No 3 (2022)

The content of mercury compounds in the industrial wastes of the Baikalsk Pulp and Paper Mill, in soils on the territories of sludge storage sites, in the bottom sediments of Lake Baikal as well as small rivers flowing into the lake has been studied. There observed an increased content of total mercury and methylmercury in the sludge lignin waste.

The aim of this study was to investigate mercury concentration and forms of its occurrence in the dust component of the atmospheric air (street dust) to assess the geo-ecological condition of the area where coal is mined, processed and transported. The mean mercury concentration of 29 street dust samples collected along a uniform network throughout the city was 36.4 ± 4.7 ng/g, with a minimum (4.6 ng/g) and a maximum (104.6 ng/g) value, respectively. This value was much lower than the mean concentration in soil samples taken previously at the same sites (58.4 ng/g) but higher than the mean concentration in snow solids (29.8 ng/g), which was likely due to precipitation that washed out mercury from the street dust and to the wind blowing.

The method of successive chemical extraction revealed a weakly bonded water-soluble form, inorganic poorly sorbed mercury compounds, an organic form of mercury, and mercury associated with minerals. The proportion of each fraction accounted for on average 10.94%, 10.32%, 44.76%, and 33.97%, respectively. Water-soluble and acid-soluble mercury forms were less common. The bulk of mercury had metal-organic and sulfide forms.

The study of mercury distribution based on particle size indicated that the mercury concentration increased as the diameter of the grains of dust material decreased. The fine fraction with a diameter of 20 to 50 µm contained the bulk of mercury, which stayed in suspension form for a long time before settling on the surface.

The results of the study of the gross mercury content in the bottom sediments of small lakes in the taiga zone (humid sedimentogenesis) are summarized. It is shown that mercury concentrations in organomineral sediments correspond mainly to its contents in rocks of the upper continental crust (background values). In bottom sediments, mercury is adsorbed by organic matter, biogenic silica and layered silicates. The regularities of the vertical distribution of gross mercury in stratified sections of bottom sediments of lakes of the taiga zone, geographically located in different regions of Siberia and on the southeastern edge of the Baltic Shield, have been established.

The role of mercury in the development of various neuropathologies is well known. The biogeochemical cycles of mercury indicate the possibility of its introduction into various organisms (including humans) through the corresponding trophic chains. However, as it turns out from the literature analysis, until recent years, there have been almost no works on the dynamic microscopic study (either in situ or in vivo) of the processes of connectome involution in aquatic organisms (including fishes, marine mammals, etc.) under the action of mercury. In this regard, we attempted to study the dynamics of morphogenesis and breakdown of the emerging connectome under the mercury exposure. A dynamic study of frames with the dynamics of the axonal path search was carried out in a series with an address-time code, on which it is possible to track the vector fields of displacements and reaction-diffusion processes in the cell culture immediately after the introduction of a drop of mercury or a mercury-containing liquid using capillary pipettes. This paper describes the observed effects and the possible mechanisms underlying them.

The aim of this study was to assess the mercury hazard to the health of the population in the Arctic zone on the example of the Yamalo-Nenets Autonomous Okrug (YaNAO). The study included two stages. At the first stage, we assessed the potential risk associated with the mercury intake in the body with local food products and water based on the hazard quotient (HQ). At the second stage, we examined the selected groups of the adult population living over 20 years in the Arctic and analysed the mercury concentrations in biological substrates to identify the dependence of the somatic and neuropsychic disorders on the mercury concentrations. The mean values of mercury intake in the body with food products were 0.001 mg/kg for adults per week, and 0.0015 mg/kg – for children. HQ was acceptable and correlated with the mercury concentrations in biological substrates. We identified the risk of low stress resistance (OR=2.4 [1.3-6.2]) in people who had elevated mercury concentrations in their hair. In the risk group, the proportion of the examined people with elevated mercury concentrations in their hair was 46.0%, while in the comparison group it was 38.8%, and the mean concentrations of this toxicant were also higher, 2.51 µg/g and 1.69 µg/g, respectively. The risks of low self-assessment of health (OR=5.7 [2.1-15.2]) and low stress resistance (OR=3.3 [1.3-8.3]) were typical of people with low neuropsychic adaptation. Therefore, despite the absence of somatic health hazard for the newly arrived population of YaNAO, the people with elevated mercury accumulation showed a decrease in the neuropsychic adaptation, which determines the need to introduce biomonitoring in the medical examination system for the population of the Arctic.

This article presents the results of a layer-by-layer study of the ice thickness in the main channel of the Amur River (Khabarovsk city area) and Pemzenskaya and Amurskaya channels. Spectral and microbiological methods were used to assess the nature of ice contamination with organic compounds. The study of suspensions from ice melts by mass spectrometry (ICP MS) confirmed mercury pollution. Among the cultivated heterotrophic bacteria from the ice mass (cryomicrobiocenoses), there were communities adapted to high mercury concentrations (up to 0.001 mg/L). In some layers of the ice, we recorded a high portion of sulfate-reducing bacteria involved in mercury methylation. In the mainstream of the Amur River, a layer of ice (70-117 cm) had a high content of mercury, dissolved organic matter, plant detritus, and the maximum number of bacteria resistant to mercury pollution. This ice layer was formed during the period of technological discharges from reservoirs to combat the consequences of a major flood in the Amur River Basin. The indicator of resistance of cryomicrobiocenoses to high mercury concentrations was due to the adaptive potential of heterotrophic microorganisms, including active mercury methylators, i.e. sulfate-reducing bacteria. This indicator can be used for a retrospective assessment of mercury pollution of rivers during the freeze-up period.

The article presents the original data on the total Hg concentration in the needles of different tree species in the recreational zones of settlements on the south coast of the Republic of Crimea. Mean Hg concentrations were lower than in the Tomsk Region and the Republic of Sakha-Yakutia but higher than in Southern Siberia. Hg concentrations increased from west to east along the south coast of Crimea. Pine needles showed increased sorption properties relative to mercury, juniper needles had the least sorption. There was no dependence of the element input on height relative to sea level. Calculated indicators indicated elevated Hg concentrations in needles relative to the background, the temporary allowable concentration and the mean value for terrestrial plants.

This paper presents data on mercury concentrations in samples of lichen and moss, as well as needles of trees (larch, cedar and pine), taken in September 2019 along a rare sampling network on the meridional transect from the Novy Urengoy area in the north to Tobolsk in the south. The mean Hg concentration (ng/g) in samples of moss, lichen and larch needles was 26, 15 and 17, respectively. The Hg concentrations in samples of annual needles of pine and cedar were below the detection limit of the method (<10 ng/g). We discuss possible factors that affect the heterogeneity of the Hg distribution in biomonitors and the discrepancy between the Hg concentrations for samples taken at the same sites. There was a systematic increase in background mercury concentration near the Novy Urengoy city and the Gubkinsky town. We assume a possible decrease in the Hg concentration in the mosses of the middle part of Western Siberia compared to its northern part.

This article discusses the features of mercury distribution in the water of the Baikal ecosystem. We present an analysis of Hg concentrations in the surface and deep water of Lake Baikal, its outflow, the Angara River, and the largest tributaries of Lake Baikal. The study revealed that all significantly elevated mercury concentrations in Baikal water were preceded by earthquakes or geodynamic impacts. We propose a death of Baikal endemic species, Baikal seal, due to mercury intoxication.

We studied the distribution of Hg in mushrooms and fish on the example of three objects (Kurai mercury zone, Ursk ore field and Saralinsk ore field) located in the area with the elevated geochemical background of this element (Altai-Sayan province) and affected by the mining waste. Maximum mercury concentrations in mushrooms and fish were observed in the Ursk ore field. Both in mushrooms and in fish, Hg concentrations exceeded MPC, posing significant human health risks if consumed.

We present long-term (2011 – 2021) data on air mercury monitoring that was started within the GMOS (Global Mercury Observation System) project (2011-2015) at the Listvyanka station located on the shore of Lake Baikal, Siberia. Monitoring shows an obvious seasonal variation in the background mercury concentration in the air, which increases in the cold season and decreases in the warm season. Short-term anomalies are associated with the wind carrying air from industrial areas where several large coal-fired power plants are located (Irkutsk and Angarsk). A positive correlation between mercury, SO₂ and NO₂ concentrations is observed both in short-term variations and in average monthly concentrations. The analysis of the forward and backward trajectories obtained with the HYSPLIT model demonstrates possible mercury emission sources. Concentration-weighted trajectory (CWT) analysis has revealed potential remote regions of mercury emissions from where mercury can be transported by air masses to the area of Lake Baikal, including the territories of Transbaikalia and Mongolia (Erdenet). During the 2018 cruise, the continuous air mercury survey above Lake Baikal covered 1800 km. The mean mercury concentration above Lake Baikal is significantly lower than the mean value obtained at the onshore Listvyanka station during the same days of the cruise. That can lead to the conclusion that Lake Baikal is a sink of atmospheric mercury.

This study discusses one of the aspects of the mercury problem, which is the relationship between aquatic and terrestrial ecosystems. We indicate that the mercury concentration in the Amur tiger fur (Panthera tigris altaica) is higher in the coastal area than in the inland area because the coastal areas are exposed to the impact of marine atmospheric fog, a potential source of monomethylmercury. The total mercury concentration from the Khasansky District varied from 0.16 to 0.45 mg/kg, on average 0.22 ± 0.04 mg/kg, in tiger fur, from 0.07 to 1.01 mg/kg, on average 0.64 ± 0.05 mg/kg, in leopard fur (P. pardus orientalis) and from 0.055 to 1.233 mg/kg, on average 0.336 ± 0.056 mg/kg, in Himalayan bear fur (Ursus thibetanus). The total mercury concentration in the fur of the last predators from the inland areas is unknown. Further research is needed.

On the west coast of Lake Baikal, we defined long-term and short-term variations in Hg concentrations of groundwater in 2017 to 2019 and from 2019 to the present, respectively; the latter variations were associated with the 2020–2021 Baikal-Khubsugul seismic reactivation of active faults. We inferred that increasing Hg concentration in groundwater was due to crustal extension with the highest Hg enrichment related to aftershocks. We argue that a Hg flux depends on the nature of fault activities and elevated Hg concentrations in sedimentary layers may designate the release of Hg_gas and Hg_gw from seismically active faults in the past 14.4 Ka.

Mercury is a global pollutant. The main source of mercury in the human body is seafood and freshwater fish. More than 90% of methylmercury from total mercury is found in fish muscles. The main aim of this study was to investigate the mercury levels in the hair of the population of the Vologda Oblast, Northwest Russia, where the heterogeneous distribution of rivers and lakes is the resource base of fishing. The mean mercury concentration in the hair of residents of the Vologda Oblast was 0.445 ± 0.018 mg/kg. 10.7% of the samples studied had mercury concentrations exceeding 1 mg/kg. The minimum mercury concentrations were detected in residents of Cherepovets and the eastern districts of the Vologda Oblast. Residents of western districts, where local reservoirs are the main sources of commercial fish, had the maximum concentrations. There were no differences in the amount of this metal between men and women. At the same time, mercury concentrations in men and women from the western districts of the Vologda Oblast had a higher percentage of exceeding the recommended standards.

The ability of plants to accumulate pollutants from natural and technogenic environments has found a wide application for cleaning up polluted areas. Most of the works published on this topic are related to the study of the plants efficiency to extract pollutants from polluted areas, including the intensification this process. However, much less attention is paid to the influence of chemical factors on the intensity of the elements accumulation as a function of their speciation. However, the chemical form of the element determines its migration pathways (mobility), bioavailability and toxicity. This issue is in the focus of the present work where the results of the study of mercury accumulation are discussed on the example of white mustard (Sinápis álba) depending on the chemical form of the element initially introduced into the growing matter. We have indicated that methylmercury is the most intensively accumulated species in comparison with mercury chloride and mercury sulfide.

Mercury (Hg) has various sources of natural and anthropogenic emissions, can be transferred for a long distance in the atmosphere, and accumulate in deponent media and food chains. Due to its toxicity, mercury is considered a global pollutant. The Minamata Convention on Mercury (Articles 19 and 22) stipulates mercury monitoring to obtain information on the environmental cycle, transport, deposition, transformation, and fate of mercury and mercury compounds in various ecosystems. The developed monitors based on Zeeman atomic absorption spectrometry allow the fully automatic real-time determination of mercury in such different media as ambient air, industrial, and process gases.

The paper presents a case study of mercury in two types of paleoarchives: ice cores and prehistoric animal hair, to assess the potential of Hg using as a proxy for environmental and climate changes. Belukha ice core is well-suitable for reconstruction short-term and long-term Hg deposition, recording global and regional, natural and anthropogenic emissions as well as regional climate changes during 320 years. Hg concentrations in hair of mammoth fauna mammals reflect the variation in Hg level in the environment during period from 45 to 10 ka yr BP. Hg concentrations changes following climatic changes are in a good agreement with other paleoarchive data (Hg fluxes of the EPICA Dome C ice core and Lake Baikal sediments).

We took 41 samples for a quantitative assessment of the total and dissolved mercury concentrations in the snow of the city of Irkutsk during winter 2021-2022. The maximum concentration of total mercury was recorded near the Eternal Flame memorial (248 ng/dm³); the minimum concentration was 6 ng/dm³ at the Jewish cemetery. The maximum concentration of dissolved mercury was recorded near the Aviation Plant (11.5 ng/dm³), and the minimum – near the Maratovskoye traffic circle and Secondary School No. 66 (0.1 ng/dm³). In four samples, we did not detect dissolved mercury. Determining the mass concentration of mercury revealed that the concentrations of mercury compounds in the snow from Irkutsk were much lower than the MPC. Based on the results of the analysed samples, we created a cartographic material.

Large industrial enterprises are located on the territory of the city of Cherepovets, which are potential sources of mercury entering the environment. The study involved residents of the Vologda Oblast without cardiovascular diseases (men n=82; women n=266) and with cardiovascular diseases (men n=192; women n=309). The average mercury content in the hair of the study participants was 0.572±0.686 mg/kg. In healthy men and men with cardiovascular diseases, the indicators of alanine aminotransferase, aspartate aminotransferase are statistically significantly (on average 1.2-1.5 times) higher than in women. A significant correlation was established between the concentration of ALT, AST from the amount of mercury in the hair of the study participants: in men ALT - RS=0.168, p≤0.008 and AST- RS=0.183, p≤0.004, respectively; in women ALT: RS=0.121, p≤0.007, AST is not statistically significant RS=0.035 p≤0.442. The increase in mercury affects the human body with cardiovascular diseases, increasing the enzymatic activity of alanine aminotransferase, aspartate aminotransferase. The causes of gender differences in CVD are: different reproductive function; different prevalence of autonomous regulation of vascular functions and stress; different features of the development and prevalence of coronary atherosclerosis.

In addition to carbon, oxygen, hydrogen and nitrogen, fossil fuels contain other chemical elements, some of which may be hazardous to human health and the environment. Mercury and its compounds are one of the most dangerous among them. Therefore, information about mercury contents in coals and products of their processing is extremely important for both mining and processing enterprises and consumers. Mercury compounds may be accumulated in coal mining and processing wastes, and if they transfer into water-soluble forms, may lead to damaging of the environment. In the view of above, a standard method for the determination of mercury content has been developed, which is applicable not only to coals and products of their processing, but also to coal mining and combustion wastes. Also, to control the correctness of measurements by the developed method, reference samples with a certified mercury contents were developed.