Anthropogenic and semianthropogenic soils prevail in the soil cover structure of the Vorob’evy Gory nature park (Moscow), adding up to ∼90%. Their chemical properties are typical of technosols and characterized by a relatively high content of organic carbon, neutral or alkalescent pH, and high saturation of SEC by exchangeable basic cations. Thus, the features of urban forest-park soils more closely resemble technosols than natural soddy-podzolic soils.

The features of cesium-137 (137Cs) root uptake by spring oat ( Avena sativa L.) and lettuce ( Lactuca sativaL.) plants have been studied in a model experiment with simulation of radionuclide fallout...

To elucidate the features of bioaccumulation and phytotoxic effects of long-lived artificial radionuclides, a hydroponic experiment was carried out with the cultivation of onion (Allium cepa L.) in low-mineralized solutions spiked with ¹³⁷Cs (250 kBq L^-1) or ²⁴³Am (9 kBq L^-1). After the 27-day growth period, ≈70% of ¹³⁷Cs and ≈14% of ²⁴³Am were transferred from the solutions to onion biomass with transfer factor values ≈ 400 and ≈ 80, respectively. Since the bioaccumulation of both radionuclides mainly took place in the roots of onion (77% ¹³⁷Cs and 93% ²⁴³Am of the total amount in biomass), edible organs - bulbs and leaves - were protected to some extent from radioactive contamination. At the same time, the incorporation of the radionuclides into the root tissues caused certain changes in their biometric (geometric and mass) traits, which were more pronounced under the ²⁴³Am-treatment of onion. Exposure to ²⁴³Am significantly reduced the number, length, and total surface area of onion roots by 1.3-2.6 times. Under the influence of ¹³⁷Cs, the dry-matter content in roots decreased by 1.3 times with a corresponding increase in the degree of hydration of the root tissues. On the whole, the data obtained revealed the specific features of ¹³⁷Cs and ²⁴³Am behaviour in "hydroponic solution - plant" system and suggested that biometric traits of onion roots could be appropriate indicators of phyto(radio)toxicity.

Soils of the Vorob’evy Gory nature park (Moscow) are characterized by a high content of technogenic ecotoxicants. Dangerous levels of pollution are fixed on ∼60% of soil cover for benzopyrene, ∼40% of soil cover for heavy metals, and ∼6% of soil cover for mineral oils. Besides the total high aerogenic load, the local sources of soil pollution in cities are highways; increased concentrations of heavy metals are also registered near unauthorized dumps. Benzopyrene and mineral oils are characterized by high migratory ability in soils and can form secondary auras of pollution in accumulative landscape facies.

Ecological and geochemical characteristics of urbanozems (Urbic Technosols) were evaluated, using an integrated analysis of official data of the Russian Meteorological Service on the content of priority heavy metals (Cd, Pb, Zn, Cu, and Ni) in soils of 23 cities in Volga Federal District and of the data of the Federal Service of State Statistics on socio-economic parameters of these settlements. Possible relationships between parameters of soil pollution and urban features of cities were revealed with the help of multivariate statistical analyzes (cluster and factorial). Admissible levels of Cd, Pb, Zn, and Cu were established for soils of most cities in the region with mean socio-economic parameters, average concentrations of which are close to abundance values in urban soils in Russia. The APC of Ni in soils is exceeded in small and medium cities of the Republic of Bashkortostan, which reflects regional natural and anthropogenic geochemical anomaly in the east of Volga Federal District, but no correlations between nickel pollution and socio-economic parameters of settlements are revealed. Moderately hazardous level of complex pollution in urbanozems with dominant Cd accumulation and significantly lower concentrations of other heavy metals (the cities of Belebei, Davlekanovo, and Dzerzhinsk) is not correlated with demographic parameters of settlements. In case of more complicated profile of soil pollution (Cd–Zn in Penza or Cu–Cd–Zn in Mednogorsk), the total birth rate is lower and the mortality rate is higher as compared with the mean regional parameters. Different directions of gradients of increasing concentrations of Cd, Pb, Zn, and Cu in soils, as well as of the Zc total parameter of soil pollution in relation to indices of natural population growth and the absence on the ordination diagram of a noticeable relationship between ecological and geochemical characteristics of soils and the age of the city, the number and density of the population, and the density of the street road network are shown, using the example of cities in the Volga Federal District.

Some aspects of the application of simulation modeling of radionuclide behavior in food chains of land ecosystems are discussed. A model of behavior of 137