ИСТИНА

The aim of the study was to assess the load of transport sources on the local urban ecosystem, according to the spatial distribution of marker compounds in complex of environmental components. The effectiveness and fundamental advantages of integrated models have recently been demonstrated by leading research groups. The object of analysis is the campus territory of the RUDN-University (Moscow, Russia), surrounded by transport facilities, including a major highway with a powerful transport stream during the day. The condition of the study area is monitored at 33 monitoring points according to a unique program developed at RUDN-University in the framework of cooperation with UI Green Metric. Multicomponent pollution models based on generally accepted algorithms have shown the probability of a significant excess of permissible loads in many physicochemical parameters. The actual state of the interconnected urban environment components (atmospheric deposition, soils, roots and aerial parts of vegetation) is evaluated in detail using following approaches. The pressure indicators are polycyclic aromatic hydrocarbons (PAHs) - geochemical markers reflecting natural and anthropogenic processes in the biosphere, including mass flows of pollutants. PAH indicator ratios confirmed the leading source of pollution - vehicle emissions. An analysis of the accumulation and migration of PAHs in ecosystem components was carried out using concentration coefficients and estimates of the entropy, Gibbs energy, and enthalpy of PAH associations in media. These parameters are the basis for assessing the disturbance of bonds in the ecosystem components. The resulting assessment of the dynamics and spatial distribution of PAHs made it possible to differentiate the territory by the degree of pollution under the influence of roads and parking lots. Zones with different levels of pollution and conditions of accumulation and migration of indicator compounds were identified as a result of classification of the territory (cluster analysis of 16 PAH concentrations at 33 points). An analysis of the anisotropy of the distribution of PAHs across the campus in the soil-vegetation system shows a pronounced dynamics of PAH accumulation near roads, which is confirmed by estimates of the toxicity coefficients of PAH complexes (defined as an integrated toxicity characteristic of 16 priority PAHs taking into account their danger compared to benzo[a]pyrene). Assessment of PAH migration shows a significant difference in the spatial distribution of emissions in the “background” and technologically loaded parts (predominance of multi-ring PAHs). However, there are differences also in the conditions of PAH migration between the components of the considered system: for some territories, the aerial supply of PAHs to the terrestrial parts of plants is predominantly confirmed, in other cases, it is apparent from the soil. Sites of the campus ecosystem were identified where almost complete “saturation” of PAH components is identified, and therefore their migration does not occur, despite high concentrations in the media. The presented detailed studies were carried out for the first time for local objects. They make it possible to obtain an objective comprehensive assessment of the state of urban ecosystems and determine the sustainability of its condition under conditions of intense anthropogenic pressure.