Compositional-geochemical characterization and multi-element pollution and risk assessment of potentially toxic elements in the urban landfill soil.

Urban areas are characterized by the presence of various pollution sources including landfills. During the recent decade, urban landfills were investigated as a source of pollution by potentially toxic elements and potential deposits for landfill mining. The contents of Cr, V, Ti, Ca, K, Mo, Zr, Sr, Rb, As, Zn, Cu, Co, Fe, Mn, Pb, Ba in soils of Vanadzor city landfill site (VL) were determined using the X-ray fluorescence spectrometer to assess multi-element pollution and ecological risk and to identify potentially toxic elements geochemical associations through the application of compositional data analysis.

Geochemical characterization of changes in the chemical composition of river sediments under the continuous anthropogenic influence of Yerevan, Armenia.

The long-term study of the chemical composition of river sediments within urban areas and the establishment of baseline values of major and trace elements is an important task. Therefore, this study aims to provide a geochemical characterization of the sediments, establish a local geochemical baseline, unveil geochemical associations of elements, study the trend of changes in element pollution levels and the associated ecological risks. The results indicate that the change of the local physical characteristics across the river flow (canyon-flat relief surrounded by buildings-reservoir-flat relief under the influence of contamination sources) and locations of contamination sources conditioned the formation of positive extreme values detected for the majority of the studied elements.

Compositional-geochemical characterization of lead (Pb) anomalies and Pb-induced human health risk in urban topsoil.

Urban areas are characterized by a constant anthropogenic input, which is manifested in the chemical composition of the surface layer of urban soil. The consequence is the formation of intense anomalies of chemical elements, including lead (Pb), that are atypical for this landscape. Therefore, this study aims to explore the compositional-geochemical characteristics of soil Pb anomalies in the urban areas of Yerevan, Gyumri, and Vanadzor, and to identify the geochemical associations of Pb that emerge under prevalent anthropogenic influences in these urban areas.

Geospatial patterns and geochemical compositional characteristics of molybdenum in different mediums of an urban environment.

Urban areas are characterized by the presence of certain potentially toxic elements including molybdenum (Mo). Therefore, compositional data analysis combined with geospatial mapping was applied in this study to reveal the spatial distribution characteristics of Mo in courtyard surface dust (dust), soils, and river sediments (sediments), to identify potential sources of Mo, and to reveal Mo geochemical associations in different urban environmental mediums. The mean contents of Mo decreased in the following order: dust (11.

Exploring relationship of soil PTE geochemical and "VIS-NIR spectroscopy" patterns near Cu-Mo mine (Armenia).

PTE contamination of soils remains one of the global environmental concerns. The ways of detecting and monitoring PTE concentrations in soils varies including traditional field sampling accompanied by sample preparation and chemical analysis and state of the art visible and near-infrared (Vis-NIR) spectroscopic approaches. Among the different Machine Learning (ML) to extract soil information from spectra and to explore the relationship between spectral reflectance data and soil PTE content PLSR method is a well-established one to construct a soil PTE estimation model.

Factors conditioning soil PTE contents and the associated health risk in an area with mixed land use.

The study of soil chemical composition and geochemical characterization is of great concern. In 2020, a soil survey of the Ararat region (Armenia) was conducted to study the contents of soil elements (Cr, V, Ti, As, Zn, Cu, Co, Fe, Mn, Ba, Pb, Mo, Ca, and K), identify pollution sources and factors conditioning their spatial distribution patterns, and assess the health risk associated with potentially toxic elements (PTEs). The combined application of compositional data analysis and geospatial mapping allowed to reveal three subsamples with unique chemical signatures.

Compositional features of Pb in agricultural soils and geochemical associations conditioning Pb contents in plants.

Soil geochemical data is compositional. Hence the studies targeting the potential of accumulation of toxic elements (TE) in plants have to consider the compositional nature of soil chemical environment. In this study, the combined application of compositional data analysis and geospatial mapping was used to investigate Pb geochemical associations in agricultural soils, revealing the link between these associations and Pb contents in plants, as well as identifying source-specific transfer of Pb from soil to plants.

Multifractal features of activity concentration and stochastic risk assessment of naturally occurring and technogenic radionuclides in the soil of Yerevan, Armenia.

Spatial patterns and background ranges of naturally occurring radionuclides (NORs) (i.e. U-238, Th-232, K-40) and Cs-137 were studied in the urban soils of Yerevan, the capital city of Armenia.

Toxic element contents and associated multi-medium health risk assessment in an area under continuous agricultural use.

Soils and contaminated plants are in the group of significant environmental pathways of human exposure to toxic elements (TEs). This study aimed to assess the soil-to-plant transfer of TEs (Pb, As, Cd, Hg), as well as the plausible health risks via different exposure pathways in the Armavir region of Armenia. The contents of TEs were determined in soil, fruit and vegetable samples using X-ray fluorescence and atomic absorption spectroscopy, respectively, and the soil-to-plant transfer of TEs and induced chronic non-carcinogenic risks were evaluated.

Potentially toxic elements contents and the associated potential ecological risk in the bottom sediments of Hrazdan river under the impact of Yerevan city (Armenia).

This research aims to assess the ecological status of the Hrazdan river (Armenia) section that flows through Yerevan. The distribution of potentially toxic elements (PTE) (Cr, V, As, Zn, Cu, Ni, Co, Mn, Pb, Ti, Mo, Fe, and Ba), the bottom sediments pollution level, and the ecological risk were assessed employing the single pollution index (SPI), the enrichment factor (EF), the geo-accumulation index (I), and the potential ecological risk index (RI). On sampling sites, water quality parameters (turbidity, DO, electrical conductivity (EC), salinity, TDS, pH, temperature °C) were measured as well.

Revealing Soil and Tree Leaves Deposited Particulate Matter PTE Relationship and Potential Sources in Urban Environment.

Trees play a pivotal role in improving urban environmental quality and provide several ecosystem services including the removal of pollutants from the air, such as particular matter (PM) and potentially toxic elements (PTE). Therefore, understanding the tree PM and PTE capturing potential, also in connection with plant species, is of great concern, especially in urban areas. This study aims to reveal the link between the elemental composition of PM deposited on tree leaves and soils PTE contents, as well as to rank the PM capturing efficiency of 10 different tree species growing under the impact of urban environments.

Revealing XRF data quality level, comparability with ICP-ES/ICP-MS soil PTE contents and similarities in PTE induced health risk.

Portable X-ray fluorescence spectroscopy (XRF) was recognized as an efficient and promising tools to study the contents of chemical elements in various media including soils under the impact of anthropogenic activities. However, the quality of data and the equality of chemical elements with other common analytical methods such as aqua-regia extraction vary depending on site, sample conditions, and analysis time. In this study, we examine the adequacy of XRF and ICP-ES/ICP-MS aqua-regia extractable (AR) results obtained for lab-type pretreated samples (N = 15) for Ti, Fe, Mn, Co, V, Pb, Zn, Cu, Cr, Mo, Sr, and As contents in soils under the impact of copper smelter and assess the equality of PTE contents induced health risk.

Yerevan soil radioactivity: Radiological and geochemical assessment.

Spatial pattern of naturally occurring radionuclides (NOR): Ra, Th, K, and artificial Cs was studied using soil samples of the multipurpose geochemical survey of the city of Yerevan, capital of Armenia. High purity Ge detector-based gamma spectrometry system was used for the determination of radionuclides activity concentrations in urban soils. A combination of compositional data analysis, geochemical mapping and radiological assessment were applied to reveal potential factors of technologically enhanced natural radioactivity and excess lifetime cancer risk for Yerevan's population due to NOR and artificial Cs in the urban environment.

Identification of spatial patterns, geochemical associations and assessment of origin-specific health risk of potentially toxic elements in soils of Armavir region, Armenia.

The study of soil potentially toxic elements (PTE) contents and establishment of the geochemical characterization of areas which have never been studied is of great concern. In 2019, soil survey of the Armavir region (Armenia) was conducted in order to investigate the spatial pattern of PTE, reveal PTE geochemical associations and assess the origin-specific health risks. The application of compositional data analysis and geospatial mapping allowed to identify two clusters of samples.

Combination of compositional data analysis and machine learning approaches to identify sources and geochemical associations of potentially toxic elements in soil and assess the associated human health risk in a mining city.

Mining activities change the chemical composition of the environment and have negative reflection on people's health and there is no single measure to deal with adverse consequences of mining activities, as each case is specific and needs to be understood and mitigated in a unique way. In this study, the combination of compositional data analysis (CoDA), k-means algorithm, hierarchical cluster analysis applied to reveal the geochemical associations of potentially toxic elements (PTE) in soil of Alaverdi city (Armenia) (Ti, Fe, Ba, Mn, Co, V, Pb, Zn, Cu, Cr, Mo, As). Additionally, to assess PTE-induced health risk, two commonly used approaches were used.

Continuous impact of mining activities on soil heavy metals levels and human health.

Soils samples collected during different geochemical surveys of the city of Kajaran located near the biggest Cu-Mo mining area in Armenia were subjected to the multivariate geostatistical analysis and geochemical mapping in order to reveal soil heavy metals spatial distribution pattern and assess human health risk level under continuous impact of mining activities. In addition, human health risk assessment was done for the contents of Pb, Cu, Zn, Co, Mo, Mn, Ti, and Fe. The results of Principal Component Analysis and Cluster Analysis verify each other and were also complemented by the spatial distribution features of studied heavy metals indicating that two groups of elements have been generated.

Human health risk assessment and riskiest heavy metal origin identification in urban soils of Yerevan, Armenia.

The pollution of urban soils by heavy metals remains a topical issue because of the risks it represents to human health. Heavy metal pollution levels of Yerevan's soils were evaluated using Pollution index and Enrichment factor, while associated health risk was assessed by US EPA model. The heavy metals with significant amount of PI > 1 values were observed for V (100%), Cr (95.

Heavy metals pollution levels and children health risk assessment of Yerevan kindergartens soils.

Children, the most vulnerable urban population group, are exceptionally sensitive to polluted environments, particularly urban soils, which can lead to adverse health effects upon exposure. In this study, the total concentrations of Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti, V, and Zn were determined in 111 topsoil samples collected from kindergartens in Yerevan. The objectives of this study were to evaluate heavy metal pollution levels of kindergarten's soils in Yerevan, compare with national legal and international requirements on heavy metal contents in kindergarten soil, and assess related child health risk.