Annotation of the results obtained in 2022
The main aims of urban air pollution monitoring are to optimize the interaction between humanity and nature, to combine and integrate environmental databases, and to develop sustainable approaches to the production and the organization of the urban environment. Even despite the growth of the economy in megacities, modern cities are becoming more people-unfriendly, while urban ecosystems face various problems, including air, water and soil pollution, excess incidences of infection diseases due to the high population density, a higher risk of developing mental illness compared to rural areas, the limited access of poor people to high-quality and nutritious food, which results in health problems. In addition to these problems, excess noise levels is also critical due to the annually growing number of motor vehicles and other sources, which often lead to increased levels of stress and irritability. Existing methods of urban environmental monitoring do not provide a complete picture of the threats and human health risks. Thus, during air pollution monitoring, it is necessary to clearly understand that, it is impossible to fully establish the degree of danger to human health and the environment by assessing only the concentrations of standardized pollutants, . For example, the main problem of PM2.5 and PM10 air pollution is not only their air concentration but also the composition of various toxicants present in them, including metalloids. The presence of heavy metals such as As, Cr, Co, Cd, Ni and Pb in PM2.5 and PM10 significantly increases the risk of cancer, and chronic exposure to these particles can cause various problems in the gastrointestinal tract in the form of dysbacteriosis, and also lead to impaired glucose metabolism and other negative changes for the body at the cellular level. Currently, it is not enough to monitor the concentration of PM2.5 and PM10, it is necessary to know the amount of metalloids and other substances included in PM2.5 and PM10. The main objective of the project is to identify patterns of distribution of potentially toxic elements such as As, Bi, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sr, V and Zn and identify their sources in various objects of the urban environments (soils, urban dust, snow cover, atmospheric aerosols) on the example of Chelyabinsk. as typical industrial Russian city. The aim of the project is to develop a unified methodological approach to the analysis of the composition and distribution mechanisms of potentially toxic elements in various objects of the urban environment. Guidelines have been developed for carrying out ecological and geochemical monitoring of urban environment pollution by potentially toxic elements. The main anthropogenic sources of pollution (transport, industry) for each studied metal(oid)a have been determined. The obtained data will allow the city authorities to develop measures to minimize the pollution of the urban environment with metal (oids) and the associated environmental risks. Air samples containing PM10 and PM2.5 particles were collected on Chelyabinsk urban area. The collected particles were studied by scanning electron microscopy. Maps of the spatial distribution of lead concentrations in PM2.5 from all sampling sites were compiled. As part of the project, studies were carried out to find out whether there is a reliable relationship between heavy metal pollution of an urbanized area and cancer incidence in the population. An assessment of correlations showed that socio-economic characteristics make a significant contribution to the formation of the incidence of malignant neoplasms in the population of the study region. With the help of regression analysis, it was clarified that when the emission factors of metals and their compounds are included in the regression model, the model also remains statistically significant. As a result of the project, three articles were published in peer-reviewed scientific journals, including one in a journal of the first quintile, the results were reported at four international scientific conferences, team members made a total of 6 oral presentations on the research topic.

 

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Annotation of the results obtained in 2023
For the reporting year 2023, the concentrations of dissolved and suspended forms of metals and metalloids in the snow cover were determined. The largest part of metals is concentrated in the solid phase, while the liquid phase accounts for no more than 10%. The background dust load (9 kg/km2 per day) was close to the same indicator (~10 kg/km2) for the flat continental territory of temperate latitudes, remote from urbanized areas. The highest dust load in the city of Chelyabinsk was 198-256 kg/km2 per day and was typical for transport points, which corresponds to a moderate level of environmental risk. For points located near industrial enterprises, the dust load was 158-187 kg/km2 per day, and for courtyards and parks 95-115 and 35-67 kg/km2 per day, this is less than 200 and corresponds to a low level of environmental hazard. The insoluble fraction of the snow cover was most enriched in metalloids at points located near metallurgical enterprises. High concentrations of As, Bi, Cd, Cr, Cu, Mn, Pb, Sb, and Zn were found in the snow cover. Maps of spatial distribution were constructed, which showed that for the majority of heavy metals concentrated in the solid phase and of anthropogenic origin As, Bi, Cd, Cr, Cu, Mn, Pb, Sb, Zn, there are “hot spots” near large industrial enterprises in the city where maximum metal deposition occurs. To quantify the contamination of snow cover with metals, a range of statistical methods of multivariate analysis was applied. Spearman correlation coefficients were calculated. The largest number of significant correlations were identified for metalloids in the solid phase, the sources of which are industrial enterprises of the city: As, Bi, Cd, Cu, Ni, Pb, Sb, and Zn. To identify possible sources of pollution, factor analysis was used - the method of principal components. The values of eigenvectors were obtained, which are considered as “traces” of emission sources. According to the Kaiser criterion, the first three components with eigenvalues greater than 1 have a dominant influence. These three factors account for 89.46% of the total sample variance. The percentage of explained variance for the first component (PC1) is the largest and amounts to 59.91%, which indicates the existence of one dominant emission source or group of emission sources of some elements. For the remaining components, the percentage of variance is: PC2 –17.37%, PC3 –12.19%. Three factors have been identified that explain the dispersion of the content of metalloids in undissolved form in the snow cover in the city of Chelyabinsk. The first factor significantly affects the distribution of As, Bi, Cd, Cu, Ni, Pb, Sb, and Zn, the second - on Cr and Mn, and the third - on Co and V. The distribution of strontium is influenced by the first and second factors. Presumably the first source is the Chelyabinsk zinc plant, the second is the electrometallurgical plant producing ferrochrome and ferromanganese, and the third group is represented by metals that are predominantly of natural origin. A comprehensive methodology was developed for monitoring the state of snow cover in the territory of an industrial agglomeration using Earth remote sensing technologies and physical and chemical analysis methods. Remote sensing can be successfully integrated into environmental monitoring in a smart city. Monitoring at the regional level makes it possible to identify sources of pollution such as energy, industry and transport. Construction of the digital twin and model is being carried out at the city level. At the regional level, a bottom-up approach is being implemented. The global level combines ground-based measurements and remote sensing. Global monitoring takes a top-down approach. Combining the two approaches allows us to develop a better strategy for protecting the urban environment. The isotopic ratios of lead, copper and zinc in PM10 and PM2.5 particles collected from various locations in the city were determined. Comparison of the isotopic ratios of lead, copper and zinc in PM10 and PM2.5 with isotope ratios obtained for industrial dusts, soils, and road dust will allow us to determine with high reliability the dominant sources of these elements. A model was developed based on the isotopic characteristics of the main sources of pollution: transport (20%), industry (60%) and other activities (20%) Multiisotopic systems of Pb, Cu and Zn can be used to search for sources of metals in air, soil and snow . The content of bioavailable metals and metalloids in urban environments was assessed. An assessment of the overall carcinogenic risk caused by the presence of As, Cr, Co, Cd, Ni and Pb in samples showed that an individual lifetime risk corresponds to 1 to 100 additional cases of serious illness or death per 1 million exposed individuals and the conditionally acceptable zone ( acceptable) risk. At this level, most foreign and recommended by international organizations hygienic standards for the population as a whole are established. Acceptable risk levels are subject to constant monitoring and if there is an upward trend, additional measures are required to reduce them.

 

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