Chemical Contaminants In Soil Research Articles

Metal(loid)s in urban soil from historical municipal solid waste landfill: Geochemistry, source apportionment, bioaccessibility testing and human health risks

Landfills, especially those poorly managed, can negatively affect the environment and human beings through chemical contamination of soils and waters. This study investigates the soils of a historical municipal solid waste (MSW) landfill situated in the heart of a residential zone in the capital of Slovakia, Bratislava, with an emphasis on metal (loid) contamination and its consequences. Regardless of the depth, many of the soils exhibited high metal (loid) concentrations, mainly Cd, Cu, Pb, Sb, Sn and Zn (up to 24, 2620, 2420, 134, 811 and 6220 mg/kg, respectively), classifying them as extremely contaminated based on the geo-accumulation index (Igeo >5). The stable lead isotopic ratios of the landfill topsoil varied widely (1.1679–1.2074 for 206Pb/207Pb and 2.0573–2.1111 for 208Pb/206Pb) and indicated that Pb contained a natural component and an anthropogenic component, likely municipal solid waste incineration (MSWI) ash and construction waste. Oral bioaccessibility of metal (loid)s in the topsoil was variable with Cd (73.2–106%) and Fe (0.98–2.10%) being the most and least bioaccessible, respectively. The variation of metal (loid) bioaccessibility among the soils could be explained by differences in their geochemical fractionation as shown by positive correlations of bioaccessibility values with the first two fractions of BCR (Community Bureau of Reference) sequential extraction for As, Cd, Mn, Ni, Pb, Sn and Zn. The results of geochemical fractionation coupled with the mineralogical characterisation of topsoil showed that the reservoir of bioaccessible metal (loid)s was calcite and Fe (hydr)oxides. Based on aqua regia metal (loid) concentrations, a non-carcinogenic risk was demonstrated for children (HI = 1.59) but no risk taking into account their bioaccessible concentrations (HI = 0.65). This study emphasises the need for detailed research of the geochemistry of wastes deposited in urban soils to assess the potentially hazardous sources and determine the actual bioaccessibility and human health risks of the accumulated metal (loid)s.

Phytoremediation of soils contaminated as a result of military and anthropogenic impact

Military conflicts and anthropogenic accidents cause significant soil contamination with heavy metals, oil products, pesticides, and other toxic substances. The purpose of this study was to highlight the factors of influence of military-anthropogenic load on soils and to analyse the available methods of their remediation. The study summarised the available and promising phytoremediation methods with an assessment of their impact on soil contamination by chemicals that are typical pollutants during military conflicts. The study summarised, classified, and compared the groups of pollutants that are most common during military operations; analysed the impact of pollutants on the fertile soil layer and their mobility; and analysed the available remediation methods. It was found that the available soil remediation technologies, which can be used individually or in combination, provide the necessary tools to address the problem of chemical contamination of soils due to toxic products such as explosive derivatives and heavy metals. The degree of economic feasibility was considered, which, accordingly, suggested that soil phytoremediation may be the most economically feasible under certain conditions. This opens wide possibilities for further investigations, where the synergy of ecology, economics, and agrobiology will enable the development of mechanisms for optimising soil phytoremediation methods, considering their type, profile, and intended use. An algorithm of actions for remediation of soils as a result of military-anthropogenic load was proposed, which includes a related set of related actions on zoning, demining, assessment, and return of land to industrial use. The findings of this study can be used to clean industrial areas that have been contaminated during production processes or accidents

К оценке опасности выщелачивания некондиционного сырья в кучах

The issues of identification of environmental hazards when implementing the concept of the involvement of poor metal-containing raw materials and tailings from ore processing through the application of a new leaching technology with a detailed version of heap leaching on the earth have been considered. The methodology of identification of the environmental consequences of the implementation of the technology of deep processing of non-conventional mineral raw materials considering the impact of mineral waste on the environment of the field development region has been formulated. An environmental component of the complex ecological and economic effect comprised of the consistently implemented stages of the existence of the enterprise has been considered. The main factors of negative environmental impact received a quantitative assessment; the territories adjacent to the enterprise have been ranked by the degree of the anthropogenic impact. The options to determine the extent of damage caused by the contamination of ecosystems with heavy metals have been proposed. Models to determine the environmental damage caused by industrial effluents as the main transporting medium and the efficiency of utilization of substandard raw materials based on the profit criterion have been formulated. The mechanism of removal of reagents and solutions to the environment by airflows has been specified. An approximate calculation of parameters of the environmental contamination for ore leaching of ore raw materials in the Sadonskoye deposit has been provided. It has been demonstrated that the chemical contamination of soils is prioritized when determining the environmental hazard and the hazard for the enterprise employees. It has been proved that the combined ecological and economic model of assessment of the efficiency of utilization of substandard raw materials joins ecological and economic aspects within a single natural and anthropogenic system, whereas the ecological and economic efficiency of production is a function of integrating methods of field development, including the application of a safety criterion for ecosystems of the environment. The study results can be used for the adjustment to the legislation on mining in the Russian Federation.

Ecological and hygienic assessment of soils on the content of heavy metals and arsenic in an industrial city with glass production

Introduction. The paper presents the results of a study on assessing the level of soil contamination with heavy metals and arsenic in a city with a long-term glass production.
 Materials and methods. The object of the study is the soil cover of the city of Gus-Khrustalny, widely known for the products that are produced at its enterprises. The city-forming industry, the mention of which begins in the second half of the 18th century, is the production of glass and crystal.
 Results. The presence of polyelement pollution of the soil cover of the city was established, which is probably associated with the specifics and duration of the functioning of the glass industry. The priority pollutants of urban soil are primarily those belonging to the first hazard class, Zn, Pb, and As. The maximum levels of pollution were recorded in the industrial urbanozems, the minimum – in the landscape and recreational zone. An extremely dangerous chemical contamination of the soil in terms of the total indicator was revealed on the territory of the currently non-functioning part of the glass plant, which in fact is a local technogenic lithogeochemical anomaly. An assessment of the level of chemical contamination of soils as an indicator of an adverse impact on the health of the population showed most of them to live in the zone of moderately hazardous or hazardous soil categories.
 Limitations. The limitations of the study are associated with one-time sampling and a small number of reference areas, which limits the possibility of a broader interpretation of the data obtained. 
 Conclusion. To justify measures to reduce the risk to the environment and health of the population living here, it is necessary to manage constant environmental and hygienic monitoring of the territory. To reduce soil pollution in the city, there are required the modernization of industrial enterprises and the creation of expanded sanitary protection zones around them. It is necessary to carry out measures to detoxify contaminated soilsusing modern methods, primarily biological treatment as phytoremediation, phytorecultivation.

Comparative Assessment of the Resistance to Lead (Pb) Pollution of Forest, Forest-Steppe, Steppe, and Mountain-Meadow Soils of the Central Ciscaucasia and the Caucasus Regions

Lead (Pb) is one of the most hazardous heavy-metal pollutants in the environment. However, the resistance of different soils and ecosystems to Pb pollution varies greatly. In the present study, the comparative assessment of the resistance to Pb contamination in the forest, forest-steppe, steppe, and mountain-meadow soils of the Central Ciscaucasia and the Caucasus regions was conducted. There were 10 types and subtypes of objects from the forest, forest-steppe, steppe, and mountain-meadow soils which were selected for this study. The laboratory modeling of the effect of chemical soil contamination with lead (II) oxide (PbO) at different concentrations, 100, 1000, and 10,000 mg/kg, were introduced into the soil to check the microbiological, biochemical, and phytotoxic properties of the soil after 30 days of incubation. Soil resistance to Pb stress was assessed by the degree of the decrease in the most sensitive and informative biological indicators of the soil condition. It has been found that the forest-steppe and steppe soils showed a greater resistance than that of the forest and mountain-meadow soils. The regional maximum permissible concentration (rMPC) of Pb was developed for the first time, according to the degree of violation of the ecosystem functions of the soils. The forecast maps were developed for the deterioration of the soil condition during the Pb contamination at variable concentrations in the Central Ciscaucasia and the Caucasus regions.

Chemical pollution of soils of the Primorsky Region as a risk factor for population health

The article presents the results of a hygienic study to assess the chemical contamination of soils in residential areas of Primorsky Krai based on the results of social and hygienic monitoring from 2018 to 2020. The analysis of the actual concentrations of heavy metals in the soil was carried out for 7 chemical elements: lead, zinc, copper, nickel, cadmium, manganese, mercury in 12 administrative territories of the region. Soil safety control points are certified using a system of geoinformation technologies. It has been established that a feature of the administrative territories of the northern part of the region is a sharp predominance of natural sources of chemical pollution over all others. Contamination with toxic elements of soils in the southern part of the region, especially in places of compact residence of the population, is of a pronounced technogenic character. The leading mechanism for the accumulation of microelements in the soils of the cities of Primorsky Krai is their intake from the atmospheric air, heavily polluted by man-made emissions, the leading sources of which are motor vehicles, railroad and sea transport.

Metal(loid) concentrations, bioaccessibility and stable lead isotopes in soils and vegetables from urban community gardens

Community gardens are “green oases” of recent cities with many benefits for human society. From a human health perspective, these benefits can be damaged by chemical contamination of soil and cultivated vegetables. Using geochemical approaches, this study characterised (i) total metal(loid) concentrations in soils and two commonly grown vegetables in urban community gardens (Bratislava, Slovakia), (ii) gastrointestinal bioaccessibility using a modified physiologically based extraction test (PBET), and (iii) stable lead (Pb) isotopes in order to identify sources of metal(loid)s, solubilisation in the human body and migration of Pb from soil to vegetables. While some soils could be considered contaminated when compared to the Slovak legislation for agricultural soil, the bioaccessibility of metal(loid)s did not exceed 20% in the intestinal phase, with the exception of cadmium (Cd). Tomatoes and lettuce contained low total and bioaccessible concentrations of metal(loid)s, being safe for people who consume their own grown vegetables. There were differences in Pb isotope composition among bulk soils, vegetables and bioaccessible Pb, with less radiogenic Pb being preferentially mobilised. Statistical methods considering the compositional nature of the geochemical data and the enrichment factor (EF) distinguished well metal(loid)s of natural origin (As, Co, Cr, Fe, Mn, Ni, V) from those with anthropogenic contributions. This research has shown the usefulness of integrating different methodologies to better understand the geochemistry of metal(loid)s in urban soils with their highly diversified sources.

Analysis of the influence of technogenic facilities of the Lysychansk-Rubizhne industrial hub on the ecological state of the natural environment

Formulation of the problem. The paper is devoted to the study of the ecological state of the natural environment components in connection with the impact of technogenic facilities of the Lysychansk-Rubizhne industrial hub. The purpose of the paper is to analyze the technogenic impact of the Lysychansk-Rubizhne industrial hub on the natural environment components. Materials and methods. The natural environment components data including atmospheric air, soil, surface water, groundwater from the Regional Report on the natural environment state in Luhansk region were used and analyzed. The total pollution index was calculated to determine the level of soil contamination in the areas of biggest technogenic impact. The places furthest from the cities with powerful sources of the natural environment pollution are allocated. Mathematical processing of geochemical information was performed on separate samples. The containing of specific chemical elements in the soils of Lysychansk-Rubizhnе industrial hub is calculated. The obtained data were used to calculate the concentration coefficient. The level of chemical contamination of soils as an indicator of adverse effect on public health is determined by following indicators: 1) the chemical substance concentration coefficient (Kc), which is determined by the ratio of its actual containing in the soil (C) to the background containing (Cb); 2) the total pollution index (Zc), which is equal to the sum of the concentration coefficients of chemical elements. Results. As a result of the study, it was found that the territory of the Lysychansk-Rubizhne industrial hub is still under a huge technogenic impact, despite the closure of many enterprises. Abandoned settling tanks, sludge collectors, spoil tips, landfills of various industrial wastes and other are one of the main sources of the natural environment pollution today. The ecological state of the natural environment components (atmosphere, surface water, soil and groundwater) is described in the paper. Quite positive changes are observed only in the situation with atmospheric air. The tendency to reduce emissions of pollutants into the atmosphere is associated with the liquidation of industrial enterprises over the past 20 years. The state of other natural environment components remains unsatisfactory: surface water, soil and groundwater are contaminated with heavy metals, petroleum products, nitrates, nitrites, etc. (the nature of the pollutants depends on the nearby technogenic facilities). It is noted that these technogenic facilities lose their waterproofing over the years, so they are currently sources of pollutant migration to the natural environment. Scientific novelty and practical significance. An integral assessment of the Lysychansk-Rubizhne industrial hub impact on the natural environment components, which allowed us to talk about the different degree of technogenic impact and different influence factors, is the scientific novelty of the study. The different genesis of pollution in the given area is proved. It is established that there is an infiltration from the surface on the left bank and pollution of deep origin on the right bank. The long-term forecasts of changes in the ecological state of the Lysychansk-Rubizhne industrial hub territory are given as practical use of the obtained results. It is proposed to carry out continuous monitoring of the natural environment for a more detailed study of the environmental situation.

Assessment of the Ecological State of Soils Near the Platinum Deposit

The research is devoted to the ecological state of soil resources in the area of the Konder platinum placer deposit in the Khabarovsk Territory. The environmental impact of the Konder mine activities was established based on chemical analyses performed. In general, the study has demonstrated that the Konder field development and operation cause a complex multicomponent pollution of the landscapes. The pollution is more than local in nature, since the environmental problem related to violation of soil resources and to chemical contamination of soils and natural watercourses in areas of mineral development is becoming increasingly acute. As a result of the studies, geochemical features of the soil space and the main sources and factors of the soil contamination have been determined.

Accumulation of heavy metals in the soil – plant system in areas with the developed mining industry

Introduction. The proximity of mining enterprises to settlements contributes to the pollution of the soil cover with heavy metals. Crops grown in garden plots accumulate chemical elements and are an intermediate link in the “soil - plant - human” chain. Purpose of the work. Assessment of the level of anthropogenic load on the territory adjacent to the mining enterprise, based on the study of the translocation of metals in the soil - plant system. Materials and methods. For the purpose of hygienic assessment of the chemical composition of the soil and vegetable products grown on it, the content of 7 microelements was determined by atomic absorption spectrometry. With the help of the coefficient of concentration of a chemical substance (Kc) and the total indicator of pollution (Zc), the level of chemical contamination of soils was determined. Using the total coefficient of anthropogenic load (Ka.n. = ∑Ci/PDUi), the territory was ranked according to the contamination of vegetables with toxic elements. The rate of accumulation of metals by vegetable crops was assessed by the coefficient of biological absorption (Ax) and the index of biochemical activity of the species (BAS). Results. The soil cover in the district is contaminated with a complex of metals, the content of gross forms of which exceeds the MPC by up to 1.9 times, mobile - up to 4.6 times. At a distance of up to 5 km around the mining enterprise, the maximum indicators of the total soil pollution (Zc = 44-65) have been established. Lead and zinc are elements of “biological accumulation” for all types of studied vegetable products grown in the zone of influence of the mining enterprise; cadmium is additionally concentrated in beets and carrots, and nickel in carrots. In vegetable samples, exceeding the permissible levels of cadmium and lead was noted. The most significant accumulation of heavy metals was found in the southern, southeastern, northern and northwestern directions from emissions. Conclusion. To eliminate the toxic effects of heavy metals in vegetables produced in the zone of influence of mining enterprises, it is recommended to include additional monitoring of nickel and zinc content in the social and hygienic monitoring system.

ВИВЧЕННЯ ВПЛИВУ ГІПЕРТЕРМІЧНОЇ ОБРОБКИ НАСІННЯ САЛАТУ ТА ХІМІЧНОГО ЗА-БРУДНЕННЯ ҐРУНТУ НА РОСТОВІ ПОКАЗНИКИ ПРОРОСТКІВ

Purpose. Establishing the influence of hyperthermal treatment of lettuce seeds and chemical contamination in the soil on the growth rates of seedlings. Methodology. The paper determines the level of influence of two factors on the growth characteristics of lettuce used for biotesting of soil contaminated with petroleum products. In accordance with the purpose of the study, lettuce seeds were pre-heat treated at a temperature of 60 C. Processing time - 5 minutes Pre-viously, a study was conducted to select the inhibitory and hormesis action of heat treatment (heat treatment time). After heat treatment, the envelopes with the seeds were dried. Next, lettuce seeds were sown in the plant. Originality. If we consider that heat treatment simulates the action of certain factors, or the complex action of certain factors, it means that we must take this into account and use certain sensitized objects in the practice of biotesting. Practical meaning. The effect of chemical soil contamination (aviation kerosene) on the sensitized plant object has been determined. Namely, lettuce used in the practice of biotesting of soil contaminated with petroleum products. The dependence of lettuce growth characteristics on the level of excess aviation fuel content in the soil is determined. Conclusions. As a result of the analysis of the received experimental data it is established that for the minimum of the used concentrations of pollu-tant (1 OAC for aviation kerosene) the sensitizing effect of additional influence of another factor - by nature - hyper-thermia is possible. This fact requires the improvement of the practice of determining the OAC, because in real condi-tions, the objects are exposed to a set of factors, the negative effects of which may be mutually reinforcing.

Application of tillage methods and seed disinfection techniques for the development and spread of diseases in spring wheat crops

Improving the tillage system will stabilize the agricultural sector of the Krasnoyarsk Region and meet the growing demand for agricultural products. The principles of minimizing mechanical tillage and preserving plant residues on its surface are the basis of the technology of conservation agriculture. Among the new agro-ecological advantages of the technology is the reduction of dependence on weather conditions thanks to effective moisture conservation. Improvement of the soil structure by reducing the pressure on it, partial replenishment of natural fertility by reducing (by 25-30%) the rate of humus mineralization. It is based on soil fertility management, minimum and combined tillage; differentiated fertilizer system. Zero sowing on the predecessor stubble - an element of technology - contributes to the accumulation of moisture, disruption of the plough-pan, an increase in the microbiological activity of the soil, etc. Presowing seed preparation is a technological technique that can increase the yield of wheat. Seed disinfection techniques significantly affect the development and spread of diseases in spring wheat crops. A systematic, scientifically grounded approach to phytosanitary rehabilitation of agrocenoses will ensure the prevention of chemical contamination of soil and agricultural products, an increase in yield (by 15-20%), a decrease in production costs per unit of produced products (by 10-15%), and an increase in production profitability.

Plant Disease Management: Leveraging on the Plant-Microbe-Soil Interface in the Biorational Use of Organic Amendments.

Agriculture is faced with many challenges including loss of biodiversity, chemical contamination of soils, and plant pests and diseases, all of which can directly compromise plant productivity and health. In addition, inadequate agricultural practices which characterize conventional farming play a contributory role in the disruption of the plant-microbe and soil-plant interactions. This review discusses the role of organic amendments in the restoration of soil health and plant disease management. While the use of organic amendments in agriculture is not new, there is a lack of knowledge regarding its safe and proper deployment. Hence, a biorational approach of organic amendment use to achieve sustainable agricultural practices entails the deployment of botanicals, microbial pesticides, and organic minerals as organic amendments for attaining plant fitness and disease suppression. Here, the focus is on the rhizosphere microbial communities. The role of organic amendments in stimulating beneficial microbe quorum formation related to the host-plant-pathogen interactions, and its role in facilitating induced systemic resistance and systemic-acquired resistance against diseases was evaluated. Organic amendments serve as soil conditioners, and their mechanism of action needs to be further elaborated to ensure food safety.

An amyotrophic lateral sclerosis hot spot in the French Alps associated with genotoxic fungi

Between 1990 and 2018, 14 cases of amyotrophic lateral sclerosis (ALS) were diagnosed in residents of, and in visitors with second homes to, a mountainous hamlet in the French Alps. Systematic investigation revealed a socio-professional network that connected ALS cases. Genetic risk factors for ALS were excluded. Several known environmental factors were scrutinized and eliminated, notably lead and other chemical contaminants in soil, water or home-grown vegetation used for food, radon and electromagnetic fields. Some lifestyle-related behavioral risk factors were identified: Prior to clinical onset of motor neuron disease, some patients had a high degree of athleticism and smoked tobacco. Recent investigations on site, based on a new hypothesis, showed that all patients had ingested wild mushrooms, notably poisonous False Morels. Half of the ALS cohort reported acute illness following Gyromitra gigas mushroom consumption. This finding supports the hypothesis that genotoxins of fungal origin may induce motor neuron degeneration.

The multifactorial assessment of the Zn impact on high and low temperature stress towards wheat seedling growth under diverse moisture conditions (optimal and wet) in three soils

Anthropogenic activities leading to chemical contamination of soil and global climate change may increase the level of stress for plants. Recent decades studies (mainly two-factors) have reported that the ecotoxicity of soil contaminants could be modified by climate factors. To date, little is known about: the combined climate-chemical stress on plants; the interaction of chemicals with high soil moisture conditions; the impact of soil properties on the combined climate-chemical stress and questions regarding the response of organisms to combined effect of all key factors influencing the ecotoxicity of chemicals under field conditions remain unanswered. Our study sought to fill the knowledge gap on the multifactorial interaction of four main factors encounter in polluted areas (soil chemical contamination: heavy metal (Zn); temperature: 10, 23, 35 °C, moisture: 55, 80%WHC; soil properties). The assessment of combined effect of multiple stressors based on the multiple ANCOVA model (n = 108; adjusted R2 = 0.68) and calculated indicators showed: 1) all studied factors significantly interacted and influenced the phytotoxic effect of Zn; 2) Zn modified the plant response to temperature stress depending on moisture conditions and soil properties. This study improves methods for assessing the hazardous effects of soil chemical contamination in the real environment.

Contamination of soils with heavy metals in the parks of Vologda

Soil contamination with heavy metals is a major threat to both the natural environment and human health. The study of soil contamination with heavy metals in urban environments is an important applied task. In the course of this study, the gross content of heavy metals in the soils of parks in Vologda was determined, consolidate figures of soil contamination were calculated and a comparative analysis of soil contamination in parks was made. Determination of the gross content of heavy metals in soils was carried out at the Agrochemical Service Centre “Vologodsky” in the Molochnoye settlement using generally accepted methods. The level of chemical contamination of soils was assessed on the basis of a total contamination indicator. The study concluded that sod-podzolic, loamy soil type with acidity ranging from 6.7 to 7.2 prevails in the parks of the city of Vologda under study. In general, 6 parks in the city of Vologda are classified as a permissible pollution category in terms of total soil pollution, while 2 parks are classified as a moderately hazardous pollution category. The most heavily metal-contaminated soils are found in Victory Park and the Kremlin Garden. The least heavily metal-contaminated soils are Evkovka, Mira and 50th anniversary of October parks.

Chemical Contamination of Soil on Urban Territories With Aluminum Production in the Baikal Region, Russia

The study was conducted in 2 urbanized areas of the Baikal region of Russia. These are the cities of Shelekhov and Tayshet with their suburbs. Aluminum production has been carried out in Shelekhov for over 60 years and in Tayshet for 5 years. The purpose of the study was to determine the pollution of urban soils with toxic elements—Al, F, Be, Li, as well as Cr, Ni, Pb, and so on under the influence of industrial enterprises (aluminum and cable plants, thermal power plants). Also, the purpose of the research was to determine the effect of increased fluorite (F) in the environment on children’s health. Pure aluminum is used much less frequently than in alloys. The addition of various elements (Be, B, Li, Fe, Si, Mg, Mn, Zr, Ag, Pb, Cu, Ni, and others) increases the hardness, density, thermal conductivity, and other properties of the alloys. The area of high F content in urban soil is 15 times higher than the regional context. The maximum content of Na, Be, and Al is 2 to 4 times higher than the regional background. An increased Li content is marked only near aluminum smelters. The F content in urine samples from children living in areas with long-term pollution exposure (Shelekhov) is 1.5 to 2 times higher than in the group of children with a short exposure period (Tayshet).

Structure of Microbial Complexes in Modelling of Polymetallic Pollution and Remediation of Agrosoddy-Podzolic Soils

In a model vegetation experiment (30 days), the responses of microbial communities of agro soddy-podzolic soil of two sites (Chashnikovo, Moscow oblast) with different organic carbon content (Corg 3.86 and 1.30%) to polymetallic pollution with heavy metals (HM) (Cu 660, Zn 1100, Pb 650 mg/kg) and treatment with biochar (5%) and lignohumate (0.25%). Classical microbiological culture-dependent analysis using Czapek agar and analysis of soil lipid profiles by gas chromatography–mass spectrometry revealed the differences in abundance colony forming units (CFUs), fungal and bacterial biomass, as well as in the diversity of cultivated fungi both in humus-rich and humus-poor soil. HMs did not have a significant effect on the number of CFUs and the number of cultural-morphological types of colonies, but reduced fungal and bacterial biomass in both soils; this decrease was more significant in a humus-poor soil. In addition, differences between the soils in the increase in the proportion of resistant melanized forms of fungi under the influence of HM in humus-rich (by 25.9%) and in humus-poor soil (by 45.7%) were observed. The sensitivity and universal significance of structural indicators as indicators of the stability of microbial complexes under chemical contamination of soils with different humus content were discussed. It was shown that the most sensitive and reliable indicators among the studied included the proportion of melanized fungi.

Biochar-Facilitated Soil Remediation: Mechanisms and Efficacy Variations

Recent research suggests that biochar amendment is a promising approach to mitigate soil contamination via immobilizing heavy metals and organic pollutants. Through intensive literature review, this paper was aimed to better understand the processes, mechanisms, and effectiveness of biochar immobilizing chemical contaminants in soil. The quality characteristics of biochar as a soil amendment varied greatly with the feedstock materials and the pyrolysis conditions. Biochar products from different sources demonstrated remarkably diversified capacities and efficiencies for stabilizing soil contaminants. Soil-incorporated biochar was able to stabilize Cd, Cu, Ni, Pb, and Zn and reduce their bioavailability through enhanced sorption (based on electrostatic attraction, ion exchange, and surface complexation) and chemical precipitation (incurred from soil pH elevation and ash addition of carbonates and phosphates). The stabilization efficacy was largely determined by cation exchange capacity (CEC), pH, and ash content of biochar. Biochar amendment increased the mobility of anionic toxic elements (e.g., CrO42-, AsO3-, and Sb(OH)6-) in soil. Soil-incorporated biochar was also able to adsorb nonpolar organic compounds (through pore-filling, partition, and hydrophobic effect) and polar organic compounds (via H-bonding, electrostatic attraction, specific interaction, and surface precipitation). The adsorption efficiency was controlled by the biochar surface properties specific surface area (SSA), microporosity, and hydrophobicity. Biochar may facilitate mineralization of organic pollutants by enhancing soil microbial activities. The effectiveness of biochar-facilitated soil remediation was case-specific, changing with the biochar source, amendment rate, placement, soil type, and pollutant species. More field studies are needed to evaluate the long-term effectiveness of biochar-facilitated soil remediation under practical circumstances.

Assessment of mutagenic activity of toxic waste polygon (Kalush) soil’s chemical pollution by the level of cytogenetic disorders in Triticum aestivum L.

Aim. To study the frequency and spectrum of cytogenetic disorders in Triticum aestivum L. with prolonged action on soil xenobiotic seeds of toxic waste storage areas and to explore the level of their mutagenic activity in comparison with the action of NMS’s moderate and high concentrations. Methods. Cytogenetic disorders induced by soil’s chemical contamination of toxic waste landfill of Dombrovsky Quarry dump (Kalush city) and influence of NMS’s moderate and high concentrations were determined in the cells of the meristem root using the ana-thelophase method. Results. Soil’s chemical contamination of the studied objects exhibits high mutagenic activity, which exceeds the control level by 1.8–3.8 times and does not yield to the mutagenic activity of NMS’s moderate concentrations. The high frequency of chromosomal aberrations at the low concentration of hexachlorobenzene in the soil of the Dombrovsky Quarry dumps is a consequence of its complex interaction with natural mineral compounds of the mountain chemical raw materials. Conclusions. The increasing of the spectrum of cytogenetic disorders induced by chemical soil contamination the proportion of bridges and the chromosomal rings testify radiomimetic properties of the mutagenic factors. The increasing of the number of cells with multiple aberrations indicates a high genotoxicity of hexachlorobenzene and the risk of serious genetic consequences in the case of falling it’s into the environment.
 Keywords: Triticum aestivum L., toxic waste, mitosis disorders, chromosomal aberrations, mutagenic activity.