High Mercury Concentrations Research Articles

Melastoma malabathricum Fruit Extract-Mediated Synthesis of Silver Nanoparticles with Sensing Ability for High Concentrations of Mercury (II) Nitrate

A strategic approach was developed to synthesize silver nanoparticles from AgNO 3 using Melastoma malabathricum seed extract. The reaction of silver ions with the organic compounds in the seed extract proceeded smoothly at room temperature without any additional capping agent. The appearance of an absorption peak around 427 nm provided evidence for the presence of silver nanoparticles in the reaction mixture. A diluted solution of the silver nanoparticles was treated with various concentrations of mercury (II) nitrate solutions and the resulting reaction was monitored using UV-Vis spectrophotometry

Prediction of mercury bioavailability to common carp (Cyprinus carpio L.) using the diffusive gradient in thin film technique

The mercury bioaccumulation by common carp (Cyprinus carpio L.) tissues (gills, skin, eyes, scales, muscle, brain, kidneys, liver, and spleen) and the capability of the diffusive gradient in thin film (DGT) technique to predict bioavailability of mercury for individual carp's tissues were evaluated. Carp and DGT units were exposed to increasing concentrations of mercury (Hg2+: 0 μg L−1, 0.5 μg L−1, 1.5 μg L−1 and 3.0 μg L−1) in fish tanks for 14 days. In the uncontaminated fish group, the highest mercury concentration was determined in the muscle tissues and, in fish groups exposed to mercury, the highest mercury concentration was determined in the detoxification (kidneys) and input (gills) organs. A strong and positive correlation between the rate of mercury uptake by the DGT technique and the rate of mercury accumulation by fish tissues (gills, skin, scales, and eyes) was observed.

Mercury Exposure: Protein Biomarkers of Mercury Exposure in Jaraqui Fish from the Amazon Region.

This study presents data on the extraction and characterization of proteins associated with mercury in the muscle and liver tissues of jaraqui (Semaprochilodus spp.) from the Madeira River in the Brazilian Amazon. Protein fractionation was carried out by two-dimensional electrophoresis (2D-PAGE). Mercury determination in tissues, pellets, and protein spots was performed by graphite furnace atomic absorption spectrometry (GFAAS). Proteins in the spots that showed mercury were characterized by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The highest mercury concentrations were found in liver tissues and pellets (426±6 and 277±4μgkg-1), followed by muscle tissues and pellets (132±4 and 86±1μgkg-1, respectively). Mercury quantification in the protein spots allowed us to propose stoichiometric ratios in the range of 1-4 mercury atoms per molecule of protein in the protein spots. The proteins characterized in the analysis by ESI-MS/MS were keratin, type II cytoskeletal 8, parvalbumin beta, parvalbumin-2, ubiquitin-40S ribosomal S27a, 39S ribosomal protein L36 mitochondrial, hemoglobin subunit beta, and hemoglobin subunit beta-A/B. The results suggest that proteins such as ubiquitin-40S ribosomal protein S27a, which have specific domains, possibly zinc finger, can be used as biomarkers of mercury, whereas mercury and zinc present characteristics of soft acids.

Mercury speciation and mobility in soils of industrial areas in the Baikal region, Southern Siberia, Russia

Mercury speciation and mobility in soils as a result of the chlor-alkali and metallurgy industries in Baikal region was investigated. In the period from 1973 to 1998, chlorine and alkali at the plant were produced using metallic mercury. Within the period of plant operation, the total mercury emissions release to the environment amounted to 1327 tons. The former Angarsk metallurgic plant for the production of arsenic is another technogenic source of mercury. The plant was shut down in 1949, but the technogenic dumps with high concentrations of arsenic, mercury and another heavy metals were located in the town for more than 60 years. These plants are located on the banks of the Angara River and are significant sources of technogenic mercury for the environment of the Baikal region. Mercury speciation was studied in soils near these plants. Mercury species were extracted by sequential extraction, and included water-soluble, acid-soluble, organic, tightly bound and sulfide fractions. High mercury concentrations were found in organic (41–61%) and tightly bound (38–56%) fractions in soils near the chlor-alkali plant. For the metallurgical plant soils, mercury was mainly found in the tightly bound (40–64%) and sulfide (31–51%) fractions. Mercury concentrations in mobile water and acid-soluble fractions of soils were low (0.17–2.27 and 0.04–1.06%, respectively). Such mercury distribution in the fractions was dependent on the primary mercury species that entered the soils from the two technogenic sources. The results indicate high mercury immobilization in soil and low potential bioavailability by plants.

Mercury emissions from dynamic monitoring holes of underground coal fires in the Wuda Coalfield, Inner Mongolia, China

The Wuda Coalfield, Inner Mongolia, China, is one of the largest coalfields suffering from coal fires in China, and has experienced fires for >50years. With the aim of observing the active state of underground coal seam fires to protect the main roadways of the coal mine, 44 drill holes were drilled in five fire areas of the Suhaitu coal mine to monitor gas emissions. A LumexRA-915+ Portable Mercury Analyzer was used to measure mercury concentrations in the exhaust gas. The drill holes exhibited high gaseous mercury concentrations, with an average of 4165ng/m3 (34–62,513ng/m3, n=1584), which was 45 times higher than that measured in the near-surface atmosphere around the drill holes. This finding indicates that the mercury emissions originate from underground coal fires. Furthermore, mercury concentration has a positive correlation with CO content and gas temperature, implying that mercury has the potential to act as a supplementary coal-fire index gases to monitor the prevailing underground coal fire in north China on the basis of traditional indicators. Whether it can perform satisfactorily in practical applications requires further comprehensive study.

Coupling process study of lipid production and mercury bioremediation by biomimetic mineralized microalgae

Considering the high concentration of mercury in industrial wastewater, such as coal-fired power plants and gold mining wastewater, this research study investigated the coupling process of lipid production and mercury bioremediation using microalgae cells. Chlorella vulgaris modified by biomimetic mineralization. The cultivation was divided in two stages: a natural cultivation for 7days and 5days of Hg2+ addition (10–100μg/L) for cultivation at different pH values (4–7) after inoculation. Next, the harvested cells were eluted, and lipid was extracted. The fluorescein diacetate (FDA) dye tests demonstrated that the mineralized layer enhanced the biological activity of microalgae cells in Hg2+ contaminated media. Hg distribution tests showed that the Hg removal capacity of modified cells was increased from 62.85% to 94.74%, and 88.72% of eluted Hg2+ concentration was observed in modified cells compared to 48.42% of raw cells, implying that more mercury was transferred from lipid and residuals into elutable forms.

Intentional ingestion of elemental mercury requiring multi-step decontamination and prophylactic appendectomy: a case report and treatment proposal

Background: Ingestion of elemental mercury (Hg0) is considered non-toxic. After massive ingestion, local intestinal complications may develop: retention within appendix is quite frequent but treatment is debated. We describe a case of intentional ingestion of Hg0 requiring multi-step decontamination and prophylactic appendectomy.Case detail: A 19-year-old woman was admitted to ED for abdominal pain. History revealed ingestion of large amount of Hg0 as suicide attempt. To prevent absorption, facilitate elimination, and avoid complications a conservative approach was started. Due to inefficacy of initial maneuvers colonoscopy with irrigation/aspiration was performed, repeated whole bowel irrigation was continued and second colonoscopy was performed to clean residual metal. Abdominal plain films confirmed the presence of retained mercury within the appendix in asymptomatic patient. To reduce risk of appendicitis, potential perforation, and possibly systemic toxicity, a prophylactic laparoscopic appendectomy was performed at day 5 with removal of all retained mercury without peritoneal spillage. Highest mercury concentration was 22.7 mcg/L in serum (1-4.5 mcg/L) and 5.1 mcg/L in urine (0.1–5 mcg/L).Conclusions: After ingestion, metal retention in appendix is quite frequent. Evidence about optimal treatment are different and based on case reports. A multi-step approach with multidisciplinary evaluation tailored to the patient is suggested.

Atmospheric dust deposition on soils around an abandoned fluorite mine (Hammam Zriba, NE Tunisia)

The present study focuses on the eolian dispersion and dust deposition, of major and trace elements in soils in a semi-arid climate, around an old fluorite (CaF2) and barite (BaSO4) mine, located in Hammam Zriba in Northern Tunisia. Ore deposits from this site contain a high amount of metal sulphides constituting heavy metal pollution in the surrounding environment.Samples of waste from the surface of mine tailings and agricultural topsoil samples in the vicinity of the mine were collected. The soil samples and a control sample from unpolluted area, were taken in the direction of prevailing northwest and west winds. Chemical analysis of these solids was performed using both X-ray fluorescence and X-ray diffraction. To determine the transfer from mine wastes to the soils, soluble fraction was performed by inductively coupled plasma and ionic chromatography.The fine grained size fraction of the un-restored tailings, still contained significant levels of barium, strontium, sulphur, fluorine, zinc and lead with mean percentages (wt%) of 30 (calculated as BaO), 13 (as SrO), 10 (as SO3), 4 (F), 2 (Zn) and 1.2 (Pb). Also, high concentrations of cadmium (Cd), arsenic (As) and mercury (Hg) were found with an averages of 36, 24 and 1.2mgkg−1, respectively. As a result of the eolian erosion of the tailings and their subsequent wind transport, the concentrations of Ba, Sr, S, F, Zn and Pb were extremely high in the soils near to the tailings dumps, with 5%, 4%, 7%, 1%, 0.8% and 0.2%, respectively. Concentration of major pollutants decreases with distance, but they were high even in the farthest samples. Same spatial distribution was observed for Cd, As and Hg. While, the other elements follow different spatial patterns.The leaching test revealed that most elements in the mining wastes, except for the anions, had a low solubility despite their high bulk concentrations. According the 2003/33/CE Decision Threshold, some of these tailings samples were considered as hazardous. Furthermore, other waste samples, considered non hazardous, were not inert. In contrast, the SO42-, Ba, Pb and Sb leachable contents measured in most of the soil samples were relatively high, exceeding the inert threshold for landfill disposal of wastes.

Bioregeneration of spent mercury bearing sulfur-impregnated activated carbon adsorbent.

Among various adsorbents studied, sulfur-impregnated activated carbon is one of the most promising adsorbents for mercury removal from flue gas. However, a large amount of spent activated carbons containing high content of mercury are generated after adsorption. To make the adsorption a more viable option, the regeneration and reuse of the spent activated carbon should be considered. The purpose of this study is to develop a novel technique for bioregeneration of sulfur-impregnated activated carbons after adsorption of mercury from flue gases by sulfur-oxidizing bacteria. The optimal operating parameters for this bioregeneration process were studied using central composite design (CCD) and response surface methodology (RSM). Results showed that the sulfur oxidation rate was increased with increasing activated carbon dosage. Furthermore, the increase of inoculum size only caused a slight increase of sulfur oxidation rate in the bioregeneration. The maximum mercury removal efficiency of more than 50% was obtained at 10% (w/v) activated carbon dosage and 20% (v/v) inoculum size. After the bioregeneration process, Brunauer-Emmett-Teller (BET) surface area and micropore volume of spent activated carbon increased due to the bio-oxidation of mercury bearing sulfur on the surface of activated carbons.

Distribution of Mercury Concentrations in Tree Rings and Surface Soils Adjacent to a Phosphate Fertilizer Plant in Southern Korea.

This study aimed to determine mercury concentrations in tree rings and surface soils at distances of 4, 26 and 40km from a fertilizer plant located in Yeosu City, Korea. Mercury concentrations in all tree rings were low prior to the establishment of the plant in 1977 and became elevated thereafter. The highest average mercury concentration in the tree rings was 11.96ngg-1 at the Yeosu site located nearest to the plant, with the lowest average mercury concentration of 4.45ngg-1 at the Suncheon site furthest away from the plant. In addition, the highest mercury content in the surface soil was 108.51ng cm-3 at the Yeosu site, whereas the lowest mercury content in the surface soil was 31.47ng cm-3 at the Suncheon site. The mercury levels decreased gradually with increasing distance from the plant.

Brine shrimp grazing and fecal production increase sedimentation to the deep brine layer (monimolimnion) of Great Salt Lake, Utah

Great Salt Lake (Utah) has a monimolimnion with high concentrations of salts, particulate matter, nutrients, and mercury. To test the importance of brine shrimp (Artemia franciscana) grazing on particulate matter flux, we created salinity gradients in 160-cm high columns, reflecting the lake’s gradient. Two experiments were performed in replicated columns with or without Artemia. Sediment traps were positioned at the bottoms of the mixolimnion (95 cm), chemolimnion (105 cm), or monimolimnion (140 cm). We hypothesized that because of the high salt densities of the monimolimnia, greater accumulation of sediments would be in the lower chemocline, than in the monimolimnia. The presence of Artemia significantly decreased chlorophyll, total nitrogen, and total phosphorus in the mixolimnion and increased particulate matter collected in sediment traps by 28–90%. As hypothesized, the largest increase of sedimenting material was at the top of chemocline, but only in the absence of Artemia. When present, the largest increase of collected matter was in the bottom traps. Artemia significantly decreased the molar TN:TP ratio of collected material, suggesting nitrogen-deficient fecal material. The experiments demonstrated the importance of Artemia grazing for increasing material flux from the mixolimnion to the bottom, and determining the stoichiometry of accumulated material.

Polycyclic aromatic hydrocarbons and heavy metals in the Cispata Bay, Colombia: A marine tropical ecosystem

The concentrations of polycyclic aromatic hydrocarbons and heavy metals were evaluated in shallow sediments, water, fish and seabird samples from the Cispata Bay, Colombia. The heavy metals concentrations in the sediment was in the following order: Cu>Pb>Hg>Cd. The heavy metal concentration was different (p<0.05) in juvenile and adult birds. High concentrations of mercury were registered in the seabird (10.19±4.99mgkg−1) and fish (0.67μgg−1) samples. The total concentration of polycyclic aromatic hydrocarbons ranged from 7.0–41ngg−1 in sediment, 0.03–0.34ngmL−1 in water samples, 53.24ngg−1 in fish, and 66ngg−1 in seabirds. The high concentrations of heavy metals in seabirds may be explained by their feeding habits. The presence of polycyclic aromatic hydrocarbons in the Cispata Bay may be due to hydrocarbon spills during oil transport at the nearby oil port.

Mercury in aqueous tank waste at the Savannah River Site: Facts, forms, and impacts

ABSTRACTOver the past two years, there has been an intense effort to understand the chemistry of mercury across the Savannah River Site’s high-level liquid waste system to determine the impacts of various mercury species. This effort began after high concentrations of mercury were measured in the leachates from a toxicity characteristic leaching procedure (TCLP) test on the low-level cementitious waste form produced in the Savannah River Saltstone facility. Speciation showed the dominant form of leached mercury to be the methylmercury cation. Neither the source of the methylmercury nor its concentration in the Saltstone feed was well established at the time of the testing. This assessment of mercury was necessary to inform points in the process operations that may be subject to new separation technologies for the removal of mercury.

A Grey Water Footprint Assessment of Groundwater Chemical Pollution: Case Study in Salento (Southern Italy)

The worsening of groundwater quality is a huge problem for some regions, especially where a karst aquifer system is the most important water resource because of the deficiency of a well-developed superficial water supply. In this study the chemical quality of a deep aquifer of the Salento peninsula (Southern Italy), where a shallow aquifer and an extensive deep aquifer are exploited as a source of drinking water and irrigation water, was monitored. The indicator used to assess the sustainability of pollution produce by human activities is the “grey water footprint” (GWF) which measures the amount of water required to assimilate a polluting load produced from anthropic activity. The GWF, calculated for each chemical parameter, shows a widespread contamination by Mercury (Hg), Vanadium (V) and Ammonium (NH4+) with concentrations above the limits (Lgs. D. 31/2001). The high Mercury and Vanadium concentrations may thus be associated with anthropic pressures on the aquifer, while Ammonium derives mainly from fertilizers used in agriculture. The situation that emerged involves reflections on the continuous human pressure on natural resources. Therefore, the management of groundwater quality requires a multidisciplinary approach focused on identifying the measures necessary to protect our water resources.

Geochemical Characteristics of Mercury in Oil and Gas

As an important element in oil and gas, the process of mercury formation, migration and enrichment, has an important practical significance to determine the nature and preservation status of deep oil-gas reservoirs, which can provide reliable geochemical basis for oil-gas exploration departments. Therefore, basing on the study of mercury formation, migration and enrichment, the geochemical anomaly patterns of mercury are determined, and the geochemical characteristics in oil and gas are discussed. Study shows that the mercury have strong affinity with oil and gas, and it will migrate and accumulate with the maturation of kerogen; Because of the abyssal faults, magmatic activity and deep geological process, in some petroliferous basins, the oil type gas have higher mercury content; On the basis of geochemical anomaly characteristics and morphological combination of mercury in surface, the anomaly patterns in oil and gas geochemical exploration are summarized to guide the anomaly interpretation and evaluation of testing zone, so as to provide the reliable geochemical basis for oil and gas exploration department.

ANALYSIS OF TIME-DEPENDENT MERCURY FLOWS THROUGH THE USE OF THERMOMETERS AND SPHYGMOMANOMETERS IN THAILAND

Thermometers and sphygmomanometers pose a potentially large source of mercury emissionsto the environment due to their high elemental mercury content. Many countries, e.g. most Europeancountries, US have banned their uses already and many more strictly limited their use. However, in Thailandthese mercury-based devices are still used, accumulating large stocks in the use phase as well as in landfills.To understand the development of mercury stocks and flows from thermometers and sphygmomanometers, atime-dependent mathematical material flow model is used in this study. The flows of mercury through thesetwo products were calculated based on data between the years of 1962 and 2013. The simulation showed thatthe stock of mercury in thermometers is about 20 times smaller than the stock in sphygmomanometers.However the sum of waste flows and emissions to air and water from thermometers is 3 times larger thanfrom sphygmomanometers. The reason is the lifetime of thermometers which is about 70 times shorter thanthe lifetime of sphygmomanometers. The calculated emission to air from mercury thermometers in hospitalscan explain the higher mercury level measured in urine of health care staff. In order to reduce the mercuryflows to the environment mercury thermometers should be replaced by alternative products as soon aspossible.

Post-breeding dispersal of frigatebirds increases their exposure to mercury

Migration and dispersal can expose wildlife to threats in different parts of their range, particularly for localized anthropogenic threats. Wildlife exposure to metal contaminants may correlate with local anthropogenic emissions. Feather mercury concentrations of adult and juvenile Lesser Frigatebirds (Fregata ariel) and Great Frigatebirds (F. minor) were determined for individuals breeding in the eastern Indian Ocean. Low mercury concentration in juveniles relative to adults, higher mercury concentration in adult females than adult males, and a trend for Lesser Frigatebirds to have higher mercury concentration than Great Frigatebirds implicate non-breeding ground exposure as the major influence on mercury burden. Aspects of foraging ecology are congruent with high exposure occurring in inshore waters of the non-breeding range, particularly in the South China Sea. These findings highlight the need for tighter mercury emission regulations in southeast Asia to minimise the potential threat to frigatebirds and other species dependent on marine resources including humans.

Mercury in fish products: what’s the best for consumers between bluefin tuna and yellowfin tuna?

A total of 205 bluefin and yellowfin tuna samples were examined for mercury detection in order to verify possible differences and have a detailed risk assessment of the two tuna species. The results showed significant higher mercury concentration in muscle tissue of bluefin tuna respect yellowfin tuna (p < 0.001) with mean concentration of 0.84 mg/kg and maximum value of 1.94 mg/kg. These differences can be due the different biological and ecological aspects of the two tuna species and to different oceanographic aspects between Atlantic Ocean and Mediterranean sea. The results obtained in this study suggest an advisable containment of the sources of pollution and further studies on the closed-loop farming of bluefin tuna, in order to ensure the product safety.

Air Contamination by Mercury, Emissions and Transformations\u2014a Review

The present and future air contamination by mercury is and will continue to be a serious risk for human health. This publication presents a review of the literature dealing with the issues related to air contamination by mercury and its transformations as well as its natural and anthropogenic emissions. The assessment of mercury emissions into the air poses serious methodological problems. It is particularly difficult to distinguish between natural and anthropogenic emissions and re-emissions from lands and oceans, including past emissions. At present, the largest emission sources include fuel combustion, mainly that of coal, and “artisanal and small-scale gold mining” (ASGM). The distinctly highest emissions can be found in South and South-East Asia, accounting for 45% of the global emissions. The emissions of natural origin and re-emissions are estimated at 45–66% of the global emissions, with the largest part of emissions originating in the oceans. Forecasts on the future emission levels are not unambiguous; however, most forecasts do not provide for reductions in emissions. Ninety-five percent of mercury occurring in the air is Hg0—GEM, and its residence time in the air is estimated at 6 to 18 months. The residence times of its HgII—GOM and that in Hgp—TPM are estimated at hours and days. The highest mercury concentrations in the air can be found in the areas of mercury mines and those of ASGM. Since 1980 when it reached its maximum, the global background mercury concentration in the air has remained at a relatively constant level.

An evaluation of mercury offloading in two Central California elasmobranchs

Elasmobranchs occupy high trophic levels, accumulate high concentrations of mercury in their tissues, and have high energetic levels of maternal investment to offspring, which may cause embryos to be exposed in utero to harmful concentrations of mercury. We investigated the maternal transfer of mercury in two common coastal elasmobranch species, Triakis semifasciata and Platyrhinoidis triseriata, to determine which reproductive parameters may influence mercury offloading, and whether embryos are at risk to mercury toxicity. Mercury concentration was measured in female muscle, female liver, and embryonic tissues. The behavior of mercury in adult female tissues differed between species, as liver mercury concentration was significantly correlated to muscle mercury concentration in P. triseriata but not in T. semifasciata. Embryos of both species were found with potentially harmful mercury concentrations in their muscle tissues. Embryo mercury concentration increased with female muscle mercury concentration, but the relationship to female liver mercury was more variable. The rate of mercury transfer and overall offloading potential were significantly greater in P. triseriata than T. semifasciata. It appears that female mercury concentration, either in muscle or liver, is an important influencing factor for mercury offloading, but the impact of the differing reproductive modes in these two species was less clear. More study on this subject will continue to elucidate the factors influencing mercury offloading in sharks and rays, and how contaminant risk affects populations on a whole.