Vast areas of Europe were contaminated by the fallout of ¹³⁷Cs and other radionuclides, as a result of the Chernobyl accident in 1986. The post-fallout redistribution of Chernobyl-derived ¹³⁷Cs was associated with erosion and sediment transport processes within the fluvial system. Bottom sediments from lakes and reservoirs can provide a valuable source of information regarding the post-fallout redistribution and fate of ¹³⁷Cs released by the Chernobyl accident. A detailed investigation of sediment-associated ¹³⁷Cs in the bottom sediments of a reservoir in a Chernobyl-affected area in Central Russia has been undertaken. A new approach, based on the vertical distribution of ¹³⁷Cs activity concentrations in the reservoir bottom sediment makes it possible to separate the initially deposited bottom sediment, where the ¹³⁷Cs activity reflects the direct fallout of Chernobyl-derived ¹³⁷Cs to the reservoir surface and its subsequent incorporation into sediment deposited immediately after the accident, from the sediment mobilized from the catchment deposited subsequently. The deposits representing direct fallout from the atmosphere was termed the “Chernobyl peak”. Its shape can be described by a diffusion equation and it can be distinguished from the remaining catchment-derived ¹³⁷Cs associated with sediment accumulated with sediments during the post-Chernobyl period. The ¹³⁷Cs depth distribution above the "Chernobyl peak" was used to provide a record of changes in the concentration of sediment-associated ¹³⁷Cs transported from the upstream catchment during the post-Chernobyl period. It was found that the ¹³⁷Cs activity concentration in the sediment deposited in the reservoir progressively decreased during the 30-year period after the accident due to a reduction in the contribution of sediment eroded from the arable land in the catchment. This reflects a reduction in both the area of cultivated land area and the reduced incidence of surface runoff from the slopes during spring snowmelt due to climate warming.

A webcam was installed on the shore of the South-Eastern Baltic (Kaliningrad Oblast, Russia) to monitor the beach dynamics and beach-cast (BC) daily from November 1, 2019, to October 31, 2020. The beach was formed not the whole year (77%). The most frequent BC residence time was one day (1–21, 4.1 on average, and 1–19, 4.3 on average days to the west and east of the groin, respectively). The BC consisted primarily of algae. Fresh BC occupied smaller area, and its layer was thicker than that of long-discarded and trampled BC. The specific amount of material (per m²) in a fresh BC was 3.7 times higher in volume and 2.6 times higher in weight than in long-discarded and trampled BC. For fresh and old BC, the specific volumes were 63 and 17 l per m², respectively, and the specific masses were 48 and 18 kg per m², respectively.

The purpose of the present study was to determine levels of POPs (dieldrin, endrin, HCH isomers, DDT metabolites, and PCB congeners) in organs of chum (Oncorhynchus keta), pink (O. gorbuscha), sockeye (O. nerka), masu (O. masou), and Chinook salmon (O. tshawytscha), and to identify the patterns of toxicants' distribution in organisms and the environment of the northwestern Pacific. Principal component factor analysis showed that all the salmon species typically exhibit relationships between the PCB congeners and are characterized by a similar pattern of entry of PCBs 101, 118, and 153. The OCPs levels in the organs of Pacific salmon are decreasing from 2012 to 2018, which suggests the elimination of these toxicants from the northwestern Pacific Ocean.

This paper studies the activity of natural and technogenic radionuclides in bottom sediments and surface water of the Pechora River estuary, which is the largest Arctic river within the European part of Russia. The relevance of conducting radioecological studies of this region is associated with active oil and gas activities in the Pechora basin and the presence of potential sources of radiation hazard. The average activities of ¹³⁷Cs, ²²⁶Ra, ²³²Th, and ⁴⁰K in bottom sediments were 0.16, 18.72, 13.36, and 373.59 Bq·kg⁻¹, respectively. The average activity of ²²⁶Ra in the bottom sediments of the Pechora delta was two times higher than in other rivers of the Arctic basin of the European part of Russia, which is associated with oil and gas activities that are carried out in the Pechora basin. This is due to the fact that the decay products of uranium are the main by-products of oil and gas production. The specific activity of technogenic ¹³⁷Cs in bottom sediments of the Pechora River delta was low and did not exceed 2.2 Bq·kg-1. We did not detect any radioactive ⁹⁰Sr in bottom sediments. The low ¹³⁷Cs activity in the bottom sediments of the Pechora delta was associated with both the larger granulometric composition of the sediments in comparison with the estuaries of the Siberian rivers, and with low concentrations of ¹³⁷Cs in the terrigenous material (soil) entering the river from the catchment area. This was due to the low levels of ¹³⁷Cs contamination in the soil of the Pechora river basin. We did not find any negative radiation effects of the underground nuclear explosion “Pyrite” carried out in the northern part of the delta, since there were no other technogenic radionuclides. The values of the radionuclides ³H, ¹³⁷Cs, ²²⁶Ra, ²³²Th and ⁴⁰K, as well as the total alpha activity in the surface waters of the Pechora River delta, turned out to be below the detection limit. In surface waters, we were able to determine only the total beta activity, which varied over a range from 19.6 to 59.6 Bq·m⁻³ with an average value of 33.9 Bq·m⁻³, which was significantly lower than the radiation safety standards. The values of the radiation hazard parameters were below the world average levels and were not significantly hazardous to the health of people living in the area of the Pechora River delta. We concluded that at present, in the Pechora River delta, there are pastures for reindeer with low levels of natural and man-made radioactivity. These conducted studies are the source material in a series of comprehensive studies of the current radioecological state of the tundra territories of the European part of Russia.

The study presents the results of the field expedition in the Russian Arctic held by a group of NGO members, scientists and volunteers in summer-autumn 2020 in the Arkhangelsk Region (Russia). The survey showed microplastics presence in 7 out of 13 remote and sparsely inhabited locations in lakes, rivers and coastal areas of the White Sea basin, with microplastic particle average concentration 1.14 part/m³, that is in agreement with other recent regional studies. Mostly PE, PET and PVC were found. A simple, cheap and easy-to-use microplastics monitoring protocol was developed and tested to be used by volunteers in remote Arctic communities. Video-lectures and tutorials are available online in an open-aсcess mode. 200 volunteers from polar communities are trained in microplastic sampling and litter separation, learning about microplastic pollution, including local residents, schoolchildren and students.

Several studies have estimated global inputs of plastic into the environment, relying on national statistics and modeling approaches. However, these estimates exhibit uncertainty driven by limited primary municipal solid waste management data. We compare mismanaged plastic estimates from three global studies (Jambeck et al. (2015), Lebreton and Andrady (2019), and Borrelle et al. (2020)), finding significant differences. Specifically, 58 countries show at least a 25 percentage point difference in estimated mismanagement rates, 27 countries show at least a 50 percentage point difference, and 9 countries show at least a 75 percentage point difference. Further, several top plastic generators exhibit large discrepancies in mismanagement estimates, including China, Russia, and Indonesia. The limitations of global plastic pollution estimates are well-known in the scientific community, and some variation is expected. However, these discrepancies limit policy design and mitigation. Thus, municipal, national, and international monitoring of plastic management and pollution must be improved.

This study obtained the first dataset on the solubilities and partitioning of metals and metalloids (MMs), including Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Th, Ti, Tl, U, V, W, Y, Zn, and Zr, during spring rains in Moscow. MM concentrations were determined using inductively coupled plasma mass spectrometry and atomic emission spectroscopy. The metals Ti, Zr, Al, Sn, Fe, W, Th, Li, V, Cs, Bi, and Y were predominant in the insoluble fraction of the rainwater, whilst Sb, Zn, Ca, Cd were prevalent in the soluble fraction. The end of the winter heating season, together with a weaker dilution effect due to lower precipitation in April, caused higher soluble and insoluble MM concentrations in rainwater than those in May. MM solubilities increased with decreasing pH and longer periods of precipitation, and declined with an increase in precipitation intensity, the length of the antecedent dry period, and the content of solid particles in the rainwater. A 20%–50% increase in solubility in acid rains compared to non-acid rains was observed for Y, Pb, U, Be, Na, Ni, Th, Cu, W, Fe, Mg, Cr, Tl, and Ba. Anthropogenic sources contributed significantly to the concentration of soluble MMs (>90% for Sb, Pb, Se, Cd, Zn, Cu, Bi, Ca, Mo, Sc, Ba, As, W, Sr, Mn, Sn, Co, Tl, Ni, and Be). For the insoluble MM, crustal materials were the important contributors. During public holidays in Russia in the first decade of May, an increase in the proportion of insoluble MMs was observed.

This article presents the results of studies of the activity of radionuclides in peat-bog profiles of the European subarctic of Russia. Two peat profiles were collected in different areas of the Arkhangelsk region. The peat cores were used to determine ²¹⁰Pb, ¹³⁷Cs, ²⁴¹Am, ²³⁹Pu, ²⁴⁰Pu, ²³⁸U, and ²³⁴U content. To estimate the relationship between radionuclide activity and physicochemical parameters of peat, the content of organic matter, water-soluble salts, carbonates and ash, and the pH of aqueous and salt extracts were studied. Radionuclide activity concentrations in peat samples were measured using inductively coupled plasma mass spectrometry (ICP-MS), low-background semiconductor gamma spectrometry with a high-purity germanium (HPGe) detector, and alpha spectrometry. The ²¹⁰Pb chronology of peat cores was studied using a constant flow model based on the Monte Carlo simulation method. Comparison of ²¹⁰Pb dating data showed that the position of the maximum activity peaks of anthropogenic radionuclides shifted along the peat profile. This is probably due to the relative mobility of different radionuclides in the peat massif. Measurement of the atomic ratio ²⁴⁰Pu/²³⁹Pu showed that the main sources of pollution in the peatlands of the European subarctic of Russia are global fallout from atmospheric tests from the 1950s through 1980 and fallout from the Chernobyl nuclear accident in 1986. This study shows that a complex of radioactive isotopes in peat deposits can provide valuable information on the environmental pollution loads of subarctic territories.

This article is devoted to the study of physicochemical parameters and the assessment of the accumulation and distribution of metals in peat deposits from the North European part of Russia (Arkhangelsk region). Peat profiles were selected both in the area with a high anthropogenic load and in a bog remote from industrial pollution. The determination of metals was carried out by using the methods X-ray fluorescence analysis and atomic absorption spectroscopy. It was determined that the studied bogs can be attributed to the low ash type, and the recorded pH and mineralisation values make it possible to attribute these deposits to the acid-oxidising facies of oligotrophic peatlands, characteristic of taiga landscapes. Assessment of metal accumulation showed a high content of titanium, chromium, lead, nickel, vanadium, cobalt, aluminium, silicon, and copper in peat, mainly caused by the burning of fossil fuels and industrial production, as well as the burning of urban and industrial waste. The peat profiles are characterised by significant fluctuations in the content of elements in different horizons. Studies have shown the need to monitor the content of metals in peatlands from the Arkhangelsk region to assess atmospheric pollution from industrial emissions, both at the moment and in the past.

The Kaban Lakes Integrated Assessment Model (KLIAM) was developed for the lake hydrology, chemistry, and plankton dynamics of the Nizhniy Kaban and Sredniy Kaban lakes, Kazan, Russia. KLIAM is able to describe the variations seen in the Kaban lakes chemical and biological states as far seen through measurements available at the moment. KLIAM is able to reconstruct the lake history as it is approximately known from the data and written narratives. KLIAM was used to assess the measures to return the lakes to their original pre-urban status as alkaline and semi-oligotrophic lakes. The Kaban Lakes periodically goes through plankton blooms, as seen in the lake in the last decades since before World War II, which are caused by plankton growth promoted by phosphorus and nitrogen coming to the lakes as pollution from the human environment. In the new plans for development of the area surrounding the Nizhniy Kaban and Sredniy Kaban lakes, we suggest that attention is paid to reducing phosphorus and nitrogen flows to the lakes, as the best way to improve their ecological status. This is based on simulations with KLIAM. We recommend that the monitoring of lake chemistry and lake ecology is improved with reoccurring analysis of samples from the Kaban Lakes.