Total,methyl and organic mercury in sediments of the Southern Baltic Sea

Distribution of sedimentary mercury in the Southern Baltic was investigated. Sediment samples were collected from the Southern Baltic in the period from 2009 to 2011, and concentrations of sedimentary total mercury (average 102 ng/g, range 5.8–225 ng/g) and methyl mercury (average 261 pg/g, range 61–940 pg/g) were measured in the manner that the influence of both patchiness and seasonal changes were assessed. Moreover, sedimentary mercury extracted with organic solvent- the so-called organic mercury was also analyzed (average 425 pg/g, range 100–1440 pg/g). There is a statistically significant dependence between organic mercury and both methyl mercury and total mercury concentrations in the sediments. Methyl mercury contribution to total mercury varied from 0.12% to 1.05%, while organic mercury contributed to 2% of total concentration on average. The area studied, although mercury concentrations exceed threefold the geochemical background, can be regarded as moderately contaminated with mercury, and methylmercury.     

Serious mercury contamination of sediments in a Norwegian semi-enclosed bay

Thirteen surface sediment samples from a shallow, semi-enclosed bay, Gunnekleivfjorden, South-West Norway, were analysed for total mercury. The concentrations ranged between 90 and 350 ppm dried sediment. The median value (250 ppm mercury) is more than twice the median value of sixteen sediment samples collected in Minamata Bay in 1963. The surface area of Gunnekleivfjorden is approximately 1 km², implying that minimum 10 tons of mercury is accumulated in the upper 5 cm of the sediments of the bay. The extensive contamination is caused by discharge of inorganic mercury from a chlor-alkali plant during the last 25 years.     

Intra- and inter-specific variability in total and methylmercury bioaccumulation by eight marine fish species from the Azores

We relate fish biological and ecological characteristics to total and organic mercury concentrations to determine whether accumulation is influenced by trophic level, Hg concentration in the diet, and vertical distribution. Levels of total mercury and methylmercury were determined in the muscle tissue of eight species of fish: Pagellus acarne, Trachurus picturatus, Phycis phycis, P. blennoides, Polyprion americanus, Conger conger, Lepidopus caudatus and Mora moro, caught in the Azores. All such fishes are commercially valuable and were selected to include species from a wide range of vertical distributions from epipelagic (<200 m) to mesopelagic (>300 m) environments. Methylmercury was the major form accumulated in all species, comprising an average of 88.1% of total mercury. Concentrations of mercury (total and methylmercury) increased with age, length and weight. Based on data from other studies, mercury concentrations in fish diet were estimated. Mercury levels in food ranged from 0.08 to 0.32 ppm, dry weight. Hg concentrations in the food and in muscle tissue from different species were positively correlated. Total Hg levels in the muscles were approximately nine times those estimated in food. Total mercury concentrations in muscle were positively correlated with both trophic level and median depth. Such enhanced mercury bioaccumulation in relation to depth appears to be determined primarily by concentrations in food and ultimately by water chemistry, which controls mercury speciation and uptake at the base of the food chain.     

Mercury content in hair from fishing communities of the State of Penang,Malaysia

The total mercury content of hair from a number of fishing communities in the state of Penang averaged, for different age-groups: over 40 years, 9.19 ppm; 19–40 years, 7.90 ppm; and 1–18 years, 7.36 ppm. The highest values found in these age groups were 16.10, 14.8 and 12.8 ppm, respectively, for different communities. Examinations of the mercury content of eight species of finfish taken at each of the fishing communities (with one exception where bivalves were substituted) showed values ranging up to 3.265 ppm in muscle, 16.345 ppm in heart and 7.50 ppm in liver, but there was no correlation between biodeposited mercury in hair of the three age groups and mercury concentrations in local fish.     

Mercury content of several predacious fish in the Andaman sea

During April 1975 thirty-six muscle samples of six predacious species of fish from the Andaman sea were collected for an analysis of their total mercury concentrations. The total mercury levels ranged from 0.026 to 0.234 ppm in yellowfin tuna (Neothunnus albacora), from 0.027 to 0.233 ppmin bigeye tuna (Parathunnus sibi), and from 0.057 to 0.478 ppm in four species of shark. Statistical analysis also showed positive linear regression and there was correlation between the mercury concentration and the weight of the yellowfin tuna, bigeye tuna, and shark. The rates of total mercury accumulation in yellowfin and bigeye tuna were not significantly different. A comparison between the total mercury level in the Andaman yellowfin and the Central Pacific yellowfin tuna is discussed.     

Methyl mercury, total mercury, and selenium in snapper from two areas of the New South Wales coast, Australia

The muscle tissue of snapper (Chrysophrys auratus: Sparidae) from two areas of the New South Wales coast was analysed for methyl mercury, total mercury and selenium concentrations (134 samples from the Sydney area and 186 samples from the Nowra area, about 120 km to the south of Sydney).

The Sydney snapper ranged from 0.08 to 1.66 mg kg⁻¹ total mercury (mean 0.32 mg kg⁻¹), while the Nowra snapper ranged from 0.01 to 0.78 mg kg⁻¹ total Hg (mean 0.11 mg kg⁻¹). These latter results appear anomalously low relative to other studies in Australia and New Zealand.

Methyl mercury averaged 94.7% of the total mercury content of the Sydney snapper, and 91.3% for the Nowra snapper.

The concentrations of selenium in the muscle tissues of snapper from both areas were similar and did not increase with increasing mercury concentrations. The highest selenium concentration was 0.85 mg kg⁻¹.     

Total mercury concentrations in lionfish (Pterois volitans/miles) from the Florida Keys National Marine Sanctuary,USA

Strategies to control invasive lionfish in the western Atlantic and Caribbean are likely to include harvest and consumption. Until this report, total mercury concentrations had been documented only for lionfish from Jamaica, and changes in concentrations with increasing fish size had not been evaluated. In the Florida Keys, total mercury concentrations in dorsal muscle tissue from 107 lionfish ranged from 0.03 to 0.48 ppm, with all concentrations being less than the regulatory threshold for limited consumption. Mercury concentrations did not vary consistently with standard lengths or wet weights of lionfish. In 2010, lionfish from the upper Keys had mean concentrations that were 0.03–0.04 ppm higher than lionfish from the middle Keys, but mean concentrations did not differ consistently among years and locations. Overall, total mercury concentrations in lionfish were lower than those in several predatory fishes that support commercial and recreational fisheries in Florida.     

Rare-earth and trace elements and hydrogen and oxygen isotopic compositions of Cretaceous kaolinitic sediments from the Lower Benue Trough,Nigeria: provenance and paleoclimatic significance

This study evaluated the Cretaceous(Campanian–Maastrichtian) kaolinitic sediments of the Ajali/Mamu and Enugu/Nkporo Formations from the Lower Benue Trough of Nigeria. A combined method of inductively coupled plasma–mass spectrometry and isotope ratio mass spectrometry was used to investigate trace and rareearth element geochemistry and hydrogen and oxygen isotopic compositions. These data were then used to infer the sediments' provenance and paleoclimatic conditions during their deposition. The sediments contained low concentrations of most trace elements, with the exceptions of Zr(651–1352 ppm), Ba(56–157 ppm), V(38–90 ppm),and Sr(15.1–59.6 ppm). Average values of Co and Ni were1.5 and 0.7 ppm, respectively. Trace and rare earth element values were lower than corresponding values for upper continental crust and Post-Archean Australian Shale, with the exception of Zr. The samples showed only slight light rare-earth enrichment and nearly flat heavy rare-earth depletion patterns, with negative Eu and Tm anomalies,typical of felsic sources. Geochemical parameters such as La/Sc, Th/Sc, and Th/Co ratios support that the kaolinitic sediments were derived from a felsic rock source, likely deposited in an oxic environment.^(18 )O values ranged from+ 15.4 to + 21.2% for the investigated samples, consistent with a residual material derived from chemicalweathering of felsic rock and redeposited in a sedimentary basin(typical values of + 19 to + 21.2%). While in the basin, the sediments experienced extended interactions with meteoric water enriched in d D and d16 O. However,the variation in d D and d16 O values for the investigated samples is attributed to the high temperature of formation(54–91 °C). The d D and d^(18 )O values suggest that the sediments, although obtained from different localities within the Lower Benue Trough, formed under similar hot,tropical climatic conditions.     

Depth profiles of lithogenic and anthropogenic mercury in the sediments from Thane Creek,Mumbai, India

Mercury（Hg） is well known as one of the most toxic elements to man.The coastal environments adjacent to industrial areas are reported to often be contaminated with mercury.Mercury becomes more toxic in the form of methylmercury（Me-Hg） which is converted from inorganic mercury in aqueous systems by microbial activity and can bio-magnify through the food chain.A simple method for the determination of total mercury and methylmercury in sediments was optimized by slightly modifying an old method using the direct mercury analyzer technique.Core sediment samples from Thane Creek,Mumbai,India were collected and analysed for total mercury and methylmercury.The Hg concentration in the creek varied between 0.54 to 16.03 μg g~（-1） while Me-Hg concentrations ranged between0.04 to 1.07 μg g~（-1）.In surface sediment,mercury concentrations ranged from 4.33 μg g~（-1） to 12.16μg g~（-1）.Total organic carbon content was found to be around 2 percent in different layers of the sediments.The enrichment factors,which indicate the extent of pollution in sediments,were estimated to range from 26 to 50 at different locations in the creek.Lithogenic and anthropogenic concentrations of mercury in the creek were also determined to compare the impact of anthropogenic and natural sources.Anthropogenic inventories were about 5-70 times more in concentration than the lithogenic in the different core sediments.     

Mercury concentrations in red drum, Sciaenops ocellatus, from estuarine and offshore waters of Florida

Dorsal muscle tissue from 712 red drum, Sciaenops ocellatus, from Florida waters were analyzed for total mercury content. Mercury levels detected in these red drum varied but in most study areas were usually lower than regulatory threshold guidelines. Total mercury levels in individual fish from all study areas ranged from 0.020 to 3.6 ppm (wet weight). Total mercury levels detected in red drum from the Florida Keys-Florida Bay area were often higher than those in fish from all other estuarine study areas. Positive relationships between total mercury levels and fish size (length and weight) and fish age were observed in most Florida study areas, indicating that mercury levels tend to increase over time as red drum grow. The majority of large, mature red drum examined contained mercury levels greater than the 0.5-ppm threshold level set by the Florida Department of Health (DOH). Approximately 94% of all adult red drum from offshore waters adjacent to Tampa Bay contained mercury levels greater than or equal to the 0.5-ppm threshold level, and 64% contained levels greater than or equal to the DOH 1.5-ppm "no consumption" level. All fish from this area with mercury levels greater than 1.5 ppm were large individuals (670 mm SL). Eight percent of legal-size red drum from Florida waters contained total mercury levels greater than or equal to the 0.5-ppm threshold level. The majority (52%) of these legal-size fish greater than or equal to 0.5 ppm were from the Florida Keys-Florida Bay area. In the Florida recreational fishery, the current maximum size limit for this species is an effective filter that prevents humans from consuming those red drum with the greatest likelihood of containing high mercury levels.     

Atmospheric Particulate Concentration Measured in an Urban Area Bandung

— Atmospheric particulate concentration for total suspended particles (TSP) and for PM₁₀ (particulate matter under 10 micron) was measured in Jalan Braga and ITB campus, Bandung. Six samples were collected over one- or two-day time periods using High Volume Sampler (HVS) for TSP and Low Volume Sampler (LVS) or Anderson Cascade Impactor for PM₁₀. Samples were further analyzed to determine concentrations of metals, sulfate and nitrate. Concentration of NO_x (NO and NO₂) was also measured hourly and simultaneously during the sampling period. The results from this study show that the atmospheric particulate concentration in Jalan Braga for TSP ranged from 304.04 to 363.17, and for PM₁₀ concentration ranged from 277.02 to 336.44 μg/m³. The lead concentrations were 1.42–2.37 μg/m³ in the TSP and 0.81–1.57 μg/m³ in the PM₁₀. The nitrate concentrations were 5.89–6.51 μg/m³ and 2.27–3.45 μg/m³ for the TSP and PM₁₀, respectively. The hourly NO_x concentration varied between 0.14–0.35 ppm. The total elements (metals, sulfate and nitrate) found in the samples contribute from 20 to 25% of the total particulate concentration.     

The source and fate of sediment and mercury in Hunza River basin,Northern Areas,Pakistan

This article presents results of mercury in surface waters from Hunza River basin, Northern Areas, Pakistan. Small‐scale gold mining activities along the Hunza and Gilgit rivers are long known to be discharging mercury in the amalgamation and roasting processes. Previous studies reported high mercury concentrations in soils close to mining operations as well as serious health problems for miners. However, none of the studies have focused on the level of contamination in aqueous environments. This is the first study on the investigation of source and fate of sediment and river‐borne mercury in the Hunza River. The samples collected near gold panning sites showed higher mercury concentrations than critical levels established by the U.S. Environmental Protection Agency. The observed dissolved mercury concentrations ranged from 5.10 to 25.25 ng/l, whereas particulate‐bound mercury ranged from 4.85 to 154.62 ng/l. Particulate‐phase mercury corresponded to more than 75% of the total observed mercury concentrations for all of the sampled rivers. Thus, suspended sediments represented the major pathway of the riverine mercury transport. A mass balance calculation suggested an annual mercury flux of 48.6 g/km² into the Hunza River basin. The samples collected from the most affected river, the Shimsal River, averaged to have 108 ng/l total mercury. This amount was close to the average soil mercury data of 151 ng/l as reported by the Pakistan Mineral Development Corporation in 2001. The dominant source of contamination was shown to be the leaching of large quantities of mercury from the mercury‐rich sediment and flood plain soil into the rivers, rather than the direct release from mining activities. Significant decrease in both dissolved and particulate‐bound mercury concentration downstream of Attabad Lake suggested that mercury is being accumulated or consumed in the lake. Although minimization or elimination of mercury loses from the mining process seems important for the well‐being of the miners, preventing the remobilization of accumulated mercury is equally important in mercury control in this region. Copyright © 2014 John Wiley & Sons, Ltd.     

Mercury in plankton from a polluted Norwegian Fjord

Plankton of mixed composition has been collected from Sorfjørden and Hardangerfjørden, on the west coast of Norway and analysed for total mercury by flameless atomic absorption. Different methods of decomposing the samples prior to analysis were tested, showing no significant variations in the recovery of mercury. The high levels of mercury (0.52-25.21 ppm dry weight) are apparently associated with a source of industrial pollution. Indications of higher mercury concentrations in phytoplankton than in zooplankton were noticed and suggest a lack of food chain amplification within the lower trophic levels.     

Total and methylmercury in a Brazilian estuary,Rio de Janeiro

Guanabara Bay, in Rio de Janeiro state, is impacted by organic matter, oil and heavy metals. The present study evaluated the total mercury (THg) and methylmercury (MeHg) concentrations and the MeHg to THg ratio (%MeHg) in water samples from different points of the bay and in 245 organisms of three different trophic levels sampled between 1990 and 2000. Dissolved mercury concentration in estuarine water samples ranged from 0.72 to 5.23 ngl(-1). THg and MeHg in mussel, ranging from 11.6 to 53.5 microg THg kg(-1) wet wt. and 4.5-21.0 microg MeHg kg(-1) wet wt., varied according to sampling point and water quality. Planktivorous fish and mussel presented similar MeHg concentrations, meanwhile THg in planktivorous fish were lower than in mussel. Carnivorous fish showed higher THg and MeHg concentrations (199.5 +/- 119.3, 194.7 +/- 112.7 microg kg(-1) wet wt. respectively) than organisms from other feeding habits and lower trophic levels. There was a significant difference in the %MeHg among trophic levels: mussel presented lower MeHg percentage (33%) than planktivorous fish (54%) and carnivorous fish (98%).     

Organochlorine and heavy metal concentrations in blubber and liver tissue collected from Queensland (Australia) dugong (Dugong dugon)

Tissue samples of liver and blubber were salvaged from fifty-three dugong (Dugong dugon) carcasses stranded along the Queensland coast between 1996 and 2000. Liver tissue was analysed for a range of heavy metals and blubber samples were analysed for organochlorine compounds. Metal concentrations were similar in male and female animals and were generally highest in mature animals. Liver concentrations of arsenic, chromium, iron, lead, manganese, mercury and nickel in a number of individual animals were elevated in comparison to concentrations previously reported in Australian dugong. Dieldrin, DDT (and its breakdown products) and/or heptachlor epoxide were detected in 59% of dugong blubber samples. In general, concentrations of organochlorines were similar to those reported in dugong 20 years earlier, and were low in comparison to concentrations recorded from marine mammal tissue collected elsewhere in the world. With the exception of lead, the extent of carcass decomposition, the presence of disease or evidence of animal starvation prior to death did not significantly affect dugong tissue concentrations of metals or organochlorines. The results of the study suggest that bioaccumulation of metals and organochlorine compounds (other than dioxins) does not represent a significant risk to Great Barrier Reef dugong populations, particularly in the context of other pressures associated with coastal development and other anthropogenic activities.     

Mercury in wahoo, Acanthocybium solandri, from offshore waters of the southeastern United States and the Bahamas

Wahoo, Acanthocybium solandri, are predatory oceanic fish that occur and are harvested in all tropical and subtropical oceans. Total mercury concentrations analyzed in dorsal muscle tissue of 208 wahoo from offshore waters of the southeastern United States and the Bahamas ranged from 0.021 to 3.4 mg/kg (wet weight), with a mean of 0.50 mg/kg (± 0.595 SD). Analyses indicated significant positive linear relationships between mercury and length, as well as, age of wahoo. The piscivorous nature, generally high trophic position, fast growth rate, and associated high metabolism of wahoo within tropical offshore pelagic environments may lead to comparatively higher concentrations of mercury over relatively short time periods. Mercury in wahoo, a highly mobile species consisting of one world-wide population, is regionally influenced by large-scale spatial differences in available mercury in selected prey fish species - many of which have been found to contain relatively high concentrations of mercury.     

Mercury levels in fish,invertebrates and sediment in a recently recorded polluted area (Nissum Broad,western Limfjord,Denmark)

High concentrations of mercury were measured in sediment and animals collected in the immediate vicinity of a closed-down chemical factory. Sediment contained up to 22 ppm (dry wt) of mercury, deposit-feeding bivalves between 1.4 and 4.4 ppm (wet wt), suspension-feeding bivalves between 0.9 and 1.9 ppm and predatory fish between 0.3 and 0.8 ppm. Outside the ‘hot spot’ area, the mercury concentration in sediment and mussels (Mytilus edulis) rapidly decreased with increasing distance from the former factory. Mercury concentration in flounders (Platichthys flesus) also decreased with distance from the source; the decline was, however, much less marked.     

Lithium isotope variations in Tonga–Kermadec arc–Lau back‐arc lavas and Deep Sea Drilling Project (DSDP) Site 204 sediments

Lithium isotopes have been identified as a promising tracer of subducted materials in arc lavas due to the observable variations in related reservoirs such as subducting sediments and altered oceanic crust. The Tonga–Kermadec arc–Lau back‐arc provides an end‐member of subduction zones with the coldest thermal structure on Earth. Reported here are Li isotope data for 14 lavas from the arc front and 7 back‐arc lavas as well as 12 pelagic and volcaniclastic sediments along a profile through the sedimentary sequence at DSDP Site 204. The arc and back‐arc lavas range from basalts to dacites in composition with SiO₂ = 48.3–65.3 wt% over which Li concentrations increase from 2 ppm to 16 ppm. Li/Y ratios range from 0.08 to 0.77 and from 0.24 to 0.65 in the arc and back‐arc lavas, respectively. The majority of the lavas have δ⁷Li that ranges from 2.5 ‰ to 5.0 ‰ with an average of (3.6 ±0.7) ‰, similar to that reported from other arcs and there is no distinction between the arc front and back‐arc lavas. The pelagic sediments have variable Li concentrations (33–133 ppm) and δ⁷Li that ranges from 1.2 ‰ to 10.2 ‰ while the volcaniclastic sediments have an even greater range of Li concentrations (3.6–165 ppm) and generally higher δ⁷Li values (8–14 ‰). However, δ⁷Li in the lavas does not correlate with commonly used trace element ratio or isotope signatures indicative of slab‐derived fluids or the sediments. This is probably because the range of δ⁷Li in the lavas and sediments overlap. Calculated sediment mass‐balance models require significantly more sediment than previous estimates based on Th–Nd–Be isotopes. This may indicate that a sizeable proportion of the total Li budget in the lavas is provided by Li‐enriched fluids from the subducting sediments and/or altered oceanic crust.     

A Dynamic Model to Simulate Arsenic,Lead, and Mercury Contamination in the Terrestrial Environment During Extreme Floods of Rivers

Beside damages of infrastructure in industrial regions, extreme floods can cause contamination with particle‐bound pollutants, e. g., due to erosion of soils and sediments. In order to predict contamination with inorganic pollutants, the transport and fate of arsenic, lead, and mercury during a fictive flood event of River Vereinigte Mulde in the region of Bitterfeld (Germany) with 200 years recurrence time was modeled. The finite element model system Telemac2D, which is subdivided into a hydrodynamic (Telemac‐2D), a transport (Subief‐2D), and a water quality module (wq2subief) was applied. The transport and water quality model models were calibrated using results of sediment trap exposures in the floodplain of River Vereinigte Mulde. Model results exhibited that the spatial patterns of particle‐associated arsenic and lead concentrations significantly changed. Extended, mostly agriculturally used areas showed arsenic and lead concentrations between 150 and 200 mg kg^–1 and 250 and 300 mg kg^–1, respectively, while urban areas were to a great extent spared from high contamination with arsenic and lead. Concentrations of particle‐associated mercury showed a pattern distinct from those of arsenic and lead. Outside of small patches with concentrations up to 63 mg kg^–1, concentrations of particle‐associated mercury remained close to zero. Differences in the spatial patterns of the three pollutants regarded mainly arise from significantly different initial and boundary conditions. Sensitivity analyses of initial and boundary conditions revealed a high sensitivity of particle‐bound pollutant concentrations, whereas the sensitivities of concentrations of suspended sediments and soluble pollutants were mediocre to negligible.     

Chronology and petrogenesis of the Hejiazhuang granitoid pluton and its constraints on the Early Triassic tectonic evolution of the South Qinling Belt

The Hejiazhuang pluton is located in the South Qinling Tectonic Belt(SQTB)in the north side of the Mianxian-Lueyang Suture Zone,and consists dominantly of granodiorites.LA-ICP-MS zircon U-Pb dating and Lu-Hf isotopic analyses reveal that these granodiorites of the Hejiazhaung pluton emplaced at~248 Ma,and show a large variation in zirconεHf(t)values from4.8 to 8.8.These granodiorite samples are attributed to high-K to mid-K calc-alkaline series,and characterized by high SiO2(66.6%–70.0%),Al2O3(15.04%–16.10%)and Na2O(3.74%–4.33%)concentrations,with high Mg#(54.2–61.7).All samples have high Sr(627–751 ppm),Cr(55–373 ppm)and Ni(17.2–182 ppm),but low Y(5.42–8.41 ppm)and Yb(0.59–0.74 ppm)concentrations with high Sr/Y ratios(84.90–120.66).They also display highly fractionated REE patterns with(La/Yb)N ratios of 18.9–34.0 and positive Eu anomalies(δEu=1.10–2.22)in the chondrite-normalized REE patterns.In the primitive mantle normalized spidergrams,these samples exhibit enrichment in LILEs but depletion in Nb,Ta,P and Ti.These geochemical features indicate that the granodioritic magma of the Hejiazhuang pluton was derived from the partial melting of hybrid sources comprising the subducted oceanic slab and sediments,and the melts were polluted by the mantle wedge materials during their ascent.The emplacement ages and petrogenesis of the Hejiazhuang pluton prove that the initial subduction of the Mianlue oceanic crust occurred at~248 Ma ago,and the SQTB was still under subduction tectonic setting in the Early Triassic.