Approximate Permissible Concentration Research Articles

Analysis of nickel distribution in soil profiles of sod-podzolic types

The research is aimed at studying the peculiarities of distribution of gross nickel in genetic horizons of soil profile of sod- podzolic sandy loamy and sandy soils of agricultural land in the Ryazan region and determining the current background concentration. To solve the set objectives were laid 10 pits up to 150 cm deep in Kasimovsky, Ermishinsky, Shilovsky, Sasovsky, Klepikovsky, Kadomsky districts of the Ryazan region in the period from 2016 to 2023, analyzed the depth and features of the structure of soil layers, the influence on the conditions of nickel migration. According to the results of nickel content determination the calculation of background concentration was performed. The comparative analysis of the proposed modern regional background value with well-known values of global and domestic researchers: approximate background concentrations for the average strip of Russia, hygienic standards characterizing the approximate permissible concentration of the substance in the soil, soils of the world according to the materials of the international geochemical atlas, soils of the world according to A.P. Vinogradov, global, zonal, regional values of the background according to Y.E. Saet, data of other researchers on the Ryazan land. The structure of soil profiles of soil at a depth of 110-130 cm has the following form: O – A - EL - ELBt - Bt - BtC - C. At the same time weakly noticeable geochemical barriers are noted in horizons A and Bt. Values of gross nickel were located in the concentration range of 3.3 - 16.8 mg/kg. A background concentration of 9.5 mg/kg was proposed, which differs from the generally known values presented in the comparative analysis and gives a modern idea of the regional background content of the gross form of nickel.

Regulation of cadmium in the soil according to its effect on plants

Introduction. There is discussed the influence of various concentrations of Cd in the soil taking into account their established limiting values on plants in the publication.
 Materials and methods. An express experiment was performed with Cd concentrations (0.5; 1.0; 2.5; 5.0 mg/kg) on Avena sativa L. and Sinapis alba L. using the phytotesting method. In a series of vegetation experiments, cultures of Lactuca sativa var. capitata and Hordeum vulgare L. were used. In this case, the Cd concentration increased to 15 mg/kg.
 Results. A pronounced level of toxicity (>50%) is manifested in the concentration of cadmium above 5 mg/kg, as established in preliminary experiments 
 on podzolic soil. The results of vegetation studies indicate a pronounced negative effect of cadmium at concentrations above 5 mg/kg, regardless of the forms of its intake (State standard sample (SSS) and Cd(NO3)2). The biomass of barley and lettuce plants) is reduced by 54 and 36%, respectively (Cd in the form of SSS) and by 35 and 44% (Cd in the form of Cd(NO3)2). An increase in the content of Cd in the soil at a level of ~8–13 mg/kg accompanied by a high level of its accumulation in plants from 18.5 to 33.0 µg/g.
 Limitations. When studying the effect of cadmium at concentrations of 0.5–15 mg/kg in soil on plants in acute and chronic experiments, the following crops were used: Avena sativa L. and Sinapis alba L., Hordeum vulgare L. and Lactuca sativa var. To restrict a chemical element in the soil-plant system, one should strive to extend the duration of the study and diversify the choice of crops.
 Conclusion. The tested doses of cadmium may have some negative effects and increase the risk to human health. Doses of cadmium corresponding to the approximate permissible concentrations of this element in the soil reduce the quality of plant material, confirmed by its high concentrations.

An integrated approach to assessing the ecological state of urban park soils, Kirov, Russia

Aim. Assess the ecological state of soils in park areas and public gardens in the city of Kirov, Kirov region, Russia, which are located near areas of heavy traffic, using an integrated approach based on data from physicochemical, microbiological analyzes and biotesting.Material and Methods. Soil samples were taken at various sites in the 60th Anniversary of the USSR Square, in the S.M. Kirov Park and in the 50th Anniversary of the Komsomol Park. The concentration of inorganic ions and the content of polycyclic aromatic hydrocarbons (PAHs) in the soils were determined by ionic and high‐performance liquid chromatography, respectively. The total content of heavy metals (HM)was determined by atomic absorption spectroscopy. Quantitative registration of microorganisms was carried out by the method of limiting dilutions with subsequent inoculation on selective nutrient media. Biotesting was carried out using the protozoa Paramecium caudatum and the Ecolum bacterial test system.Results. The features of the ionic composition of soils in Kirov parks were studied. In the aqueous extract of the studied soils, sulphate and chloride ions predominated among anions, and calcium ions among cations. Among the groups of microorganisms studied, ammonifying bacteria take the leading positions, the share of which in the microbial complex reaches 65.35–86.54%. There is a close relationship between the content of nutrients and the number of ammonifiers. The gross concentration of HMs in soil samples from parks in Kirov did not exceed their approximate permissible concentration, while the content of Pb, Zn, and Cо was up to 3.1 times higher than the regional background. The highest content of PAHs, maximum values of total carcinogenic activity and toxicity to P. caudatum were found in soil samples taken from areas near highways. Conclusion. The ecological state of urban park soils in Kirov in general can be characterised as satisfactory. Nevertheless, for park soils in the immediate vicinity of highways, increased values of PAH concentration were revealed. Determination of the PAH content in soils can be recommended for inclusion in the environmental monitoring programme in cities because of the persistence of PAHs in the environment, their mutagenic and carcinogenic properties, and the lack of standards for the content of most PAHs in natural environments.

Monitoring of the radionuclides and heavy metals content in the agroecosystems of the forest-steppe zone of the Central Chernozem Region of Russia

The research was carried out as part of the state agroecological monitoring program in the southwestern part of the Central Chernozem region in the Belgorod region. The soil cover of the forest-steppe zone was represented by typical chernozems. All analytical studies were carried out in an accredited testing laboratory according to generally accepted methods. The territory of the region after the accident at the Chernobyl NPP in 1986 was subjected to radioactive pollution. As a result of the studies, it was found that the average gross content of typical heavy metals in arable chernozems forms the following decreasing series (mg/kg): Mn (345) > Zn (36.5) > Cu (13.9) > Pb (10.3) > Co (8.48) > As (4.18) > Cd (0.23) > Hg (0.022). In terms of the content of mobile forms of heavy metals, the pattern is slightly different: Mn (16.7) > Pb (0.40) > Zn (0.39) > Cu (0.09) > Co (0.08) > Cd (0.05). According to the specific activity of radionuclides, they form a series (Bc/kg): 40К (530.2)>232Th (38.1)>226Ra (23.8)>137Cs (17.3). There was no excess of the standards of the approximate permissible and maximum permissible concentrations of the studied elements in the studied arable soils. The availability of arable soils with mobile forms of Zn, Cu and Co is assessed as low, in which microfertilization containing these elements is recommended to increase crop yield. In winter wheat grains, the content of the studied elements and the specific activity of the 137Cs were significantly lower than the maximum permissible levels.

Effect of Long-Term Use of Sewage Sludge and Lime on the Gross Content and Concentration of Mobile Forms of Heavy Metals in Sandy Loam Sod-Podzolic Soil

The long-term dynamics of the gross content and concentration of mobile forms of heavy metals (TM) in the soil of a microfield experiment laid in 1984 on sod-podzolic gleevate sandy loam soil on moraine loam (Vladimir region) is considered. Various large doses of municipal sewage sludge (MSS) and lime (dolomite flour) were introduced as meliorants. Despite the duration of the field experiment, sampling to compare the variants of the experiment on the content of TM in the soil turned out to be insufficiently systematic. Therefore, comparisons were made only on the basis of 3-4 years, and with insufficient comparability of analytical data. As a result, if in some years a significant dependence of the TM content in the soil on the doses of meliorants was obtained, then in the long-term plan, basically we can only talk about trends. From the point of view of contamination of the arable soil layer, it was found that the gross content of Cd, Zn, As was greater than the standard of approximate permissible concentration (APC) in all variants of the experiment (including control); the same is shown for Cu in all variants except control, and for Ni at maximum doses of MSS. Soil contamination in the control appears to be associated with lateral transport. Most of the total Cd and Cu content was extracted with mononormal acids. The content of mobile copper (AAB pH 4.8) (compared with acidsoluble) reacted poorly to the introduction of ameliorants.

Recognizing the Importance of an Urban Soil in an Open-Air City Museum: An Opportunity in the City of Madrid, Spain

This article examines the presence of urban soil buried under anthropogenic debris in an air-museum park in the Madrid city center (Spain), and highlights the particularities of this singular urbanized setting to indicate ecological evaluation options for soils. The study of a soil profile (with a thickness of about 2.30 m), classified as Urbic Technosols, allowed us to devise that it is formed by a series of filled-in amounts of artifacts (construction debris and other anthropogenic waste) of about 10–30%, plus organic and mineral materials. These soils’ composition and morphology depend on the natural conditions of the territory and also on anthropogenic activities. The soil properties (analyzed by conventional techniques) are moderate in acidity reaction and have relatively higher organic matter content. The Pb, Cu and Zn concentrations in anthropogenic horizons do not exceed the approximate permissible concentrations by 1.5–10-fold. Over the course of time, the soil profile has been transformed as a result of the impact of pedogenetic processes developing under the Mediterranean climate and man’s hand. Although urban environments present a certain complexity, at least the role of soil should be recognized regarding flood mitigation, recycling of wastes and toxins, filtering of nutrients or carbon storage and GHG regulation. The analysis of our results concludes the need to better perceive this soil profile and its green space to improve the urban ecosystem and to ensure better citizen well-being.

Chemical and sanitary assessment of coal spoil heaps in the south of the Kuznetsk Basin

Due to the large amount of pollution at coal spoil heaps, soil reclamation is slow and requires development and use of microbial preparations, selected based on assessments of the biochemical parameters of soil and the extent of its contamination. The material for this study was mine soils sampled in three different zones (Ka, Kb, Kc) of the Korchakol coal spoil heap. The studied sanitary and chemical indicators did not exceed the approximate permissible concentrations (APC) / maximum allowable concentrations (MAC), except for oil products (in the Ka, Kb, Kc zones, the excess averaged 2.2, 1.4, 1.2 times, respectively). The study found a direct correlation between the zinc content and the enzymatic activity of polyphenol oxidase, the level of Ni and peroxidase, as well as an inverse correlation between the As and Cu concentrations with invertase and nitrite reductase, respectively. The index of bacteria of the Escherichia coli group (coliform bacteria) in different zones exceeded the standard values by 61 and 171 times. Even though the sanitary indicators studied do not exceed permissible levels, they can slow down growth and development of plants. Thus, successful reclamation of mine soils requires introduction of biological preparations based on microorganisms that biotransform heavy metals and rhizobacteria.

ОЦЕНКА СОДЕРЖАНИЯ ТЯЖЕЛЫХ МЕТАЛЛОВ В СОПЛОДИЯХ ХМЕЛЯ ОБЫКНОВЕННОГО С ПОРОДНОГО ОТВАЛА УГОЛЬНОГО РАЗРЕЗА «КЕДРОВСКИЙ»

Abstract. Heavy metals content has been analyzed in plant raw materials of the wild hop (Humulus lupulus L.) cones the hemp family (Cannabaceae) representative growing on the waste dump "Yuzhny" coal mine "Kedrovsky". This perennial liana is found throughout the Kemerovo region-Kuzbass. It is a valuable medicinal plant material. It contains a rich biologically active compounds complex. Heavy metals content analysis in the studied embryozems samples showed that the maximum values are for Mn (54.438±15.900 mg/kg) and Fe (38.278±9.539 mg/kg), the minimum for Cu (0.218±0.016 mg/kg) and Cd (0.167±0.016 mg/kg). The study did not reveal their excess in comparison with the hygienic standards of maximum permissible concentration (approximate permissible concentration). It was experimentally found that wild hop cones accumulate to a greater extent two biophile elements - Cu and Zn. In addition, there are quite significant differences in the quantitative characteristics of the content of these elements in the seedlings of common hop and conjugated embryozems from the places of its growth. With a slight accumulation of these elements’ mobile forms in embryozems: Zn (1.481 ± 0.101 mg / kg), Cu (0.218 ± 0.016 mg / kg), in plant raw materials, the accumulation of these elements is a priority: Zn - 15.20 ± 0.153 mg / kg, Cu – 5.123±0.054 mg/kg. These elements also describe with the greatest biological mobility. For Cu and Zn, the coefficient of biological mobility (Bx) is maximal in the wild hop cones - 23.50 and 10.26 respectively. Obtained data analysis showed that there was no standardized heavy metals MPC excess in the raw material Humulus lupulus L. adopted for medicinal plant materials, which does not pose a danger to human life and health.

THE INFLUENCE OF HEAVY METALS ON THE BIOLOGICAL ACTIVITY OF RETISOLS

Environmental problems have not lost their relevance for the Non-Chernozem zone of Russia, the southern part of which belong to the Ryazan region, where in a number of areas there is a critical situation of cultural landscapes contamination of with heavy metals. The aim of the research was to assess the influence of multi-level heavy metal contamination of Retisols for the parameters of its phytotoxicity and the activity of soil enzymes. In the model experiment on Retisols, it was shown that the complex effect of heavy metals that are priority for the Ryazan region such as copper, zinc, lead, cadmium, at doses of 1.5 and 3.5 UEC (approximate permissible concentration) reduces the activity of soil enzymes and has a toxic effect on the cereal-legume mixture. In the variant of the experiment with heavy metal content of 0.5 UEC in the soil, the studied elements, mainly zinc and copper, act as chemical meliorants for Retisols depleted with trace elements. The combined effect of heavy metals (Cu, Zn, Pb, Cd) in doses of 1.5 and 4.5 UEC is phytotoxic what negatively affects the biometric indicators of the cereal-bean mixture, and also leads to accumulation in the biomass in quantities exceeding the permissible standards.

Biochemical transformation of organophosphate matter in soils contaminated with heavy metals

The aim of the work was experimental modeling in laboratory and field conditions of the influence of various doses of lead, which belongs to heavy metals of hazard class I, on the processes of transformation of phosphorus-containing organic matter in soils, which take place with the participation of enzyme systems. Relevance and choice of objects of study are due to increased development pressure on the soil and reduce their fertility, as well as the participation of a hydrolytic enzyme phosphatase in providing living organisms available phosphorus. The experiment was carried out on medium loamy soils: in field conditions on typical chernozem and in laboratory conditions on typical chernozem, gray forest and urban soil. The introduced doses of the toxicant (Pb) were in the range of-1-4 UEC (approximate permissible concentration). It was shown that metal doses equal to or higher than the ODC significantly inhibited the transformation processes of phosphorus-containing organic matter in soils. The observed effect increased with an increase in the content of metals in the soil.

Оценка состояния почв необрабатываемых сельскохозяйственных угодий по показателям ферментативной активности, гумуса и тяжелых металлов

Studies were conducted to determine such indicators as humus, heavy metals, and enzymatic activity in the soils of uncultivated farmlands of the Vladimir region located in the Klyazma river basin. In the course of field research in 2018, soil samples were selected at 13 points representing various landscape areas belonging to the Klyazma river basin. According to the results of research, a positive relationship between the activity of soil enzymes and the content of humus was established. In the soils of uncultivated farmland, where there is a high concentration of soil enzymes, a high percentage of humus was found from 2.88% to 3.96%. The dependence between the indicators of activity of soil enzymes and anthropogenic impact was revealed. Thus, the transition from deposits to the meadow, i.e. reduce anthropogenic impact on the soil, there is a sharp increase in the activity of soil invertase, catalase and dehydrogenase, an active process of humification of soil. The detected concentrations of heavy metals in soil samples of uncultivated farmland do not exceed the standards set for the approximate permissible concentrations, but their quantitative content has increased significantly over the past decade, their accumulation occurs and there is a potential danger in the case of secondary input of these soils into agricultural use.

Methods to determine the affinity of heavy metals for the chemically extracted carrier phases in soils.

A new index is proposed to determine the affinity of heavy metals (HM) to their carrier phases (AHM-fraction), which, in contrast to the traditional index CHM = 100 CHM-fraction/CHM-soil, considers the sum of all metals in the fraction as a share of the bulk content of all HM in the soil. The metal has affinity for the given phase if AHM-fraction > 1; vice versa, the affinity is absent if AHM-fraction < 1. Comparison of the affinity series of metals for a certain phase based on two indices revealed their discrepancy in most cases. The new index can take into consideration the discrepancy in affinity of the given metal for phases extracted by different strength reagents. The effect of the new indicator was tested on several contaminated soils: Haplic Chernozem, Stagnic Phaeozems, and Calcaric Fluvic Arenosol, as well as on two Spolic Technosols. Compared with the index CHM, the results of the new analysis of contaminated soils with the ATM fraction demonstrated that the Zn content in Calcaric Fluvic Arenosol is decreased considerably due to its low buffer capacity. Since the content of organic matter in Calcaric Fluvic Arenosol is insignificant, only organophile elements, such as Cu and Pb, can make up complexes with organic ligands, in contrast to the fixation of Ni and Mn by organic matter in Chernozems. Due to the low buffering capacity of Calcaric Fluvic Arenosol, the mobile forms of Cd and Zn increased, and these forms of Cr decreased. Therefore, the low buffering soil cannot fix Cd and Zn. Increase in contamination in Spolic Technosols (approximate permissible concentration, APC > 5) as compared to the index CHM, the value of the AHM-fraction of metals in the residue (except for cadmium) increased. In addition, the share of Pb and Cu increases in the organic matter. Thus, the use of a new indicator-the affinity of heavy metals to the carrier phases showed their advantage over the traditional index CHM.

The Effect of Granular Activated Carbon and Biochar on the Availability of Cu and Zn to Hordeum sativum Distichum in Contaminated Soil.

The presence of heavy metals in the soil could impose serious problems on soil-plant systems due to the accumulation of heavy metals in plants. Even vital elements such as Cu and Zn have a toxic effect in the case of excessive intake by living organisms. The present work aimed to investigate the content of loosely bound (exchangeable, complexed, and specifically sorbed) compounds of Cu and Zn and their availability to spring barley (Hordeum sativum distichum) in contaminated Haplic Chernozem soil under the conditions of a model experiment (five approximate permissible concentrations (APC) and 10 APC of metal). Changes in the bioavailability of the metals upon application of carbon sorbents were observed. An increase in loosely bound metal compounds has been shown under conditions of soil contamination with metals (up to 57% of the total content). The increase in the availability of Cu in the soil was mainly due to the formation of complexed metal forms with organic matter (up to 17%). The availability of Zn was found to be associated with an increase in exchangeable (up to 21%) and specifically sorbed compounds (up to 27%). Granular activated carbon (GAC) and biochar have high sorption properties. A decrease in the content of loosely bound compounds of metals was established, especially in the most mobile forms such as exchangeable and complexed forms. The introduction of sorbents into the soil opened up a new venue for binding heavy metals in situ, eventually leading to a decrease in their bioavailability. The inactivation of Cu and Zn in the soil upon the application of sorbents led to a decrease in metal absorption by spring barley. The highest efficiency of biochar application was established at a dose of 2.5% and 5% in soil contaminations of 5 APC and 10 APC of Cu or Zn. The efficiency of the use of sorbents was more influenced by the dose of application than by the type of sorbent. There was no significant difference between biochar and GAC. Stabilization and inactivation of metals may improve soil fertility and plant growth.

Effect of meliorative doses of phosphogypsum on the agrochemical properties of the soil and the yield of sunflower

The influence of meliorative doses of phosphogypsum application on agrochemical soil properties and sunflower yield was studied. The results of experiments carried out in the Volga region on light chestnut soils are presented. It was revealed that the content of heavy metals for all variants of the experiment did not exceed the approximate permissible concentration; application of phosphogypsum shifted the reaction of the soil environment towards neutral. The use of this agricultural technique increased the content of nutrients in the soil and labile organic matter, most of all, this was noted in the variant with a phosphogypsum dose of 8 t/ha. It was concluded that the combined application of mineral fertilizers and phosphogypsum at a dose of 4 t/ha leads to a significant increase in yield by 0.65 t/ha. The use of phosphogypsum as an ameliorant solves the environmental problem of utilizing wastes after the production of mineral fertilizers accumulated in the Russian Federation in the amount of about 50 million tons. The studies carried out have confirmed the soil-improving and fertilizing properties of phosphogypsum, as well as its environmental safety.

Distribution of trace elements in soil and plants under the action of bio-organic and mineral fertilizers

The deficiency of trace elements in the soil is often among the factors limiting the degree of realization of the genetic potential of crops. As a rule, the availability of trace elements to plants from soil is determined by their concentration in it, which is in the easily hydrolyzed phase. At the same time, some trace elements with increasing concentration in soil are considered as one of the most dangerous pollutants. After exceeding the established maximum permissible concentrations (MPC) and approximate permissible concentrations (APC), some trace elements are classified as heavy metals.

Resource-Saving Technology Based on Sewage Sludge

The issues of waste disposal are currently having a global technological and economic complexity. The severity of the environmental problem is specified by the accumulation of large volumes of various wastes, including sewage sludge (SS). Modern technologies can provide its disposal with environmental and economic benefits. SS is a rich source of nutrients with a high fertilization potential. This work aims to study the utilization of wastewater sludge in recycling technology for agriculture. The composition of urban sewage sludge and its impact on the properties of gray forest soil were studied. It was shown that its application in a dose of 40-60 t/ha promoted an increase in the content of humus, mobile phosphorus and exchangeable potassium in the soil and a decrease in acidity. The noted increase in the content of the studied heavy metals upon the introduction of various doses of sludge did not exceed the approximate permissible concentration (APC) in the soil. The results showed that the use of SS as a fertilizer restores the balance of organic matter in soils and improves their agroecological properties. This technology, as a safe way of recycling waste into a valuable complex fertilizer, contributes to resource conservation.

ПЛОДОРОДИЕ ОРОШАЕМЫХ ЗЕМЕЛЬ В ЮЖНОЙ ЛЕСОСТЕПИ ОМСКОЙ ОБЛАСТИ

Unsustainable irrigation of chernozems can lead to secondary salinization and other negative consequences. The purpose of the research was to assess the fertility and hydrochemical composition of meadow-chernozem soil of the forest-steppe of Western Siberia under conditions of prolonged irrigation. The surveys were carried out in the fields of the agricultural production cooperative (APC) “Pushkinsky” and Federal State Unitary Enterprise (FSUE) “Omskoye”; cultivation technology – adaptive system of irrigated agriculture. The studies were conducted in 2015–2020 on the Pushkin irrigation system. The object of the research – irrigated meadow-chernozem heavy loamy soil. The methods of route field research and laboratory analyzes were used. The results obtained were compared with the baseline values (1978). With long-term irrigation and intensive agricultural use, the fertility indicators of meadow-chernozem soil did not significantly deteriorate. The arable horizons have a neutral and close to neutral reaction (pH 5.8–6.2), average humus content (5.9–7.2%). The supply of nitrate nitrogen, as a rule, remained at a low and medium level (6.0–14.7 mg/kg) due to the high removal by vegetative crops and the absence of fallow fields in the structure of irrigated arable land. Long-term systematic application of phosphorus-containing fertilizers and creation of a positive P balance led to the improvement of soil phosphate status (99–177 mg/kg). The content of exchangeable potassium remains high (144–353 mg/kg) and is stable over time, which is a feature of chernozems with a heavy particle size distribution. The content of mobile forms of lead, zinc and cadmium does not exceed approximate permissible concentrations in the soil. When analyzing the cation-anionic composition of the water extract of the soil profile of FSUE “Omskoe”, a weak salinity of the chloride type was revealed in the 0.6-1.4 m layer; of the sulfate-chloride type – in the 1.4-1.8 m layer. In the future, it may lead to secondary salinization and serve as a limiting factor for high yields. The absorbing complex of meadow-chernozem soil in the southern forest-steppe is highly saturated with bases. Sodium concentration is minimal; calcium and magnesium cations prevail. The groundwater samples are moderately fresh and of good quality. Among the anions, HCО3- prevails, among the cations – Mg2+ and Ca2+, which indicates the need to control the groundwater level to maintain a favorable ecological state of meadow-chernozem soil.

Monitoring of technogenic pollution of soil in the region

The purpose of the study is to conduct monitoring of technogenic pollution of soil in the Samara region. The objectives of the study are to identify the sources of technogenic pollution of soil, to analyze the minimum and maximum concentrations of heavy metal on long-term observation plots and background plots, to assess the average and the maximum values of total petroleum hydrocarbons (TPH) in soil of observed land plots. The allowable concentration levels of heavy metals (manganese, lead, cadmium, copper, nickel and zinc) in the soil of the Samara region are not exceeded. Mean heavy metal concentrations in soil did not exceed the maximum permissible concentration (MPC) and the approximate permissible concentration (APC) and was 0.1-0.6 MPC (APC). The maximum concentration of metals in soil was 0.1-0.9 MPC (APC). However, the obtained results were higher than background concentrations of metals. The mean concentrations of aluminium exceeded the background levels by a factor of 3.4-6.7. The maximum concentrations of aluminium in soil was observed in the area of the Samara metallurgic plant (ZAO ‘Arconik’) and was 9.2 of background.

Assessment of the ecological state of soils in roadside territories using chemical and biological indication

Chemical and bioindication studies of soils in the roadside areas of railways and highways have been carried out. The studies have shown that on the territories directly adjacent to the transport routes, the concentrations of the petroleum products in soils are 1.6-32.4 times exceeding the APC (approximate permissible concentration). The most substantive exceedances of the APC are recorded in the highways roadside spaces. We have investigated the dependence of the petroleum products concentration in the soils and their bioindication indices on the distance to transport routes. It has been established that the pollution of roadside soil by petroleum products decreases sharply at a distance of 10-15 m from transport routes. And bioindicators show different dynamics with increasing distance from the source of pollution (and, consequently, decrease in concentration of petroleum products in soils): the intensity of respiration of soils increases, and catalase activity decreases, which reflects its characteristic as an enzyme of stress.According to bioindication data, it has been shown, that the soils of the roadside space (especially, as for railways) retain high restorative potential.

Assessing the Geoecological Status of the Floodplain-Terrace Complex of the Tuul River Within Ulaanbaatar (Mongolia)

The paper gives characteristics of natural and anthropogenic factors responsible for the geoecological situation inside the boundaries of the floodplain-terrace complex of the Tuul river within Ulaanbaatar. Among them, the geological structure and orography (occurrence in the intermontane depression), the specific character of climate-forming (frequent temperature inversions) and hydrological (mainly summer feed by rain water) characteristics, the degree of economic development (high pressure on the central city zone) and population density in administrative districts, etc. have been distinguished. Results obtained from hydro- and geochemical analyses of the territory and published previously (during 2009–2013) were used in the typification of the areas of the floodplain-terrace complex of the Tuul river according to the intensity of anthropogenic impact. An analysis was made of the sources of pollution, primarily of large industrial enterprises and facilities of housing and communal services: combined heat and power plants, industrial, meat-packing and biological plants, the poultry farm, sewage treatment plants, etc. Based on a comparative analysis of average concentrations of the component composition of the river waters and floodplain soils, maximum exceedances of maximum and approximate permissible concentrations of pollutants were determined. Categories of the intensity of anthropogenic impact were identified to vary from decreased to very high. It is shown that, in spite of a high degree of geochemical understanding of the urban territory of Ulaanbaatar, no detailed investigations have been made within the floodplain-terrace complex of the Tuul river. The first-time assessment of the geoecological status of the sites across the study territory determined the migration routes of chemical substances and correlated their occurrence in natural environment with the sources of pollution. According to the intensity of anthropogenic impact, for each site of the floodplain-terrace complex we have suggested environmental and water protection measures. Results of the assessment are presented in the form of cartographic material.