclic aromatic hydrocarbons (PAHs) content in soils adjacent to power plants is essential to determine the environmental risks. The monitoring was carried out over 3 years on the ...territory under the emissions of Novocherkassk Power Station (NPS). A significant excess in the PAHs content (up to 84-86%) in the soils under long-term industrial pollution was found compared to the background soil. The total PAHs content in the NPS emissions zone soils increased from 3553.1±25.4 to 4137.0±37.6 μg kg-1 at the most contaminated area located 2.1 km away from the enterprise in the prevailing wind direction. The increment was mostly observed in the content of high molecular weight (HMW) PAHs near the territories used for agricultural production. The LMW PAHs/HMW PAHs ratio of more than 1 indicates PAHs natural origin in the reference area soil. Moreover, it was found that in the NPS emissions zone soils the LMW PAHs/HMW PAHs ratio was 0.12-0.34 on the average, which is less than 1, that shows an anthropogenic origin of PAHs. The increase of this ratio with distance from NPS indicates lower anthropogenic pressure on the soil with longer distance from the emission source.
Aeolian sands and ancient dune fields are widely widespread in the southern part of Western Siberia. Aeolian landscapes formed in the bottom part of large ancient valleys, on the surfaces of modern ...fluvial terraces and near large lake systems are characterized by the unique soil cover which is determent by the sedimentalogical, mineralogical and granulometric properties of sands and very slightly dependent from local vegetation and climate. Soils of ancient inland dune landscapes located within the ancient valleys of Ob-Tom interfluve were investigated. It was shown that local topography is the main factor controlling the diversity of soils. Soils developed in dune topographical sequences differ from each other in the thickness of eluvial-illuvial horizons, content of humus and oxalate-extractable iron. Humus accumulation and podsolization process are rather poor because of the low ash content in the litter, intensive natural and anthropogenic dynamics of aeolian landscapes and adjacent soils. The fact that processes of lateral podsolization determine the processes of soil development in such landscapes has been established. All soils are characterized by a small thickness of the modern profile − 50 cm and even less for the flat surfaces of dunes. Clayey lamellaes typical for aeolian sediments are present in the bottom parts of soils profiles, located in the lower part of the dune-interdune sequence. It is rather obvious that thick cemented lamellaes are a powerful soil-geochemical barriers that largely determines the conditions for lateral and radial migration.
PDF
