Levels Of Mercury Contamination Research Articles

High levels of mercury contamination in a necrophage dung beetle of the Amazon rainforest (Scarabaeidae: Scarabaeinae)

AbstractThis study represents the first evidence of mercury contamination in the family Scarabaeidae, with a close focus on Coprophanaeus lancifer, the largest copro‐necrophagous beetle in South America. This work shows the repartition of total mercury (THg) in the insect body and lays the groundwork for additional future studies.Abstract in Spanish is available with online material.

Hydrogeochemistry and Mercury Contamination of Surface Water in the Lom Gold Basin (East Cameroon): Water Quality Index, Multivariate Statistical Analysis and Spatial Interpolation

Artisanal and small-scale gold mining activities have an impact on natural resources and human health. This study addresses the assessment of surface water quality in the Lom gold basin. A combined approach of water quality index calculation, multivariate statistical analysis and spatial interpolation was used. Sampling was performed at 15 stations during low- and high-water periods in 2021 for classical physicochemical parameters and total mercury measurements. The results show that the physicochemical parameters were below drinking water standards for both periods, except for pH, total suspended solids and total mercury. These waters show a large cation deficit as well as an anion deficit. The water chemistry is controlled by precipitations and silicate dissolutions in rock that convert the water into the Ca-HCO3 and Ca-Mg-HCO3 types. The level of mercury contamination varied from acceptable to high due to high flow rates during high water that cause a dilution effect for the mercury concentration upstream and its accumulation downstream. The water quality varied from excellent to very poor with better quality during the high-water period. The Lom watershed is locally affected by physical and chemical pollution due to the abundance of suspended solids and mercury resulting from the different gold mining activities.

Relationships between maternally-transferred mercury and hatchling development, behavior, and survival in the American alligator (Alligator mississippiensis)

Mercury is a toxic and pervasive environmental contaminant that can be transferred from mother to offspring during development. Consequences of maternally-transferred mercury have been observed in vertebrate taxa, including reduced clutch viability, reduced offspring size, and behavioral alterations. These sublethal effects have been assumed to decrease survivorship, though this is seldom assessed. Here, we examined how maternally-transferred mercury interacts with incubation temperature to influence reproductive success, offspring behavior, and subsequent survival in the American alligator (Alligator mississippiensis). We collected nine clutches of eggs from a mercury contaminated reservoir on the Savannah River Site, South Carolina, and incubated eggs at either female- or male-promoting temperatures. Clutch-averaged mercury in egg yolk was high relative to other studies in crocodilians and ranged from 0.248 to 0.554 ppm compared to 0.018–0.052 ppm at a site with low levels of mercury contamination; mercury levels in hatchling blood ranged from 0.090 to 0.490 ppm (x¯ = 0.240 ppm, n = 158). We found few, mostly negligible correlations between life history traits and mercury but noted a positive relationship with egg mass, possibly mediated by correlated maternal effects such as resource provisioning. Incubation temperature exerted strong effects on hatchling phenotypes, with warmer, male-promoting temperatures producing larger and bolder hatchlings. Presumptive females, produced from cooler incubation temperatures, spent more time in warm areas during behavior trials. Hatchlings were released 10–15 days post-hatch and surveyed over eight months to assess survival. Survivorship was positively correlated with hatchling size and negatively correlated with proportional time spent in warm areas. Presumptive females had much lower survival, and overall survivorship for the eight-month period was 0.185–0.208, depending on the modelling approach. Our study suggests that, within the range of concentrations we observed, incubation temperature has a stronger effect on offspring behavior and survival than maternally-transferred mercury pollution in American alligators.

Mercury Exposure from the Consumption of Dietary Supplements Containing Vegetable, Cod Liver, and Shark Liver Oils.

Vegetable and fish oils constitute a significant part of all dietary supplements. Due to increasing environmental pollution, the raw materials used for their production may be contaminated with toxic substances, including metals. The aim of the present study was to determine the mercury (Hg) content in vegetable oils, shark liver oils, and cod liver oils. The tests conducted were to help determine the level of mercury contamination of the tested preparations and the related potential threat to human health. The amount of Hg in the tested dietary supplements was compared, and the amount of the metal consumed at various times of use was determined. A total of 36 preparations of dietary supplements available on the Polish market were used for the study. The method of atomic absorption spectrometry using the amalgamation technique was used for the determinations (AMA 254, Altec, Czech Republic). Among the sample of all of the tested preparations, the Hg concentration ranged from 0.023 to 0.427 µg/kg, with an average of 0.165 µg/kg. Differences in Hg content in the various tested preparations (shark liver oil, cod liver oil, and vegetable oils) were statistically significant. The average concentration of Hg in the vegetable oils (0.218 µg/kg) was more than twice that of the cod liver oils (0.106 µg/kg) and shark liver oils (0.065 µg/kg). In none of the tested preparations did the amount of Hg exceed the acceptable standard for dietary supplements (0.10 mg/kg). The analysis showed that the Hg content in vegetable oils, shark liver oils, and fish oils from the Polish market is at a low level, guaranteeing the safety of their use, and as such, they do not pose a threat to health.

Total mercury determination in bivalves Anadara tuberculosa sold in open markets from Quito, Ecuador

This study aimed to quantify the amount of total mercury in bivalves Anadara tuberculosa supplied from Esmeraldas Province and sold in markets in the Metropolitan District of Quito, Ecuador. The determined total mercury concentration was compared to the permissible limits established by the European Commission and World Health Organization-Food and Agriculture Organization and health risk subsequently assessed. Sampling was conducted in five open markets and involved collecting fifteen specimens from each market. Total mercury was measured through cold vapor atomic fluorescence spectrophotometry. Results showed that samples did not exceed the total mercury threshold value (0.5 mg kg−1). However, samples of Anadara tuberculosa from the Ofelia market, which receives fresh products from Eloy Alfaro canton, contained the highest mean levels of mercury contamination, 0.055 mg kg−1. This result could be associated to the influence of illegal mining activity in this area. In addition, methylmercury potential non-carcinogenic risk for consumers exceeded the threshold limit (>1) established by the US Environmental Protection Agency. The daily consumption rate (Rclim) was determined to be 26.61–38.50 g for a child weight of 14.5 kg, and 128.44–185.84 g for an adult weight of 70 kg. Thus, consuming a higher amount of Anadara tuberculosa could negatively affect human health.

Mercury contamination level is repeatable and predicted by wintering area in a long-distance migratory seabird

The environmental presence of mercury has dramatically increased over the past century, leading to increased uptake, especially by top predators such as seabirds. Understanding the exact sources of contamination requires an individual-level approach, which is especially challenging for species that migrate. We took such an approach and located the wintering areas of 80 common terns (Sterna hirundo) through tracking, and, across years, collected feathers grown in those areas to assess their mercury levels using atomic absorption spectrometry. Although feathers of males and females did not differ in their mercury level, we found the average feather mercury level to be highest in birds wintering in the Canary Current (3.87 μg g−1), medium in birds wintering in the Guinea Current (2.27 μg g−1) and lowest in birds wintering in the Benguela Current (1.96 μg g−1). Furthermore, we found considerable inter-annual fluctuations in feather mercury levels, a within-individual repeatability of 41%, that the mercury levels of 17% of feather samples exceeded the admitted toxicity threshold of 5 μg g−1, and that the overall mean concentration of 3.4 μg g−1 exceeded that of other published reports for the species. Further studies therefore should assess whether these levels lead to individual-level carry-over effects on survival and reproductive performance.

Mercury contamination levels in rivers and resident wells in Padesa and Sepukur Villages, Lantung District, Sumbawa Regency, Indonesia

Traditional mining business activities for processing gold ore in Lantung District are amalgamated using mercury (Hg) from 2015 to 2021 and are still ongoing. On average, there are ten to fifteen logs in each village, the waste being discharged only through ditches or small streams leading to rivers. Mercury that enters the aquatic environment will experience precipitation, dilution, and dispersion, absorbed by organisms living in these waters. Mercury water will be converted into methyl mercury by certain bacteria called biomethylation. In methyl-mercury (MeHg), mercury has toxic properties, firm binding, and high solubility. If consumed by biota, it will experience bioaccumulation in the body, and if consumed by humans for a long time, it can cause various types of diseases up to death. This study aims to determine mercury levels in the rivers and wells of residents in Sepukur Village and Lantung District. The research method is a survey with a sampling technique that is purposive sampling based on the distance from the logs to the residents' wells and rivers. The results showed that mercury levels in the Padesa Village river and springs were 0.002 mg/L. The average mercury level in the Sepukur Village River is 0.0004 mg/L, dug wells are 0.0014 mg/L, and drilled wells are 0.0024 mg/L. It can be concluded that the mercury levels in the springs in the village of Sepukur exceed the standard, and the river is classified in class 3. Mercury levels in the drilled wells of the residents of Sepukur Village exceed the standard, and the dug wells are still within the safe limits of the standard. Meanwhile, the river level in the Village of Sepukur is still relatively safe.

Solid biofuels properties of Miscanthus X giganteus cultivated on contaminated soil after phytoremediation process

Following the objectives of the 2030 climate and energy framework as well as the European Green Deal strategy to 2050, renewable energy sources have been defined as an important factor in the process of climate change mitigation. Renewable energy sources are the basis of the aspirations of the EU to achieve low-carbon energy self-sufficiency. Under the classification of renewable energy sources biomass obtained by cultivating energy crops is also included. In order to avoid collisions between energy production and food/feed production, the cultivation of energy crops should be based on marginal soils, which also include soil contaminated by heavy metals. The use of energy crops in the process of phytoremediation is a multifunctional methodology that manifests itself through the cleaning of contaminated soil with the biomass production. The usefulness of using certain biomass types in the ignition process is valorized by the determination of biomass properties. The aim of this three years’ investigation was to analyze the biomass quality (proximate and ultimate analysis, calorific values, micro and macroelements) of Miscanthus x giganteus cultivated on soils with three cadmium (Cd) and mercury (Hg) contamination levels. All analyzed parameters, except Cd, K and Cr, are compatible with or have only expected differences from the literature data and/or ISO 17225–1:2014 norm for solid biofuels. The values of ash, volatile matter, C content and lower heating value as one of the most important energy parameters, are in the range 1.35–3.66%, 86.28–90.39%, 46.34–49.91% and 16.24–16.93 MJ/kg respectively.

The Mercury Content in the Upper Layers of Soils in the Selected Area of the Masovian Landscape Park

Due to the high toxicity of the element itself and its compounds, mercury poses a significant threat to the human natural environment, in particular to the soil and water environment. An additional risk is the possibility of mercury accumulation in various elements of the environment. Soil is one of the most important elements of the natural environment and is the main link in the mercury cycle. The cycle of this element is related to both the natural processes taking place in the environment and human activity. The presence of mercury in the natural environment poses a particularly high risk of its re-accumulation as a result of its re-emission. The aim of the research was to determine the mercury content in the upper layers of soils collected from the area and buffer zone of the Mazowiecki Landscape Park as a potential source of this element’s re-emission to the environment. The paper presents the results of research on mercury content in the upper soil layer from the areas adjacent to the communication routes running through the area of the Mazowiecki Landscape Park and its buffer zone. The mercury content in the analyzed soil samples collected from the area of the Mazowiecki Landscape Park ranged from 0.082 mgHg·kg−1 dm to 0.183 mgHg·kg−1 dm, and in the soils from the cover, these values were slightly higher and ranged from 0.125 mgHg·kg−1 dm up to 0.362 mgHg·kg−1 dm. In order to avoid uncontrolled re-emission and, consequently, possible accumulation of this element in the environment, it is necessary to continue monitoring the level of mercury contamination, among others, in soil.

Heavy metal contamination of Hg and Pb in water, sediment and Violet Batissa (Batissa violacea Lamark, 1818) meat in Teunom River, Aceh Jaya Regency, Indonesia

Violet Batissa (Batissa violacea) is an important economic organism on the west-south coast of Aceh, because it is relatively high consumed by the community. However, gold mining activities carried out around the watershed are estimated to pollute the river and cause B. violacea to also be affected. The purpose of this study was to determine the level of mercury (Hg) and Lead (Pb) contamination in clam meat in Teunom, Aceh Jaya Regency. The research was conducted from June to September 2021. Sampling of clam was done by purposive sampling method. Hg and Pb were analyzed in clam meat using the Atomic Absorption Spectrophotometer (AAS) method. The results of the analysis showed that the Hg content in clam meat was between 0.12-0.63 mg/kg (mean 0.35±0.26 mg/kg), water 0.0026-0.0103 mg/kg (mean 0.0052±0.004 mg/kg), and sediment 1.3224-3.8767 mg/kg (mean 2.2324±1.427 mg/kg). Furthermore, the results of the analysis showed that the Pb content in clam meat, water and sediment had the same value at 3 stations with values 0.0002±0 mg/kg, 0.0003±0 mg/kg, and 0.0002±0 mg/kg, respectively. The conclusion of this study is that the Hg content in water and sediment has exceeded the threshold, while the clam meat is still in good quality standards. The Pb content in clam meat, water and sediment were also in good quality standards. Based on our study, B. violacea is still safe for consumption, while the water has been polluted and is recommended not to be utilized for human consumption.Keywords:Heavy metalRiverWaterSedimentBatissa violacea

Features of the immune profile and polymorphism of candidate genes in children population of an industrially developed region with excessive contamination of the biological medium with mercury

Introduction. Analyzing the negative impact of technogenic chemicals on the health of the children’s population of industrially developed regions is an urgent problem of preventive medicine. Excessive accumulation of mercury in the human body causes disadaptation changes in the immune regulation of physiological processes. Therefore, the analysis of the features of the immune profile associated with polymorphic variants of candidate genes as markers of early disorders of the child population’s health status is relevant in preserving the health of the population of industrialized regions. Materials and methods. A clinical and laboratory examination of the biological environment of 215 children aged 4-6 years was carried out. The observation group consisted of 133 people living in an industrially developed region. The comparison group consisted of 82 people living in a relatively clean territory. The level of contamination of the biological medium with mercury was determined by inductively coupled plasma mass spectrometry. Identification of CD3+CD4+ -, CD3+CD8+- and CD19+ - lymphocytes was performed by flow cytofluorometry. The study of the phagocytic activity of leukocytes was carried out using formalized ram erythrocytes. The level of IgG production was determined using radial immunodiffusion by Mancini, specific IgG to mercury was carried out using allergosorbent testing with an enzyme label. Identification of single-nucleotide polymorphic variants (SNP) of the GSTA4 (rs3756980), FOXP3 (rs3761547), MTR (rs1805087), TERT (rs10054203) genes was carried out by real-time PCR. Results. Children living near the territory of the chemical industry enterprise in conditions of mercury exposure at a level not exceeding hygienic standards are characterized by an increased level of mercury contamination of urine, exceeding the reference level and the level of the comparison group by 1.8 times (p<0.05). The immune profile of children in the observation group is characterized by a decrease in the CD4+/CD8+ immunoregulatory index due to the decline of CD3+CD4+ helpers and hyperproduction of CD3+CD8+ cytotoxic lymphocytes, inhibition of the phagocytic activity of leukocytes (percentage of phagocytosis, phagocytic number, phagocytic index) against the background of an increase in CD19+ lymphocytes, serum IgG and a marker of specific sensitization - IgG to mercury (p<0.05). Changes in the immune profile of children with an increased level of mercury contamination are associated with the C-allele and TC-heterozygous and CC-homozygous genotypes of the GSTA4 gene (rs3756980), the C-allele and CC-genotype of the FOXP3 gene (rs3761547), the A-allele and AA-genotype of the MTR gene (rs1805087) (OR>1, p<0.05), the G-allele and GG-genotype of the TERT gene (rs10054203) (p<0.05). These genes are responsible for the features of detoxification processes, immunoregulation and longevity programs. Conclusion. The established features of cellular (decrease in CD4+/CD8+ due to CD3+CD4+ deficiency with simultaneous increase in CD3+CD8+, inhibition of phagocytosis) and humoral (hyperproduction of IgG, specific IgG to mercury, CD19+) immunity associated with polymorphic variants of the glutathione S-transferase GSTA4 (rs3756980), transcription factor FOXP3 (rs3761547), MTR (rs1805087), TERT telomerase (rs10054203) in children with excessive contamination of the biological medium with mercury, a complex of immune and genetic markers of the effect and sensitivity of mercury exposure is formed.

Clandestine gold mining and pollution risks of sediments from Bagoue river (Niger watershed, Cote d’Ivoire)

Mercury used in gold amalgamation is a global concern and a major source of contamination and dispersion in environmental aquatic of Cote d’Ivoire, mainly in the North where clandestine gold mining activities are a local interest. The aim of this study was to assess the level of total mercury (Hg-T) contamination of sediments from Bagoue River. Water and sediments samples were collected during wet and dry seasons from six stations differently impacted. Spatial and seasonal variations in physical and chemical parameters were assessed. Results revealed that the level of Hg-T in water was 0.68±0.03 µg.L-1 and in the sediments, dry weight concentration was 0.064±0.01 mg.kg-1. The Hg-T concentration in sediments was significantly higher (p< 0.05) during the dry season (0.089±0.053 mg.kg-1) than that recorded in the wet season (0.064±0.039 mg.kg-1). Ultimately, strong and positive correlations have been observed between Hg-T in sediments and sandy sediments (r = +1), as well as suspended materials (r = +0.85). The pollution status of mercury in sediments according to the geo-accumulation index was uncontaminated (- 47.03) at all the seasons whereas enrichment factor has been moderate over climatic seasons at downstream stations heavily impacted by gold mining. The sandy texture of the River sediments favours the infiltration of mercury and its accumulation in groundwater. As a rate, the health risks associated with the consumption of these waters are potentially high.

ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS

Female birds whose bodies contain environmental contaminants produce eggs with shells that are likewise contaminated, making bird eggshells appropriate indicators for monitoring environmental toxins. Common contaminants include organic mercury compounds, especially methylmercury, which are known to bioaccumulate and biomagnify in the food chain. Black storks (Ciconia nigra) predominantly consume fish and are thus at risk for high mercury intake. In this study, we used eggshells of black storks as a proxy to reconstruct the concentration levels and distribution of mercury, a well-known toxic element, in various parts of Latvia. Preliminary analyses have shown that deposition levels of mercury vary in different parts of the eggshell. Specifically, the shell and shell membrane differ in their level of mercury contamination by an average factor of nine; therefore, we measured the mercury content in these components separately whenever possible. We analysed 34 eggshell samples from nesting sites in Latvia using an atomic absorption spectrometer with Zeeman correction Lumex RA-915M and its attachment for pyrolytic combustion. We found that mercury concentrations varied from 5 to 22 ng/g in eggshells and from 42 to 293 ng/g in shell membranes. We discuss possible contamination sources and reasons behind this disparity.

KARAKTERISTIK SIFAT KIMIA TANAH DAN KANDUNGAN MERKURI PADA LAHAN BEKAS TAMBANG EMAS DAN LAHAN PERKEBUNAN KELAPA SAWIT (Elaeis guineensis Jacq.)

The present study was conducted in Tebing Tinggi Village, Pulau Punjung Sub-district, Dharmasraya District was motivated by a desire to exploit land resources, especially open access land that was formerly a gold mine by cultivating oil palm plants. The objectives of this study were to determine the characteristics of soil chemical properties, the soil fertility level, and the level of mercury (Hg) contamination in former gold mining land by compared with the soil chemical fertility of oil palm plantations. The research method was a survey by purposive sampling. The Soil sampling for analysis of soil chemical properties was carried out by drilling of 0-40 cm deep with 12 sample points divided into 4 locations, where 3 locations in the former gold mine area that were grouped into three segments, namely segments 1, 2 and 3 and one location was in oil palm land. The parameters of soil chemical properties observed were pH, Al-dd, C-organic, C / N Ratio, N, P, K and Hg (Mercury). The results of this research, shows that the characteristics of soil chemical properties in the former gold mining area have decreased the level of soil fertility, characterized by the very low pH value and C-organic content, ​​so that the nutrients contained in the land are very limited when compared to the soil fertility in oil palm land. This is indicated by the fact that the oil palm land has a high C-organic content and a moderate level of N-total content. The utilization of the land resources of the former gold mine, it is necessary to do land improvementsin terms of soil physically, chemically and biologically.

Pengembangan Sensor Kimia Berbasis Strip Tes untuk Deteksi Logam Berat Merkuri pada Sampel Produk Jamu

The use of plants as a traditional medicine in the modern era is still in high demand. One of the herbs commonly used by Indonesian is analgesic herbal medicine. The safety aspect of herbal medicine should be considered, such as heavy metal contamination. Mercury is the typical heavy metal found in polluting herbal plants. The maximum mercury level allowed in a medicinal preparation has been regulated by BPOM RI, as much as ≤ 0.5 ppm. A high level of mercury contamination causing toxic effects on the body due to protein precipitation, which inhibits enzyme activity and acts as a corrosive material. A technology that allows the detection of mercury is a chemical sensor. The strip test is optimal if the reagent 1-(2-thiazolyl azo)-2-naphthol (TAN) concentration at 1000 ppm and the sample has been confirmed at pH 7. The results of the strip test characterization showed that the response time was in the range of minutes 17 to 24, the use time of the test strips for 28 days if stored in room temperature and 29 days if stored at in refrigerator temperature, linearity with r = 0.998, Vx0 = 3.96%, p-value = 0.00000172, LOD = 0.102 ppm and LOQ = 0.306 ppm, interference value &lt;5%, precision with RSD 6.54%, and accuracy with the value of % recovery 98.007%. T-test analysis showed p= 0.872, meaning no significant difference between the application of TAN-based test strips with the ICP-AES method.

Background concentrations of mercury in Australian freshwater sediments: The effect of catchment characteristics on mercury deposition

Waterways in the Southern Hemisphere, including on the Australian continent, are facing increasing levels of mercury contamination due to industrialization, agricultural intensification, energy production, urbanization, and mining. Mercury contamination undermines the use of waterways as a source of potable water and also has a deleterious effect on aquatic organisms. When developing management strategies to reduce mercury levels in waterways, it is crucial to set appropriate targets for the mitigation of these contaminated waterways. These mitigation targets could be (1) trigger values or default guideline values provided by water and sediment quality guidelines or (2) background (pre-industrialization) levels of mercury in waterways or sediments. The aims of this study were to (1) quantify the differences between existing environmental guideline values for mercury in freshwater lakes and background mercury concentrations and (2) determine the key factors affecting the spatial differences in background mercury concentrations in freshwater lake systems in Australia. Mercury concentrations were measured in background sediments from 21 lakes in Australia. These data indicate that background mercury concentrations in lake sediments can vary significantly across the continent and are up to nine times lower than current sediment quality guidelines in Australia and New Zealand. This indicates that if waterway managers are aiming to restore systems to ‘pre-industrialization’ mercury levels, it is highly important to quantify the site-specific background mercury concentration. Organic matter and precipitation were the main factors correlating with background mercury concentrations in lake sediments. We also found that the geology of the lake catchment correlates to the background mercury concentration of lake sediments. The highest mercury background concentrations were found in lakes in igneous mafic intrusive regions and the lowest in areas underlain by regolith. Taking into account these findings, we provide a preliminary map of predicted background mercury sediment concentrations across Australia that could be used by waterway managers for determining management targets.

Mercury content of sarotherodon melanotheron and chrysischthys nigrodigitatus of Lake Nokoue and Porto Novo lagoon in Benin

Ratification of Minamata Convention by Bénin requires identification of contaminated sites and preservation of health. In this context, the Ministry of Living Environment and Sustainable Development supported the study by making its mercury analyzer DMA80 available. The study aims to identify the level of mercury contamination in two highly valued fish species caught in one of the most productive water bodies where mercury is reported. So, three monthly sample collection campaigns were carried out from April to juin 2018 at nine (09) sites. The back flesh of sarotherodon melanotheron and chrysischthys nigrodigitatus of lake Nokoue and Porto Novo lagoon was analyzed by direct mercury analyzer (DMA 80). it Its operating principle is atomic absorption after thermal decomposition coupled with a gold sensor. The average mercury contents are 20.8 ± 15.5 μg / kg and 6.5 ± 3.8 wet μg / kg weight respectively for Chrysichthys nigrodigitatus and Sarotherodon melanotheron. The highest values obtained at the Porto-Novo bridge for both species remain well below the standard (0.5 mg / kg wet weight). With consumption habits of fish in Benin, the weekly exposure doses seem to be much lower than WHO recommendation. However, deepened studies are needed.Keywords: Fish, mercury, spatial distribution, NoKoué Lake, Porto-Novo Lagoon.

The Relationship between Cytokine Profile and Hypertension among the Mercury-Exposed Residents of Temirtau Region in Central Kazakhstan.

Background:Mercury is a common environmental contaminant and it is also harmful to human health. Among reported toxicities, its harmful effect on hypertension is poorly documented. In Kazakhstan, Temirtau city has been reported to have a high level of mercury contamination from an acetaldehyde production factory. Therefore, we aimed to investigate the association between serum profile of cytokines and the development of hypertension among the exposed citizens.Methods:We selected 81 individuals for study, out of them, 41 exposed ones suffered hypertension and 40 – unexposed healthy controls in villages Chkalovo, Samarkand, Gagarinskoye, Tegiszhol, Rostovka in 2016. Mercury content in urine was studied by inversion voltammetry. Cytokine levels of IL-2, IL-6, IL-10 and TNF-α were determined by ELISA.Results:Mercury-exposed citizens, especially those with hypertension, had significantly higher concentrations of inflammatory cytokines TNF-α, IL-2, IL-6 and anti-inflammatory cytokine IL-10 as compared to the unexposed population. The dependence of the mercury level in urine on IL-2 content was also detected. Therefore, chronic low doses of exposure to mercury were associated with an increase in serum levels of immune markers and with the increased risk of hypertension.Conclusion:The presence of mercury in the body probably affected the expression of interleukin-2, one of the main cytokines that coordinate immune response.

Survey of Methylmercury Exposures and Risk Factors Among Indigenous Communities in Guyana, South America.

Background.Gold mining activities in forested areas across Guyana have been a common practice for more than a century. The intensification of artisanal and small-scale gold mining (ASGM) in recent decades caused by global market demand is contributing to the mobilization of mercury into aquatic systems. Indigenous populations who consume high levels of locally sourced fish are greater at risk for methylmercury poisoning from ingestion of contaminated fish.Objectives.The aim of the present study was to investigate the levels of mercury contamination and identify the risk factors associated with hair mercury levels in four indigenous communities in Guyana.Methods.Concentrations of total mercury were measured in hair samples from 99 participants from four indigenous communities in the south Rupununi region in Guyana. The findings of this study were compared with those of previous studies to assess the prevalence of mercury contamination in indigenous communities across Guyana.Results.Hair mercury levels were found to be above the World Health Organization (WHO) reference value for residents who live close to ASGM activities and who consume high quantities of locally sourced fish. Our results are not only consistent with those obtained in previous studies, but also evidence that mercury poisoning has become a generalized problem for indigenous communities in Guyana.Conclusions.Fish is the main source of protein for many riverine communities and consumption of mercury-contaminated fish poses a serious health hazard for these vulnerable populations. The situation is especially dire for community members of Parabara with 100% of participants showing elevated (>15 μg*g−1) hair mercury levels. It is therefore crucial that Parabara residents be evaluated by relevant health agencies for clinical symptoms related to mercury toxicity.Participant Consent.ObtainedEthics Approval.The study protocol was approved by the Institutional Review Board of the Ministry of Public Health, Guyana.Competing Interests.The authors declare no competing financial interests.

Main drivers of mercury levels in Southern Ocean lantern fish Myctophidae

Myctophids are the most abundant fish group in the Southern Ocean pelagic ecosystem and are an important link in the Antarctic marine food web. Due to their major ecological role, evaluating the level of mercury (Hg) contamination in myctophids is important as a step towards understanding the trophic pathway of this contaminant. The concentrations of total Hg were determined in muscle, gill, heart and liver tissue of 9 myctophid species to quantify tissue partitioning variability between species. Organic Hg concentration and proportion in muscle was also determined. Hg concentrations were higher in the liver and heart than in muscle and gills, but the proportion of organic Hg was almost 100% in muscle, indicating that the main uptake route for Hg is through the diet. Most of the species analysed have similar vertical and horizontal distributions, and similar feeding modes and prey. Geographical and temporal variability of Hg concentrations was examined using samples from 3 different sampling cruise (2007/08, 2015/16 and 2016/17) and 2 locations (South Georgia and South Orkneys Islands). Our results appear to indicate a decreasing trend in Hg contamination over the last decade, particularly gill tissue, which is in agreement with a previous study on squid from the same region. There was no significant variability in Hg concentration between the different sampling locations. Hg levels were consistent with values reported previously for myctophids around the world, indicating low global-scale geographic variability. A positive relationship between fish size and Hg concentration was found for most species, with the exception of Electrona antarctica females, which may be explained through Hg elimination by egg laying. We estimate that myctophids collectively comprise a Southern Ocean mercury ‘reserve’ of ≈1.82 metric tonnes.