Petr Fedotov

Nanoparticles (NPs) of urban dust can be hazardous to human health due to the possibility of a high accumulation of potentially toxic elements (PTEs), high penetration ability into organisms, and their ability to cause injury to cells, tissues, and organs. The composition of NPs of urban dust may vary during the year; however, there are so far no studies on the seasonal changes in their elemental composition and related ecological and health risks. The current work was carried out using samples of urban dust from Moscow, the largest megacity in Europe, collected in spring, summer, and autumn. It was found that NPs of urban dust are polluted by PTEs, namely W, Bi, Hg, P, S, Sn, Mo, Cu, Cd, Pb, Sb, and Zn. The highest pollution and ecological risks were found in NPs of urban dust collected in summer (RI = 592) as compared to autumn (RI = 399) and spring (RI = 231). The same regularity was observed for health risks. The highest possible cancerogenic risk was found in summer NPs (CTCR = 3.0 × 10⁻⁴) followed by autumn NPs (CTCR = 2.5 × 10⁻⁴) and spring NPs (CTCR = 3.5 × 10⁻⁵). However, the difference between mean values obtained for the three seasons was not statistically significant. Additionally, it was demonstrated that vehicle emissions are one of the main sources of pollution of NPs, and their intensity does not significantly change throughout the year in Moscow. The results obtained offer new insights into the regularities of seasonal variations in elemental composition, pollution, and related ecological and health risks of NPs of urban dust.

Development of novel methods for the separation, characterization, and analysis of microplastics is an urgent task. Countercurrent chromatography (CCC) has been proven to be an efficient method for the separation and preconcentration of microplastics from aqueous samples using two-phase water–oil systems. However, the efficiency of separation of microplastics from natural seawater by CCC has not been studied so far. Here we demonstrate the high efficiency of separation of microplastics from Black Sea water samples by CCC. The separation efficiency of PE, PP, PS, PVC, PET microparticles of different size (<63, 63–100, 100–250 μm) from spiked seawater samples is about 100%. The method enables the separation of microplastics with size at least down to 1 μm to be performed. The combination of CCC and pyro-GC-MS was applied to the quantification of microplastics in Black Sea water samples. Seven microplastics (μPE, μPP, μSBR, μPVC, μPET) were determined in the seawater samples under study. The total concentration of determined microplastics was about 6.5 μg/L. It was shown that the combination of CCC and pyro-GC-MS enabled robust analytical data to be obtained and hence can be applied to an accurate quantification of microplastics in seawater.

Urban dust particles are a major pathogenic factor in respiratory diseases such as asthma and chronic obstructive pulmonary disease, and also increase the

Urban dust particles are a major pathogenic factor in respiratory diseases such as asthma and chronic obstructive pulmonary disease, and also increase the risk of cardiovascular disease and lung cancer. Nanoparticles (NPs) of various origins are an important component of urban dust, but their effects on the human body are barely studied. In the present work, the effect of urban dust NPs on innate immune cells, neutrophils and macrophages was investigated in vitro. Urban dust nanoparticles were isolated from urban dust samples using coiled tube field-flow fractionation technique. Urban dust NPs were shown to induce a slight increase in the production of reactive oxygen species in human neutrophils. Preincubation of neutrophils with dust NPs resulted in a significant increase in ROS production in response to the chemoattractant peptide N-formylmethionine-leucyl-phenylalanine (fMLP). This suggests an effect of neutrophil priming with nanoparticles. On macrophages differentiated from the monocytic line THP-1, urban dust NPs stimulated the secretion of pro-inflammatory cytokines, tumor necrosis factor, and interleukin-6. The inflammatory activation of neutrophils and macrophages was reduced by antibiotic polymyxin B, which is able to bind bacterial wall lipopolysaccharide. The results suggest that the pro-inflammatory effect of urban dust NPs on neutrophils and macrophages is, at least in part, due to the presence of LPS.

Rare earth elements (REEs) are currently used in fertilizers, but their behavior in the soil–plant system remains poorly studied. The assessment of the binding of REEs to various organomineral phases of soils remains an important task. Using soddy-podzolic soil and typical chernozem as examples, we performed a comparative study of the dynamic fractionation of REEs in a rotating coiled column (RCC) and a microcolumn (MC). We isolated the exchangeable fraction, specifically adsorbed fraction, and fractions bound to manganese oxides, bound to organic matter, and bound to amorphous and weakly crystallized iron and aluminum oxides using, 0.05 M Ca(NO₃)₂, 0.43 M CH₃COOH, and a 0.1 M NH₂OH·HCl solution (pH 3.6), a 0.1 M K₄P₂O₇ solution (pH 11.0), and a 0.1 M (NH₄)₂C₂O₄ solution (pH 3.2), respectively. Concentrations of elements in the initial samples and eluate fractions were determined by atomic emission spectrometry and inductively coupled plasma mass spectrometry. The results suggest that the main extractable REE form (up to 40% of the total content) is provided by organometallic complexes extracted with a 0.1 M K₄P₂O₇ solution. For chernozem (soils with a high content of organic matter), fractionation in the RCC and MC yielded comparable results. For soddy-podzolic soil, some differences were observed in the isolation of the first three fractions: exchangeable, specifically adsorbed, and bound to manganese oxides. Both RCC and MC can be successfully used for the dynamic fractionation of REE in soils; however, it is preferable to use an MC in analyzing many samples as a simpler and more affordable device.

Obtained data on the composition and properties of ash nanoparticles from Klyuchevskoy, Tolbachik, Kizimen, and Shiveluch volcanoes (Kamchatka, Russia) are generalized. It has been shown that the concentration of toxic and potentially toxic metals and metalloids (Ni, Cu, As, Se, Ag, Cd, Sn, Te, Hg, Tl, Pb, Bi) in volcanic ash nanoparticles can be 10–535 times higher than their concentration in bulk polydisperse samples. The most volatile elements such as As, Sn, Te, Hg, Tl, and Bi have the highest concentration factors in the range of 100–535. Based on the data on single particle inductively coupled plasma mass spectrometry, it is assumed that the listed metals and metalloids are accumulated in the fraction of volcanic ash nanoparticles mainly through the condensation of these elements or their compounds from the gaseous phase and the formation of individual (single) nanophases with an average size in the range of 12–74 nm. It should be noted that approximately an order of magnitude less nanoparticles have been isolated from the acidic volcanic ashes of the Kizimen and Shiveluch volcanoes as compared to those of basic ashes of the Tolbachik and Klyuchevskoy volcanoes. This fact is inconsistent with published data showing that the fraction of fine ash is usually larger for acidic explosive eruptions compared to basaltic eruptions. The Pearson correlation coefficients between the basicity index of volcanic ash and the concentration of more than 50 elements in the ash and ash nanoparticles have been calculated. Some elements have a correlation coefficient |R| > 0.7, which, according to the Chaddock scale, indicates the high degree of correlation. It is noted that a number of elements have an opposite correlation between the basicity index of ash and the concentration of elements in ash and ash nanoparticles. For example, Hg and Tl content in ash have a negative correlation with basicity index, that is, their concentration decreases with increasing basicity index of the ash, whereas their concentrations in nanoparticles positively correlate with ash basicity index. The concentration of Ca, Ho, and Er in the ash increases with an increase in the ash basicity index, whereas ash nanoparticles show an opposite correlation. The revealed regularities are unexpected and confirm the unique features of nanostructures and raise new questions of nanogeochemistry.

Study of the Chemical Composition of Ash Nanoparticles from the Volcanoes of Kamchatka Изучение химического состава наночастиц пепла вулканов Камчатки

Культ орла в веровании якутов (саха), довольно подробно был описан в начале 20-го века в статьях В.М. Ионова (1913) и Л.Я. Штенберга (1925). В последние годы к вопросу семантики образа орла в традиционной культуре якутов обращалась У.П. Суздалова (2020), значению этой хищной птицы в мифологических представлениях саха и бурят – В.В. Ушницкий (2021). Кроме этого, в ряде работ связанных с мифологией якутов есть упоминания о культе орла для саха (Кулаковский, 1923; Алексеев, 1984; Гоголев, 2002 и др.).

Ageing processes of vehicle catalytic converters inevitably lead to the release of Pt and Pd into the environment, road dust being the main sink. Though Pt and Pd are contained in catalytic converters in nanoparticulate metallic form, under environmental conditions, they can be transformed into toxic dissolved species. In the present work, the distribution of Pt and Pd between dissolved, nanoparticulate, and microparticulate fractions of Moscow road dust is assessed. The total concentrations of Pt and Pd in dust vary in the ranges 9–142 ng (mean 35) and 155–456 (mean 235) ng g⁻¹, respectively. The nanoparticulate and dissolved species of Pt and Pd in dust were studied using single particle inductively coupled plasma mass spectrometry. The median sizes of nanoparticulate Pt and Pd were 7 and 13 nm, respectively. The nanoparticulate fraction of Pt and Pd in Moscow dust is only about 1.6–1.8%. The average contents of dissolved fraction of Pt and Pd are 10.4% and 4.1%, respectively. The major fractions of Pt and Pd (88–94%) in road dust are associated with microparticles. Although the microparticulate fractions of Pt and Pd are relatively stable, they may become dissolved under changing environmental conditions and, hence, transformed into toxic species.