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Abstract Fe–Mn oxide modified biochar (FMBC) was produced to explore its potential for remediation of Hg–Cd contaminated paddy soils. The results showed that the application of FMBC decreased the contents of bioavailable Hg and Cd by 41.49–81.85% and 19.47–33.02% in contrast to CK, while the amount of labile organic carbon (C) fractions and C-pool management index (CPMI) was increased under BC and FMBC treated soils, indicating the enhancement of soil C storage and nutrient cycling function. Dry weight of different parts of Oryza sativa L. was enhanced after the addition of BC and FMBC, and the contents of Fe and Mn in root iron–manganese plaques (IMP) were 1.46–2.06 and 6.72–19.35 times higher than those of the control groups. Hg and Cd contents in brown rice under the FMBC treatments were significantly reduced by 18.32–71.16% and 59.52–72.11% compared with the control. FMBC addition altered the composition and metabolism function of soil bacterial communities, especially increasing the abundance of keystone phyla, including Firmicutes, Proteobacteria and Actinobacteria. Partial least squares path modelling (PLSPM) revealed that the contents of Na2S2O3–Hg, DTPA–Cd and IMP were the key indicators affecting Hg and Cd accumulation in rice grains. These results demonstrate the simultaneous value of FMBC in remediation of Hg and Cd combined pollution and restoring soil fertility and biological productivity. Graphical Abstract

Wild boars, being a common game species, inhabit regions across Eurasia, the southern regions of Asia and certain Indonesian islands. Being omnivorous and due to their relatively long lifespan, wide distribution and a relatively high number of shot animals per annual legal hunting season, they are suitable to be biological indicators of occurrence of heavy metals. Concentrations of cadmium, lead, arsenic and mercury were analyzed by atomic absorption spectrometry and cold vapor atomic absorption spectrometry in the livers of free-living wild boars (n = 58) from two locations in the Republic of North Macedonia. In all four examined heavy metals, no statistically significant difference between the locations was found (p > 0.05). The mean levels of heavy metals were Cd 0.391 mg/kg and 0.339 mg/kg; Pb 0.213 mg/kg and 0.204 mg/kg; Hg 0.034 mg/kg and 0.037 mg/kg; As 0.035 mg/kg and 0.029 mg/kg in the livers of boars from Bitola and Gevgelija hunting sites, respectively. Although some samples (two samples of Hg, ten samples of Cd and two samples of Pb) exceeded the legal limits, the average values for all heavy metals were far below the maximum permitted values. These findings are promising since they suggest that the ecosystem in the Republic of North Macedonia is stable concerning heavy metal pollution.

Relevance. The need to study the features of aerogenic effects of the Norilsk industrial complex on the natural environment. Aim. To study the features of the aerogenic effects of the Norilsk industrial complex in the south-southwest zone at a distance of 40–60 km using lichens Cladonia rungeferina and Cetraria sp. Objects. Soil, lichens Cladonia rungeferina and Cetraria sp. Methods. Soil and lichen samples were taken 40–60 km south-southwest of the Norilsk Industrial district. Sampling was carried out according to the scheme of two profiles with a length of 14 and 20 km. The samples were analyzed using a set of methods consisting of X-ray fluorescence (S4 Pioneer Bruker AXS), atomic absorption methods (KVANT-2A, Julia-5K) and induction-coupled plasma mass spectrometry (ELEMENT-2) in the laboratory of the GIN RAS, Moscow. The concentration of Ti, V, Ni, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Rb, Cd, Sb, Ba, La was determined. Results. The authors have obtained the data on the concentration of the 21 elements in soils and lichens. The paper demonstrates the calculation of distribution of elements in soil and lichens relative to the concentration in the upper part of the continental crust. The authors calculated the enrichment factor EF for Mn, Ni, Cu, Hg, Pb and estimated the distribution of this coefficient for both profiles. It is shown that the technogenic component of the aerogenic effect for Mn, Ni, Cu, Pb to the south-southwest of the Norilsk industrial complex at a distance of 40–60 km is practically absent. The increased values of the enrichment factor EF in lichens for Hg are explained by a combination of two factors – the constant presence of mercury in significant concentrations in ecosystems and tundra fires that took place in this zone in 2019–2020, which ultimately led to the re-deposition of Hg in the burnt areas.

Estuarine sediments serve as significant reservoirs for mercury (Hg) and methylmercury(MeHg), which can also interconvert in the external environment. The release of Hg in response to human activities raises concerns about its potential ecological and human health effects. Sediment samples were collected in December 2021 from four locations (sites), and Hg cycling by measuring the concentrations of, and controls on, the spatial distribution of total Hg (THg) and methylmercury (MeHg) in high-tidal zone (HTZ) and mid-tidal zone (MTZ) sediments of a mangrove forest (MF) and oyster farm (OF) was examined in northwestern Zhanjiang Bay, including simultaneous determination of sediment particle size, oxidation-reduction potential (Eh), pH, total organic carbon (TOC), sulfide concentration (S2-), and sulfate reducing bacteria (SRB). The research results indicated that concentrations of both THg and MeHg ranged between 20.0–104.0 ng/g and 0.011–0.277 ng/g in the sediments, respectively. The highest methylation potentials within the MF and OF were in sediments located approximately 10–15 cm below the surface. MeHg in the HTZ of the OF was likely derived from exogenous inputs as Hg methylation appears limited, and the formation of MeHg depended not only on the amount of inorganic mercury available for methylation in SRB, but also on the TOC, pH, Eh and S2- content in the sediment. A risk assessment of MeHg during the anthropogenic disturbance of this estuaries conducted on individuals eating oysters demonstrated that health risks are low.

Diabetic retinopathy (DR), a major complication of diabetes causing blindness, is characterized by retinal damage due to capillary degeneration and vascular leakage. Current treatments are not fully effective, highlighting the need for searching new therapeutic targets. Hematopoietic cell kinase (HCK), a protein involved in various diseases, has been identified as a potential biomarker in DR, but its role in disease progression requires further investigation. Here we investigated the role of HCK in DR and its potential mechanism. We found the expression of HCK increased under the stimulation of high glucose (HG) in human retinal capillary endothelial cells (HRECs). Knockdown of HCK can improve HREC cell viability and the integrity of the internal blood–retinal barrier. HCK depletion suppressed the AMPK pathway in HG-induced HRECs. In summary, HCK may be a potential target for the treatment of DR, which provides a theoretical basis for the development of new treatment strategies.

Bonnethead and Caribbean sharpnose sharks frequent coastal waters, rendering them vulnerable to overexploitation, with the bonnethead shark listed as endangered by the IUCN. Marine Protected Areas (MPAs) have been suggested as a management strategy to regulate shark-exploitation. Moreover, it’s essential to identify key areas where nursery grounds (NG) and adult habitats overlap to prioritize conservation zones within MPAs. Along the Caribbean Sea, several NG have been identified for larger shark species, but little is known for smaller sharks. In Bocas del Toro (BDT-Panamanian Caribbean), both bonnethead and Caribbean sharpnose sharks are distributed, with the former appearing to be genetically isolated. The local MPA in BDT doesn't include a NG identified near Solarte Island. In this study, to provide ecological information on bonnethead and Caribbean sharpnose sharks within this potential NG, we evaluated stable isotopes (δ13C and δ15N) and total-mercury (THg) values in their fins. The results revealed a higher proportion of small-adult sharks in the NG, emphasizing the necessity of conducting a comprehensive study to further characterize this area. Moreover, there was no niche-partitioning between the two species and their diets primarily consisted of small prey-items, as evidenced by the significant and negative relationship between isotopic values. Both species exhibited low THg levels in their fins. Based on these initial results and previous genetic data, it appears that BDT plays a critical role as a habitat for sharks. Thus, extending the local MPA to cover the potential NG could effectively ensure conservation of bonnethead and Caribbean sharpnose sharks in BDT.

The aim of this study was to explore the connection between growth and feeding ecology and mercury (Hg) levels in Japanese anchovy (Engraulis japonicus). We measured the amounts of Hg and stable carbon and nitrogen isotopes in the muscle of 143 Japanese anchovy specimens obtained from the open seas of the Northwest Pacific Ocean (39°2′ N~42°30′ N, 154°02′ E~161°29′ E) between June and July 2021. The results showed that there were significant differences (p < 0.05) in the δ13C and δ15N values of Japanese anchovies across all body length groups. As individuals grew, δ13C tended to decrease first and then increase, and δ15N tended to gradually increase. The standard ellipse corrected area showed an increasing and subsequently decreasing pattern with growth. It reached its greatest value (0.80) in the 111–120 mm group. Compared to the body length group of 91–120 mm, the niche overlap decreased for the 121–140 mm group in Japanese anchovy. Hg levels increased gradually with body length. Linear regression models revealed a positive correlation between Hg levels and δ13C in fish. Hg levels increased gradually, while δ15N remained relatively constant in the 7–9‰ range. In our study, a distinct shift in diet was observed for Japanese anchovy with increasing body length, and the differences in diet among life stages could be responsible for the changes in Hg levels.

The levels of mercury (Hg) were examined in the leg muscle of the crab Grapsus grapsus from five sites on four islands within the Galápagos archipelago. Mercury values obtained using a Milestone DMA 80 evo direct mercury analyzer varied both within and among sites. Total mercury concentrations (mg kg−1 dry weight) ranged from the lowest at a protected location at Isabela Island (0.06 ± 0.02) to the highest at the San Cristóbal urban location (2.04 ± 0.069). Crabs from South Plaza Island also had surprisingly high levels of mercury with a mean of 1.2 ± 0.6. Values from urban sites at Isabela Island and Academy Bay, Santa Cruz, had intermediate values. When converted to wet weight, crabs from both San Cristóbal and South Plaza were within or above the levels (0.3–0.5 mg kg−1 wet weight set by various government agencies) considered potentially harmful to human health if ingested. A lesser number of both oysters and barnacles were also analyzed for mercury at South Plaza and Academy Bay, and while the values were lower compared to the crabs, they followed the same pattern of elevated levels at South Plaza compared to Academy Bay. It is unclear as to whether the mercury comes from natural sources, such as volcanism, or anthropogenic causes.

A comprehensive investigation of the Hg2+ coordination chemistry and 197m/gHg radiolabeling capabilities of cyclen-based commercial chelators, namely, DOTA and DOTAM (aka TCMC), along with their bifunctional counterparts, p-SCN-Bn-DOTA and p-SCN-Bn-TCMC, was conducted to assess the suitability of these frameworks as bifunctional chelators for the 197m/gHg2+ theranostic pair. Radiolabeling studies revealed that TCMC and DOTA exhibited low radiochemical yields (0%–6%), even when subjected to harsh conditions (80°C) and high ligand concentrations (10–4 M). In contrast, p-SCN-Bn-TCMC and p-SCN-Bn-DOTA demonstrated significantly higher 197m/gHg radiochemical yields (100% ± 0.0% and 70.9% ± 1.1%, respectively) under the same conditions. The [197 m/gHg]Hg-p-SCN-Bn-TCMC complex was kinetically inert when challenged against human serum and glutathione. To understand the differences in labeling between the commercial chelators and their bifunctional counterparts, non-radioactive natHg2+ complexes were assessed using NMR spectroscopy and DFT calculations. The NMR spectra of Hg-TCMC and Hg-p-SCN-Bn-TCMC suggested binding of the Hg2+ ion through the cyclen backbone framework. DFT studies indicated that binding of the Hg2+ ion within the backbone forms a thermodynamically stable product. However, competition can form between isothiocyanate binding and binding through the macrocycle, which was experimentally observed. The isothiocyanate bound coordination product was dominant at the radiochemical scale as, in comparison, the macrocycle bound product was seen at the NMR scale, agreeing with the DFT result. Furthermore, a bioconjugate of TCMC (TCMC-PSMA) targeting prostate-specific membrane antigen was synthesized and radiolabeled, resulting in an apparent molar activity of 0.089 MBq/nmol. However, the complex demonstrated significant degradation over 24 h when exposed to human serum and glutathione. Subsequently, cell binding assays were conducted, revealing a Ki value ranging from 19.0 to 19.6 nM. This research provides crucial insight into the effectiveness of current commercial chelators in the context of 197m/gHg2+ radiolabeling. It underscores the necessity for the development of specific and customized chelators to these unique “soft” radiometals to advance 197m/gHg2+ radiopharmaceuticals.

Relevance. The need to study contribution of biogenic factors to migration of elements and response of ecological and geochemical system to natural and technogenic situation, which makes it possible to identify the presence of biogeochemical anomalies. Aim. To determine ecological and geochemical features of mercury load in the south of Western Siberia (Tomsk region, Kemerovo region, Altai Territory) according to research (leaves of aspen (Populus tremula L., family Salicaceae)). Objects. Aspen leaves, widely used to analyze the biogeochemical cycle of chemical elements and their migration in the "soil–plant" system, reflect the elemental composition of growing environment and can act as a biogeoindicator for biogeochemical studies. Methods. Sampling of aspen leaves, drying at room temperature, grinding, atomic absorption analysis of mercury on an RA-915M analyzer with the PIRO-915+ attachment (pyrolysis method). The application program STATISTICA 12 was used to process the data analysis and calculate eco-geochemical indicators: concentration factor, enrichment factor, bioaccumulation factor, concentration clarke. Results. The article presents original data on Hg gross concentration in aspen leaves in Tomsk, Kemerovo regions and Altai Territory. The authors have revealed the features of pollutant accumulation depending on the area of growth, geography and orography of the territory, geochemical features of the study areas, and the influence of anthropogenic factors. Calculations of the main geo-environmental indicators of the mercury load were made. The calculation results indicate that the concentrations are higher than the background, the Clarke of the noosphere, and the average for the dry matter of terrestrial plants. The presence of the element in the form available to plants was revealed in the substrate, as evidenced by the results of calculating the bioaccumulation coefficient. Geographically, Hg accumulation in aspen leaves in the south of Western Siberia is associated with the prevailing wind direction and the impact of anthropogenic sources.

Abstract This study investigated the characteristics of mercury emitted from a large-scale coal-fired power plant in Taiwan via intensive sampling campaigns. The air pollution control devices equipped in this coal-fired power plant include selective catalytic reduction, fabric filter and seawater flue gas desulfurization. During three sampling campaigns, mercury concentrations emitted from this large-scale coal fired power plant ranged from 0.04 to 0.35 μg Nm−3. In addition, solid and liquid samples including coal, bottom ash, fly ash and inlet/outlet seawater were collected and analyzed for mercury content to provide the mass flows of mercury in this plant. The results indicate that mercury emitted from this coal-fired power plant is dominated by Hg0, and the emission factor of mercury ranges from 0.37 to 3.37 mg Hg t−1 coal, which is relatively lower than those reported in other studies. The relative enrichment factor of mercury in fly ash (0.23–1.22) is significantly higher than that of bottom ash (0.10 × 10–3–0.89 × 10–3). Although this coal-fired power plant has a relatively low mercury atmospheric emission which accounts for 6.4% of the total mercury output, it is essential to further control mercury released from fly ash (62.6% of the total mercury output) and discharged seawater (33.7% of the total mercury output) to reduce environmental damage and human health effects.

The elements in blood normally reflect the levels in prey, indicating a recent exposure. Laughing gulls (Leucophaes atricilla) eat mainly horseshoe crab eggs (Limulus polyphemus) in the spring in Delaware Bay, New Jersey. The levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in the blood of laughing gulls foraging on crab eggs were examined in Delaware Bay to provide information on a species that is normally a generalist, and to determine if the levels of these elements were similar in 2019 and 2022/2023, were intercorrelated, and were related to those in crab eggs. Hg increased from 2019 (136 ± 31 ng/g) to 2022/2023 (473 ± 75 ng/g), while Cd and Se decreased. There were some significant correlations among elements and a close relationship between the element levels in blood and those in crab eggs collected in the same month (except for As). The levels differed between laughing gulls and three species of shorebirds for As and Cd. The elements in the blood of gulls and shorebirds should be similar because they eat mainly the same eggs in the same places. A significant proportion of laughing gull blood samples had levels of Hg and Se that were above the levels associated with adverse effects, which requires further examination.

Pawara area is a mining district in the eastern region of Cameroon. Mining in the area is generally artisanal and semi-mechanized, practiced by the local miners and immigrants from neighboring African countries and China. The lack of strict regulations and control of mining activities permits the miners to use illegal substances, especially Hg in gold separation. These expose the area to toxic and heavy metals pollution. This study highlights the source of heavy metals concentration in the Pawara soils and the potential adverse effects of Hg on gold separation to the environment and health. Three mining sites and one control site were investigated, namely Site A, Site B and Site C. The control Site 0 (background) is an area where no mining and agricultural activities have taken place. Soil samples were collected at depth of 20 cm, with six from each site (24 samples). Samples were analyzed for Al, Cd, Cr, Cu, Fe, Hg, Pb, Cd and Zn content using atomic absorption spectrophotometry in a graphite furnace. The metals, except for Fe, show high values for all three sites exceeding the background levels in the soils. Hg shows the highest concentration on Site A with a value of 1590 mg kg−1. Pb is highest on Site B with a concentration of 12,274 mg kg−1. The contamination degree was assessed with the help of contamination indices (Igeo—index of geo-accumulation; PLI—pollution load index; RI—potential ecological risk; Eri—ecological risk; Pi—single pollution index; CF—contamination factor) and all parameters show a high degree of contamination on all three sites compared to the control site. Hg, Pb, Cd, Cr and Cu as single pollutants show the highest ecological risk on Site A and Site B where intense mining is taking place. The absence of industrial and large-scale agricultural activities in the Pawara area, the nonexistence of contaminants on the control site and the presence of contaminants on Site C where farming is high and mining is low jointly show that the discharge of mine wastes onto the soils and stream channels are the main source of contaminants and potential pollutants of the Pawara ecological environment.

Background: Heavy metals are considered as pollutants polluting aquatic ecosystems because of their toxic effects and bioaccumulation in organisms. They can cause chronic poisoning when ingested by human. The present study was conducted to determine the concentration of heavy metals, mercury (Hg), lead (Pb), cadmium (Cd), and chromium (Cr) in the muscle tissue of Liza abu and Brachirus orientalis fish in Mahshahr, and also, to estimate the risk of muscle consumption of these fish. Methods: Forty samples of both fish species were randomly selected and after preparation and extraction and digestion processes, the metals were measured using ICP-OES Agilent Model 5100. Results: The mean concentrations of Hg, Pb, Cd, and Cr in the muscle tissue of the Liza abu fish were 0.616 ± 0.383, 1.227 ± 1.77, 0.076 ± 0.030, and 0.567 ± 0.267 mg/kg dry weight, and in the muscle tissue of the Brachirus orientalis fish were 0.846 ± 0.659, 0.515 ± 1.245, 0.061 ± 0.047, and 0.586 ± 0.548 mg/ kg dry weight, respectively. HI for Liza abu and Brachirus orientalis was 0.025 and 0.336, respectively. Conclusion: According to the results of this study, the concentrations of Hg and Cr in the muscle tissue of Liza abu and Brachirus orientalis were slightly higher than some global standards such as the World Health Organization (WHO) and Food and Agriculture Organization (FAO). HQ index was below 1 for two fish species, meaning that there was no non-carcinogenic risk. In all samples analyzed, carcinogenic risk Cr was slightly above the permissible limit of 1×10-4 to 1×10-6 ،other metals were in this range.

In order to assess the influencing factors of the presence of mercury in a river within the Savanna biome (Cerrado), we surveyed total mercury (THg) in bottom sediment from 50 lakes along 750 km of the Middle Araguaia floodplain. The sampling sites included non-urban and urban surroundings over three distinct geomorphologies. We measured water physicochemical parameters at each site and tested statistically if land use nested within the geological formation influenced the THg concentration in bottom sediments and related water parameters. Multivariate results indicate that the interaction between geological groups and land use is statistically significant (p < 0.05). Nested ANOVA and Tukey HSD tests confirmed that the geological formation with its nested land use influences the THg, pH, DO, conductivity, and TDS (p < 0.05). THg was significantly lower in Quaternary terrains (p < 0.05) and differed significantly between non-urban and urban areas in Neoproterozoic terrains (p = 0.02). The spatial projections of the THg eigenvector on the main axes with the scoring factors of the Neoproterozoic/Paleoproterozoic terrains, and urban/non-urban, confirmed the spatial correlations. These results indicate that the association of land use and geology could be the main driver of THg in the bottom sediments of lakes from the Middle Araguaia floodplain.

The Ya-Er Lake is a seriously polychlorinated dibenzo-p-dioxins/dibenzo-furans (PCDD/Fs) and mercury (Hg)-contaminated lake by pesticide and chlor-alkali plants in China. The oxidation pond method has been conducted to control pollution, moreover, the contaminated sediment was dredged and stacked, becoming a sediment stack yard for vegetable cultivation. To assess effects of oxidation pond method and dredging programme on pollution management and long-term risks of PCDD/Fs and Hg, the concentrations of PCDD/Fs, total Hg (THg), and methylmercury (MeHg) in soil and vegetable sampled from the sediment stack yard were measured and analyzed. Significantly positive relationships between concentrations of PCDD/Fs (p

Research in environmental sciences has demonstrated that land in close proximity to brownfields and heavily trafficked highways is contaminated with toxic metals. Despite this, little is known about the influence of brownfields and highways on metal levels in residents living nearby. We used data from 774 participants in the Detroit Neighborhood Health Study to estimate the effect of residential proximity to brownfields, highways, and present-day traffic on serum levels of lead, mercury, manganese, and copper using generalized estimating equations. We found that a 1 standard deviation increase in residential brownfield density within 200m was associated with increased serum lead levels (β: 0.04, 95% CI: −0.01, 0.09). The same modeled increase in a subset of historic industrial-use brownfields was associated with elevated serum mercury (β: 0.06, 95% CI: 0.03, 0.09). Increased highway and traffic density was positively associated with serum manganese (β: 0.02, 95% CI: 0.01, 0.04). Highway and traffic density was also positively associated with serum lead (β: 0.02, 95% CI: 0.01, 0.03) after restricting the analysis to participants who did not move during the study follow-up period. These findings draw attention to the importance of remediating polluted post-industrial sites in heavily populated areas, particularly as residents continue to move into densely populated cities around the globe.

This study focuses on implementing a wind turbine emulator based on a permanent magnet synchronous machine with excitation auxiliary windings and thoroughly investigates the space harmonics created by this innovative topology in MATLAB/Simulink. A Hybrid Generator (HG) is a robust generator that does not have slip rings or brushes in its structure. Furthermore, the flux of the hybrid generator HG may be easily adjusted as it is created by direct current excitation coils and permanent magnets. Unfortunately, the space harmonic rate in the HG is relatively high. In other words, the mechanical vibrations caused by the electromagnetic torque ripple threaten the drive train’s behaviour and, ultimately, the wind turbine’s lifespan. This study describes two methods for decreasing the ripple in electromagnetic torque. Both circuit architecture and robust H∞ control techniques are considered. After simulating the two approaches, a list of requirements is provided for the maximum allowable amplitude of the inductance and the flux harmonics.

Understanding variations in metal levels in biota geographically and under different environmental conditions is essential to determining risk to organisms themselves and to their predators. It is often difficult to determine food chain relationships because predators may eat several different prey types. Horseshoe crab (Limulus polyphemus) eggs form the basis for a complex food web in Delaware Bay, New Jersey, USA. Female horseshoe crabs lay thumb-sized clutches of eggs, several cm below the surface, and often dislodge previously laid eggs that are brought to the surface by wave action, where they are accessible and critical food for migrant shorebirds. This paper compares metal and metalloid (chromium [Cr], cadmium [Cd], lead [Pb], mercury [Hg], arsenic [As] and selenium [Se]) concentrations in horseshoe crab eggs collected on the surface with concentrations in eggs from clutches excavated from below the sand surface, as well as examining metals in eggs from different parts of the Bay. The eggs were all collected in May 2019, corresponding to the presence of the four main species of shorebirds migrating through Delaware Bay. These migrating birds eat almost entirely horseshoe crab eggs during their stopover in Delaware Bay, and there are differences in the levels of metals in blood of different shorebirds. These differences could be due to whether they have access to egg clutches below sand (ruddy turnstones, Arenaria interpres) or only to eggs on the surface (the threatened red knot [Calidris canutus rufa] and other species of shorebirds). Correlations between metals in clutches were also examined. Except for As and Cd, there were no significant differences between the metals in crab egg clutches and eggs on the surface that shorebirds, gulls, and other predators eat. There were significant locational differences in metal levels in horseshoe crab eggs (except for Pb), with most metals being highest in the sites on the lower portion of Delaware Bay. Most metals in crab eggs have declined since studies were conducted in the mid-1990s but were similar to levels in horseshoe crab eggs in 2012. The data continue to provide important monitoring and assessment information for a keystone species in an ecosystem that supports many species, including threatened and declining shorebird species during spring migration.

Landmine contamination is a vital contributor to long-lasting destructive effects on terrestrial ecosystem. Libya has experienced severe landmine impacts involving soil contamination with hazardous heavy metals. This study was conducted in Benghazi, Libya, to examine the phytotoxicity of soil contaminated with residues of a recent exploded mine, on seed germination and seedling growth of field beans (Vicia faba L.). Results revealed that soil contents of heavy metals (Pb, Cd, and Hg) showed a gradual decreasing trend from the explosion site with higher concentrations recorded near the site centre, and lower concentrations at a greater distance (6 m). At 50 cm, 1, 2, 4, and 6 m, respectively from the explosion site, mean Pb concentration was 1240, 960, 510, 180, and 28.5 mg/kg, whereas, mean Cd concentration was 44, 38, 21, 8.4, and 0.8 mg/kg and mean Hg concentration was 52, 38, 28.5, 16.2, and 0.51 mg/kg. A strong inverse correlation was obtained between seed germinationand soil content of heavy metals. Seeds sown at the closest distance to the explosion site failed to germinate, whereas, germination percentage for seeds sown at 1, 2, 4, and 6 m from the explosion site was 15%, 15%, 30%, and 60%, respectively, relative to 95% for control seeds. Above-ground vegetation variables of the surviving seedlings, Leaf number plant−1 and plant height, were negatively correlated with soil contamination level. Findings of this study demonstrated the severity of damage caused by landmine contamination to the site soil . Furthermore, the intolerance shown by V. faba to stress associated with the explosive-contaminated soil revealed that the soil was highly polluted and unsuitable for cultivating crop plants.

The estuarine environments surrounding coastal Louisiana create favorable conditions for microbially mediated mercury (Hg) methylation and subsequent bioaccumulation by biota. In 2010, the Deepwater Horizon (DWH) oil spill released large amounts of oil which, despite having low Hg concentrations, had the potential to influence methylmercury (MeHg) bioavailability in the coastal zone. To explore this possibility, we assessed Hg concentrations and trophodynamics in the coastal Louisiana food web prior to and immediately following the DWH oil spill and compared these metrics with an adjacent coastal ecosystem in the northern Gulf of Mexico. We found no differences in MeHg concentrations between oysters collected in years prior to the spill (1986–2007) and those collected during or in the months immediately after the spill (May to December 2010). When comparing tissue MeHg concentrations and carbon and nitrogen stable isotope values across 13 species of bivalves, shrimp, crabs, fishes, and birds we found evidence of significant biomagnification within the coastal Louisiana food web driven by species’ trophic position and their use of differing basal carbon sources. In addition, Hg trophodynamics also differed between two adjacent coastal ecosystems, post-spill coastal Louisiana (2010) and pre-spill coastal Alabama (2008–2009). While there was a higher trophic magnification factor in coastal Louisiana relative to coastal Alabama, food web baseline MeHg concentrations were higher in coastal Alabama. The high degree of biomagnification in coastal Louisiana, and significant regional variation, underscores the need to monitor Hg trophodynamics over space and time to better evaluate the short and long-term ecological consequences of events like the DWH oil spill.

Background. An abnormally high content of heavy metals is an important predictor of the formation of a peculiar territorial elemental background in the components of urban ecosystems, which ultimately affects people's health. A 25-year monitoring of the ecological state of the territory of the city of Amursk showed a high concentration of mercury in soil, water, liquid and solid biosubstrates of animals and humans. The goal is to study the balance of microelements in the “water –soil – plants – animals – man” ecosystem against the background of the impact of technogenic mercury pollution of the environment, due to the long-term absence of work on dismantling and demercurization of the territory of the Amursk Pulp and Cardboard Mill. Materials and methods. The analysis of impurities contained in the drinking water of centralized water supply (n = 25) was carried out; soil (n = 20); vegetable products of summer cottages (potatoes, carrots, cucumbers); human biosubstrates (hair, blood serum, n = 194); wool of mammals (n = 13). The content of elements: Cd, Hg, Pb, Ca, Fe, Co, Cu, Se, Zn, Mo, To, U, P (n = 12). Results. Analysis of the composition of water impurities from drinking sources of centralized and decentralized water supply in the territory of the cities of Amursk and Khabarovsk showed that, in 100 % of cases, the main factor influencing the sexual development of adolescents is high concentrations of P, Mn and low – Mo and Se. 65 % of boys and 80 % of girls are a low level of sexual development in Amursk. In foodstuffs of the daily ration of teenagers in the city of Amursk, the content of Hg hazardous to health was revealed. 68 % of adolescent boys and 80 % of girls in the city of Amursk have disharmonious physical development, mainly associated with a lack of body weight. Conclusions. In the studied urban ecosystem, contaminated with mercury over the past 25 years, a dysfunctional and maladaptive nature of indicators of somatic and reproductive health of the population, including the younger generation, was revealed.

Environmental pollution and medicine safety have aroused increasing public concerns due to human health. Amongst various contaminants, mercury is of special attention owing to their environmental persistence and biogeochemical recycling and ecological risks. Herein, a simple and highly parallel electrochemical biosensor for Hg determination was designed and investigated. The proposed biosensor was prepared and compared between (1) DTT/MB-DNA/Au with configuration occupation approach and (2) MCH/MB-DNA/Au with passivation approach. According to the combined results of scanning electrochemical microscope (SECM) and Randles-Sevcik equation, the DTT modified electrode exhibited high uniformity on DNA distribution and superb stability on electron transfer in Hg2+ detection. Evidentially, the response value of proposed DTT/MB-DNA/Au was increased from 57.518% to 97.607%, while RSD% between duplicate runs had dropped from 22.658% to 0.223% (n = 3). Moreover, the increased proportion of effective working area was 467.380% compared with general sensors. Besides, DTT concentration, DNA concentration as well as assembly time were optimized, utilizing electrochemical impedance spectroscopy (EIS), Cyclic Voltammetry (CV) and Square Wave Anode Stripping Voltammetry (SWASV). This optimized biosensor exhibited an excellent selectivity toward Hg2+ over Cu2+, As2+, Cd2+, Pb2+, Cr3+, Ni2+ and Zn2+ etc., and the stability of DTT/MB-DNA/Au were at least two times better even after 3 days under room temperature. Also, a linear relation was observed between the peak current and Hg2+concentrations in a range from 0.25 nM to 2.00 μM with a detection limit of 53.00 pM under optimal conditions. Finally, DTT/MB-DNA/Au was applied for plants and medical products analysis. In all, this optimized DTT/MB-DNA/Au with advantages of high repeatability and sensitivity would provide a new insight into the design and application of biosensor for reliable sensing in safeguarding plant protection and medicinal safety.

Contaminant monitoring in biota is important for determining environmental status and to detect or prioritize action on hazardous substances. Predators higher up a food chain are often used for monitoring of contaminants that bioaccumulate. However, it is not always possible to find higher predators that are both abundant and have a wide distribution for national or international contaminant monitoring. Great cormorants (Phalocrocorax carbo) are a widespread and increasingly common top predator of fish in fresh, brackish and salt water. We evaluate the suitability of great cormorant eggs as a matrix for contaminant monitoring by using stable isotopes of carbon, nitrogen and sulfur. Despite the fact that cormorants are migratory, egg isotope values showed a significant separation between five breeding colonies in Sweden (1 fresh water lake, 3 Baltic sites and 1 marine site). This high degree of separation indicates that eggs are primarily produced using local resources (not stored body resources) and that contaminants (mercury concentrations in this study) measured in eggs likely reflect levels in fish prey caught close to the breeding area. Compound specific stable isotope analysis was used to estimate cormorant trophic position (TP) and concentrations of mercury in eggs were positively related to TP. The results show that a multi-isotope approach, combined with good ecological diet knowledge allow for meaningful and comparative interpretation of mercury concentrations in biota and that great cormorant eggs appear a suitable matrix to measure locally derived and maternally transferred contaminants.

Relevance of the study is determined by the necessity to provide ecological and geochemical assessment of technogenic impact on environment and population health related to urbanization and industrial development resulting in contamination of natural assets with various pollutants. The aim of the study is to assess mercury loads onto the natural components of an urbanized territory with a well-developed industrial infrastructure by studying leaves and cores of balsam poplar (P. balsamifera L.). Subjects of research are poplar leaves and annual rings. This species of poplar is very common in urban localities of temperate zone. It has a number of features allowing it to capture significant amounts of dust particles and aerosols, namely, relatively large area, wax covering and presence of both abaxial and adaxial stomata; the tree serves as an indicator of community air. Research methods were sampling of poplar leaves through the period of 2014–2018 and following a 4×4 uniform area grid with a further concentration of 1×1 km near assumed pollution sources; sampling of wood from separate trees at a distance of 0,5 to 1 km from the assumed pollution source; atomic absorption spectrometry of Hg by pyrolysis; statistical processing of data; plotting maps and graphs. Results. During the field and laboratory works, the authors have obtained the data on geochemical features of Hg distribution through the leaves and annual rings of balsam poplar (P. balsamifera L.) in the territory of the city of Novosibirsk. In the northwestern part of the city, a biogeochemical halo of Hg concentrations was identified; it is isometric in form, has an area of approximately 25 km2 and is characterized by Hg content of over 100 ng/g. In 2017, a high Hg concentration (1300 ng/g) in poplar leaves was recorded in Kalininsky district, near the industrial site of the Novosibirsk Chemical Concentrates Plant. The studies have shown a clear trend for Hg accumulation in poplar leaves throughout the vegetation period. Maximum average content was found in leaf litter at 2006 ng/g (the range is 1153–2425 ng/g). However, the average Hg content in soil is 294 ng/g, which is significantly lower than the maximum allowable concentration of 2100 ng/g. Distribution of Hg content in poplar leaves depending on leaf position in the tree crown was studies for a tree in the epicenter of biogeochemical halo of Hg concentrations. Upwind the emission source, Hg concentration in the leaves is on average 1,5 times higher than in the wind shadow. During the studies of Hg forms in poplar leaves it was established that Hg is primarily found in free and physically-bound forms, which are the most mobile, prone to increased migration, transformation and methylation under the environmental conditions. Studies of wood cores in the vicinity of the pollution source allowed establishing three periods of Hg emission: the first period, with the maximum emission covers 1967–1985, the second period of 1991–2000 shows a decrease in Hg content; the third period of 2000–2007 is characterized with a relatively low level of Hg concentration. A large biogeocheimcal halo of Hg concentrations was mapped in the city of Novosibirsk, a possible emission source was found. Dendrobiogeochemical methods applied in the epicenter of the area with the highest mercury content allowed establishing long-term dynamics in Hg content in the subjects of the study. A period with the highest technogenic impact on the urban environment was established. In residential and industrial zones in the northeast of Novosibirsk, in the territory of a large biogeochemical Hg-related halo, the authors recommend to establish environmental and geochemical monitoring with mercury metering of air samples, studies of soil and plant cover, monitoring of sanitary and hygienic indicators of population’s health.

BACKGROUND The ecological risk of heavy metal anomaly in soil is widespread due to human activities and natural processes. Hg anomaly in urban soil and Cd anomaly along rivers are the typical cases. Recently, the chemical sequential extraction method is widely used for Hg, Cd and other heavy metals to analyze the content of water-soluble fraction, exchangeable fraction, organic bound fraction, and ferric-manganese oxidation in soil. Normally the contents of different heavy metals at the above different chemical extraction forms constitute the basis for ecological effect evaluation. However, no further discussion has been conducted on the natural occurrences of Hg and Cd in soil. OBJECTIVES To provide basis for studies on the key factors of ecological risk assessment. METHODS The content of Hg was determined by atomic fluorescence spectrometry (AFS) after dissolution by aqua regia. The content of Cd was determined by inductively coupled plasma-mass spectrometry (ICP-MS) after digestion by hydrochloric acid-nitric acid-hydrofluoric acid-perchloric acid complexes. The existence forms of Hg were determined by chemical analysis, pyrolytic Hg method, heavy mineral identification, electronic probe and Raman spectrum. The existing forms of Cd were determined by AB-DTPA extraction, X-ray diffractometer and laser particle sizer analyzer. The ecological effects of Hg and Cd were evaluated based on the content of these elements in rice. RESULTS The results show that sulfide was the main natural existence form of Hg in Hg anomaly soil around Changchun, Nanjing, Zhangzhou and Guangzhou. At least a part of Hg was in the form of cinnabar, which resulted in the relatively low percentage of bio-availability content to total content of Hg in soil. The proportion of rice grain with Hg content exceeding the standard of pollution-free food was only 3.4% when the average total content of Hg in soil was up to 500μg/kg. Cd in Cd anomaly area along the Yangtze River and the Pearl River presented as clay adsorption, resulting in about 50% Cd was bio-availability. The ratio of rice grain with Cd content exceeding the standard of pollution-free food was up to 43% when the average content of Cd in soil was 1000μg/kg. CONCLUSIONS This reveals that the sensitivity of the ecological effects of heavy metal elements such as Hg and Cd in soil is more directly affected by naturally occurring forms. Hg in the form of cinnabar is 'inert' and is not easily absorbed by crops, so it is not sensitive to ecological effects. Cd in the form of clay mineral adsorption is more active and easily absorbed by crops, resulting in sensitive ecological effects. After the heavy metal elements such as Hg and Cd are absorbed by crops and even the human, their existence forms and their transformation characteristics are the keys to assess whether there is an ecological risk.

The continuously increasing flow of toxic heavy metals to the environment due to intensive industrial activity and tightening requirements with regard to the content of metal ions in drinking and discharged waters urges the development of affordable and sensitive devices to the field control of pollutants. Here, we report a new thiated Rhodamine-lactam probe for Hg2+ detection and demonstrate how its sensitivity can be increased via the incorporation of the probe molecules into the optically transparent siloxane-acrylate coatings on polymethyl methacrylate and, alternatively, into the water-dispersible light-harvesting FRET nanoparticles (NPs), in which dye cations are separated by fluorinated tetraphenylborate anions. We have shown that the optimization of the FRET NPs composition had allowed it to reach the antenna effect of ~300 and fabricate “off/on” sensor for Hg2+ ion determination in aqueous solutions with the detection limit of ~100 pM, which is far below the maximum permissible concentration (MPC) of mercury in drinking water recommended by the World Health Organization. Although this work is more proof-of-concept than a ready-to-use analytical procedure, the suggested approaches to fabrication of the FRET NPs based on the popular rhodamine-lactam platform can be used as a background for the development of low-cost portable sensing devices for the extra-laboratory determination of hazardous metal ions.

Atmospheric mercury emission scenarios from artisanal and small-scale gold mining for 56 tropical and subtropical countries have been elaborated and assessed for their comparative significance. A multi-step quantitative method that yields narrow and robust confidence intervals for mercury emission estimates was employed. Firstly, data on gold production for different years, the ratio of mercury used in the different amalgamation processes, and ancillary input parameters were retrieved from official and unofficial sources, and their potential for emission reduction examined. Then, a Monte Carlo method to combine the data and generate mercury emission samples was used. These samples were processed by a non-parametric re-sampling method (bootstrap) to obtain robust estimates of mercury emissions, and their 95% confidence intervals, both for the current state and for the emission scenarios designed in this study. The artisanal and small-scale gold mining mercury emission (to the atmosphere) estimates agree with those reported in the Global Mercury Assessment 2018; however, the overall uncertainty is reduced from roughly 100% in the Global Mercury Assessment (779.59 tons/y; uncertainty range: 361.07–1197.97) to 27% (1091.93 tons/y; confidence interval at 95% level of confidence: 964.54–1219.77) in this study. This is a substantial outcome since the narrowing of the confidence intervals permits a more meaningful evaluation of the different emission scenarios investigated, which otherwise, given the broad uncertainty of other estimates, would have led only to vague conclusions in a study of this nature.

This paper presents for the first time data on the lateral distribution of total mercury in the water-suspended matter-bottom sediments system for the entire water area of Lake Onego, the second largest lake in Europe. The patterns of the total mercury vertical distribution in two types of bottom sediments stratification, have been established. The total mercury content in the Lake Onego water averages 0.32 ± 0.07 μg/L. The most common form of mercury in water is dissolved+colloid, with the exception of water samples from the Kondopoga and Povenetsky Bays. In the material of the sedimentation traps, the mercury content is 0.5 ± 0.3 μg/g, and in the upper and lower parts of the bottom sediments section is 0.067 ± 0.003 and 0.041 ± 0.001 μg/g, respectively. The paper considers the factors responsible for the mercury content increasing from the bottom sediments up through the sections. These factors include anthropogenic pollution, migration of Hg and its redeposition at the geochemical barrier together with Fe and Mn.

Inorganic mercury (Hg) can be methylated to the highly toxic and bioavailable methylmercury (MeHg) by microorganisms in anaerobic environments. The Hg methylation rate may be affected by forest management activities, which can influence the catchment soils, water, and sediments. Here, we investigate the influence of forest management in the form of ditch cleaning and beaver dam removal, as well as the seasonal variations, on sediment chemistry and microbiota. The relationships between MeHg concentrations in sediment samples and archaeal and bacterial communities assessed by 16S rRNA gene amplicon sequencing were investigated to determine the microbial conditions that facilitated the formation of MeHg. Concentrations of MeHg were highest in undisturbed catchments compared to disturbed or slightly disturbed sites. The undisturbed sites also had the highest microbial diversity, which may have facilitated the formation of MeHg. Low MeHg concentrations and microbial diversity were observed in disturbed sites, which may be due to the removal of organic sediment layers during ditch cleaning and beaver dam removal, resulting in more homogenous, mineral-rich environments with less microbial activity. MeHg concentrations were higher in summer and autumn compared to winter and spring, but the temporal variation in the composition and diversity of the microbial community was less than the spatial variation between sites. Beta diversity was more affected by the environment than alpha diversity. The MeHg concentrations in the sediment were positively correlated to several taxa, including Cyanobacteria, Proteobacteria, Desulfobacterota, Chloroflexi, and Bacteroidota, which could represent either Hg-methylating microbes or the growth substrates of Hg-methylating microbes.

The requirement of high data rate information transmission is rising exponentially for supporting different services including social networking, web streaming, and biomedical sensor data transmission. Such services required high channel bandwidth with secure information transmission and immunity to electromagnetic interference. Radio over free space optics (RoFSO) is witnessed as a promising technological solution to provide high data rate transmission over free space channel. We report on the design of a 2×10 Gb/s-10 GHz RoFSO transmission system using the mode division multiplexing technique and evaluate its transmission performance over varying levels of dust weather conditions. The comparison of non-return to zero (NRZ) and return to zero (RZ) binary digital optical modulation techniques is carried out in the proposed system. It is found that the proposed system using NRZ modulation serves 14.5 km transmission range; however, in the case of RZ modulation, it was restricted to 10 km for a target bit error rate (BER) of 10−6, thus resulting in a noticeable link enhancement of 4.5 km. Also, we demonstrate NRZ-based MDM-RoFSO link performance and availability in dust weather conditions using the BER, maximum reachable link range, and eye diagram as key performance parameters. We obtain a reliable transmission of 20 Gb/s-20 GHz data through HG00 and HG01 channels over a link range of 2500–108 m depending on the external dust weather condition. Furthermore, since this investigation shows the feasibility of RoFSO for small size cells, which is an essential feature of 5G mobile network, the proposed system can thus be implemented as a backhaul/fronthaul link for high-band (above 6 GHz) 5G services and for providing secure transmission of biomedical sensor data.

BACKGROUND Crude oil had a great influence on the determination of mercury and arsenic in oil-bearing cores by atomic fluorescence spectrometry. At present, the main methods of removing organic matter such as crude oil are high-temperature firing and high-temperature oxidation with strong acid. In these methods, high reaction temperature will cause loss of mercury and arsenic, resulting in lower results. OBJECTIVES To develop a separation method with low operating temperature. METHODS Mercury and arsenic in oil-bearing cores were determined by atomic fluorescence spectrometry with Soxhlet extraction at a low temperature for this method of 75℃ and the remaining part was decomposed by 50% aqua regia. RESULTS The detection limits were 0.003mg/kg and 0.10mg/kg for mercury and arsenic, respectively. The relative standard deviations were 7.3% and 5.1%, respectively. The relative standard deviation of mercury decreased from 33.0% to 7.3%, and the relative standard deviation of arsenic decreased from 25.0% to 5.1%. The recoveries of standard addition were greater than 92.5%. CONCLUSIONS Compared with traditional methods, this method avoided the problems of insufficient contact between samples and aqua regia due to the hydrophobicity of crude oil, incomplete decomposition of samples and mercury loss due to excessive reaction temperature. The proposed method provides a reference for the determination of other elements in oil-bearing cores.

Abstract Background Podocyte plays an important role in maintaining the integrity and function of the glomerular filtration barrier. Various studies reported that forkhead transcription factor (Fox) O1 played a key role in anti-oxidative signaling. This study aimed to investigate the role of Stat1 in high glucose (HG) -induced podocyte injury. Methods Under normal glucose, hypertonic and HG stimulated podocyte conditions, cell counting kit-8 (CCK-8) assay, flow cytometry and western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were respectively carried out to determine cell viability, apoptosis, reactive oxygen species (ROS) production and related genes expressions. We then respectively used silent Stat1, simultaneous silencing Stat1 and FoxO1 and over-expression of FoxO1, to observe whether they/it could reverse the damage of podocytes induced by HG. Results High glucose attenuated cell survival and promoted cell apoptosis in MPC-5 cells at the same time, and it was also observed to promote the protein expression of Stat1 and the FoxO1 expression inhibition. Silencing Stat1 could reverse HG-induced podocytes injury. Specifically, siStat1 increased cell viability, inhibited cell apoptosis and attenuated ROS level in a high-glucose environment. Cleaved caspase-3 and pro-apoptosis protein Bax was significantly down-regulated, and anti-apoptosis protein Bcl-2 was up-regulated by siStat1. The antioxidant genes Catalase, MnSOD, NQO1 and HO1 were up-regulated by siStat1. We found that silencing FoxO1 reversed the protective effect of siStat1 on the HG-induced podocytes injury. Conclusions Silencing Stat1 could reverse the effects of high glucose-triggered low cell viability, cell apoptosis and ROS release and the functions of Stat1 might be involved in FoxO1 mediated-oxidative stress in nucleus.

Red kupang lives permanently dan eats by filtering food in waters so that it has high potential to be contaminated with heavy metals. The presence of heavy metals in kupang can cause health problems if consumed by humans. One of the efforts to reduce the heavy metal of kupang merah by adsorption method uses natural ingredients such as clover which is rich in secondary metabolites. The content of secondary metabolites in plants acts as a binder for heavy metals. The purpose of this study was to determine the concentration of clover juice dan the best time of immersion in kupang merah to reduce the level of heavy metals in kupang merah meat. This study used a complete random factorial pattern design with two factors with 2 replications. First factor: clover juice concentration 10%, 20%, 30% dan second factor: contact time is 60 minutes, 90 minutes, 120 minutes. The results of clover analysis showed that fresh clover contained terpenoids/steroids, saponins, flavonoids, polyphenols dan phenols in total 86.935 ± 2.004 mg TAE/gram. The results of fresh red kupang analysis showed protein content of 9.82 ± 0.3111%, water content of 81.527±0.545%, ash content of 1.840±0.014%, copper metal content of 47.491±0.386 ppm, lead 21.309±1.93 ppm, chromium 2,333±1,102 ppm, cadmium 1,648±0,083 ppm dan mercury 0,539±0,027 ppm. The best treatment in the study of the best metal content reduction at 30% clover juice concentration and 120 minutes soaking time can reduce the contamination of kupang Merah heavy metals, namely Cu to 19.862 ppm (down 58.177%), Pb to 0.886 ppm (down 95.842%), Cr to 0.758 (down 67.609%), Cd becomes 0.813 ppm (50.668%), Hg becomes 0.024 ppm (95.547%). The characteristics of kupang Merah meat after soaking are 9.10% protein content, 1.781% ash content dan 84.506% moisture content.

In this study, the surface of vermiculite-montmorillonite was modified by MnO2 loading. The modified vermiculite-montmorillonite was added to remediate the potentially toxic trace element (PTE) Hg present in soil containing coal gangue. Pot experiments were conducted to analyze and compare the pH values, Hg contents and Hg species present in coal gangue-containing soil, with and without the modified materials added, to determine whether the addition of modified materials had an effect on the growth of Brassica chinensis L. Results showed that with the addition of 35 g·kg−1 modified vermiculite-montmorillonite, the pH of soil increased by a value of 0.79, compared with that in the control group. When 15 g·kg−1 was added, the concentration of Hg in soil decreased by 98.2%. The addition of modified materials promoted the transformation of Hg in soil from a bioavailable form to an unavailable form; that is, the content of the residual form increased. The plant height and biomass of Brassica chinensis L. also increased, which indicated that the addition of modifiers can increase soil productivity, reduce the effects of PTEs on organisms in soil, and promote plant growth. Therefore, the addition of modified vermiculite-montmorillonite can achieve remediation of coal gangue-containing soil.

The Chuan–Dian region, situated in the middle part of the north-south seismic zone of mainland China in a highly deformed area of the eastern margin of the Tibetan Plateau, is one of the principal areas for monitoring earthquake activities in China. In this study, the geochemical characteristics of soil degassing (of CH4, H2, CO2, Rn, and Hg) and, the relationship between degassing and fault activity, were investigated in the Xianshuihe–Xiaojiang fault system (XXFS) at the eastern boundary of the Chuan–Dian rhombic block. The mean soil-gas concentrations of CH4, H2, CO2, Rn, and Hg in the XXFS were 8.1 ppm, 9.9 ppm, 0.5%, 15.1 kBq/m3 and 12.9 ng/m3, respectively. The δ13CCO2 and δ13CCH4 values of the hot-spring gases varied from −11.9‰ to −3.7‰ and −62.5‰ to 17‰, respectively. The He-C isotopic ratios indicate that the carbon in the northern and middle parts of the XXFS may have originated from deep fluids, whereas the carbon in the southern part of the XXFS is of organic origin. The high concentrations of soil gas were distributed near the faults, indicating that the faults could act as channels for gas migration. The distributions of the high soil-gas concentrations in the XXFS coincide with the highest stress and maximum strain rates, indicating that the fault activity enhanced permeability and increased the emission rates of the gases. The results of this study will be helpful for degassing in active fault zones and earthquake monitoring.

A wide range of species, including marine mammals, seabirds, birds of prey, fish and bivalves, were investigated for potential population health risks resulting from contemporary (post 2000) mercury (Hg) exposure, using novel risk thresholds based on literature and de novo contamination data. The main geographic focus is on the Baltic Sea, while data from the same species in adjacent waters, such as the Greater North Sea and North Atlantic, were included for comparative purposes. For marine mammals, 23% of the groups, each composing individuals of a specific sex and maturity from the same species in a specific study region, showed Hg-concentrations within the High Risk Category (HRC) and Severe Risk Category (SRC). The corresponding percentages for seabirds, fish and bivalves were 2.7%, 25% and 8.0%, respectively, although fish and bivalves were not represented in the SRC. Juveniles from all species showed to be at no or low risk. In comparison to the same species in the adjacent waters, i.e. the Greater North Sea and the North Atlantic, the estimated risk for Baltic populations is not considerably higher. These findings suggest that over the past few decades the Baltic Sea has improved considerably with respect to presenting Hg exposure to its local species, while it does still carry a legacy of elevated Hg levels resulting from high neighbouring industrial and agricultural activity and slow water turnover regime.

Hg is an environmental pollutant with severe biotoxicity. Epiphytic Tillandsia species, especially Spanish moss T. usneoides, are widely used as the bioindicator of Hg pollution. However, the effects of different Hg concentrations on Tillandsia have been rarely studied and the occurrence of hormesis in Tillandsia species has not been determined. In this study, T. usneoides was subjected to stress induced by 15 concentrations of gaseous Hg ranging from 0 to 1.8 μg m–3 through a misting system and then Hg content and eight common biomarkers in leaves were measured. The results showed that leaf Hg content significantly increased with Hg concentration, showing a linear relationship. However, there were no obvious mortality symptoms, indicating that T. usneoides showed strong resistance to Hg. Conversely, there were no simple linear relationships between changes in various biomarkers following Hg treatment of T. usneoides and Hg concentration. With increasing Hg concentration, malondialdehyde (MDA) content did not change significantly, superoxide anion radical content decreased gradually, superoxide dismutase (SOD) content decreased to the bottom and then bounced back, electrical conductivity increased, and glutathione (GSH) and metallothionein (MT) content increased to the peak and then dropped. The coefficient of determination of the dose-effect curves between SOD, GSH, and MT contents and Hg concentration was high, and the dose-effect relationship varied with hormesis. The present study is first to confirm hormesis induced by heavy metal pollution in Tillandsia species.

Approximately 50% of the 2600 decommissioned mines in South Korea are implicated in toxic metal/metalloid releases. One of the problems experienced in orchards situated near abandoned mines is the transport of heavy metals including mercury (Hg) into the plants. Due to high levels of Hg observed in orchard soils, heavy metal remediation is needed. The stabilization process is one of the widely used techniques to immobilize heavy metals in contaminated soil and waste. In this study, two types of starfish, Asterias amurensis (ASF) and Asterina pectinifera (PSF), were considered as stabilizing materials for remediating Hg-contaminated soil. In addition to natural starfish, the Hg immobilization effectiveness of calcined forms (CASF and CPSF) was also evaluated comparatively. The effect of particle size reduction on Hg immobilization was assessed for the ASF treatment. Total dosages of less than 10 wt% of ASF and PSF and less than 5 wt% of CASF and CPSF were applied to the Hg contaminated soil. Following treatment and curing for 28 days, the effectiveness of the stabilization process was evaluated using 1N HCl extraction tests. Overall, the stabilization results showed a decrease in Hg leachability with increasing dosages of ASF, PSF, CASF and CPSF. Generally, ASF outperformed the PSF treatments and calcined forms (CASF, CPSF) were more effective than natural forms (ASF, PSF). A reduction of approximately 79% was attained in Hg leachability for the 10 wt% ASF treatments. The -#20 mesh materials were more effective on Hg immobilization than the -#10 mesh materials. The Hg immobilization effectiveness exhibited the following increasing order: PSF (-#10 mesh) < ASF (-#10 mesh) < CPSF (-#10 mesh) < ASF (-#20 mesh) < CASF (-#10 mesh). It was found that effective Hg immobilization was most probably associated with the existing sulfur content in the starfish. The results of scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) indicated that a HgS compound and pozzolanic reaction products were responsible for effective Hg immobilization.

Microorganisms are key players in the transformation of mercury into neurotoxic methylmercury (MeHg). Nevertheless, this mechanism and the opposite MeHg demethylation remain poorly understood. Here, we explored the impact of inorganic mercury (IHg) and MeHg concentrations from 0.05 to 50 μM on the production and degradation of MeHg in two sulfate-reducing bacteria, Pseudodesulfovibrio hydrargyri BerOc1 able to methylate and demethylate mercury and Desulfovibrio desulfuricans G200 only able to demethylate MeHg. MeHg produced by BerOc1 increased with increasing IHg concentration with a maximum attained for 5 μM, and suggested a saturation of the process. MeHg was mainly found in the supernatant suggesting its export from the cell. Hg L3-edge High- Energy-Resolution-Fluorescence-Detected-X-ray-Absorption-Near-Edge-Structure spectroscopy (HERFD-XANES) identified MeHg produced by BerOc1 as MeHg-cysteine2 form. A dominant tetracoordinated βHgS form was detected for BerOc1 exposed to the lowest IHg concentrations where methylation was detected. In contrast, at the highest exposure (50 μM) where Hg methylation was abolished, Hg species drastically changed suggesting a role of Hg speciation in the production of MeHg. The tetracoordinated βHgS was likely present as nano-particles as suggested by transmission electron microscopy combined to X-ray energy dispersive spectroscopy (TEM-X-EDS) and nano-X ray fluorescence (nano-XRF). When exposed to MeHg, the production of IHg, on the contrary, increased with the increase of MeHg exposure until 50 μM for both BerOc1 and G200 strains, suggesting that demethylation did not require intact biological activity. The formed IHg species were identified as various tetracoordinated Hg-S forms. These results highlight the important role of thiol ligands and Hg coordination in Hg methylation and demethylation processes.

The superconducting transition temperature, Tc, can be calculated for practically all superconducting elements using the Roeser–Huber formalism. Superconductivity is treated as a resonance effect between the charge carrier wave, i.e., the Cooper pairs, and a characteristic distance, x, in the crystal structure. To calculate Tc for element superconductors, only x and information on the electronic configuration is required. Here, we lay out the principles to find the characteristic lengths, which may require us to sum up the results stemming from several possible paths in the case of more complicated crystal structures. In this way, we establish a non-trivial relation between superconductivity and the respective crystal structure. The model enables a detailed study of polymorphic elements showing superconductivity in different types of crystal structures like Hg or La, or the calculation of Tc under applied pressure. Using the Roeser–Huber approach, the structure-dependent different Tc’s of practically all superconducting elements can nicely be reproduced, demonstrating the usefulness of this approach offering an easy and relatively simple calculation procedure, which can be straightforwardly incorporated in machine-learning approaches.

Although the suitability of some biochars for contaminants’ sorption separation has been established, not all potential feedstocks have been explored and characterized. Here, we physicochemically characterized cherry pit biochar (CPB) pyrolyzed from cherry pit biomass (CP) at 500 °C, and we assessed their As and Hg sorption efficiencies in aqueous solutions in comparison to activated carbon (AC). The basic physicochemical and material characterization of the studied adsorbents was carried out using pH, electrical conductivity (EC), cation exchange capacity (CEC), concentration of surface functional groups (Boehm titration), and surface area (SA) analysis; elemental C, H, N analysis; and Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX). AsO43− anions and Hg2+ cations were selected as model contaminants used to test the sorption properties of the sorption materials. Characterization analyses confirmed a ninefold increase in SA in the case of CPB. The total C concentration increased by 26%, while decreases in the total H and N concentrations were observed. The values of carbonate and ash contents decreased by about half due to pyrolysis processes. The concentrations of surface functional groups of the analyzed biochar obtained by Boehm titration confirmed a decrease in carboxyl and lactone groups, while an increase in phenolic functional groups was observed. Changes in the morphology and surface functionality of the pyrolyzed material were confirmed by SEM–EDX and FTIR analyses. In sorption experiments, we found that the CPB showed better results in the sorption separation of Hg2+ than in the sorption separation of AsO43−. The sorption efficiency for the model cation increased in the order CP < CPB < AC and, for the model anion, it increased in the order CPB < CP < AC.

The research about utilization of nitrogen gas as a carrier gas in the determination of Hg ions by using Cold Vapor-Atomic Absorption Spectrophotometer (CV-AAS) method has been conducted. To optimize the measurement results, several parameters that affect hydride generator have been studied. Some specified important parameters are SnCl2 concentration as reductant, acid concentration, and the analytical performance such as repeatability and reproducibility (% RSD), linearity (r), limits of detection (LOD) and limits of quantitation (LOQ), and accuracy have been studied. The results of the research showed that the nitrogen gas can be used instead of argon gas as a carrier gas. It was shown by the repeatability values as % RSD < 2/3 CV Horwitz values, the LOD was 0.0338 µg/L and the LOQ was 0.0838 µg/L. The accuracy of this method was well shown by a recovery percentage was 102.24%. Based on the result of this research, the nitrogen gas can be used as a carrier gas for the determination of Hg ions by using the CV-AAS method with valid results.

Abstract Exposure to long-range transported industrial chemicals, climate change and diseases is posing a risk to the overall health and populations of Arctic wildlife. Since local communities are relying on the same marine food web as marine mammals in the Arctic, it requires a One Health approach to understand the holistic ecosystem health including that of humans. Here we collect and identify gaps in the current knowledge of health in the Arctic and present the veterinary perspective of One Health and ecosystem dynamics. The review shows that exposure to persistent organic pollutants (POPs) is having multiple organ-system effects across taxa, including impacts on neuroendocrine disruption, immune suppression and decreased bone density among others. Furthermore, the warming Arctic climate is suspected to influence abiotic and biotic long-range transport and exposure pathways of contaminants to the Arctic resulting in increases in POP exposure of both wildlife and human populations. Exposure to vector-borne diseases and zoonoses may increase as well through range expansion and introduction of invasive species. It will be important in the future to investigate the effects of these multiple stressors on wildlife and local people to better predict the individual-level health risks. It is within this framework that One Health approaches offer promising opportunities to survey and pinpoint environmental changes that have effects on wildlife and human health.

This study investigated the dynamics of the accumulation and release of Hg2+ in lichens, using Evernia prunastri (L.) Ach. as a model species. Thalli were incubated with solutions containing 1, 10, and 100 µM Hg2+ and then exposed for 1, 2, 3, 6, 12, 18, and 24 months at the Botanical Garden of the University of Siena (a location free from local Hg sources). Lichen samples accumulated Hg proportionally to the exposure concentration, and after the exposure, reductions over time were evident, already starting from 1–2 months. After 24 months, samples released 72–74 (healthy thalli) to 94% (unhealthy thalli) of the accumulated Hg, but control values of untreated samples were never reached. Depending on the Hg content after the exposure, stable decreased concentrations were reached after 6–24 months. The results of this study highlight the ability of the lichen E. prunastri to reflect rapidly increasing environmental Hg concentrations, as well as to indicate an ameliorated situation (e.g., the closure of an Hg source). However, we have found evidence that an acute pollution episode can influence the content of Hg in lichens for several years.

The impacts of human activities on Zoige peatlands are poorly documented. We determined the concentrations and accumulation rates of As and Hg in a 210Pb-dated peat profile collected from this area and analyzed the correlations between accumulation rates of both As and Hg and other physicochemical properties. To reconstruct recent conditions of As and Hg, we analyzed peat sediments of Re’er Dam peatland in Zoige using 210Pb and 137Cs dating technologies. The concentrations of total As (86.38 to 174.21 μg kg−1) and Hg (7.30 to 32.13 μg kg−1) in the peat profile clearly increased after the first industrial revolution. From AD 1824 to AD 2010, the average accumulation rates were 129.77 μg m−2 yr−1 for As and 18.24 μg m−2 yr−1 for Hg. Based on our results, anthropogenic emissions significantly affected the atmospheric fluxes of As and Hg throughout the past 200 years, and As was also likely to be affected by other factors than atmospheric deposition, which needs further identification by future studies. The historical variations in As and Hg concentrations in Re’er Dam peatland in Zoige mirror the industrial development of China.

Two white lupin (Lupinus albus L.) cultivars were tested for their capacity to accumulate mercury when grown in Hg-contaminated soils. Plants inoculated with a Bradyrhizobium canariense Hg-tolerant strain or non-inoculated were grown in two highly Hg-contaminated soils. All plants were nodulated and presented a large number of cluster roots. They accumulated up to 600 μg Hg g−1 DW in nodules, 1400 μg Hg g−1 DW in roots and 2550 μg Hg g−1 DW in cluster roots. Soil, and not cultivar or inoculation, was accountable for statistically significant differences. No Hg translocation to leaves or seeds took place. Inoculated L. albus cv. G1 plants were grown hydroponically under cluster root-promoting conditions in the presence of Hg. They accumulated about 500 μg Hg g−1 DW in nodules and roots and up to 1300 μg Hg g−1 DW in cluster roots. No translocation to the aerial parts occurred. Bioaccumulation factors were also extremely high, especially in soils and particularly in cluster roots. To our knowledge, Hg accumulation in cluster roots has not been reported to date. Our results suggest that inoculated white lupin might represent a powerful phytoremediation tool through rhizosequestration of Hg in contaminated soils. Potential uptake and immobilization mechanisms are discussed.

The total Hg and methyl Hg in waters and sediments, as well as particulate total Hg (PTHg), were analyzed to study their distribution and partitioning in the Danshuei River Estuary (DRE), northern Taiwan. TOC and grain size were also determined in the sediment samples. The dissolved total Hg (DTHg) in waters ranged from 24.0 to 45.8 ng/L. The dissolved methyl Hg (DMeHg) concentrations contributed 0.6–30.4% of the DTHg pool, with the higher percentage appearing in the upper estuary. The DMeHg concentration positively correlated with the Chl.a within the estuary, suggesting that phytoplankton plays an important role in influencing the DMeHg concentration. The partitioning results indicated that DTHg chiefly dominates the THg (DTH + PTHg) pool, especially at a salinity of >15 psu region. The value of partition coefficient, log(KD), was within a range of 3.54 to 4.68, and the value linearly decreased with increasing salinity. The sediment total Hg (STHg) concentrations ranged from 80 to 379 ng/g, and most data exceeded the NOAA guidelines value (ERL < 150 ng/g), indicating that the DRE is contaminated with Hg. The STHg concentrations inversely and positively correlated with the grain size and TOC content, respectively, suggesting that sediment Hg distributions are strongly influenced by the both parameters.

Mercury can indicate the presence of deposits or mineralization, which is an important tracer element of geological processes, thus making the determination of mercury very important. Due to the low abundance of mercury in ore deposits, it is difficult to directly determine and thus pre-separation enrichment is needed. Presently, most of the separation and preconcentration methods are off-line with a low degree of automation. Graphene oxide/chitosan microspheres modified by dithizone were prepared and applied as adsorption materials for solid phase extraction column. The effect of experimental parameters including acidity, adsorbent type, and adsorption volume on the absorption efficiency was evaluated. Sampling/elution time and the sampling/elution rate during solid phase extraction were optimized. Based on these conditions, an analytical method for the determination of trace mercury in geological samples by on-line enrichment-atomic fluorescence spectrometry with solid phase extraction was established. The results show that when the pH value is 3.0, the adsorption rate of mercury is more than 90% at 5 mL/min sampling rate. The elution rate was >95% when 20 g/L of thiourea and 1.0 mol/L HNO3 were used as elution solution and elution for 1 min at the rate of 1 mL/min. The working curve showed a good linear relationship when the concentration was between 0.050 μg/L and 5.0 μg/L. The enrichment factor was 22 and the detection limit was 0.0019 μg/L. The relative error of the measured value of Hg and the reference value was less than ±13% when this method was used to determine soil and sediment national standard materials. Compared with the off-line analysis, this method has advantages such as high sensitivity and simple operation.