Priority organic pollutants in soils of the arboretum in the Botanical Garden of Moscow State University

The distribution of different homological groups of polychlorinated biphenyls (PCBs) in the urbanozem profile of the arboretum in the Botanical Garden of Moscow State University has been considered. The levels of their content, the composition of a congener spectrum, potential sources, and the ecotoxicological impact of soil pollution are assessed. The maximal concentrations of di-, tri-, and tetrachlorbiphenyls are observed in the technogenic layer of soil at a depth of 20–40 cm (0.30, 0.44, and 24.25 μg/kg, respectively), and penta- and hexachlorbiphenyls in the surface humus layer (42.33 and 17.89 μg/kg, respectively). The content of hepta- and oñtachlorbiphenyls varies insignificantly with increasing the depth (0.67–1.25 and 0.15–0.41 μg/kg, respectively). Penta- and hexachlorbiphenyls contribute most to the spectrum of PCBs in urbanozem.     

Dioxin Soil Contamination near Former Landfills

Eurasian Soil Science - Dioxin contamination levels and profiles of soils in New Moscow area were studied to identify the potential sources of contamination at a distance of 300 to 1000 m from the...     

The profile of congeners of polychlorinated biphenyls in soils of Moscow

The profiles of 19 indicative and dioxin-like congeners of polychlorinated biphenyls (PCBs) in the surface soils of distinct types of land use in Moscow are investigated. The penta- and hexachlorobiphenyls (46.7 and 31.6%, respectively) contribute significantly to the PCB spectrum. They used to make up the bulk of coolants and insulating fluids for electrical equipment, especially transformers. Among the congeners, the indicative PCB-101, -110, -138, and -153 and dioxin-like congeners PCB-105 and -118 dominate. They possess extremely high persistence and capability of bioaccumulation and exert harmful toxic influence, which should be taken into account when estimating an urban ecosystem??s ecotoxicological state.     

Polychlorinated dibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxins and dibenzofurans in Moscow soils

Data are given on the content of polychlorinated dibenzo-p-dioxins (PCDD) and 10 polychlorinated dibenzofurans (PCDF) with chlorine atoms in positions 2, 3, 7, and 8 in the upper horizons of Moscow soils, in the structure of profiles of congeners and their accumulation in the city top-soil. An average equivalent of toxicity of the totality of PCDD/PCDF is in the range of 48.66–0.27 ng of I-TEQ/kg, while for 2,3,7,8-TCDD, it reaches 1.78 ng of I-TEQ/kg, which is in accordance with permissible European norms. About half the stress of dioxins on urban topsoil-soil is determined by the most toxic congeners 2,3,7,8-TCDD, 2,3,4,7,8-PeCDF, and 1,2,3,7,8-PeCDD, which have a high ability to accumulate in adipose tissue of organisms. The concentration coefficients of PCDD/PCDF congeners in the soil are in tens of units.     

Polychlorinated dibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxins,dibenzofurans, and biphenyls in soils of Moscow

The contents of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in the soils of Moscow were estimated. The concentrations of PCDDs and PCDFs mainly vary in the range of 0.27–16.1 ng WHO-TEQ/kg with single points of very high contamination up to 57.3 ng WHO-TEQ/kg; the concentrations of PCBs are in the range of 2.1–50.8 ng/g with sites of high contamination up to 4020 ng/g. The contribution of dioxin-like PCBs to the total dioxin toxic equivalent is very high: from 16 to 85%. The high levels of PCDDs and PCDFs in the soils indicate the strong contamination of the atmospheric air. The main source of these compounds is apparently motor transport.     

Polycyclic aromatic hydrocarbons in soils of Moscow

The contents of polycyclic aromatic hydrocarbons (PAHs) in the upper horizons of Moscow soils range up to 1400 mg/kg for individual compounds and up to 10000 mg/kg for their sum. The concentration coefficients of PAHs in the soil vary from 0.7 to 200 depending on individual polyarene properties and land use. The heavy polynuclear structures of technogenic origin have the highest concentration coefficients. The highest accumulation of PAHs is observed for the soils of dumping sites, residential-transport areas, and industrial zones. According to the state sanitary norms set in the Russian Federation for the content of benzo[a]pyrene in soils, more than one-third of the urban soils studied are classified as pure, and about half soils are classified as acceptable.