Permissible Concentration Research Articles

Impact of Fires at Illegal Waste Storage Sites on Soil Contamination—A Study of Five Cases from Poland

In recent years in Poland, there has been an increasing issue with waste management. Despite waste sorting and fees paid by residents for waste collection, many of these waste materials are illegally disposed of. Such formally unclassified waste poses a significant threat to the surrounding residents and exerts toxic effects on soil and as well as surface- and groundwater and also fauna and flora in the vicinity. Due to the significant number of illegal storage site fires in Poland, the authors of this article assessed the impact of five different fires at illegal waste storage sites in Poland on the soil by analyzing the composition of the ashes remaining after a fire. Based on the chemical evaluation of the ashes, it was found that there are substances present in quantities exceeding permissible concentrations. Therefore, the authors concluded that some of these substances may have a negative impact on human health and degrade the surrounding flora and fauna in the storage areas. Consequently, it is essential to exercise stricter control over waste storage locations, classifying the waste left there to prevent adverse environmental and human impacts in case of a fire. Further research is necessary to assess the influence, for example, of leachate following a fire on the quality of the natural environment.

Features of the Formation of Strontium Pollution of Drinking Groundwater and Associated Health Risks in the North-West of Russia

The purpose of this research was to determine the natural factors that contribute to maintaining the standard quality of fresh drinking groundwater in areas with high strontium content. Hazard index values for the consumption of water containing strontium were also calculated to assess the overall non-carcinogenic health risk from combined ingestion and dermal exposure. The results showed that the groundwater with strontium concentrations exceeding the maximum permissible concentrations had an increased correlation of strontium concentrations with total dissolved solids and celestite and gypsum saturation indices. A decrease in calcium content was recorded with a simultaneous increase in the concentration of magnesium and strontium. Reducing conditions in the aquifer were also favorable for the conservation of these waters. In waters of standard quality, all these factors did not appear, which indicates their formation in sediments with discretely located small inclusions of celestite and gypsum. These waters were characterized by a calcium bicarbonate composition, low total dissolved solids (TDS), and oxidizing conditions. Elevated radiocarbon contents indicate their relatively young age. In general, it was found that children in the study area are most vulnerable to risks. Fifty percent of wells supply drinking water that is unsafe for consumption. The water from about a third of the wells studied is dangerous for adults.

Transpiring, phytoncidal and gas-absorbing properties of indoor plants and their role in improving the air quality in preschool environments

BACKGROUND: The high incidence of respiratory diseases among children attending preschool educational institutions highlights the need for prevention of respiratory tract infections. With children spending on average up to 10 hours a day in educational settings, the quality of the indoor air environment, including microbial contamination and low relative humidity, poses a risk for respiratory diseases. Placing a selection of plants in organized groups of children can offer a promising and cost-effective approach to promote health and well-being in the modern preschool education system. AIM: To select indoor plants based on their species and quantity to improve the air quality in organized children’s groups. Moreover, the paper presents recommendations for the installation and maintenance of the plants to create healthier environment for children. MATERIALS AND METHODS: Among more than 820 species of indoor plants, we have identified the most suitable options for preschool institutions. The selection process involved measuring the dimensions of the plants and the surface area of their leaves using a metric method. To assess the air quality, we conducted air sampling throughout the working week, once per hour, using an aspiration method with a sampling device PU-1B. Simultaneously, we measured the microclimate parameters in all the rooms included in the study. Furthermore, we studied the gas absorption capacity of indoor plants in controlled laboratory conditions within seed chambers with a volume of 200 liters. RESULTS: In rooms where plants were present, the levels of microorganisms varied. The average relative humidity values in all rooms were consistently below the hygienic standard of 40–60%, as outlined in SanPiN 1.2.3685-21, except for specific times. At 8:00, 9:00, 10:00, and 18:00, the relative humidity ranged from 15–35%. When exposed to a formaldehyde concentration of 3 times the maximum permissible concentration (MPC) Chlorophytum comosum reduced it to the regulated value of 0.01 MPC within 38 hours while the corresponding values for Sansevieria trifasciata and Cyperus alternifolius were 24 and 27 hours, respectively. CONCLUSION: Introducing a variety of indoor plants into a preschool educational setting can have significant benefits for air quality. The plants possess phytoncidal, transpiring, and gas-absorbing properties that contribute to a reduction in the overall number of microorganisms, a decrease in chemical pollutants, and an increase in air humidity. Our analysis showed that in the presence of indoor plants, the concentration of formaldehyde decreases to a regulated and safe level.

THE NITROGEN COMPOUNDS CONCENTRATION IN WATER ECOSYSTEMS OF DIFFERENT TYPES

The study researches the changes in the nitrogen compounds concentration (NH4+, NO2¯ і NO3¯) in water ecosystems of different types (the river Stubelka, the Khrinnyky reservoir, Lake Zasvitske and Morozivka quarry) and discusses ecological consequences of their balance shift. The author defines ammonium and nitrites as the predominant form of the nitrogen compounds. It was recorded the exceeding of the maximum permissible concentrations of ammonium nitrogen in the water of river Stubelka (1.16–3.44 times), the Khrinnyky reservoir (1.26-2.06 times), Lake Zasvitske (1.49 times) and Morozivka quarry (1.62 times) that is primarily caused by precipitation, household and agricultural land sewage as a result of mineral and organic fertilizers use. The nitrites concentration exceeds the standard values in the water of the river Stubelka (2.26 times), the Khrinnyky reservoir (1.48-1.77 times) and Lake Zasvitske (3.90-24.64 times) that indicates a slowdown in their oxidation to nitrates and a high risk of secondary pollution of water reservoirs. The nitrates concentration is within the limits of permissible values. It is demonstrated that the nitrogen compounds concentration in water reservoirs changes as follows: NH4+ – river > reservoir > quarry > lake; NO2¯ – lake > river > reservoir > quarry; NO3¯ – reservoir > river > quarry > lake. The balance shift in the ammonium ↔ nitrite ↔ nitrate system towards nitrates is most often characteristic of all water reservoirs in summer and towards ammonium in autumn. NO3¯/NH4+ maximum ratio was found in the Khrinnyky reservoir (94.81), Morozivka quarry (9.55), Lake Zasvitske (5.84) and the river Stubelka (3.80). The pH changes in the water of the river Stubelka (6.7-7.3), the Khrinnyky reservoir (7.0-7.5), Lake Zasvitske (5.9-7.2) and Morozivka quarry (6.5-7.4). The study researches fluctuations in the dissolved oxygen concentration in the water of the river Stubelka (5.7-8.5 mg O2/dm3), the Khrinnyky reservoir (4.4-9.5 mg O2/dm3), Lake Zasvitske (8.6-10.0 mg O2/dm3) and Morozivskyi quarry (8.7-9.3 mg O2/dm3). The concentration of dissolved oxygen in water reservoirs is as follows: lake > quarry > reservoir > river. The presence of an indicator of «fresh» water pollution (ammonium nitrogen) in all reservoirs indicates a constant influx of pollutants, especially intensively to the river Stubelka and the Khrinnyky Reservoir.

Research on an eco-safe filtration plant for wastewater treatment made of natural raw materials

Purpose. To develop a new eco-safe filtration plant for wastewater treatment based on natural and secondary raw materials, which will allow rational use of natural resources with further mathematical modeling of hydrodynamics of mixing treated wastewater in bioponds to predict removal of residual concentrations from the filter. Methodology. A complex of modern methods of theoretical and experimental research was used to solve the tasks. Concentration of pollutants was determined using methods of atomic adsorption spectroscopy, titrimetry and gravimetric methods, as well as pyrometric analysis. A laboratory installation was created, which included a receiving tank, a filter column, and a tank for collecting purified wastewater. Prediction of distribution and mixing of treated effluent in bioponds was carried out using mathematical and computer software. Findings. An environmentally safe filtration plant (containing sand, fallen leaves of linden, poplar, and plastic residues separated by a polymer mesh) was created to purify wastewater from suspended substances and nitrates. Kinetics of changes in concentration of suspended solids and nitrates in urban wastewater were studied. When using the filtration plant, concentration of suspended solids decreased by 85–92 %. Concentration of nitrates in purified water processed with such a plant is reduced from 12 to 0.25–0.05 mg/dm3. A mathematical model concerning distribution of purified water in a biopond was obtained, which allows predicting possible migration distributions of residual concentrations in purified water during its natural movement downstream. Originality. For the first time, influence of the species origin of fallen leaves on the performance indicators of wastewater filtration plant of urban sewage treatment constructions was investigated, which made it possible to substantiate a new way of disposal of this type of waste. For the first time, it was established that wastewater treatment using an eco-safe filtration plant based on natural and secondary raw materials, containing layers of sand, fallen oak, linden, and poplar leaves, gives an opportunity to reduce contents of suspended solids in wastewater by 1.5 times of the maximum permissible concentration; and such treatment also reduces concentration of nitrates by 4 times from the initial level. Pollutants from wastewater are mechanically fixed in pockets (microcracks, cracks) of fallen leaves, formed during drying of leaves, which is explained by hardening of intercellular spaces with formation of a specific geometry of holes. For the first time, mathematical modeling of purified wastewater movement in a biological pond with a complex geometry was performed, which allows estimating the concentration of the pollutant at its outlet from the pond. Practical value. The created environmentally safe wastewater filtration plant gives an opportunity to perform not only filtering, but also an effective biological purification of wastewater from nitrates on the surface of layers of fallen leaves. The wide use of the proposed installation will allow attracting plastic of polyethylene bottles used in everyday life as a secondary raw material. Based on the proposed mathematical model of movement of purified liquid containing residual concentrations of pollutants, it is possible to carry out qualitative forecasting and optimization of the process of cascade wastewater treatment at industrial and economic enterprises.

Chromatographic methods for the determination of free bisphenol A in technical and food products

The article provides a brief overview of chromatographic methods for the determination of free bisphenol A in technical and food products. Bisphenol A (BPA) is used as a monomer in the production of some plastics and epoxy resins. Free BPA may be present in quantities exceeding acceptable levels in plastic food containers and in food products packaged in these containers. Maximum permissible concentration (MPC) of BPA in the air of the working area is 5 mg/m3, which in terms of liquid is 5 µg/dm3. Maximum permissible concentration for the content of BPA in water, in water bodies for domestic, drinking and community water use is 0.1 mg/dm3. In European countries for plastics in contact with food, the BPA migration value is 0.6 mg/kg. Despite the relatively low toxicity of BPA, it can accumulate in the human body and cause harmful effects. To determine BPA in plastic, food products, and biological fluids, gas chromatography with preliminary derivatization by silylation or acylation of the analyte is most often used. Gas chromatographic techniques for direct chromatography on heat-resistant columns have also been developed. A fluorometric detector and a mass spectrometric detector are used as detection devices, along with a flame ionization detector. An alternative method for determination of BPA is HPLC with optical and mass spectrometric detection methods. The TLC method was also developed for the determination of BPA. For the preparation of BPA samples, solid-phase extraction (SPE), liquid-liquid extraction (LLE), dispersive liquid-liquid microextraction (DLLME), combined extraction method with acetonitrile separation (QuEChERS) are used.

Environmental approach to ensuring the security of modern enterprises

The development of integration processes and globalization requires an increase in enterprises' level of security. It becomes a necessary condition for their functioning. Issues related to the environmental and economic security of enterprises become relevant in modern conditions of rapid development of production and foreign economic relations and require further research not only at the level of the country but also at the level of regions and enterprises. Therefore, for enterprises, an essential point in their work is ensuring environmental safety without negatively impacting economic safety. Ensuring the enterprise's economic security is always important because it determines its ability to be stable on the market and flexible. Suppose the enterprise needs to pay attention to measures to counter environmental threats. In that case, it may lead to significant financial losses and even stop work. It is emphasized that the ecological component of the enterprise's economic security must guarantee the society's safety from business entities carrying out industrial and commercial activities. For this purpose, the manufacturer must carefully comply with the national norms of the minimum permissible content of harmful substances entering the environment and the ecological parameters of the manufactured products. It has been proven that enterprises' effective use of natural resources will contribute to producing quality products, increase competitiveness, and, most importantly, be environmentally safe for people's health. It is noted that an essential problem in ensuring control over the management system of the ecological component of safety is the reliability of the reported data of the enterprises' users of natural resources. It emphasized the need to introduce stricter requirements for environmental reporting by enterprises, which should lead to strict compliance with the norms and requirements of legislation in the field of ecology and, therefore, increase the environmental and economic security of the enterprise. Enterprise management is built on a balanced solution to environmental and economic problems, finding the optimal relationship between ensuring environmental safety and the expediency of enterprise activity. Keywords: ecological component, enterprise, safety, environmental economy, resources.

Removal of bromate ions from aqueous solutions via electrodeionization

Bromate (BrO3−) is a disinfection byproduct formed during the chemical oxidation of water containing bromide. Due to the carcinogenic effect of bromate, its maximum permissible concentration in drinking water has been set to 10 μg/L by the World Health Organization. In this study, the removal of BrO3− ions from aqueous solutions via electrodeionization (EDI) was investigated. The removal rate of BrO3− varied with the applied potential, and at 10 V, a removal rate of 99% was achieved. However, further increasing the applied potential to 30 V had a negative effect on the removal rate. Additionally, a low bromate concentration in the product water was achieved by reducing Na2SO4 conductivity in the electrode compartment. The removal of BrO3− is pH dependent, and at pH 1, only 17.5% was removed. However, increasing the pH of the solution to 5 increased the removal rate to 99.6%. Increasing the operating time and number of cells in the EDI stack improved the removal rate of BrO3−, and its concentration decreased from 5 mg/L to 1.4 μg/L. The calculated flux for BrO3− was 2.17 × 10−5 mol/m2s, specific power consumption was 89.98-W/hg KBrO3, and mass-transfer coefficient was 5.4 × 10−4 m/s at 10 V.

Influence of the gene pool of the breed on the content and variability of copper in the liver of pigs

The average level and variability of copper in the liver of pigs of different breeds were studied. Samples of parenchymal organs from pigs were taken immediately after slaughter and analysed at the analytical centre for collective use of V.S. Sobolev Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences using the method of atomic absorption spectrometry with flame and electrothermal atomisation on the SOLAAR M6 spectrometer (USA) by GOST 26929-94 Raw materials and food products— sample preparation Mineralization to determine the content of toxic elements. A normal distribution of the trait was found only in the Landrace breed (W = 0.94). In pig breeding areas, the content of heavy metals in soil, water and feed was studied, which did not exceed the maximum permissible concentration. The most significant variability of the microelement was observed in the Kemerovo breed, the least - in the Landrace breed. The full copper content was marked in the early ripening meat breed and the minimum in the Landrace breed. A smaller interquartile range about the Kemerovo and early meat breeds characterised the level of copper in the liver of Landrace pigs.

Reducing Outdoor Air Pollutants through a Moss-Based Biotechnological Purification Filter in Kazakhstan

This study considers the creation of a network of moss-based biotechnological purification filters under the Smart City concept. The extent of the absorption of heavy metals and gases by Sphagnopsida moss under different conditions was investigated. The efficiency of air purification with biotechnological filters was also investigated in the city of Almaty, Republic of Kazakhstan, where an excess of the permissible concentration of harmful substances in the air, according to the WHO air quality guidelines, is recorded throughout the year. Data on the level of pollution recorded with sensors located in the largest Kazakhstani cities from 21 June 2020 to 4 June 2023 were selected as the basis for calculating purification efficiency. In total, there are 220 in 73 settlements of the Republic of Kazakhstan, with 80 such sensors located in the city of Almaty. Since creating a single biotechnological filter is expensive, our task was to calculate the air purification effect in the case of increasing the number of filters placed in polluted areas. We show that 10 filters provide an air purification efficiency of 0.77%, with 100 filters providing an air purification efficiency of 5.72% and 500 filters providing an air purification efficiency of 23.11%. A biotechnological filter for air purification based on moss was designed at Astana IT University by taking into consideration the climatic features, distribution, and types of pollution in the Republic of Kazakhstan. The obtained results are essential for ensuring compliance with the standard for environmental comfort in the Republic of Kazakhstan. Additionally, the research findings and the experience of implementing a moss-based biotechnological filter can be applied to designing similar air purification systems in other cities. This is of great importance for the advancement of the field of urban science.

CONTENT OF HEAVY METALS IN THE SNOW COVER OF THE EASTERN INDUSTRIAL ZONE OF PAVLODAR

This article analyzes the content of heavy metals in the snow cover of the industrial areas of the city of Pavlodar, which made it possible to identify the presence of the problem of environmental pollution. Data on the content of various elements in snow by hazard class were analyzed: in the first hazard class, Zn has the highest content, on average 187.5 mg/kg, the greatest variation in the content of elements is observed in Cd – the coefficient of variation is 118.5%, a high concentration coefficient for Pb and Zn; in the second class – Cr has the highest content, on average 259.1 mg/kg, the greatest variation is observed in Cu – the coefficient of variation is 92%, the concentration coefficient is high in Cr; in the third class – Ba has the highest content, on average 777.5 mg/kg, the coefficient of variation and concentration of Mn. Studies have shown that the content of heavy metals in the snow increases in the northeast direction from the industrial enterprises of the eastern industrial zone of Pavlodar. According to calculations, the content of all heavy metals of the first hazard class in the snow exceeds the maximum permissible concentration (MPC) of soils. The content of cadmium exceeds the maximum permissible concentration by more than 17 times. Heavy metals of the second hazard class are in the range of 0.4–3.2 times the MPC. Strontium exceeds MPC by 25 times. The analysis carried out is an important step in understanding the ecological situation in Pavlodar and can be useful for taking measures to protect the environment and improve the ecological situation in this area.

The impact of destruction of the Kakhovka dam on the environmental status of the Odesa area of the Black Sea

The paper provides a chronological description of the aftermath and the effect of blowing up the Kakhovka hydroelectric power plant dam by Russian occupation forces of 6 June 2023 on the seawater quality in the coastal zone of Odesa agglomeration, according to the results of operational environmental monitoring in the early weeks upon the man-made disaster. Such a description is indispensable for assessing the scope of pollution of marine water areas and calculation of the damage inflicted on the marine ecosystem and its natural resources, adjustment and verification of mathematical models which will further be used to prognosticate the consequences of the dam destruction for the marine ecosystem. According to the data published in open sources, development of the environmental, sanitary and microbiological situation in the coastal zone of the city of Odesa over June 2023 is described, the dynamics of some indices of the sea water quality are shown, and the pollutants the concentration of which exceeded the maximum permissible concentrations set for them, as well as sanitary and microbiological indices, according to which the population is forbidden from swimming in the sea, are indicated. In addition, as a consequence of the abnormal desalination of sea waters and the inflow of a large amount of nutrients and organic matter into the sea, the phenomenon of algal bloom is described, and a qualitative forecast of its consequences is provided. It is concluded that owing to the accumulated reserves of organic matter in the bottom sediment probability of hypoxic conditions and suffocation of hydrobionts in the summer periods will increase in the years to follow. It is in view of the accumulation of pollutants in bottom sediments and the expected secondary pollution of sea water that the biological diversity of the marine ecosystem within the Odesa region will degrade and the quality of its biological resources will deteriorate.

A new approach to producing a prospective energy resource based on coalmine methane

The paper describes topical issues of a prospective method for coalmine methane utilization for obtaining an additional valuable energy resource for the regional development of coal-mining areas. It is noted that the development of the extraction of methane resources is very urgent and is of great economic importance for ensuring the energy independence of Ukraine. The experience and technologies of using methane and coalmine gas by global coal-mining companies are analyzed. Modern prospects and opportunities for using coal gas are studied. There is a need to transform the coalmine methane removal system and directions for maximizing the use of its resources in a wide range of concentrations in the composition of gas-air mixtures based on the development of innovative technologies to improve the efficiency and cost-effectiveness of functioning coal-mining enterprises. Attention is focused on the advantages of using gas hydrate technologies for obtaining additional energy resource under conditions of changing coalmine methane concentrations. The specifics of the process of mixed gas hydrate formation from gas mixtures of various geneses have been studied. It has been revealed that it is the coalmine gas-methane composition that determines and forms the basic condition for hydrate formation. The thermobaric conditions for the hydrate formation process at different methane concentrations in gas mixtures of degassing systems have been experimentally determined. The results obtained are the basis for further research on efficiency of creating gas hydrates from coalmine methane and determining its minimum permissible concentration in the gas mixture of degassing systems according to the technological and economic criteria of hydrate formation.

Pd(II)–Cu(II) compositions fixed on dispersed silica from ammonia solutions for carbon monoxide oxidation with air oxygen

The samples of dispersed silica, tripoli from the Konoplyansky deposit, were used in this work. Pd(II)–Cu(II) compounds fixed on dispersed silica for the oxidation of carbon monoxide with air oxygen were obtained by impregnation of the carrier, which was previously boiled in distilled water for one hour, through NH3-coordination in the presence of ethyl alcohol, followed by maturation of the catalyst at 200C for 20 hours and drying at 3000C for 4 hours. The initial and chemically modified samples of tripoli were characterized by X-ray phase analysis, IR-spectral and thermogravimetric research methods and tested in the reaction of low-temperature oxidation of carbon monoxide with oxygen. The degree of CO conversion in the stationary mode was used to estimate the activity of the catalyst. It was established that the activity of copper-palladium catalysts is significantly affected by the method of catalyst preparation, namely: the sequence of mixing the starting solutions, the drying temperature, and the content of the catalyst components. The catalyst with the highest activity contained all the components, such as K2PdCl4, Cu(NO3)2, NH4OH, KBr, and С2Н5ОН, mixed beforehand in the specified sequence. It provides air purification from CO to a concentration that is 5 times lower than the maximum permissible concentration for the working area (MPCCO=20 mg/m3). The degree of CO oxidation reaches 98.6%. With other variations of the method of the catalyst preparation, the samples show much lower activity, which indicates the formation of surface complexes of different composition, responsible for the oxidation of carbon monoxide by air oxygen.

Совершенствование проточной части газосепараторов с использованием мультифазного коэффициента относительной скорости движения дискретных частиц

The paper analyzes features of the flowing formation fluid that contains free gas bubbles in the flow part of a vortex-type separator with the movable screw. Expressions are derived for a dimensionless multiphase coefficient of the discrete particles relative separation rate and the multiphase similarity criterion, which are making it possible to evaluate the gas separator efficiency, design and develop new devices based on the previously created highly efficient models. The derived equations allow determining the main geometric dimensions of the gas separator flow part based on the given radial dimensions, nominal flow rate and permissible content of free gas at the inlet. For the obtained geometric dimensions of the gas separator flow part, it becomes possible to construct dependences of the separation coefficient and the permissible amount of free gas at the inlet on the rotor rotation speed, flow rate and physical properties of the multiphase mixture.

Екологічні аспекти переробки ливарного алюмінієвого шлаку

Data on the influence of the aluminum slag processing process on the state of the atmospheric environment are presented. Calculations of the dispersion of pollutants (PO) in the surface layer of atmospheric air were carried out, which showed the absence of exceeding the maximum permissible concentrations (MPC) for carbon monoxide, nitrogen dioxin, sulfur dioxide, hydrogen chloride and dust. Analysis of emissions was carried out for extreme conditions of equipment operation. It was established that under such technological conditions, the maximum concentration of pollutants is: NO2 ≤ values of 0.2 MPC, and the rest of the pollutants do not exceed - 0.05 MPC. To identify the actual concentrations of hazardous substances at the border of the sanitary protection zone (SZZ), laboratory tests were performed at a distance of 300 m from the emission source. It was established that emissions of pollutants into the atmosphere from the industrial site on the territory of the enterprise and on the border of the calculated sanitary protection zone are less than the MPC of the atmospheric air of populated areas and will not have a significant harmful effect on the environment, provided that the sanitary and technological requirements for operation are met. The level of the content of harmful impurities in the air does not exceed the hygienic standards outside the sanitary protection zone, which are established for the atmospheric air of populated areas. Keywords: ecology, pollutants, maximum permissible concentration, aluminum slag.

Dispersed composition of particulate matter in the air of enterprises workplaces

The research results of the air of the working area of the metalworking, woodworking and construction industry on the presence of solid particles with the usage of gravimetric method and the following optical light microscopy of clarified filters are presented. It has been established that the mass concentrations and the dispersed composition of particulate matter in the air of the industrial plants depend on the type and technological process of the manufactured goods. Maximum mass concentration of the particulate matter has been identified in the workplace air in medium density fiberboards (MDF) milling, while the maximum amount of the particles has been discovered during the casting of metal products and the pressing of products from MDF. The most widespread fraction in the workplace air in bricks and blocks production, pressing and milling of MDF products, casting and metalworking are the particles 1–2.5 µm in size. The difference in the fraction composition of the suspended particles in the different workshops is caused mainly by the quantity of particles with a diameter 0.5–1 µm and 5–10 µm. These studies can be used to develop standards for the maximum permissible concentrations of fine dispersed fractions of particulate matter in the workplace air of enterprises, and to assess working conditions and professional risk in manufacturing processes

Mercury concentration in the snow cover of the city of Khabarovsk

The research reveals results of studies of the total mercury content in the snow cover of Khabarovsk in winter period 2021-2022. Researchers highlight a connection between mercury and non-soluble residue, with minor transition into soluble phase. The total mercury content in the non-soluble residue ranged from 0.3 to 1.4 mg/kg. On the northern border of the Bolshekhekhtsirsky Reserve, area with high content of quicksilver (3 mg/kg) was found, which exceeds the maxi-mum permissible concentration by 1.4 times. Authors consider that high concentration of quicksilver may be a result of short-term local pollution and do not exclude cross-border origin of it. Content of mercury as a part of solid atmospheric precipitation on the Earth’s surface in this area is 37.5 µg/m2, with average values of 10-18 µg/m2. The maximum content of mercury (73.9 µg/m2) was found nearby CHP-3 area. The reason is a high concentration of combustion products in snow cover. The amount of solid atmospheric precipitation in the area of CHP-1 also significantly exceeded the average values, but this did not lead to an increase in the total amount of mercury that reached the surface. The minimum concentration of quicksilver was found in the embankment park area of the city - 3.2 µg/m2.

Determining the effect of drug "Warfarin sodium" on toxicity indicators in an acute experiment

The drug "Warfarin sodium" refers to anticoagulants of indirect action. It contains only one substance - warfarin sodium, the toxicological indicator of which have been studied in many countries. Therefore, the range of indicators for DL50 of warfarin sodium is very large. However, warfarin sodium has not yet been studied in Ukraine, its maximum permissible concentration in the air of the work area has not been established. Significant volumes of production and use of the drug “Warfarin sodium” on the territory of Ukraine necessitate the clarification of its main toxicological indicators and the establishment of the maximum allowable concentration in the air of the working area, which includes several stages. The first of them is the purpose of this work, namely: to establish DL50 upon intragastric administration of the drug "Warfarin sodium" to two species of animals in the conditions of an acute experiment. Experimental animals (60 non-linear white rats and 70 non-linear white mice) were divided into 9 groups. Six groups were injected with the drug "Warfarin sodium" in different doses: the first group (female rats) – 58 mg/kg per animal, the second (also female rats) – 29 mg/kg, the third (male rats) – 323 mg/kg, the fourth (also male rats) – 161.5 mg/kg, the fifth (mice of both sexes) – 374 mg/kg, the sixth (also mice of both sexes) – 187 mg/kg. Three control groups (the first – 6 male rats, the second – 6 female rats, the third – 14 mice) received distilled water. As a result, the mortality rates of experimental animals were obtained, on the basis of which, using the probit analysis method, the toxicity indicator of DL50 was determined: for female rats – 15.85 mg/kg, male rats – 398.11 mg/kg and mice –645.65 mg/kg. The established DL50 for male rats after intragastric administration of the drug "Warfarin sodium" may indicate an increase in their resistance to the drug, and this determines the expediency of periodic repeated acute experiments in order to verify the relevance of previously established DL50 of sodium warfarin. According to DL50 upon intragastric administration to female rats, which are the most sensitive species of animals to it, warfarin sodium belongs to highly hazardous substances.

TO ASSESS THE FILTRATION CAPABILITIES OF A VERTICAL GARDENING SYSTEM

A quantitative assessment of the filtration properties of vertical landscaping systems during air purification of administrative premises has been carried out. A study was conducted in one of the offices of Izhevsk, during which more than 1,500 measurements were performed. According to the data obtained, graphs of changes in the concentrations of four gaseous pollutants were plotted in the presence and absence of a vertical gardening system. The average concentrations of all the pollutants studied were within the established sanitary and hygienic standards (average daily maximum permissible concentrations), except for formaldehyde. When processing the results, it was found out that this system with plants is able to effectively reduce the concentrations of carbon dioxide, marginal hydrocarbons, formaldehyde. The conclusion is made about the absorbing ability of the Epipremnum marble queen plant used in the vertical gardening system.