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Биогеохимические чтения памяти В.В.Ковальского

Журнальные статьи

Ambo-Rappe R. Developing a methodology of bioindication of human-induced effects using seagrass morphological variation in Spermonde Archipelago, South Sulawesi, Indonesia // Marine Pollution Bulletin. 2014. Vol. 86, № 1–2. P. 298–303.

Seagrass is particularly susceptible to environmental degradation. The objective of the study is to develop an effective bioindicator to assess human-induced effects using morphological variation and fluctuating asymmetry (FA) of seagrass. Samples were collected from eight islands situated at different distance from mainland with different human population density and therefore expected to experience different level of anthropogenic pressure. Cd, Pb, Cu, Zn, nitrate, and phosphate were measured. Metals were also measured in tissues of seagrass. Metal concentrations in sediment, water, and seagrass did not exceed the quality standards required for marine life. Heterogeneity of FA was found among sites suggesting that there are some factors changing developmental instability of seagrass which is not associated to particular toxicants. This baseline study indicates that the water condition is still natural and shows no signs of metal contamination, therefore it does not cause a detectable stress on morphological variation and FA of seagrass.

Ansari N.R. et al. Mercury distribution, methylation and volatilization in microcosms with and without the sea anemone Bunodosoma caissarum // Marine Pollution Bulletin. 2015. Vol. 92, № 1–2. P. 105–112.

Mercury (Hg) has a complex biogeochemical cycle in aquatic environments. Its most toxic form, methylmercury (MeHg), is produced by microorganisms. This study investigated how the sea anemone Bunodosoma caissarum affects Hg distribution, methylation and volatilization in laboratory model systems. Hg-203 was added to microcosms and its distribution in seawater, specimens and air was periodically measured by gamma spectrometry. MeHg was measured by liquid scintillation. After the uptake period, specimens had a bioconcentration factor of 70 and in microcosms with and without B. caissarum, respectively 0.05% and 0.32% of the initial spike was found as MeHg. After depuration, MeHg in specimens ranged from 0.2% to 2.4% of total Hg. Microcosms with B. caissarum had higher Hg volatilization (58%) than controls (17%), possibly due to Hg2+ reduction mediated by microorganisms associated with its tissues and mucus secretions. Marine organisms and their associated microbiota may play a role in Hg and MeHg cycling.

Babko R. et al. Bioindication Assessment of Activated Sludge Adaptation in a Lab-Scale Experiment // Ecological Chemistry and Engineering S-Chemia I Inzynieria Ekologiczna S. 2014. Vol. 21, № 4. P. 605–616.

The adaptation of activated sludge from the Hajdow sewage treatment plant in a laboratory SBR was studied. The structure of the ciliate assembly was considered as a criterion. 32 ciliate species were found during the experiment. The composition and changes in the ciliate community structure during the process of activated sludge adaptation was examined. In the process of adaptation, reduction was observed in the number of ciliate species together with an increase in assembly total abundance. The decrease in the Shannon diversity index and equitability index in the adaptation process was observed. In the process of adaptation, two states of ciliate assembly were marked out - unstable transient period and stable period. During the transient period, reduction of ammonium utilization efficiency down to 50% and its subsequent increase up to 80% in the stable period were observed. In the transient period, the Simpson dominance index remained low but increased in the stable period. At a temperature of 10 degrees C, the transient period lasted from six to nine days. After the stabilization process, the diversity of the ciliate assemblage remained at a lower level. Rarefaction methods showed that the number of potential ecological niches of ciliate amounted to 30 in the adaptation period, whereas there were only 15-20 ecological niches in adapted sludge.

Banuelos G.S. et al. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata // Food Chemistry. 2015. Vol. 166. P. 603–608.

Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing the Se content in food crops in Se-deficient regions of the world. In this study we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with ground shoots of the Se-hyperaccumulator Stanleya pinnata. With increasing application rates of S. pinnata, total plant Se concentrations increased to nutritionally ideal levels inside edible parts. Selenium compounds in aqueous extracts were analyzed by SAX-HPLC-ICPMS and identified as a variety of mainly organic-Se forms. Together with bulk Se K-edge X-ray absorption near-edge structure (XANES) analysis performed on broccoli florets, carrot roots and shoots, dried ground S. pinnata, and the amended soil at post-plant, we demonstrate that Se-enriched S. pinnata is valuable as a soil amendment for enriching broccoli and carrots with healthful forms of organic-Se.

Barinova S., Chekryzheva T. Phytoplankton dynamic and bioindication in the Kondopoga Bay, Lake Onego (Northern Russia) // Journal of Limnology. 2014. Vol. 73, № 2. P. 282–297.

On the basis of our collected material and historical information we assess phytoplankton dynamics in Kondopoga Bay, the Lake Onego in 1993-2011. The summer communities from continuously studied sampling stations contain 100 species belonging to eight divisions: Bacillariophyta, 40; Chlorophyta, 25; Cyanobacteria, 13; Chrysophyta, 12; Euglenophyta, 2; Dinophyta, 4; Cryptophyta, 3; and Xanthophyta, 1. Sample richness varied between 16 and 54 species, with a negative overall trend during the study period, but increases in Cyanobacteria and Dinophyta. Bioindication analysis shows that water acidification slowly rising from 1993 to 2011 with organic pollution (Index saprobity S) and the number of species with heterotrophic ability. In 1990s, the total abundance and biomass were on average 1.5 times higher than in 2000-2011, having similar fluctuation ranges (Pearson 0.74), with peaks in 1996 and 2006. At the same time, species richness decreased, showing a depletion of algal communities. Two critically impacted periods are revealed with the Shannon index in 1996 and 2007 and on the basis of the Aquatic Ecosystem State Index (WESI) calculation in 1995 and 2007, related to Kondopoga industrial wastewater influx enriched in nutrients and other contaminants. As a whole, the WESI was extremely high, reflecting a high self-purification capacity in respect to phosphate concentration in the bay. The canonical corresponded analysis (CCA) shows two different sets of taxa, those stimulated by temperature and nitric nitrogen (Anabaena scheremetievii Elenkin, Dolichospermum lemmermannii (Ricter) P. Wacklin, L. Hoffmann & J. Komarek, and Aulacoseira alpigena (Grunow) Krammer), and sensitive autotroph species inhabiting cool to temperate clear waters (Aulacoseira distans (Ehrenberg) Simonsen, Ankistrodesmus fusiformis Corda ex Korshikov, Mucidosphaerium pulchellum (H.C. Wood) C. Bock, Proschold & Krienitz). The comparative statistics with GRAPS program revealed two cores of species richness in years 1996 and 2011 that included most of species. The long-term dynamics of relative cell volume shows that phytoplankton communities were enriched with small-celled species, such as Cyanobacteria (Microcystis aeruginosa (Kutzing) Kutzing) and Cryptophyta (Cryptomonas sp. and Katablepharis ovalis Skuja) in the period between 1998 and 2006. Pearson correlation for Shannon index and relative cell biovolume is negative (-0.79), showing high stability of species rich communities under environmental impacts. Two periods of dinoflagellate blooms (1998, 2007) followed the peaks of total abundance and biomass (1996, 2006). Such correlation makes the Kondopoga Bay ecosystem comparable to those of large lakes in spite of a heavier anthropogenic impact from Kondopoga pulp and paper mill wastewater.

Bath S.C., Rayman M.P. A review of the iodine status of UK pregnant women and its implications for the offspring // Environmental Geochemistry and Health. 2015. Vol. 37, № 4. P. 619–629.

Iodine, as a component of the thyroid hormones, is crucial for brain development and is therefore especially important during pregnancy when the brain is developing most rapidly. While randomised controlled trials of pregnant women in regions of severe iodine deficiency have shown that prenatal iodine deficiency causes impaired cognition, less is known of the effects in regions of mild deficiency. This is relevant to the UK as the World Health Organisation now classifies the UK as mildly iodine deficient, based on a national study of 14-15 year old schoolgirls in 2011. We have previously published a study using samples and data from the UK-based Avon Longitudinal Study of Parents and Children (ALSPAC) that found an association between low iodine status in early pregnancy (urinary iodine-to-creatinine ratio < 150 mu g/g) and lower verbal IQ and reading scores in the offspring. Though the women in ALSPAC were recruited in the early 1990s, the results of the study are still relevant as their iodine status was similar to that reported in recent studies of UK pregnant women. This review discusses the evidence that mild-to-moderate iodine deficiency during pregnancy has deleterious effects on child neurodevelopment and relates that evidence to the data on iodine status in the UK. It has highlighted a need for nationwide data on iodine status of pregnant women and that a randomised controlled trial of iodine supplementation in pregnant women in a region of mild-to-moderate iodine deficiency with child outcomes as the primary endpoint is required.

Bessinger B.A. Use of Stable Isotopes to Identify Sources of Mercury in Sediments: A Review and Uncertainty Analysis // Environmental Forensics. 2014. Vol. 15, № 3. P. 265–280.

Mass-dependent and mass-independent mercury isotope fractionation potentially generates unique source signatures that can be used to apportion contributions to sediment contamination. This article reviews findings from previous investigations that have used mercury isotopes to identify sources. It also discusses a mass balance mercury isotope fractionation model that simulates changes in isotopic source signatures in aquatic systems caused by natural biogeochemical cycling. According to the model, the extent of source signature alteration depends on chemical speciation, with more labile forms exhibiting greater isotopic fractionation. Apportionment is tractable when differences between delta Hg-202 of sources are larger than potential changes in isotopic signatures following the release of mercury into the environment.

Coetzer K.L., Witkowski E.T.F., Erasmus B.F.N. Reviewing Biosphere Reserves globally: effective conservation action or bureaucratic label? // Biological Reviews. 2014. Vol. 89, № 1. P. 82–104.

The Biosphere Reserve (BR) model of UNESCO's Man and the Biosphere Programme reflects a shift towards more accountable conservation. Biosphere Reserves attempt to reconcile environmental protection with sustainable development; they explicitly acknowledge humans, and human interests in the conservation landscape while still maintaining the ecological values of existing protected areas. Conceptually, this model is attractive, with 610 sites currently designated globally. Yet the practical reality of implementing dual conservation' and development' goals is challenging, with few examples successfully conforming to the model's full criteria. Here, we review the history of Biosphere Reserves from first inception in 1974 to the current status quo, and examine the suitability of the designation as an effective conservation model. We track the spatial expansion of Biosphere Reserves globally, assessing the influence of the Statutory Framework of the World Network of Biosphere Reserves and Seville strategy in 1995, when the BR concept refocused its core objectives on sustainable development. We use a comprehensive range of case studies to discuss conformity to the Programme, the social and ecological consequences associated with implementation of the designation, and challenges in aligning conservation and development. Given that the Biosphere Reserve' label is a relatively unknown designation in the public arena, this review also provides details on popularising the Biosphere Reserve brand, as well as prospects for further research, currently unexploited, but implicit in the designation.

Cossaboon J.M., Ganguli P.M., Flegal A.R. Mercury offloaded in Northern elephant seal hair affects coastal seawater surrounding rookery // Proceedings of the National Academy of Sciences of the United States of America. 2015. Vol. 112, № 39. P. 12058–12062.

Methylmercury (MeHg) is a potent neurotoxin that is biomagnified approximately 1-10 million-fold in aquatic carnivores such as the Northern elephant seal (Mirounga angustirostris), whose excreta and molted pelage, in turn, constitute a source of environmental MeHg contamination at the base of marine food chains. The potential for this top-down contamination is greatest in coastal areas with productive marine ecosystems that provide ideal habitats for large marine mammal colonies that can number in the thousands. This recycling of MeHg was evidenced by comparing total mercury (HgT) and MeHg concentrations in seawater, and HgT in molted pelage of M. angustirostris, at the Ano Nuevo State Reserve pin-niped rookery with concentrations at neighboring coastal sites in Central California. Seawater MeHg concentrations around the rookery (average = 2.5 pM) were markedly higher than those at the comparison coastal sites (average = 0.30 pM), and were as high as 9.5 pM during the M. angustirostris molting season. As a consequence, excreta and molts from this marine mammal colony, and presumably other marine predator populations, constitute a major source of MeHg at the base of the local marine food chain.

Cox E.M., Arai Y. Environmental Chemistry and Toxicology of Iodine // Advances in Agronomy, Vol 128 / ed. Sparks D.L. 2014. Vol. 128. P. 47–96.

Iodine is a trace halide found in the environment. A majority of global iodine budget resides in ocean while lithosphere and pedosphere contain the rest limiting the bio-availability of iodine in terrestrial environment. Iodine cycles involve the multivalence state chemical speciation at the air-water-sediment interfaces. The mobility and reactivity of these inorganic and organic iodine species are impacted by changes in physicochemical factors (e.g., pH and ionic strength), and macro-and micro-biological activities. Although iodine aqueous biogeochemistry has been extensively investigated in marine systems in the past, the partitioning mechanisms of iodine at the geomedia-water interface remained poorly understood. This chapter covers environmental soil chemistry of iodine and the impact to human and ecological health.

Drahonovsky J. et al. Selenium uptake, transformation and inter-element interactions by selected wildlife plant species after foliar selenate application // Environmental and Experimental Botany. 2016. Vol. 125. P. 12–19.

Plants are characterized by differing capabilities to accumulate selenium. A model small-scale field experiment was set up to investigate the selenium (Se) uptake by twelve different plant species growing at an uncultivated meadow, as well as the effect of Se foliar application on the uptake of essential elements for plants calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn). Foliar application of sodium selenate (Na2SeO4) was carried out in two rates (25 and 50 g Se/ha), and an untreated control variant was included and the element contents in the aboveground biomass were determined. The results showed that selenium levels actually increased due to application of selenium where confirmed the hypothesis, that foliar application of selenium will lead to an increase of this element content, depending on the plant species. The highest Se contents were determined in Veronica chamaedrys (1.052 +/- 0.024 mg Se/kg), Stellaria holostea (0.775 +/- 0.064 mg Se/kg), Gallium aparine (0.745 +/- 0.027 mg Se/kg) and Urtica dioica (0.720 +/- 0.011 mg Se/kg) biomass whereas Cirsium arvense and Carex vesicaria showed the lowest Se uptake. No symptoms of potential Se phytotoxicity were observed at these concentration levels. Among the selenium compounds, selenate and selenomethionine (SeMet) were the predominant ones regardless of the plant species documenting relative low ability of plants to transform the applied selenate to the organoselenium compounds. Regarding the minor organoselenium compounds such as selenocystine (SeCys2) and Se-methylselenocysteine (Se-MeSeCys) the results suggested differences in Se transformation between monocotyledoneous and dicotyledoneous plants where Se-MeSeCys exceeded SeCys2 in monocotyledoneous and opposite pattern was observed in dicotyledoneous plants. These findings as well as the ambiguous changes in other essential element contents in the plant biomass needs to be investigated in further research.

Du Y. et al. Iodine Deficiency and Excess Coexist in China and Induce Thyroid Dysfunction and Disease: A Cross-Sectional Study // PLoS ONE / ed. Eugenin E.A. 2014. Vol. 9, № 11. P. e111937.

This study aimed to clarify the association of iodine deficiencies resulting from a low coverage rate of iodized salt, excess iodine intake from drinking water with thyroid function and disease in adults. A cross-sectional study was conducted in adults in different iodine nutrition areas in three provinces in China. The prevalence of thyroid nodules was 15.52%, 8.66% and 22.17% in the iodine excess, sufficient and deficient groups, respectively. The prevalence of subclinical hypothyroidism was 20.09%, 10.41%, and 2.25% in the excess, sufficient and deficient iodine groups, respectively. The prevalence of subclinical hyperthyroidism and overt hyperthyroidism in the iodine deficient group was higher than that in the iodine excess group (?=?9.302, p?=?0.002) and iodine sufficient group (?=?7.553, p?=?0.006). Thyroid-stimulating hormone (TSH) was significantly correlated with excess iodine intake (??=?1.764,P?=?0.001) and deficient iodine intake (??=??1.219, P?=?0.028). Thyroid nodules are more likely to be present in the iodine excess and deficient areas than in the iodine sufficient areas. Subclinical hyperthyroidism and overt hyperthyroidism are more likely to be prevalent in the iodine deficient areas than in the iodine excess or sufficient areas. Subclinical hypothyroidism is more likely to be prevalent in the high iodine intake areas than in the iodine deficient or sufficient areas. Median TSH may be deemed as an alternative indicator for monitoring the iodine nutrition status of the adult population in iodine excess and deficient areas.

Eiche E. et al. Selenium distribution and speciation in plant parts of wheat (Triticum aestivum) and Indian mustard (Brassica juncea) from a seleniferous area of Punjab, India // Science of The Total Environment. 2015. Vol. 505. P. 952–961.

The concentration, distribution, and speciation of selenium in different parts of wheat and Indian mustard, grown in a seleniferous area in Punjab, were investigated using synchrotron based (XAS) and classical acid digestion and extraction methods. The analyses revealed a high Se enrichment in all investigated plant parts, with Se levels in the range of 133–931 mg/kg (dry weight, dw). Such high Se enrichment is mainly due to the considerable amounts of easily available Se detected in the soil, which are renewed on a yearly basis to some extent via irrigation. Speciation analysis in soil and plants indicated selenate and organic Se as major Se species taken up by plants, with a minor presence of selenite. The analyses also revealed that the highest Se enrichment occurs in the upper plant parts, in agreement with the high uptake rate and mobility of selenate within plants. In both wheat and mustard, highest Se enrichments were found in leaves (387 mg/kg·dw in wheat and 931 mg/kg·dw in mustard). Organic species (dimethylselenide and methylselenocysteine) were found in different parts of both plants, indicating that an active detoxification response to the high Se uptake is taking place through methylation and/or volatilization. The high proportion of selenate in wheat and mustard leaves (47% and 70%, respectively) is the result of the inability of the plant metabolism to completely transform selenate to non-toxic organic forms, if oversupplied. Methylselenocysteine, a common Se species in accumulating plants, was detected in wheat, suggesting that, in the presence of high Se concentration, this plant develops similar response mechanisms to accumulator plants.

Fisher J.B. et al. Modeling the Terrestrial Biosphere // Annual Review of Environment and Resources, Vol 39 / ed. Gadgil A., Liverman D.M. 2014. Vol. 39. P. 91–123.

The land surface comprises the smallest areal fraction of the Earth system's major components (e.g., versus atmosphere or ocean with cryosphere). As such, how is it that some of the largest sources of uncertainty in future climate projections are found in the terrestrial biosphere? This uncertainty stems from how the terrestrial biosphere is modeled with respect to the myriad of biogeochemical, physical, and dynamic processes represented (or not) in numerous models that contribute to projections of Earth's future. Here, we provide an overview of the processes included in terrestrial biosphere models (TBMs), including various approaches to representing any one given process, as well as the processes that are missing and/or uncertain. We complement this with a comprehensive review of individual TBMs, marking the differences, uniqueness, and recent and planned developments. To conclude, we summarize the latest results in benchmarking activities, particularly as linked to recent model intercomparison projects, and outline a path forward to reducing uncertainty in the contribution of the terrestrial biosphere to global atmospheric change.

Fuge R., Johnson C.C. Iodine and human health, the role of environmental geochemistry and diet, a review // Applied Geochemistry. 2015. Vol. 63. P. 282–302.

Iodine is an essential element in the human diet and a deficiency can lead to a number of health outcomes collectively termed iodine deficiency disorders (IDD). The geochemistry of iodine is dominated by its volatility with volatilisation of organo-iodine compounds and elemental iodine from biological and non-biological sources in the oceans being a major component of its global cycle. As a result of the dominant oceanic source, iodine is strongly enriched in near-coastal soils, however, the major zone of marine influence generally stretches to only 50-80 km inland and terrestrial sources of volatilised iodine, from wetlands, soils and plants are also an important aspect of its global geochemical cycle. Iodine in soils is strongly bound with transfer factors from soil to plants being generally small and as a consequence there is only limited uptake of iodine through the plant root system. It is likely that uptake of atmospheric iodine by the aerial parts of plants is an essential process and, along with iodine deposited on plant surfaces, is a major source for grazing animals. Human intake of iodine is mainly from food with some populations also obtaining appreciable quantities of iodine from drinking water. Plant-derived dietary iodine is generally insufficient as evidenced from the low dietary iodine of strict vegan diets. Seafood provides major iodine-rich dietary items but other inputs are mainly from adventitious sources, such as the use of iodised salt and from dairy produce, which is a rich source mainly due to cattle-feed being fortified with iodine, and to the use of iodine-containing sterilants in the dairy industry. While the distribution and geochemistry of iodine are reflected in the global distribution of IDD, the recent upsurge of IDD in developed countries would seem to reflect changes in diet.

Gichuki S.W., Mason R.P. Wet and dry deposition of mercury in Bermuda // Atmospheric Environment. 2014. Vol. 87. P. 249–257.

Elevated concentrations of mercury (Hg) in fish from around Bermuda and fish consumers promoted a study of the atmospheric inputs of Hg to the ocean in the region. The average concentrations of total mercury in rain (THg; volume weighted mean 4.7 ng L-1) and in aerosols (particulate Hg: HgP: 9.5 pg m(-3)) were found to be comparable to other coastal locations removed from local sources at similar latitudes in North America. The estimated wet and dry deposition fluxes of Hg suggest that Bermuda is impacted by anthropogenic sources. A mass balance for Hg across the air-sea interface for the region around Bermuda also suggests that atmospheric wet plus dry deposition is less than estimated gas evasion of elemental Hg, indicating that the ocean is a net source in the region. This likely reflects historic elevated deposition of Hg to the North Atlantic, as has been suggested by historic water column data and from Hg biogeochemical modeling.

Gillings M.R., Hilbert M., Kemp D.J. Information in the Biosphere: Biological and Digital Worlds // Trends in Ecology & Evolution. 2016. Vol. 31, № 3. P. 180–189.

Evolution has transformed life through key innovations in information storage and replication, including RNA, DNA, multicellularity, and culture and language. We argue that the carbon-based biosphere has generated a cognitive system (humans) capable of creating technology that will result in a comparable evolutionary transition. Digital information has reached a similar magnitude to information in the biosphere. It increases exponentially, exhibits high-fidelity replication, evolves through differential fitness, is expressed through artificial intelligence (AI), and has facility for virtually limitless recombination. Like previous evolutionary transitions, the potential symbiosis between biological and digital information will reach a critical point where these codes could compete via natural selection. Alternatively, this fusion could create a higher-level superorganism employing a low-conflict division of labor in performing informational tasks.

Granfors A. et al. Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea // Journal of Geophysical Research-Biogeosciences. 2014. Vol. 119, № 12. P. 2276–2291.

Recent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.

Harden C.P. The human-landscape system: challenges for geomorphologists // Physical Geography. 2014. Vol. 35, № 1. P. 76–89.

Deliberately or indirectly, most of the terrestrial surface has been affected by the actions of human beings. For that reason, geomorphologists have needed to broaden their scope of inquiry to encompass the human-landscape system. Four themes related to human actions emerge in recent research in geomorphology: (1) human impacts on geomorphic systems, (2) human-landscape feedbacks, (3) geomorphic hazards and (4) stratigraphic markers of anthropogenic origin. The importance of humans as geomorphic agents challenges geomorphologists and their collaborators to move beyond unidirectional cause-and-effect (human impacts), and develop new research frameworks that better integrate the ongoing interactions between people and landscapes.

Herrmann S.J. et al. Differential Accumulation of Mercury and Selenium in Brown Trout Tissues of a High-Gradient Urbanized Stream in Colorado, USA // Archives of Environmental Contamination and Toxicology. 2016. Vol. 70, № 2. P. 204–218.

Total mercury (THg) and selenium (Se) were analyzed by Inductively Coupled Plasma Mass Spectrometry in 11 internal and external tissues and stomach contents from 23 brown trout, Salmo trutta, of a 22.9-km reach of a high-gradient stream (upper Fountain Creek) in Colorado, USA, impacted by coal-fired power plants, shale deposits, and urbanization. Trout and water were sampled from four sites ranging from 2335 to 1818 m elevation. Lengths, weights, and ages of fish between pairs of the four sites were not significantly different. The dry weight (dw) to wet weight (ww) conversion factor for each tissue was calculated with egg-ovary highest at 0.379 and epaxial muscle fourth highest at 0.223. THg and Se in stomach contents indicated diet and not ambient water was the major source of Hg and Se bioaccumulated. Mean THg ww in kidney was 40.33 mu g/kg, and epaxial muscle second highest at 36.76 mu g/kg. None of the tissues exceeded the human critical threshold for Hg. However, all 23 trout had at least one tissue type that exceeded 0.02 mg/kg THg ww for birds, and four trout tissues exceeded 0.1 mg/kg THg ww for mammals, indicating that piscivorous mammals and birds should be monitored. Se concentrations in tissues varied depending on ww or dw listing. Mean Se dw in liver was higher than ovary at the uppermost site and the two lower sites. Liver tissue, in addition to egg-ovary, should be utilized as an indicator tissue for Se toxicity.

Jerez-Valle C. et al. A simple bioindication method to discriminate olive orchard management types using the soil arthropod fauna // Applied Soil Ecology. 2014. Vol. 76. P. 42–51.

Bioindication has proved to be a useful tool to evaluate the state of conservation of an ecosystem based on the living organisms it contains, and thus many studies have used arthropods as bioindicators. In the cultivation of olive (Olea europaea L.), several management methods are employed, from organic production to conventional intensive farming. This study uses arthropod fauna as a means of discriminating between management types and takes into account the features of sampling methods and the data set used in order to make the discriminant method more effective. A total of 15 olive orchards were considered under three types of management (organic production, conventional non-tillage, and traditional conventional farming). During the summer of 2007, sampling was undertaken fortnightly using pitfall traps in the interior (under the canopy) as well as exterior (in the orchards lanes) soil. The samples were identified to the order level or taxonomic categories easiest to recognise, and two datasets were built ("management type" and "organic/non-organic"). A Linear Discriminant Analysis (LDA) was applied with cross validation by the leave-one-out (LOO) method, for all the scenarios analysed. The olive orchards under organic management registered greater abundance, diversity, and richness of orders. Also, significant differences between management types were detected with respect to the main groups, particularly between organic and non-organic. Formicidae and Coleoptera predominated in the interior and exterior soil, respectively. The soil-arthropod community considered at the order level proved useful to discriminate between management types, especially between organic and non-organic approaches. In light of the results, sampling of the interior soil and the use of the set of orders that significantly differ in the test of mean differences are suggested in order to optimise the discriminant analysis. In this way, classification accuracy reaches 100%, and 99% using cross validation with LOO.

Jozwiak M.A., Jozwiak M. Bioindication as Challenge in Modern Environmental Protection // Ecological Chemistry and Engineering S-Chemia I Inzynieria Ekologiczna S. 2014. Vol. 21, № 4. P. 577–591.

Research into and diagnosis of environmental change prior to the introduction of bioindicator methods were linked primarily to apparatus. Drawing attention to the reactions of organisms sensitive to that change and using them in environmental quality control have opened new opportunities for development of a new scientific discipline, known in the literature as bioindication. Bioindication combines several scientific disciplines, including biology, broadly conceived geography, and chemistry. It thus combines in a comprehensible manner apparatus-derived measurements (chemical analysis results) and areas of bioindicator exposure (situation and distance from the emitter), translating these parameters into bioindicators' anatomical and morphological reactions. The development of bioindicator methods progresses rapidly, and - as is usually the case under such circumstances - it is difficult to ensure that they are transparent and that no chaos ensues. In view of the above, it seems necessary to embark on a discussion of these issues and consider compiling lists of most applicable indicator organisms for examination of particular environmental toxins in particular environments.

Kelly F.J., Fussell J.C. Air pollution and public health: emerging hazards and improved understanding of risk // Environ Geochem Health. 2015. Vol. 37, № 4. P. 631–649.

Despite past improvements in air quality, very large parts of the population in urban areas breathe air that does not meet European standards let alone the health-based World Health Organisation Air Quality Guidelines. Over the last 10 years, there has been a substantial increase in findings that particulate matter (PM) air pollution is not only exerting a greater impact on established health endpoints, but is also associated with a broader number of disease outcomes. Data strongly suggest that effects have no threshold within the studied range of ambient concentrations, can occur at levels close to PM2.5 background concentrations and that they follow a mostly linear concentration–response function. Having firmly established this significant public health problem, there has been an enormous effort to identify what it is in ambient PM that affects health and to understand the underlying biological basis of toxicity by identifying mechanistic pathways—information that in turn will inform policy makers how best to legislate for cleaner air. Another intervention in moving towards a healthier environment depends upon the achieving the right public attitude and behaviour by the use of optimal air pollution monitoring, forecasting and reporting that exploits increasingly sophisticated information systems. Improving air quality is a considerable but not an intractable challenge. Translating the correct scientific evidence into bold, realistic and effective policies undisputedly has the potential to reduce air pollution so that it no longer poses a damaging and costly toll on public health.

Korobova E.M. et al. Iodine deficiency in soils and evaluation of its impact on thyroid gland diseases in areas subjected to contamination after the Chernobyl accident // Journal of Geochemical Exploration. 2014. Vol. 142. P. 82–93.

Geochemical and medical data on iodine deficiency and radioiodine "attack" after the Chernobyl accident were analyzed for the areas of Belarus Republic and Bryansk Oblast' of the Russian Federation. A concept that the spatial structure of modern iodine biogeochemical provinces is formed due to superposition of the natural and technogenic geochemical fields of this chemical element in biosphere is developed. The soil map, and the reconstructed radioiodine contamination have been used to evaluate soil iodine status and radioiodine attack capacity for particular settlements and regions and to create a combined health risk map for the Bryansk Oblast'. Obtained cartographic estimates were based on the real soil data and compared with medical data. The proposed approach helps to identify the areas of existing or possible negative biological effects with different health risk levels that might be helpful in eco-geochemical monitoring preventive steps and countermeasures.

Kroflic A. et al. Selenium and its compounds in aquatic plant Veronica anagallis-aquatica // Chemosphere. 2016. Vol. 151. P. 296–302.

The uptake, distribution and determination of Se and its compounds in macrophyte Veronica anagallis-aquatica were investigated. V. anagallis-aquatica and sediments were sampled in years 2009-2011 and in 2013 in three Slovenian watercourses flowing through an agricultural area, where addition of Se in feedstuffs has been performed for about 25 years. Se content in sediments were up to 0.86 mu g g(-1) and in whole plant varied from 0.186 to 1.535 mu g g(-1), all on dry weight basis. Se content were measured also in different plant parts; highest content were found in roots and lowest in stems. Separation of extractable Se compounds was performed by ion exchange chromatography and for on-line detection inductively coupled plasma-mass spectrometry was used. The results showed that only approximately 24% of Se in the macrophyte was extracted using enzyme Protease XIV. Extractable Se in plant parts varied from 10.5% in roots to 29.6% in leaves. Identification of Se(IV) and Se(VI) was achieved but no Se-amino acids were detected even at highest Se content. According to our results, we assume that 25 years of Se addition in feedstuff shows minimal impact on Se content in the selected agricultural area.

Lazarus J.H. The importance of iodine in public health // Environ Geochem Health. 2015. Vol. 37, № 4. P. 605–618.

Iodine (I) deficiency has been known for more than a century and is known to cause cretinism at the extreme end of the spectrum but also, importantly, impaired development and neurocognition in areas of mild deficiency. The WHO has indicated that median urinary iodine of 100–199 ?g/l in a population is regarded as indicative of an adequate iodine intake. The understanding of the spectrum of iodine deficiency disorders led to the formation of The International Council for the Control of Iodine Deficiency Disorders which has promulgated the use of household iodized salt and the use of such salt in food processing and manufacture. Iodine deficiency is particularly important in pregnancy as the fetus relies on maternal thyroxine (T4) exclusively during the first 14 weeks and also throughout gestation. As this hormone is critical to brain and nervous system maturation, low maternal T4 results in low child intelligence quotient. The recommendation for I intake in pregnancy is 250 ?g/day to prevent fetal and child brain function impairment. During the past 25 years, the number of countries with I deficiency has reduced to 32; these still include many European developed countries. Sustainability of adequate iodine status must be achieved by continuous monitoring and where this has not been performed I deficiency has often recurred. More randomized controlled trials of iodine supplementation in pregnancy are required in mild iodine-deficient areas to inform public health strategy and subsequent government action on suitable provision of iodine to the population at risk.

Li J. et al. Effects of aging on the fraction distribution and bioavailability of selenium in three different soils // Chemosphere. 2016. Vol. 144. P. 2351–2359.

Aging refers to the processes by which the mobility and bioavailability of metals in soil decline with time. Although long-term aging is a key process that needs to be considered in risk assessment of metals, few investigations has been attempted to determine whether and how residence time influences the selenium (Se) fractions and bioavailability in soil. In this study, the fractions of Se in soils was evaluated, and bioavailability were assessed by measuring Se concentration in pak choi (Brassica chinensis L.). Results showed that the change of soil available Se in all tested soils divided into two phases: rapid decrease at the initial time (42 d) and slow decline thereafter. The second-order equation could describe the decrease processes of available Se in tested soils during the entire incubation time (R-2 > 0.99), while parabolic diffusion equation had less goodness of fit. Those results indicated that Se aging was controlled not only by diffusion process but also by other processes such as nucleation/precipitation, adsorption/desorption with soil component, occlusion by organic matter and reduction reaction. Soil available Se fractions tended to transform to more stable fractions during aging. The changes of Se concentration in pak choi were consistent with the variation in soil available Se content. In addition,

Li J. et al. Iodine mobilization in groundwater system at Datong basin, China: Evidence from hydrochemistry and fluorescence characteristics // Science of the Total Environment. 2014. Vol. 468. P. 738–745.

Characterizing the speciation of iodine in groundwater is essential for understanding its hydrogeochemical behavior in aquifer systems. To quantify the variations in iodine speciation and assess factors controlling the distribution and transformation of iodine, 82 groundwater samples and 1 rain water were collected from the Datong basin, northern China in this study. Factor analysis (FA) and excitation emission matrix with parallel factor analysis (EEM-PARAFAC) were used to clarify the potential relationships among iodine species and other hydrochemical parameters. The iodine concentrations of groundwater range from 623 to 1380 mu g L-1 with 47% of samples exceeding its drinking water level of 150 mu g L-1 as recommended by the Chinese government 57% of samples have ratios of iodate to total iodine greater than 60%, while iodide as the major species in 22% of the samples. Significant amounts of organic iodine with concentrations higher than 100 mu g L-1 were observed in 9 groundwater samples. Redox conditions of groundwater system strongly affect iodine concentration and speciation of inorganic iodine in groundwater, and extremely reducing condition restricts the iodine release from sediments into groundwater. The results of FA show that iodine mobilization in groundwater is related to the nature of dissolved organic matter. EEM-PARAFAC model demonstrates the dominance of terrestrial DOM sources and the presence of microbial activities in groundwater system of the Datong basin. It is proposed that degradation of organic matter and reductive dissolution of iron oxyhydroxides are major hydrogeochemical processes responsible for the mobilization of iodine release and the genesis of organic iodine.

Li T. et al. Influence of Heavy Metals and Nutrient Concentrations on Selenium Geochemical Behavior in Soil-Rice System // Polish Journal of Environmental Studies. 2016. Vol. 25, № 1. P. 185–193.

Selenium deficiency in crops has become a subject of growing concern where soil Se concentration is low. The mechanisms of Se translocation in the soil-rice system is very complex and the influence of heavy metal elements and nutrient concentrations on Se translocation in the soil-rice system is unknown. Our study investigated concentrations of Se, heavy metals like Hg, Cd, and Pb, and nutrient elements like Ca, K, P, and S in soils and rice tissues (roots, stems, and grains) in different industrial regions in Jiangsu Province, China. The transfer of Se in the soil-rice system was calculated by transfer coefficients (TCSe) in this study. The results showed that Se transfer from soil to roots and from stems to grain were key steps for controlled Se concentration in rice grains. The multiple linear regression analysis makes an implication that some elements influence the Se transfer significantly: soil K and Hg may suppress Se entering rice roots; B, Cu, and Mo in rice root may restrain Se transfer from root to stem; and S, Cr, P, and Mg in rice stem had negative effects on Se accumulation in rice grain. Therefore, reducing heavy metal pollution and managing fertilizer amounts may elevate Se concentration in rice grain, especially when Se concentration in soils is low.

Liashenko V. Assessment of Water Quality in the Ukrainian Part of the Danube Delta Based on Biotesting and Bioindication of Bottom Sediments // Acta Zoologica Bulgarica. 2014. Suppl.7. P. 159–163.

The study presents the results of several years of monitoring (2007 to 2013) in the Ukrainian Delta region using biotesting and bioindication methods. The sampling stations were: Kilia arm (1 station), Ochakivskyi arm (2 stations), Bystryi arm (2 stations), and Vostochnyi arm (2 stations). Animal test-organism Daphnia magna Strauss together with plant test-organisms Allium cepa L. and Lactuca sativa L. were used in the biotesting. Bioindication was performed using taxonomic diversity of the macrozoobenthos organisms. The following biotic indices were calculated: Trent Biotic Index, Belgian Biotic Index, Biological Monitoring Working Party Index, and Goodnight-Whitley Index. The findings of biotesting showed a slow decrease in the toxic impact level from 2007 to 2012. However, the biotic indices mostly revealed a Poor ecological status for all sampling stations through all years of monitoring.

Liu P. et al. The Standard, Intervention Measures and Health Risk for High Water Iodine Areas // Plos One. 2014. Vol. 9, № 2. P. e89608.

Our study aims to clarify the population nutrient status in locations with different levels of iodine in the water in China; to choose effective measurements of water improvement(finding other drinking water source of iodine not excess) or non-iodised salt supply or combinations thereof; to classify the areas of elevated water iodine levels and the areas with endemic goiter; and to evaluate the risk factors of water iodine excess on pregnant women, lactating women and the overall population of women. From Henan, Hebei, Shandong and Shanxi province of China, for each of 50 similar to 99 mu g/L, 100 similar to 149 mu g/L, 150 similar to 299 mu g/L, and >= 300 mu g/L water iodine level, three villages were selected respectively. Students of 6-12 years old and pregnant were sampled from villages of each water-iodine level of each province, excluded iodized salt consumer. Then the children's goiter volume, the children and pregnant's urinary iodine and water iodine were tested. In addition, blood samples were collected from pregnant women, lactating women and other women of reproductive age for each water iodine level in the Shanxi Province for thyroid function tests. These indicators should be matched for each person. When the water iodine exceeds 100 mu g/L; the iodine nutrient of children are iodine excessive, and are adequate or more than adequate for the pregnant women. It is reasonable to define elevated water iodine areas as locations where the water iodine levels exceed 100 mu g/L. The supply of non-iodised salt alone cannot ensure adequate iodine nutrition of the residents, and water improvement must be adopted, as well. Iodine excess increases the risk of certain thyroid diseases in women from one-to eightfold.

Lynch M.D.J., Neufeld J.D. Ecology and exploration of the rare biosphere // Nature Reviews Microbiology. 2015. Vol. 13, № 4. P. 217–229.

The profound influence of microorganisms on human life and global biogeochemical cycles underlines the value of studying the biogeography of microorganisms, exploring microbial genomes and expanding our understanding of most microbial species on Earth: that is, those present at low relative abundance. The detection and subsequent analysis of low-abundance microbial populations-the 'rare biosphere' - have demonstrated the persistence, population dynamics, dispersion and predation of these microbial species. We discuss the ecology of rare microbial populations, and highlight molecular and computational methods for targeting taxonomic 'blind spots' within the rare biosphere of complex microbial communities.

Malanson G.P. Biosphere-human feedbacks: a physical geography perspective // Physical Geography. 2014. Vol. 35, № 1. P. 50–75.

Biogeography has many connections to people but fewer to human geography. Biogeography is connected to the four dimensions of anthropogenic global change, but most of this research is tied to land-use change. Biogeographers have studied several ways in which land use affects the patterns and dynamics of organisms, mostly in reference to remnants of habitat destruction, but the human dimensions of this relationship are more explicit in changing habitat quality. How biogeography affects land use is also studied, but research on topics such as ecosystem services needs more contributions from geographers. Feedbacks between people and the other organisms with which we live, with more fully linked models, are a general subject in which biogeographers can contribute to progress in the human dimensions of global change.

Miller L.L. et al. Using molecular biomarkers and traditional morphometric measurements to assess the health of slimy sculpin (Cottus cognatus) from streams with elevated selenium in North-Eastern British Columbia // Environmental Toxicology and Chemistry. 2015. Vol. 34, № 10. P. 2335–2346.

Canadian fish-based environmental effects monitoring programs use individual and population-level endpoints to assess aquatic health. Impacts of coal mining and selenium (Se) exposure were assessed in slimy sculpin (Cottus cognatus) from reference streams located both inside and outside of a coal zone, and from 1 stream with a history of coal mining, using traditional environmental effects monitoring endpoints. In addition, physical characteristics of the streams and benthic macro-invertebrate communities were assessed. To determine whether the assessment of effects could be improved by including molecular markers, real-time polymerase chain reaction assays were optimized for genes associated with reproduction (vtg, esr1, star, cyp19a1, and gys2), and oxidative and cellular stress (sod1, gpx, gsr, cat, and hsp 90). Water Se levels exceeded guidelines in the stream with historical mining (4g/L), but benthic macroinvertebrates did not exceed dietary thresholds (2-3g/g dry wt). Whole-body Se levels were above British Columbia's tissue guideline in fish from all streams, but only above the draft US Environmental Protection Agency (USEPA) criterion (7.91g/g dry wt) at the reference stream inside the coal zone. Some markers of cellular and oxidative stress were elevated in fish liver at the exposed site (sod1, gpx), but some were lower (cat, sod1, gpx, gsr, hsp90) in the gonads of fish inside the coal zone. Some of the differences in gene expression levels between the reference and impacted sites were sex dependent. Based on benthic macroinvertebrate assessments, the authors hypothesize that traditional and molecular differences in slimy sculpin at impacted sites may be driven by food availability rather than Se exposure. The present study is the first to adapt molecular endpoints in the slimy sculpin for aquatic health assessments.

Nakamaru Y.M., Altansuvd J. Speciation and bioavailability of selenium and antimony in non-flooded and wetland soils: A review // Chemosphere. 2014. Vol. 111. P. 366–371.

Studies on the sorption behaviors of selenium (Se) and antimony (Sb) are reviewed. Both Se and Sb chemical speciation can be controlled by pH and redox potential, and both of them are likely to be sorbed onto oxy-hydroxides of aluminum, iron or manganese in soils. For agricultural soils especially, there are important physico-chemical and biological differences between non-flooded and wetland soils. Se forms Se(VI), Se(IV), Se(0), Se(-II), and organic Se species at soil pH and redox conditions. Under non-flooded conditions Se solubility is governed by an adsorption mechanism onto metal oxy-hydroxides rather than by precipitation and dissolution reactions; however, for the conditions of wetland soils, it can be expected that Se(0) and organic matter-bound Se play an important role. For Sb, in the soil environment, the dominant Sb forms are Sb(III) and Sb(V). Under aerobic soil conditions, Sb(III) is likely to be oxidized to Sb(V), and the dominant sorbed Sb species should be Sb(V). Under reducing conditions Sb mobility should be lower than under oxidizing conditions due to the lower mobility of Sb(III); however, reduction of Fe and Mn oxides could lead to dissolution of Fe and Mn-bound Sb. This indicates that the risk of Sb contamination to the food chain could be increased in wetland systems.

Nitschke U. et al. Contribution of living and degrading kelp to coastal iodine fluxes // Marine Biology. 2015. Vol. 162, № 9. P. 1727–1738.

Laminaria digitata forms locally extensive and ecologically important kelp beds in northern temperate regions. Its sporophytes retain large quantities of iodine which, when released into seawater (as iodide, I-) and into air (as molecular iodine, I-2), have the potential to contribute significantly to coastal iodine biogeochemical processes. Here, standing crop of a living L. digitata bed and biomass of degrading kelp deposited near the high tide mark were quantified in western Ireland (53 degrees 09'25 '' N, 09 degrees 06'58 '' W) in summer 2011. Measurements revealed an average of 17 living individuals m(-2), accounting for 0.6 (kg dw) m(-2), and the biomass of degrading kelp averaged 0.05 (kg dw) m(-2). We further investigated the iodine-retention capacity of L. digitata and the effect of degradation. Under controlled conditions, I- release into seawater and I-2 emission into air depended on the physiological state of L. digitata. Fresh and "healthy" phylloids absorbed I-from seawater with I-2 emission rates reaching 27 nmol (g dw)(-1) h(-1). After 4 days of degradation, I-2 emission rates were enhanced by a factor of 3.1. Over 29 days of submersed degradation, similar to 4.7 mu mol I- (g dw)(-1) were released into seawater, a process which could trigger iodine recycling in coastal areas. Combined field and laboratory data suggest that living L. digitata sporophytes possess an I-2 emission capacity of similar to 16 mu mol m(-2) h(-1), whilst emersed degrading kelp contributes 1-5 mu mol m(-2) h(-1) to coastal atmospheric I-2 during summer. This study provides evidence that not only living but also degrading kelp acts as driver of coastal iodine fluxes.

Ooki A. et al. Concentration maxima of volatile organic iodine compounds in the bottom layer water and the cold, dense water over the Chukchi Sea in the western Arctic Ocean: a possibility of production related to the degradation of organic matter // Biogeosciences. 2016. Vol. 13, № 1. P. 133–145.

We conducted a shipboard observation over the Chukchi Sea and the Canada Basin in the western Arctic Ocean in September and October 2012 to obtain vertical distributions of four volatile organic iodine compounds (VOIs) in seawater. The VOIs observed in this study were iodomethane (CH3I), iodoethane (C2H5I), diiodomethane (CH2I2), and chloroiodomethane (CH2ClI). Maximum concentrations of the four VOIs were found in the bottom layer water over the Chukchi Sea shelf, in which layer the maximum concentration of ammonium (NH4+) also occurred. A significant correlation was observed between C2H5I and NH4+ (correlation coefficient R = 0.93, P < 0.01, n = 64) and between CH3I and NH4+ (R = 0.77, P < 0.01, n = 64), suggesting that the production of these VOIs increased with the degradation of organic matter. Over the northern Chukchi Sea shelf-slope area, concentration maxima of CH2I2, CH2ClI, and CH3I were found in the subsurface cold, dense water (CDW). A large nitrogen deficit (N deficit = NH4+ + NO3- + NO2- -16PO(4)(3-)) occurred simultaneously in this water, suggesting the production of the three VOIs in the sediment or the bottom layer water over the shelf, probably in association with the degradation of organic matter. We conclude that VOI production over the Chukchi Sea shelf can be largely attributed to the degradation of organic matter that is produced in the highly productive shelf water. High concentrations of CH2ClI were also found in the Alaskan Coastal Water (ACW) from the Bering Strait to the surface of the northern Chukchi slope. The VOIs that originated at the Chukchi Sea shelf are expected to be laterally transported to the Arctic Ocean basin through the CDW and the surface ACW.

Painter K.J. et al. Effects of in-channel beaver impoundments on mercury bioaccumulation in Rocky Mountain stream food webs // Ecosphere. 2015. Vol. 6, № 10. P. 194.(17pp.)

Beavers (Castor spp.) are ecosystem engineers and important modifiers of freshwater ecosystems. They create impoundments that flood the surrounding landscape and modify the flow of materials through streams, thus potentially increasing nutrients, productivity and the availability of toxic methyl mercury (MeHg) to downstream food webs. Here we quantify food web-available MeHg in water, periphyton, and invertebrates collected from 15 streams up- and down-stream from beaver impoundments in the Rocky Mountain foothills of Western Canada. While nutrients, algal biomass, and total invertebrate standing stock were not significantly elevated below ponds, MeHg concentrations (average increase of 1.7X) and percent of total Hg that was MeHg (average increase of 1.3X) showed a trend of higher values in all compartments downstream and the difference was significant in predatory invertebrates. This suggests that beaver impoundments can increase the availability and subsequent uptake of MeHg by basal food web organisms even if their immediate influence on nutrients and resources is limited. As beaver populations continue to rebound, more research is needed to fully characterise the effects of beavers on nutrient and contaminant cycling under different biogeochemical conditions.

Pan K. et al. Low mercury levels in marine fish from estuarine and coastal environments in southern China // Environmental Pollution. 2014. Vol. 185. P. 250–257.

This study is the first comprehensive evaluation of total Hg and methylmercury (MeHg) concentrations in wild marine fish from an estuarine and a coastal ecosystem in southern China. A total of 571 fish from 54 different species were examined. Our results showed that the Hg levels were generally low in the fish, and the Hg levels were below 30 ng g?1 (wet weight) for 82% of the samples, which may be related to the reduced size of the fish and altered food web structure due to overfishing. Decreased coastal wetland coverage and different carbon sources may be responsible for the habitat-specific Hg concentrations. The degree of biomagnification was relatively low in the two systems.

Parkes R.J. et al. A review of prokaryotic populations and processes in sub-seafloor sediments, including biosphere:geosphere interactions // Marine Geology. 2014. Vol. 352. P. 409–425.

A general review of the sub-seafloor biosphere is presented. This includes an update and assessment of prokaryotic cell distributions within marine sediments, current deepest 1922 m, and the impact of this on global sub-seafloor biomass estimates. These global estimates appear relatively robust to different calculation approaches and our updated estimate is 539 x 10(29) cells, taking into consideration new data from very low organic matter South Pacific Gyre sediments. This is higher than other recent estimates, which is justified as several sediments, such as gas hydrate deposits and oil reservoirs, can have elevated cell concentrations. The proposed relationship between elevated cell concentrations and Milankovitch Cycles in sequential diatom rich layers at some sites, demonstrates not only a dynamic deep biosphere, but also that the deep biosphere is an integral part of Earth System Processes over geological time scales. Cell depth distributions vary in different oceanographic provinces and this is also reflected in contrasting biodiversity. Despite this there are some clear common, sub-seafloor prokaryotes, for Bacteria these are the phyla Chloroflexi, Gammaproteobacteria, Planctomycetes and the candidate phylum JS1, and for Archaea uncultivated lineages within the phylum Crenarchaeota (Miscellaneous Crenarchaeotal Group and Marine Benthic Group B), Etnyarchaeota (SAGMEG, Marine Benthic Group-D/Fhermoplasmatales associated groups) and Thaumarchaeota (Marine Group I). In addition, spores, viruses and fungi have been detected, but their importance is not yet clear. Consistent with the direct demonstration of active prokaryotic cells, prokaryotes have been enriched and isolated from deep sediments and these reflect a subset of the total diversity, including spore formers that are rarely detected in DNA analyses. Activities are generally low in deep marine sediments (similar to 10,000 times lower than in near-surface sediments), however, depth integrated activity calculations demonstrate that sub-surface sediments can be responsible for the majority of sediment activity (up to 90%), and hence, are biogeochemically important. Unlike near-surface sediments, competitive metabolisms can occur together and metabolism per cell can be 1000 times lower than in culture, and below the lowest known maintenance energies. Consistent with this, cell turnover times approach geological time-scales (100-1000s of years). Prokaryotic necromass may be an important energy and carbon source, but this is largely produced in near-surface sediments as cell numbers rapidly decrease. However, this and deposited organic matter may be activated at depth as temperatures increase. At thermogenic temperatures methane and other hydrocarbons, plus H-2, acetate and CO2 may be produced and diffuse upwards to feed the base of the biosphere (e.g. Nankai Trough and Newfoundland Margin). Temperature activation of minerals may also result in oxidation of sulphides and the formation of electron acceptors, plus H-2 from low temperature (similar to 55 degrees C) serpentenisation and water radiolysis. New mineral surface formation from fracturing, weathering and subduction etc. can also mechanochemically split water producing both substrates (H-2) and oxidants (O-2 and H2O2) for prokaryotes. These and other biosphere:geosphere interactions may be important for sustaining a globally significant sub-seafloor biosphere.

Poeschl U., Shiraiwa M. Multiphase Chemistry at the Atmosphere-Biosphere Interface Influencing Climate and Public Health in the Anthropocene // Chemical Reviews. 2015. Vol. 115, № 10. P. 4440–4475.

Multiphase chemistry plays a vital role in the Earth system, climate, and health. Chemical reactions, mass transport, and phase transitions between gases, liquids, and solids are essential for the interaction and coevolution of life and climate. Knowledge of the mechanisms and kinetics of these processes is also required to address societally relevant questions of global environmental change and public health in the Anthropocene, that is, in the present era of globally pervasive and steeply increasing human influence on planet Earth.(1) In this work, we review the current scientific understanding and recent advances in the investigation of short-lived health- and climate-relevant air contaminants (SHCC) and their multiphase chemical interactions at the atmosphere–biosphere interface, including human lungs and skin, plant leaves, cryptogamic covers, soil, and aquatic surfaces. After an overview of different groups of SHCC, we address the chemical interactions of reactive oxygen species and reactive nitrogen species (ROS, RNS), primary biological and secondary organic aerosols (PBA, SOA), as well as carbonaceous combustion aerosols (CCA) including soot, black/elemental carbon, polycyclic aromatic hydrocarbons, and related compounds (PAH, PAC). ROS and RNS interact strongly with other SHCC and are central to both atmospheric and physiological processes and their coupling through the atmosphere–biosphere interface, for example, in the formation and aging of biogenic and combustion aerosols as well as in inflammatory and allergic immune responses triggered by air pollution.

Polechonska L., Klink A. Trace metal bioindication and phytoremediation potentialities of Phalaris arundinacea L. (reed canary grass) // Journal of Geochemical Exploration. 2014. Vol. 146. P. 27–33.

In the present study, the contents of trace metals (Zn, Mn, Fe, Pb, Cu, Ni, Cd, Co and Cr) in water, bottom sediments and different organs of Phalaris arundinacea L collected from the Bystrzyca River (Lower Silesia), that flows through regions with a high anthropopressure level, were determined by atomic absorption spectrometry. The aims of this paper were to reveal various trace metal accumulation abilities of different organs of P. arundinacea and to investigate their potential use in the biomonitoring and phytoremediation of environmental trace metal pollution. Results showed that metal contents in various organs of the reed canary grass differed significantly. Trace metal concentrations found in the plant samples generally decreased in the following order: root > leaf > stem. Limited mobility and translocation of the metals once absorbed by the reed canary grass makes it an interesting species for phytostabilization of metal contaminated bottom sediments. The highest Zn and Pb concentrations were noted in P. arundinacea from agricultural fields. Also the reed canary grass from cities showed high accumulation of Pb and Zn mainly due to vehicle traffic. Plants tested from dam reservoirs and forests had low concentrations of most trace elements. The significant, positive correlations found between the content of Co and Zn in the environment and the levels of these elements in the organs of the reed canary grass indicate potential application of P. arundinacea in the biomonitoring of environmental contamination with these metals.

Schaefer A.M. et al. Mercury concentrations in Atlantic bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, Florida: Patterns of spatial and temporal distribution // Marine Pollution Bulletin. 2015. Vol. 97, № 1–2. P. 544–547.

Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue mercury concentrations among the highest reported worldwide. Analysis of total mercury (THg) concentrations in blood collected between 2003 and 2012 showed a significant linear decrease over time (p = 0.04). Significant differences in the spatial distribution of THg in resident IRL dolphins were also observed with a general gradient in concentration from north to south. Evaluation of local biogeochemistry and accumulation of mercury in prey species is needed to better understand factors influencing the distribution of Hg in the apex predator. Analyses of temporal and spatial patterns of exposure to THg in this sentinel species may have implications for both ecosystem and public health in the region.

Selin N.E. Global Change and Mercury Cycling: Challenges for Implementing a Global Mercury Treaty // Environmental Toxicology and Chemistry. 2014. Vol. 33, № 6. P. 1202–1210.

The Minamata Convention aims to protect human health and the environment from anthropogenic emissions and releases of mercury. In the present study, the provisions of the Minamata Convention are examined to assess their influence on global biogeochemical cycling of Hg. Although the convention's scope covers all major categories of atmospheric emissions, the degree to which it will affect future emissions trajectories remains unclear. A box model analysis shows that future global biogeochemical cycling under projected technological provisions would result mainly in avoided increases and that estimated differences in atmospheric concentrations resulting from policies would be on the order of 1% to 2% per year. Present experience suggests that scientific knowledge is not currently sufficient to attribute causes to changes of this magnitude. Enhancements to capacity to measure the effectiveness of the Minamata Convention are suggested, including both measurement and modeling.

Sharma V.K. et al. Biogeochemistry of selenium. A review // Environmental Chemistry Letters. 2015. Vol. 13, № 1. P. 49–58.

Selenium levels and speciation in environmental compartments and the dynamics of global Se cycling continue to be a subject of intense interest largely because Se is both an essential element and a toxicant at elevated levels. While Se containing amino acids and proteins are known to be critical for normal metabolic functions in many life forms, selenosis, poisoning due to chronic excessive Se intake, has been associated with neurological impairment. This paper reviews the current understanding of the biogeochemistry of selenium in the natural environment. The factors that affect Se speciation in natural environments are chemical, physical, and biological processes. Several inorganic species of Se (-2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. Both HSeO3 (-) and SeO3 (2-) would be present in natural waters. Under mild oxidizing conditions, HSeO3 (-) and SeO3 (2-) are the major species, while HSe- would be the dominant species at pH greater than 4 and strong reducing conditions. The biogeochemistry of selenium is discussed in terms of variation of speciation with pH and redox conditions, sorption on solid surfaces, role of reducing species under oxic/anoxic conditions, and interaction with natural organic matter.

Sizmur T., Godfrey A., O’Driscoll N.J. Effects of coastal managed retreat on mercury biogeochemistry // Environmental Pollution. 2016. Vol. 209. P. 99–106.

We investigated the impact of managed retreat on mercury (Hg) biogeochemistry at a site subject to diffuse contamination with Hg. We collected sediment cores from an area of land behind a dyke one year before and one year after it was intentionally breached. These sediments were compared to those of an adjacent mudflat and a salt marsh. The concentration of total mercury (THg) in the sediment doubled after the dyke was breached due to the deposition of fresh sediment that had a smaller particle size, and higher pH. The concentration of methylmercury (MeHg) was 27% lower in the sediments after the dyke was breached. We conclude that coastal flooding during managed retreat of coastal flood defences at this site has not increased the risk of Hg methylation or bioavailability during the first year. As the sediment becomes vegetated, increased activity of Hg-methylating bacteria may accelerate Hg-methylation rate.

Soerensen A.L. et al. Elemental Mercury Concentrations and Fluxes in the Tropical Atmosphere and Ocean // Environmental Science & Technology. 2014. Vol. 48, № 19. P. 11312–11319.

Air-sea exchange of elemental mercury (Hg-0) is a critical component of the global biogeochemical Hg cycle. To better understand variability in atmospheric and oceanic Hg-0, we collected high-resolution measurements across large gradients in seawater temperature, salinity, and productivity in the Pacific Ocean (20 degrees N-15 degrees S). We modeled surface ocean Hg inputs and losses using an ocean general circulation model (MITgcm) and an atmospheric chemical transport model (GEOS-Chem). Observed surface seawater Hg-0 was much more variable than atmospheric concentrations. Peak seawater Hg-0 concentrations (similar to 130 fM) observed in the Pacific intertropical convergence zone (ITCZ) were similar to 3-fold greater than surrounding areas (similar to 50 fM). This is similar to observations from the Atlantic Ocean. Peak evasion in the northern Pacific ITCZ was four times higher than surrounding regions and located at the intersection of high wind speeds and elevated seawater Hg-0. Modeling results show that high Hg inputs from enhanced precipitation in the ITCZ combined with the shallow ocean mixed layer in this region drive elevated seawater Hg-0 concentrations. Modeled seawater Hg-0 concentrations reproduce observed peaks in the ITCZ of both the Atlantic and Pacific Oceans but underestimate its magnitude, likely due to insufficient deep convective scavenging of oxidized Hg from the upper troposphere. Our results demonstrate the importance of scavenging of reactive mercury in the upper atmosphere driving variability in seawater Hg-0 and net Hg inputs to biologically productive regions of the tropical ocean.

Stoch F. et al. Exploring copepod distribution patterns at three nested spatial scales in a spring system: habitat partitioning and potential for hydrological bioindication // Journal of Limnology. 2016. Vol. 75, № 1. P. 1–13.

In groundwater-fed springs, habitat characteristics are primarily determined by a complex combination of geomorphic features and physico-chemical parameters, while species assemblages are even more intricate. Springs host species either inhabiting the spring mouth, or colonizing spring habitats from the surface or from the aquifers which feed the springs. Groundwater species living in springs have been claimed as good candidates for identifying dual aquifer flowpaths or changes in groundwater pathways before reaching the spring outlets. However, the reliability of spring species as hydrological biotracers has not been widely investigated so far. Our study was aimed at analysing a large karstic spring system at three nested spatial scales in order: i) to assess, at whole spring system scale, the presence of a groundwater divide separating two aquifers feeding two spring units within a single spring system, by combining isotope analyses, physico-chemistry, and copepod distribution patterns; ii) to test, at vertical spring system scale, the effectiveness of copepods in discriminating surface and subsurface habitat patches within the complex mosaic spring environment; iii) to explore, at local spring unit level, the relative role of hydrochemistry and sediment texture as describers of copepod distribution among microhabitats. The results obtained demonstrated the presence of a hierarchical spatial structure, interestingly reflected in significant differences in assemblage compositions. Copepod assemblages differed between the two contiguous spring units, which were clearly characterized by their hydrochemistry and by significant differences in the groundwater flowpaths and recharge areas, as derived by the isotope analyses. The biological results suggested that stygobiotic species seem to be related to the origin of groundwater, suggesting their potential role as hydrological biotracers. At vertical scale, assemblage composition in surface and subsurface habitats was significantly different, both between spring units and among microhabitats, supporting strong habitat preferences of copepod species. At the smaller local scale, the response to habitat patchiness of subsurface copepod assemblages resulted in distribution patterns primarily defined by sediment texture, while the sensitivity to differences in hydrochemistry was negligible.

Stueeken E.E. et al. The evolution of the global selenium cycle: Secular trends in Se isotopes and abundances // Geochimica Et Cosmochimica Acta. 2015. Vol. 162. P. 109–125.

The Earth's surface has undergone major transitions in its redox state over the past three billion years, which have affected the mobility and distribution of many elements. Here we use Se isotopic and abundance measurements of marine and non-marine mudrocks to reconstruct the evolution of the biogeochemical Se cycle from similar to 3.2 Gyr onwards. The six stable isotopes of Se are predominantly fractionated during redox reactions under suboxic conditions, which makes Se a potentially valuable new tool for identifying intermediate stages from an anoxic to a fully oxygenated world. delta(82)/Se-78 shows small fractionations of mostly less than 2 parts per thousand throughout Earth's history and all are mass-dependent within error. In the Archean, especially after 2.7 Gyr, we find an isotopic enrichment in marine (+0.37 +/- 0.27 parts per thousand) relative to non-marine samples (-0.28 +/- 0.67 parts per thousand), paired with increasing Se abundances. Student t-tests show that these trends are statistically significant. Although we cannot completely rule out the possibility of volcanic Se addition, these trends may indicate the onset of oxidative weathering on land, followed by non-quantitative reduction of Se oxyanions during fluvial transport. The Paleoproterozoic Great Oxidation Event (GOE) is not reflected in the marine delta(82)/Se-78 record. However, we find a major inflection in the secular delta(82)/Se-78 trend during the Neoproterozoic, from a Precambrian mean of +0.42 +/- 0.45 parts per thousand to a Phanerozoic mean of -0.19 +/- 0.59 parts per thousand. This drop probably reflects the oxygenation of the deep ocean at this time, stabilizing Se oxyanions throughout the water column. Since then, reduction of Se oxyanions has likely been restricted to anoxic basins and diagenetic environments in sediments. In light of recent Cr isotope data, it is likely that oxidative weathering before the Neoproterozoic produced Se oxyanions in the intermediate redox state Se (IV), whereas the fully oxidized species Se-VI became more abundant after the Neoproterozoic rise of atmospheric oxygen.

Szymura T.H., Szymura M., Maciol A. Bioindication with Ellenberg’s indicator values: A comparison with measured parameters in Central European oak forests // Ecological Indicators. 2014. Vol. 46. P. 495–503.

Ellenberg's indicator values (EIVs), as bioindicators of primary environmental traits, are commonly applied in Europe; however, a problem exists with the appropriate interpretation of bioindication results in terms of ecological gradients. Very few studies have tested the predictive values of EIVs using validation data sets. In this study, we compared the results of bioindications of nitrogen content, soil reaction, light availability and soil moisture with measured environmental traits in Central European oak forests and assessed the ability of EIVs to predict environmental traits based on validation data sets. Additionally, the regression trees method was applied to determine which environmental traits influenced the values of EIVs. The results reveal that numerous linear correlations exist between the mean values of EIVs and measured traits. However, the correlations were rather low. The established regressions allow realistic predictions in case of Ca content and light conditions, while they did not perform satisfactory in case of moisture and nitrogen. The relatively low correlations were the result of several factors. Among these, the values of EIVs for species are inter-correlated, which might distort the results, especially for soil moisture and light availability. Moreover, the average values of EIVs assigned as an indication of particular environmental trait could be influenced by multiple ecological factors acting together and this could bias bioindication. The regression tree method, as a more flexible one, was able to detect such effect influencing average values of EIVs, while the linear method was not able to reveal it.

Todorova S.G. et al. Changes in the long-term supply of mercury species to the upper mixed waters of a recovering lake // Environmental Pollution. 2014. Vol. 185. P. 314–321.

We quantified internal processes that supply methylmercury from hypolimnetic reducing zones to the upper waters of a Hg-contaminated lake, Onondaga Lake, NY, USA. Diffusive transport continuously supplied methylmercury to the epilimnion under summer stratification, while fall mixing resulted in a pulsed release of methylmercury to the upper mixed waters. These processes were the main internal sources of methylmercury to the epilimnion, and together almost equaled the total external supply. The wind-driven entrainment represented an additional stochastic internal supply of methylmercury of approximately 9% in 2006. Considering more than 15 years of data, we estimate 1.8 wind-driven events occur per year. The mass of methylmercury inputs to the epilimnion exceeded the measured increase, suggesting that loss processes are important in regulating methylmercury accumulation. The relative contribution of internal sources of methylmercury to the epilimnion has decreased in recent years, shifting the importance to the external inputs.

Voutchkova D.D. et al. Iodine concentrations in Danish groundwater: historical data assessment 1933-2011 // Environmental Geochemistry and Health. 2014. Vol. 36, № 6. P. 1151–1164.

In areas where water is a major source of dietary iodine ( I), the I concentration in drinking water is an important factor for public health and epidemiological understandings. In Denmark, almost all of the drinking water is originating from groundwater. Therefore, understanding the I variation in groundwater and governing factors and processes are crucial. In this study, we perform uni- and multivariate analyses of all available historical Danish I groundwater data from 1933 to 2011 (n = 2,562) to give an overview on the I variability for first time and to discover possible geochemical associations between I and twenty other elements and parameters. Special attention is paid on the description and the quality assurance of this complex compilation of historical data. The high variability of I in Danish groundwater (d.l. to 1,220 mu g/l) is characterised by both small-scale heterogeneity and large-scale spatial trends, e. g. higher concentrations observed in the eastern part of Denmark. Significant trends are observed also with respect to the depth of extraction and geology, indicating the importance of older marine limestone and chalk deposits. A principal component analysis on centred log-ratio-transformed data (clr) revealed associations between I, Li, B, Ba, Br implying saline water influence. High I is also associated with reduced and alkaline groundwaters for this data set, dominated by Ca-HCO3 water type.

Vriens B. et al. Quantification of Methylated Selenium, Sulfur, and Arsenic in the Environment // Plos One. 2014. Vol. 9, № 7. P. e102906.

Biomethylation and volatilization of trace elements may contribute to their redistribution in the environment. However, quantification of volatile, methylated species in the environment is complicated by a lack of straightforward and field-deployable air sampling methods that preserve element speciation. This paper presents a robust and versatile gas trapping method for the simultaneous preconcentration of volatile selenium (Se), sulfur (S), and arsenic (As) species.

Walters D.M. et al. Mercury and selenium accumulation in the Colorado River food web, Grand Canyon, USA // Environmental Toxicology and Chemistry. 2015. Vol. 34, № 10. P. 2385–2394.

Mercury (Hg) and selenium (Se) biomagnify in aquatic food webs and are toxic to fish and wildlife. The authors measured Hg and Se in organic matter, invertebrates, and fishes in the Colorado River food web at sites spanning 387 riverkm downstream of Glen Canyon Dam (AZ, USA). Concentrations were relatively high among sites compared with other large rivers (mean wet wt for 6 fishes was 0.17-1.59gg(-1) Hg and 1.35-2.65gg(-1) Se), but consistent longitudinal patterns in Hg or Se concentrations relative to the dam were lacking. Mercury increased (slope=0.147) with N-15, a metric of trophic position, indicating biomagnification similar to that observed in other freshwater systems. Organisms regularly exceeded exposure risk thresholds for wildlife and humans (6-100% and 56-100% of samples for Hg and Se, respectfully, among risk thresholds). In the Colorado River, Grand Canyon, Hg and Se concentrations pose exposure risks for fish, wildlife, and humans, and the findings of the present study add to a growing body of evidence showing that remote ecosystems are vulnerable to long-range transport and subsequent bioaccumulation of contaminants. Management of exposure risks in Grand Canyon will remain a challenge, as sources and transport mechanisms of Hg and Se extend far beyond park boundaries.

Warren J.M. et al. Root structural and functional dynamics in terrestrial biosphere models - evaluation and recommendations // New Phytologist. 2015. Vol. 205, № 1. P. 59–78.

There is wide breadth of root function within ecosystems that should be considered when modeling the terrestrial biosphere. Root structure and function are closely associated with control of plant water and nutrient uptake from the soil, plant carbon (C) assimilation, partitioning and release to the soils, and control of biogeochemical cycles through interactions within the rhizosphere. Root function is extremely dynamic and dependent on internal plant signals, root traits and morphology, and the physical, chemical and biotic soil environment. While plant roots have significant structural and functional plasticity to changing environmental conditions, their dynamics are noticeably absent from the land component of process-based Earth system models used to simulate global biogeochemical cycling. Their dynamic representation in large-scale models should improve model veracity. Here, we describe current root inclusion in models across scales, ranging from mechanistic processes of single roots to parameterized root processes operating at the landscape scale. With this foundation we discuss how existing and future root functional knowledge, new data compilation efforts, and novel modeling platforms can be leveraged to enhance root functionality in large-scale terrestrial biosphere models by improving parameterization within models, and introducing new components such as dynamic root distribution and root functional traits linked to resource extraction.

Will-Wolf S. et al. Element analysis of two common macrolichens supports bioindication of air pollution and lichen response in rural midwestern USA // Bryologist. 2015. Vol. 118, № 4. P. 371–384.

Element analysis was conducted on naturally-growing Flavoparmelia caperata (L.) Hale and Punctelia rudecta (Ach.) Krog (26 sites) in 2003-05 for a 30-year resurvey of forest lichen communities near a power plant in Wisconsin. Cu, Cr, N, and S increased strongly with power plant impact (66 samples, both species) and are good candidate bioindicators for local pollution; Al and Fe increased weakly and are not recommended. Hg is a candidate pollution indicator from comparison with a background site (only F. caperata data: 39 samples, 23 sites). Only N and S were correlated with lichen species abundance and are thus candidate bioindicators for lichen response. Abundance of P. rudecta was lower and that of Phaeophyscia pusilloides (Zahlbr.) Essl. was higher with more N or S in lichens; abundances of F. caperata and large foliose species as a group were lower with higher modeled SO2 from the power plant (no response from four other tested lichen species or groups). Sites in more forested landscapes to the west of the power plant had more lichen species, including disturbance-sensitive taxa. Heathier lichens there may have led to higher concentrations of Al, Cr, and S, plus Li (only F. caperata data). Univariate general linear modeling (GLM) was more useful than regression to test species effect at 7 sites. Element analysis confirmed earlier records of minimal power plant impact on lichens in this area, where no truly pollution-sensitive lichen species have been recorded for decades.

Winkel L.H.E. et al. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review // Nutrients. 2015. Vol. 7, № 6. P. 4199–4239.

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

Zhang S. et al. Temporal Variation of Iodine Concentration and Speciation (I-127 and I-129) in Wetland Groundwater from the Savannah River Site, USA // Environmental Science & Technology. 2014. Vol. 48, № 19. P. 11218–11226.

I-129 derived from a former radionuclide disposal basin located on the Savannah River Site (SRS) has concentrated in a wetland 600 m downstream. To evaluate temporal environmental influences on iodine speciation and mobility in this subtropical wetland environment, groundwater was collected over a three-year period (2010-2012) from a single location. Total I-127 and I-129 showed significant temporal variations, ranging from 68-196 nM for I-127 and <5-133 pCi/I for I-129. These iodine isotopes were significantly correlated with groundwater acidity and nitrate, two parameters elevated within the contaminant plume. Additionally, I-129 levels were significantly correlated with those of I-127, suggesting that biogeochemical controls on I-127 and I-129 are similar within the SRS aquifer/wetland system. Iodine speciation demonstrates temporal variations as well, reflecting effects from surface recharges followed by acidification of groundwater and subsequent formation of anaerobic conditions. Our results reveal a complex system where few single ancillary parameters changed in a systematic manner with iodine speciation. Instead, changes in groundwater chemistry and microbial activity, driven by surface hydrological events, interact to control iodine speciation and mobility. Further radiological risk models should consider the flux of I-129 in response to temporal changes in wetland hydrologic and chemical condition.

Zhang X. et al. A mercury transport and fate model (LM2-Mercury) for mass budget assessment of mercury cycling in Lake Michigan // Journal of Great Lakes Research. 2014. Vol. 40, № 2. P. 347–359.

LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended and resuspendable solids (TSRS), dissolved organic carbon (DOC), and total, elemental, divalent, and methylmercury as state variables. Simplified processes among the mercury state variables including net methylation, net reduction of divalent mercury, and reductive demethylation are incorporated in the model. Volatilization of elemental mercury as a kinetic (phase transfer) process and partitioning of total, divalent, and methylmercury as a set of instantaneous equilibrium processes were also simulated. The model was calibrated to data collected in 1994 and 1995 and corroborated by comparing model output generated from a long-term model hindcast to total mercury measured in high quality sediment profiles. Model hindcast predictions of total mercury in the water column were within estimates of total mercury calculated from observed lake trout bioaccumulation factors. Using the model, a mass budget assessment of mercury cycling in the lake was conducted. Atmospheric deposition, including wet and dry (particle) deposition and absorption of gaseous divalent mercury, was the dominant source of total mercury to the lake, followed by sediment resuspension, and then tributary loads. The major loss mechanism of total mercury from the water was associated with the settling of solids, followed by net volatilization. Methylmercury loading associated with wet deposition was the dominant source to the lake, followed by tributary loadings, and in situ net methylation.

Zhang Y. et al. Biogeochemical drivers of the fate of riverine mercury discharged to the global and Arctic oceans // Global Biogeochemical Cycles. 2015. Vol. 29, № 6. P. 854–864.

Rivers discharge 2813Mmolyr(-1) of mercury (Hg) to ocean margins, an amount comparable to atmospheric deposition to the global oceans. Most of the Hg discharged by rivers is sequestered by burial of benthic sediment in estuaries or the coastal zone, but some is evaded to the atmosphere and some is exported to the open ocean. We investigate the fate of riverine Hg by developing a new global 3-D simulation for Hg in the Massachusetts Institute of Technology ocean general circulation model. The model includes plankton dynamics and carbon respiration (DARWIN project model) coupled to inorganic Hg chemistry. Results are consistent with observed spatial patterns and magnitudes of surface ocean Hg concentrations. We use observational constraints on seawater Hg concentrations and evasion to infer that most Hg from rivers is sorbed to refractory organic carbon and preferentially buried. Only 6% of Hg discharged by rivers (1.8Mmolyr(-1)) is transported to the open ocean on a global basis. This fraction varies from a low of 2.6% in East Asia due to the barrier imposed by the Korean Peninsula and Japanese archipelago, up to 25% in eastern North America facilitated by the Gulf Stream. In the Arctic Ocean, low tributary particle loads and efficient degradation of particulate organic carbon by deltaic microbial communities favor a more labile riverine Hg pool. Evasion of Hg to the Arctic atmosphere is indirectly enhanced by heat transport during spring freshet that accelerates sea ice melt and ice rafting. Discharges of 0.23MmolHgyr(-1) from Arctic rivers can explain the observed summer maximum in the Arctic atmosphere, and this magnitude of releases is consistent with recent observations. Our work indicates that rivers are major contributors to Hg loads in the Arctic Ocean.

Zhang Y. et al. Six centuries of changing oceanic mercury // Global Biogeochemical Cycles. 2014. Vol. 28, № 11. P. 1251–1261.

Mercury (Hg) is a global and persistent contaminant, affecting human health primarily via marine fish consumption. Large anthropogenic releases of Hg to the atmosphere by mining and coal combustion have resulted in a significant perturbation to the biogeochemical cycling of Hg. The magnitude of this perturbation and the relative roles of the ocean and land as sinks for anthropogenic Hg remain unclear. Here we use a 3-D global ocean biogeochemical model to show that surface ocean Hg concentrations have increased fourfold over the last 600years. We find that anthropogenic Hg enters the ocean's interior predominantly by absorption onto sinking organic matter particulates, which decompose and release Hg at a depth of 500-800m, implying that the human perturbation is largest in subsurface waters of biologically productive regions. Our model simulation predicts that over the last six centuries half of emitted anthropogenic Hg has accumulated in the oceans and marine sediments.

Zhang Y., Jaegle L., Thompson L. Natural biogeochemical cycle of mercury in a global three-dimensional ocean tracer model // Global Biogeochemical Cycles. 2014. Vol. 28, № 5. P. 553–570.

We implement mercury (Hg) biogeochemistry in the offline global 3-D ocean tracer model (OFFTRAC) to investigate the natural Hg cycle, prior to any anthropogenic input. The simulation includes three Hg tracers: dissolved elemental (Hg-aq(0)), dissolved divalent (Hg-aq(II)), and particle-bound mercury (Hg-aq(P)). Our Hg parameterization takes into account redox chemistry in ocean waters, air-sea exchange of Hg-0, scavenging of Hg-aq(II) onto sinking particles, and resupply of Hg-aq(II) at depth by remineralization of sinking particles. Atmospheric boundary conditions are provided by a global simulation of the natural atmospheric Hg cycle in the GEOS-Chem model. In the surface ocean, the OFFTRAC model predicts global mean concentrations of 0.16 pM for total Hg, partitioned as 80% Hg-aq(II), 14% Hg-aq(0), and 6% Hg-aq(P). Total Hg concentrations increase to 0.38 pM in the thermocline/intermediate waters (between the mixed layer and 1000m depth) and 0.82 pM in deep waters (below 1000m), reflecting removal of Hg from the surface to the subsurface ocean by particle sinking followed by remineralization at depth. Our model predicts that Hg concentrations in the deep North Pacific Ocean (>2000m) are a factor of 2-3 higher than in the deep North Atlantic Ocean. This is the result of cumulative input of Hg from particle remineralization as deep waters transit from the North Atlantic to the North Pacific on their similar to 2000 year journey. The model is able to reproduce the relatively uniform concentrations of total Hg observed in the old deep waters of the North Pacific Ocean (observations: 1.2 +/- 0.4 pM; model: 1.1 +/- 0.04 pM) and Southern Ocean (observations: 1.1 +/- 0.2 pM; model: 0.8 +/- 0.02 pM). However, the modeled concentrations are factors of 5-6 too low compared to observed concentrations in the surface ocean and in the young water masses of the deep North Atlantic Ocean. This large underestimate for these regions implies a factor of 5-6 anthropogenic enhancement in Hg concentrations.

Zhu D., Zhong H. Potential bioavailability of mercury in humus-coated clay minerals // Journal of Environmental Sciences-China. 2015. Vol. 36. P. 48–55.

It is well-known that both clay and organic matter in soils play a key role in mercury biogeochemistry, while their combined effect is less studied. In this study, kaolinite, vermiculite, and montmorillonite were coated or not with humus, and spiked with inorganic mercury (IHg) or methylmercury (MeHg). The potential bioavailability of mercury to plants or deposit-feeders was assessed by CaCl2 or bovine serum albumin (BSA) extraction. For uncoated clay, IHg or MeHg extraction was generally lower in montmorillonite, due to its greater number of functional groups. Humus coating increased partitioning of IHg (0.5%-13.7%) and MeHg (0.8%-52.9%) in clay, because clay-sorbed humus provided more strong binding sites formercury. Furthermore, humus coating led to a decrease in IHg (3.0%-59.8% for CaCl2 and 2.1%-5.0% for BSA) and MeHg (8.9%-74.6% for CaCl2 and 0.5%-8.2% for BSA) extraction, due to strong binding between mercury and clay-sorbed humus. Among various humus-coated clay particles, mercury extraction by CaCl2 (mainly through cation exchange) was lowest in humus-coated vermiculite, explained by the strong binding between humus and vermiculite. The inhibitory effect of humus on mercury bioavailability was also evidenced by the negative relationship between mercury extraction by CaCl2 and mercury in the organo-complexed fraction. In contrast, extraction of mercury by BSA (principally through complexation) was lowest in humus-coated montmorillonite. This was because BSA itself could be extensively sorbed onto montmorillonite. Results suggested that humus-coated clay could substantially decrease the potential bioavailability of mercury in soils, which should be considered when assessing risk in mercury-contaminated soils.

Zhu H. et al. Incorporation of Decomposed Crop Straw Affects Potential Phytoavailability of Mercury in a Mining-Contaminated Farming Soil // Bulletin of Environmental Contamination and Toxicology. 2015. Vol. 95, № 2. P. 254–259.

Recently, incorporation of crop straw into soils is being largely encouraged worldwide. To explore the possible influence of incorporation of decomposed crop straw on the speciation (i.e., inorganic mercury/IHg, and methylmercury/MMHg) and phytoavailability of mercury, mercury-contaminated farming soil was amended with different amounts (i.e., low, medium or high) of straw organic fertilizer (SF, mainly consisting of decomposed rice straw) or humus (HU) and incubated for a month. Potential phytoavailability of IHg, assessed by CaCl2 extraction, was significantly lower in soils amended with low/medium SF, possibly due to the immobilization effect of SF-organic matter on IHg. In contrast, phytoavailability of IHg was significantly higher in soils incorporated with high HU, possibly explained by the leaching effect of dissolved HU on soil-bound IHg. For MMHg, incorporation of medium/high

Zhu J.-M. et al. Selenium redox cycling during weathering of Se-rich shales: A selenium isotope study // Geochimica et Cosmochimica Acta. 2014. Vol. 126. P. 228–249.

Selenium isotopes are becoming an important paleoenvironmental proxy. However, few studies have focused on the behavior of Se isotopes during oxidative weathering. In this paper, a comprehensive set of Se isotopic composition and concentration data were collected from the weathering profiles of Se-rich shales of the Permian Maokou Formation in Yutangba and Shadi, China to investigate Se isotopic fractionation and Se enrichment during weathering processes. The delta Se-82/76 in fresh shales (148 +/- 118 mg/kg Se, 1SD, n = 40) from Shadi and Yutangba drill cores varies from -1.69 parts per thousand to 1.74 parts per thousand with an average of 0.40 +/- 0.71 parts per thousand (1SD, n = 40), consistent with the range in other Phanerozoic shales, suggesting that Se isotopes are not strongly fractionated during Se sequestration in the primary sedimentary environment. However, the strongly weathered Se-rich shales from Shadi and Yutangba profiles are isotopically lighter with average delta Se-82/76 values of -1.96 +/- 1.08 parts per thousand (1SD, n = 5) and -1.08 +/- 1.83 parts per thousand (1SD, n = 23), respectively. These data suggest that Se isotopes can be fractionated during oxidation and reduction processes associated with weathering, with heavier isotopes removed preferentially during oxidative weathering of shales. Such a shift, if found to be a global phenomenon, would have implications for models of the global Se cycle and interpretation of Se isotope data from past biogeochemical regimes. Locally altered shales exposed in a quarry at Yutangba are extremely enriched in Se with 1642 +/- 1505 mg/kg (1SD, n = 45), approximately 10 times greater than that in unaltered drill core samples. These rocks display very strong variation in delta Se-82/76 over short distances, with a single 60 cm transect showing the most strongly negative and positive delta Se-82/76 values (-14.20 parts per thousand to +11.37 parts per thousand) observed to date in natural samples. This suggests that Se has undergone multiple cycles of oxidation, mobilization, and re-reduction, resulting in a Se-rich redox front that has migrated downward through the organic-rich shales over time. delta Se-82/76 values vary sharply over distances as small as 10 cm, indicating that Se redox conditions change strongly with position and are controlled by fractures and rock layering. Our data and a simple conceptual model suggest that zones of increased permeability that are accessed first by infiltrating waters are isotopically light, whereas less accessible zones are heavy. Repeated redox cycling accentuates this pattern. Furthermore, the average d 82/76 Se in Se-rich shales at the Yutangba weathering system is 0.45 +/- 5.77 parts per thousand (1SD, n = 39), identical with that (0.40 +/- 0.71 parts per thousand) in fresh shales from same locality, implying that Se released by weathering accumulates in the redox front with little loss. The strong Se isotopic fractionation occurring in the redox front implies that Se isotopes can be extensively used in tracing geochemical processes of Se in groundwater system, especially related to fractures.

Архипов И.А. Биохимические особенности, определяющие ландшафтно-геохимическое поведение микроэлементов в почвах Алтая // Вестник Алтайского государственного аграрного университета. 2014. № 4 (114). С. 23-27.

Ландшафтно-геохимические и почвенно-геохимические исследования в системе высотных поясов Алтая являются приоритетными задачами региональной экологии. На территории Алтая рассмотрены особенности геохимического поведения микроэлементов в границах следующих достаточно четко выделяющихся трех биогеохимических поясов. 1. Пояс высокогорных тундр и альпийских лугов расположен на останцово-холмисто-увалистых пенепленизированных высокогорьях с маломощным суглинисто-щебнистым покровом с альпийскими и субальпийскими низкотравными и высокотравными лугами на горно-луговых почвах. Занимает верхние ярусы главных хребтов Алтая. 2. Горно-лесной биогеохимический пояс сформирован на среднегорных лесных с лиственничными и березово-лиственичными лесами на горно-лесных черноземовидных почвах. Разделяется на два биогеохимических района - Северо-Восточный и Центральный. 3. Пояс степных и сухостепных межгорных котловин и речных долин сформирован в межгорно-котловинных степных в полого-увалистых днищах котловин, сложенных щебнисто-суглинистыми и суглинистыми пролювиальными, аллювиальными и озерными отложениями, с ковыльными разнотравно-злаковыми степями на черноземах обыкновенных и южных, днищах котловин, сложенных галечниками, суглинисто-щебнистыми и суглинистыми ледниковыми, делювиальными и аллювиальными отложениями, с лапчатково-полынно-мелкодерновинно злаковыми степями на темно-каштановых и каштановых почвах. Изучаемые комплексы существенно отличаются по составу четвертичных отложений. В основу районирования положена высотная поясность, определяющая главные закономерности дифференциации как почвенного покрова, так и всего комплекса природных условий в целом. На рассматриваемой территории были изучены следующие типы и подтипы почв: горно-луговые альпийские и субальпийские, горно-лесные черноземовидные, горно-лесные бурые, черноземы обыкновенные, черноземы южные, каштановые почвы.

Гаджимусиева Н.Т. Круговорот йода в агроценозе Западного Прикаспия // Труды Института геологии Дагестанского научного центра РАН. 2015. № 65. С. 118-121.

Исследованы структуры и функционирование в агроэкоситеме западного участка Прикаспийской низменности. Получены количественные характеристики биологического круговорота йода в системе «почва- растение» методом Титляновой А.А

Гиреев Г.И., Салихов Ш.К., Луганова С.Г. Изменение параметров крови как показатель адаптации организма овец к йододефициту в биогеохимических условиях природных зон Дагестана // Вестник Тамбовского университета. Серия: Естественные и технические науки. 2014. Т. 19. № 5. С. 1667-1670.

Было проведено исследование концентрации и соотношения микроэлементов (йода, кобальта, селена, серы, меди, молибдена) в почве, растительности и водоисточниках пастбищ Дагестана (Кизлярский, Гергебильский, Гунибский административные районы). Выявлена зависимость состава крови (содержание микроэлементов, аминокислотный состав, активность ферментов) от геохимических особенностей компонентов пастбищных экосистем. Показано, что дисбаланс йода с его антагонистами и синергистами приводит к изменению картины крови овец и к патологии эндемического зоба овец.

Гиреев Г.И., Салихов Ш.К., Луганова С.Г. Метаболизм у овец при геохимическом селенодефиците // Вестник Дагестанского государственного университета. 2014. № 6. С. 107-112.

Селеновый статус пастбищных экосистем посредством биогеохимической связи влияет на обмен веществ овец. Дисбаланс в окружающей среде селена с другими микроэлементами вызывал модификации в минеральном, аминокислотном и белковом обмене, изменение активности ферментов в организме и в итоге приводил к болезни овец.

Ермаков В.В. Геохимическая экология и биогеохимические критерии оценки экологического состояния таксонов биосферы // Геохимия. 2015. № 3. С. 203-221.

Статья посвящена формированию и развитию современного научного направления - геохимической экологии как базиса биогеохимического нормирования. Рассмотрены место геохимической экологии в системе экологических наук и основные ее положения (биогеохимические пищевые цепи и параметры, биогенная миграция химических элементов, реакции организмов, включая гомеостаз, биоритмы, пороговые концентрации химических элементов и др.). Представлены новые данные о вкладе геохимической экологии в решение вопросов биогеохимического нормирования и районирования, профилактики биогеохимических эндемий и микроэлементозов. Подчеркивается актуальность проблем геохимической экологии, особенно в связи с техногенной эволюцией таксонов биосферы.

Ивашов П.В. Микроэлементы в листьях и хвое деревьев Приамурья // Устойчивое развитие горных территорий. 2014. № 4 (22). С. 61-65.

Изложены результаты изучения содержания микроэлементов в листьях и хвое древесных растений в Приамурье на полигоне Хехцир. Установлены уровни концентрации микроэлементов, в том числе и тяжелых металлов, в сравнении с мировыми кларками химических элементов в растениях. Обоснована возможность использования листьев и хвои деревьев при биогеохимическом мониторинге природных и техногенных наземных экосистем юга Дальнего Востока России.

Коробова Е.М., Рыженко Б.Н. и др. К вопросу о формах нахождения йода и селена в природных водах и их концентрирование на ландшафтно-геохимических барьерах // Геохимия. 2014. № 6. С. 554-568.

Показано, что питьевые воды Брянской области, в целом, обеднены йодом и селеном. Рассмотрены возможные формы нахождения йода и селена в питьевых водах и особенности их миграции и концентрирования в почвах в геохимически контрастных условиях. Показано, что высокая подвижность йода может обуславливаться миграцией не только в форме йодида и органических комплексов, но и в виде минеральных растворенных в воде комплексных форм (CaI+ и MgI+); при этом первый тип комплексных соединений более распространен в ландшафтах полесского типа, а второй ? в условиях опольных ландшафтов. В почвах комплексообразование йода с щелочноземельными катионами в восстановительных нейтрально-слабощелочных условиях с одной стороны, способствует миграции йода по вертикальному профилю, а с другой стороны, осаждению йода на карбонатном барьере. В тех же условиях доминирующей водорастворимой формой селена является гидроселенид, который в присутствии значительного количества железа может трансформироваться в минеральную фазу FeSe и фиксироваться на восстановительном барьере в почвах подчиненных гидроморфных ландшафтов. Высказано предположение, что общее низкое содержание йода и селена в питьевых водах и водная миграция радиоактивных изотопов йода в виде комплексных органических и минеральных соединений могло способствовать более выраженной заболеваемости щитовидной железы на всей территории Брянской области, в том числе и загрязненной после аварии на Чернобыльской АЭС радиоактивными изотопами йода.

Луганова С.Г., Салихов Ш.К., Гиреев Г.И. Влияние уровня содержания йода на физиологическое состояние овец // Вестник Дагестанского государственного университета. 2014. № 6. С. 113-117.

Выявлена зависимость состава крови (содержание микроэлементов, аминокислотный состав, активность ферментов) от геохимических особенностей компонентов пастбищных экосистем. Показано, что дисбаланс йода с его антагонистами и синергистами приводит к изменению картины крови овец и к патологии эндемического зоба.

Ляпина Е.Е. Ртуть в аэрозолях г. Томска // Оптика атмосферы и океана. 2013. Т. 26. № 6 (293). С. 490-493.

Техногенное геохимическое преобразование атмосферного воздуха урбанизированных территорий – один из актуальных вопросов современной экологии. Наиболее чутким, доступным и достоверным индикатором уровня загрязнения атмосферного воздуха и площади распространения потоков загрязняющих веществ в условиях города является снеговой покров.

Нестеров Е.М., Морозов Д.А. и др. Геохимическая индикация донных отложений в теории и практике палеоэкологических исследований // Проблемы региональной экологии. 2013. № 5. С. 71-75.

Формирование озерных осадков происходит в результате осаждения на дно автохтонного материала, образовавшегося в самом озере в результате жизнедеятельности проживающих в нем организмов, и аллохтонного, поступающего извне. В зависимости от природно-климатических условий среды роль данных источников осадкообразования может значительно меняться. Этим объясняется разнообразие геохимического состава донных отложений, обусловленное всем ходом исторического развития озера и окружающей его территории. Методика реконструкции параметров палеоэкологических обстановок окружающей среды, по данным геохимических характеристик отложений, позволяет уточнить закономерности эволюции среды, а установление локальных черт может способствовать построению ряда последовательных смен палеогеографических и палеоклиматических обстановок на протяжении позднеледниковья и голоцена. Развитие озера Лахтинский разлив в голоцене описано с помощью геохимического анализа. Выявлены черты, характеризующие особенности осадкооборазования в водоеме.

Оноприенко М.Г. Эколого-химические аномалии Большого Кавказа и Азово-Кубанской низменности // Экологический вестник Северного Кавказа. 2015. Т. 11. № 4. С. 21-26.

Рассмотрены геохимические аномалии Большого Кавказа и Азово-Кубанской низменности. Приведены примеры влияния аномалий на состояние здоровья человека и других организмов, находящихся в пределах зон аномального избытка или недостатка некоторых химических элементов и их соединений. Приведены примеры химических аномалий техногенного происхождения, указаны причины их возникновения и способы защиты от них.

Пузанов А.В., Рождественская Т.А., Салтыков А.В. Ртуть в лесных почвах низкогорий бассейна р. Томь // Проблемы региональной экологии. 2015. № 2. С. 16-20.

Изучены общее содержание ртути в почвенном покрове низкогорья в бассейне р. Томь и ее концентрация в водной и ацетатно-аммонийной (pH 3,0 и 4,8) вытяжках из гумусового горизонта этих почв. Выяснилось, что в исследуемых дерновоподзолистых и серых лесных почвах прослеживается равномерное пространственное и внутрипрофильное распределение общего содержания ртути, которое связано как с однородностью почвообразующей породы, так и с постоянством значений емкости поглощения и актуальной кислотности почвенного раствора. Несмотря на сложившиеся оптимальные условия для сорбции ртути, при воздействии жидких атмосферных осадков на гумусовый горизонт исследуемых почв происходит выщелачивание ртути как под действием собственно воды, так и в результате высвобождения в почвенный раствор водорастворимых органических и неорганических кислот, которые его подкисляют и, следовательно, увеличивают выщелачивание ртути. При увеличении кислотности самих атмосферных осадков существенных изменений в процессе выщелачивания ртути не наблюдается.

Рязанова М.С., Мартынова М.А., Хаустов В.В. Метод биогеохимической индикации и его использование при поисках углеводородов // Известия Юго-Западного государственного университета. Серия: Техника и технологии. 2014. № 2. С. 80-90.

Статья посвящена разработке и практической реализации нового научного направления исследований в области геологоразведочных работ на углеводороды - метода биогеохимического тестирования скважин для оценки продуктивности перспективных объектов. Определены аналитические параметры метода биогеохимической индикации, которые обладают высокой ценностью и заслуживают пристального внимания при решении многих научных и практических задач.

Сысо А.И., Колпащиков Л.А. и др. Элементный химический состав почв и растений Западного Таймыра // Сибирский экологический журнал. 2014. Т. 21. № 6. С. 855-862.

Изучено содержание химических элементов в почвах и растениях тундры Западного Таймыра и определены природные факторы, влияющие на концентрацию элементов в почвах и растениях. Показано нативно высокое содержание Be, Cu, Mn, Nb, Ni, Pb, Sr, V, Zn в почвах, обусловленное наличием в регионе полиметаллических рудопроявлений, и повышенное накопление растениями Fe, Mn, Ni, Pb, Cd в условиях кислой реакции среды и избыточного увлажнения почв.

Сычев В.Г., Аристархов А.Н. и др. Проблема селена и ее решение агрохимическими средствами состояние исследований по проблеме селена в агроэкосистемах // Плодородие. 2015. № 4 (85). С. 2-5.

Обсуждены состояние исследований по проблеме селена в России и целесообразность выполнения их в системах Географической сети опытов и Государственной агрохимической службы. В условиях острого селенодефицита в агроэкосистемах обогащение селеном продуктов питания для человека и растительных кормов для животных посредством применения селеновых удобрений все более актуально. Однако агрохимических исследований по этой тематике проведено крайне мало. Не установлены критерии селенодефицитности почв в географическом плане и оценочные градации содержания подвижных форм селена в почвах, не выявлены оптимальные дозы и способы применения селеновых удобрений под разные сельскохозяйственные культуры. На основе обобщения и анализа ранее проведенных исследований сформулированы предложения по их совершенствованию.

Хаустов В.В., Костенко В.Д. и др. О биогеохимической роли биогенных микроэлементов почв Курской области // Известия Юго-Западного государственного университета. Серия: Техника и технологии. 2014. № 2. С. 74-79.

По результатам статистической обработки данных заболеваемости населения и геохимических характеристик почв Курской области установлена зависимость между ними, что позволило осуществить районирование территории Курской области по преобладанию тех или иных заболеваний, в определенной степени связанных с геохимическими особенностями почв.

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