Distribution of Selenium, Mercury, and Methylmercury in Surficial Missouri River Sediments

Sediment deposition into Lewis and Clark Lake, an impoundment of the Missouri River, has caused substantial storage capacity reductions. Current proposals to hydrologically flush sediment would disturb river and reservoir sediment that may contain heavy metals. We quantified existing concentrations of selenium (Se), mercury (Hg), and methylmercury (MeHg) in surficial sediments upstream of and in Lewis and Clark Lake. We found elevated levels of Se (range 0.12–9.62 μg/g) and Hg (range 0.02–1.55 μg/g) at several sites throughout the study area; however, few sites contained levels of MeHg above detection limits. Sites with highest MeHg concentrations were found in Lewis and Clark Lake and ranged from below detection limit to 0.79 ng/g. We conclude that further investigation of sediment-sequestered contaminants in Lewis and Clark Lake should be conducted.     

Mercury Speciation and Total Organic Carbon in Marine Sediments Along the Mediterranean Coast of Israel

Along the Israeli Mediterranean Coast, three areas are considered “hot spots” of mercury (Hg) pollution: (1) Northern Haifa Bay (NHB), (2) the lower Qishon River at the southern part of Haifa Bay, and (3) a marine outfall of activated sewage sludge at the southern coast off Palmachim (sewage-sludge disposal site [SDS]). Even though the total Hg (HgT) concentrations in the sediments at the three areas are of the same order of magnitude (250–500?μg?kg^?1), Hg was shown to bioaccumulate in fish and benthic fauna from Haifa Bay but not in benthic fauna or in commercial fish caught along the southern Mediterranean Coast of Israel near the SDS outfall. The primary goal of this study was to measure the concentrations of Hg species (HgT, methyl-Hg [MeHg], and Hg in different biogeochemical fractions)—in conjunction with organic carbon—in sediments of NHB and the lower Qishon River to assess its impact on Hg transitions among the species as characterized by different bioavailability and bioaccessibility. HgT concentrations in NHB and the Qishon River ranged from 249 to 347 and 165 to 667?μg?kg^?1, respectively. MeHg was significantly higher in the Qishon River (6.3–34.0?μg?kg^?1) than in NHB (0.22–0.70?μg?kg^?1) as were total organic carbon (TOC) concentrations (average 2.5 vs. 0.13?%). The relative Hg distribution in the biogeochemical fractions in NHB was 2.3?% in the most bioaccessible fractions (F1?+?F2), 55?% in the organo-chelated species fraction (F3), 42?% in the strong-complexed species fraction (F4), and 0.7?% in the mercuric-sulfide fraction (F5). In the Qishon River, the bioavailable F1?+?F2 and F3 fractions were lower than in NHB (<0.01 and 23?%, respectively) and the more refractory F4 and F5 fractions higher (73 and 3.3?%, respectively). The fractionation of Hg in Qishon River sediments was similar to the distribution found in polluted stations at the SDS. TOC and MeHg were positively and negatively correlated, respectively, in Qishon River and NHB sediments. Methylation depended on TOC availability when its concentration was in the range of 2–4 wt%. It is possible that TOC in the sediment controlled Hg speciation: Hg in F3 decreased and in F4 increased with increasing TOC concentrations. In contrast, MeHg/HgT was significantly positively correlated with TOC and Hg in the stable F4 fraction and negatively correlated with Hg in the F3 fraction. It was therefore assumed that higher TOC concentrations enhanced microbial activity and decomposition of organic matter. Hg was released from the F3 fraction and was either transferred to the F4 fraction or made available for methylation processes.     

Methylmercury and Total Mercury in Sediments Collected from the East China Sea

No abstract available.     

Mercury Accumulation and Distribution in Medaka after the Exposure to Sublethal Levels of Methylmercury

No abstract available.     

Distribution of Arsenic in Three Geochemical Fractions of Surface Sediments from Coastal Sites of Sonora, Gulf of California, Mexico

No abstract available.     

Antibiotic and Heavy Metal Resistance in Bacteria Isolated from the Eastern Mediterranean Sea Coast

In this study it aimed to determine the microbial diversity, level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from the Eastern Mediterranean Sea coast. The resistance of 255 Gram-negative bacterial isolates to 16 different antibiotics and to 5 heavy metals was investigated. The most common strains isolated from all samples were Citrobacter koseri (9.0 %), Escherichia coli (8.2 %) and Pantoea agglomerans (8.2 %). Our results revealed a high incidence of resistance to ampicillin (74.0 %), streptomycin (70.0 %) and cefazolin (48.3 %). The multiple antibiotic resistance (MAR) index ranged from 0.2 to 0.75. Isolates showed tolerances to different concentrations of heavy metals. Our results show that the Eastern Mediterranean Sea coast has a significant proportion of antibiotic and heavy metal resistant pathogens, or opportunist Gram-negative bacteria, and these bacteria may result in a potential public health hazard.     

Selenium and Mercury Concentrations in Brood-Stock Walleye Collected from Three Sites on Lake Oahe

A decline in the walleye Stizostedion vitreum sport fishery in lower Lake Oahe, South Dakota, was documented in the early 1980s and has been attributed to poor natural reproduction and/or recruitment. Contaminants were suspected of causing low natural reproduction/recruitment in lower Lake Oahe as well as low hatchability of eggs produced from broodstock walleyes taken from lower Lake Oahe. Concentrations of dissolved selenium in the Cheyenne River, which enters lower Lake Oahe, have increased considerably over the last 15 years. To determine whether selenium concentrations contributed to the reproduction problems in the lower Lake Oahe walleye population, adult walleye were collected during spawning operations in April 1994, 1995, and 1996 to obtain tissue samples. Muscle, liver, reproductive tissue, and unfertilized eggs were analyzed with a modified fluorometric method for determining selenium concentrations in plants. These tissues were also analyzed for mercury content using cold-vapor atomic absorption. No statistical differences (p < 0.05) in selenium or mercury concentrations among sites could be determined that would explain differential walleye egg hatchability. Correlation analysis determined significant inverse associations existed between the gonadal somatic index of male walleye and gonadal tissue selenium concentrations (r =−0.41, p = 0.0012). Both walleye sexes exhibited significant inverse associations between the hepatic somatic index (HSI) and liver selenium concentrations (males r =−0.33, p = 0.0095; and females r =−0.38, p = 0.0034). Positive relationships existed for female walleye selenium concentrations in the liver and the ovaries (r = 0.37, p = 0.003) and the liver and muscle tissue (r = 0.28, p = 0.027). Mercury concentrations in walleye ovaries were positively correlated with HSI (r = 0.30, p = 0.0012), length (r = 0.36, p = 0.0046), relative weight (r = 0.36, p = 0.0054), and muscle concentrations (r = 0.49, p = 0.0001). Mercury concentrations in male walleye muscle were correlated with age (r = 0.57, p = 0.0001), length (r = 0.79, p = 0.0001), and mercury concentrations in the testes (r = 0.43, p = 0.0006). Received: 26 February 2000/Accepted: 18 August 2000     

Distribution and Accumulation of Metals in the Surface Sediments of Coleroon River Estuary,East Coast of India

This study deals with the geochemical nature of distribution of metals (iron, manganese, lead and zinc) in bulk sediments and its association with sand, silt, clay and organic carbon. Ten numbers of surface sediment samples were collected during summer season of 2009 from Coleroon estuary. The sediments are mostly sandy silt in nature. The organic carbon distribution indicates that they are brought in the surroundings of coastal areas. Correlation analysis clearly indicates that fine particles and organic carbon control the distribution of metals. The most evident the significant correlations where zinc vs manganese (r = 0.641), manganese versus iron (r = 0.618), lead versus manganese (r = 0.574). The correlation between organic carbon versus manganese (r = 0.768), organic carbon versus sand (r = 0.872), organic carbon versus silt (r = 0.902), organic carbon versus clay (r = 0.793). The degree of correlation between metals and other major constituents is often used to indicate the origin of the metals. Strong positive correlation coefficient of all the above said metals and organic carbon are mainly associated with the fine grained sediments.     

Mercury and Methylmercury Exposure in the New Jersey Pregnant Population

Methylmercury is a known fetal developmental neurotoxicant. The only significant source of fetal exposure is maternal fish consumption; however, few recent data on exposure of the pregnant population are available. The authors undertook a study of methylmercury exposure in the New Jersey pregnant population to investigate the distribution of exposure and to identify predictors of elevated exposure. Mainly first-trimester pregnant women were recruited through six New Jersey obstetric practices. Hair and blood samples were analyzed for total mercury, and a subset was analyzed for methylmercury. A questionnaire on demographics, life style, and fish-consumption practices was also administered. Although 85-90% of the pregnant population had hair mercury levels that were less than 1.0 μg/gm, 1-2% had levels in a range of possible concern for adverse developmental effects (> 4.0 μg/gm). Regression analysis suggested that blacks and individuals with some college education experienced lower exposures to methylmercury.     

氯化甲基汞染毒对亲仔两代ICR小鼠脑、肝、肾中汞分布的影响

[目的]通过ICR孕鼠饮水接触低剂量氯化甲基汞,研究汞在亲仔两代小鼠脑、肝、肾及血清中的分布及其相关性。[方法]ICR孕鼠随机分为对照组、低剂量组(0.01mg/L)和高剂量组(0.10mg/L),于怀孕第6天起分别自由饮用蒸馏水及氯化甲基汞含量分别为0.01、0.10mg/L的蒸馏水直至哺乳期结束,用原子荧光法测定汞在各脏器内的含量,并做血清汞和脏器汞含量的相关性分析。[结果]在低剂量甲基汞作用下,亲仔两代未出现明显的毒性反应。随着染毒剂量的增加,亲仔两代小鼠血清中的总汞含量增加,对照组、低剂量组和高剂量组母鼠血清中总汞含量分别为1.228、2.358和6.195μg/L,仔鼠为0.801、3.217和3.763μg/L,高剂量组和对照组间差别有显著性(P<0.05);随着染毒剂量的增加,各脏器中的总汞含量也增加,对照组、低剂量组和高剂量组母鼠肾脏总汞含量分别为13.890、25.780、253.980ng/g组织湿重,肝脏为3.710、11.520、100.820ng/g组织湿重,脑组织为2.820、3.070、23.810ng/g组织湿重;对照组、低剂量组和高剂量组仔鼠肾脏总汞含量分别为6.940、13.090、102.170ng/g组织湿重,肝脏为2.660、5.450、38.850ng/g组织湿重,脑组织为1.600、2.660、8.120ng/g组织湿重;母鼠和仔鼠脏器中总汞蓄积的模式一样:肾脏>肝脏>脑组织。在低剂量下,母鼠血清总汞含量与肝脏、肾脏、脑组织中的总汞含量的相关系数分别为0.830、0.967、0.802;在高剂量下,与肝脏、肾脏、脑组织的相关系数分别为0.997、0.833、0.850,均有较高的相关性(P<0.05)。而仔鼠在高剂量下血清总汞与肝脏、肾脏、脑组织的相关系数分别为0.737、0.672、0.702,其血清总汞和脏器总汞也有相关性(P<0.05);在低剂量时血清总汞与肝脏、肾脏、脑组织总汞的相关系数分别为0.040、0.300、0.080,没有相关性(P>0.05)。[结论]母鼠接触低剂量甲基汞即可在亲仔两代各脏器中蓄积,亲代血清总汞含量和脏器总汞含量具有明显的相关性;仔代在高剂量时血清总汞含量和脏器总汞含量有明显的相关性,而在低剂量下无相关性。     

Polycyclic Aromatic Hydrocarbons,Mercury and Arsenic Content in Soils of Larsemann Hills,Pravda Coast and Fulmar Island,Eastern Antarctica

This study is aimed at investigation of various potential contaminants (arsenic, mercury and polycyclic aromatic hydrocarbons) content in soils of different landscapes of Eastern Antarctica ice-free areas. Our data not only showed that intensive human impact might result in significant direct contamination of surrounding landforms, but also revealed a specific role of ornithogenic transport in distribution of contaminants. Analysis revealed that the contents of investigated elements were 0.100–8.055 mg kg⁻¹ (arsenic), 0.025–0.027 mg kg⁻¹ (mercury) in Larsemann Hills and 0.100–1.213 mg kg⁻¹ (arsenic), 0.023–0.593 mg kg⁻¹ (mercury) in vicinities of Mirny station and Fulmar Island. Accumulation of some elements in guano-derived and moss materials lead to higher values of other soil pollution indices at natural sites. Results of our study revealed the predominance of light molecular weight PAHs (fluorene and acenaphthylene) in studied soils. Results of our study are not completely in agreement with the idea of an practically uncontaminated Antarctic ecosystem which was previously reported for Eastern Antarctica ice-free areas. Various human activities carried out at local scale have been found to be responsible for increase of metal levels in studied Antarctic environments.

     

Mercury Distribution in Contaminated Surface Sediments from Four Estuaries,Khuzestan Shore,North Part of Persian Gulf

The distribution of mercury in surface sediment from four estuaries along the Khuzestan shore, north part of Persian Gulf, was measured. The concentration of mercury varied among sampling stations (p < 0.05). The concentrations of mercury in all estuaries were from 0.01 to 2.16 µg g^?1. Relatively high mercury concentrations were observed in sediments from Musa estuary. The percentage of mercury associated with different fractions in the sediment from all stations were in the order of residual (70.4 %) > organic matter (16.6 %) > easily and exchangeable (2.2 %) > acid reduction (0.8 %). I _geo values calculated for mercury (1.5) showed higher values in Musa estuary than in the other stations. The bioavailability of mercury in sediments could be controlled by physicochemical factors such as pH, oxidation and reduction potential, organic carbon content and cation exchange capacity.     

Concentrations and Distribution of Mercury and Other Heavy Metals in Surface Sediments of the Yatsushiro Sea including Minamata Bay, Japan

The concentrations and distribution of heavy metals, such as mercury, zinc, copper, lead, and iron in surface sediments from 234 stations of the Yatsushiro Sea including Minamata bay were investigated. High concentrations of mercury were found in sediments from Minamata bay and its vicinity, but the levels decreased gradually with distance from the bay. The concentrations of mercury in sediments decreased gradually from south to north of the Yatsushiro Sea. These imply the lack of movement of mercury from Minamata bay to the northern Yatsushiro Sea. The geographical profiles of zinc and copper were contrary to that found for mercury, indicating the presence of natural and anthropogenic sources of copper and zinc in the northern Yatsushiro Sea.     

Distribution of Total Mercury in Surface Sediments of the Western Jade Bay,Lower Saxonian Wadden Sea,Southern North Sea

A total of 114 surface sediment samples was equidistantly collected in the western part of the Jade Bay, southern North Sea, to analyse total mercury contents as well as grain size distribution and total organic carbon (TOC) contents. Total mercury was determined by oxygen combustion-gold amalgamation. Validation, precision and accuracy of the method were evaluated and controlled with two certified reference materials (HISS-1 and MESS-3). Total mercury contents varied between 8 and 243 ng/g dry sediment with a mean value of 103 ng/g dw. The mercury levels in surface sediments showed an inhomogeneous spatial distribution with higher contents in near-dike areas. The values are mostly in the range of natural background values (50–100 ng/g dw) and positively related to TOC and clay/silt contents (<63 μm). The present total mercury contents are compared to those of previous studies, in order to estimate possible temporal trends of mercury contents in the study area over the last decades. Moreover, the comparison to sediment quality guidelines indicated that the surface sediments of the Jade Bay are not mercury contaminated. These results also suggested that the current mercury contents of Jade Bay surficial sediments are mostly affected by atmospheric deposition and re-emission.     

Lactose intolerance in the Lebanese population and in "Mediterranean lymphoma".

Lactose tolerance tests were performed on 75 healthy Lebanese volunteers, 12 patients with "Mediterranean lymphoma" and 15 American and West European Caucasians. Small intestinal biopsies were done on 10 intolerant and five tolerant subjects for histological evaluation and lactase assay. Lactose malabsorption was present in 78% of the Lebanese subjects, in all patients with Mediterranean lymphoma and in five of the 15 Caucasians. Two of the five intolerant Caucasians had giardiasis. There was no difference in the prevalence rate among the various Lebanese groups nor among males and females. Symptoms occurred in 91% of the 58 intolerant Lebanese subjects: diarrhea in 71%, abdominal distension in 67%, and cramps in 48%. The increased prevalence of lactose intolerance with Mediterranean lymphoma is probably secondary to the pathological changes in the intestinal mucosa and protein depletion.     

Correction to: Polycyclic Aromatic Hydrocarbons,Mercury and Arsenic Content in Soils of Larsemann Hills,Pravda Coast and Fulmar Island,Eastern Antarctica

Bulletin of Environmental Contamination and Toxicology - The original version of the article unfortunately contained a mistake in Fig.&nbsp;2, where numbers on the plot were not decoded.     

Distribution of Polychlorinated Biphenyls in Soil Around Three Typical Industrial Sites in Beijing,China

We investigated three locations in Beijing, China, containing different industrial plants that may cause pollution of polychlorinated biphenyls (PCBs). The highest soil concentration of 1,000 pg g^?1 (dry wt) was found in the chemical plant. The concentrations of ΣPCBs tended to decrease with distance from each of the investigated sites. The principal component analysis demonstrated that there were not substantial differences in PCB homologue patterns among these industrial sites. Tri-CBs and tetra-CBs were the dominant congeners. Based on the data obtained in this investigation, further study of the emission of PCBs from these industrial sites in Beijing is warranted.