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1

Mercury baseline levels in Flemish soils (Belgium)  

Microsoft Academic Search

It is important to establish contaminant levels that are normally present in soils to provide baseline data for pollution studies. Mercury is a toxic element of concern. This study was aimed at assessing baseline mercury levels in soils in Flanders. In a previous study, mercury contents in soils in Oost-Vlaanderen were found to be significantly above levels reported elsewhere. For

Filip M. G. Tack; Thomas Vanhaesebroeck; Marc G. Verloo; Kurt Van Rompaey; Eric Van Ranst

2005-01-01

2

Investigation of mercury levels in soil around a municipal solid waste incinerator in Shenzhen, China  

Microsoft Academic Search

Within the management hierarchy of municipal solid waste (MSW), incineration with energy recovery is a desired and viable\\u000a option often used in densely populated and economically developed cities. The gaseous and particulate mercury (Hg) emitted\\u000a from MSW incinerators may accumulate in the soil entering via dry and wet deposition. To investigate the soil Hg level and\\u000a estimate the effects of

Jun-Jian Wang; Hong-Wei Zhao; Xiu-Ping Zhong; Si-Fang Kong; Yang-Sheng Liu; Hui Zeng

3

Removal of mercury from soil with earthworms  

SciTech Connect

Earthworms can live in soils containing high quantities of mercury, lead, and zinc. The worms (Lumbricus terrestris) concentrate these heavy metals in their tissues. The use of these worms to reduce the quantities of mercury and other heavy metals in soils may be practical. In July, 1993, a preliminary study was made using earthworms and soils with differing amounts of mercury, The quantities were 0.0 grams, 0.5 grams, and 1.0 grams of mercury as mercuric chloride. Earthworms were placed into these soils for two or more weeks, then harvested. The worms were rinsed with deionized water, then dissolved in nitric acid. Each sample was prepared for analysis with the addition of HNO{sub 3}, H{sub 2}SO{sub 4}, potassium permanganate, and hydrozylamine hydrochloride. A Jerome Instrument gold foil analyzer was used to determine levels of mercury after volatilizing the sample with stannous chloride. Worms exposed to contaminated soils remove 50 to 1,400 times as much mercury as do worms in control soils. In a hypothetical case, a site contaminated with one pound of mercury, 1,000 to 45,000 worms would be required to reduce mercury levels to background levels in the soil (about 250 ppb). After harvesting worms in contaminated soil they could be dried (90% of their weight is water), and the mercury regained by chemical processes. Soil conducive to earthworm survival is required. This includes a well aerated loamy soil, proper pH (7.0), and periodic watering and feeding. There are several methods of harvesting worms, including flooding and electricity. Large numbers of worms can be obtained from commercial growers.

Dorfman, D. [Monmouth Coll., West Long Branch, NJ (United States)

1994-12-31

4

Mercury Content of Illinois Soils  

Microsoft Academic Search

For a survey of Illinois soils, 101 cores had been collected and analyzed to determine the current and background elemental compositions of Illinois soils. Mercury and other elements were determined in six samples per core, including a surface sample from each core. The mean mercury content in the surface samples was 33 ± 20 µg\\/kg soil, and the background content

G. B. Dreher; L. R. Follmer

2004-01-01

5

METHYLATION OF MERCURY IN AGRICULTURAL SOILS  

EPA Science Inventory

Methylation of applied divalent mercury ion was found to occur in agricultural soils. The production of methylmercury was affected by soil texture, soil moisture content, soil temperature, concentration of the ionic mercury amendment, and time. Methylation was directly proportion...

6

Effects of Mercury Release from Amalgam Dental Restorations During Cremation on Soil Mercury Levels of Three New Zealand Crematoria  

Microsoft Academic Search

A vast amount of research has been undertaken in the last 15-20 years on the corrosion reactions occurring in dental amalgam, release of mercury from amalgam restorations, and the toxic effects of this released mercury on the human body. However, one environmental aspect of amalgam dental restorations that has not received a great deal of attention is the release of

A. K. Nieschmidt; N. D. Kim

1997-01-01

7

Mercury content of Illinois soils  

USGS Publications Warehouse

For a survey of Illinois soils, 101 cores had been collected and analyzed to determine the current and background elemental compositions of Illinois soils. Mercury and other elements were determined in six samples per core, including a surface sample from each core. The mean mercury content in the surface samples was 33 ?? 20 ??g/kg soil, and the background content was 20 ?? 9 ??g/kg. The most probable sources of mercury in these soils were the parent material, and wet and dry deposition of Hg0 and Hg2+ derived from coal-burning power plants, other industrial plants, and medical and municipal waste incinerators. Mercury-bearing sewage sludge or other fertilizers applied to agricultural fields could have been the local sources of mercury. Although the mercury content correlated with organic carbon content or clay content in individual cores, when all the data were considered, there was no strong correlation between mercury and either the organic carbon or the clay-size content.

Dreher, G.B.; Follmer, L.R.

2004-01-01

8

VOLATILITY OF MERCURY FROM SOILS AMENDED WITH VARIOUS MERCURY COMPOUNDS  

EPA Science Inventory

A study was conducted to determine the rate of mercury volatilization from soils freshly amended with mercury compounds. Mercuric nitrate, mercuric chloride, mercuric acetate, mercuric oxide, and mercuric sulfide were used in conjunction with three soils: a loamy sand, a sand loa...

9

OCCURRENCE OF MICROORGANISMS RESISTANT TO MERCURY IN MERCURY CONTAMINATED SOILS AND SEDIMENTS IN PAVLODAR, KAZAKHSTAN  

EPA Science Inventory

There is extensive mercury contamination of soil surrounding a chloralkali plant in Pavlodar, Kazakhstan that operated from 1970 to 1990. High-level mercury contamination exists within the confines of the plant, at nearby off-site waste storage and evaporation ponds, and in Balky...

10

OCCURRENCE OF MERCURY-RESISTANT MICROORGANISMS IN MERCURY-CONTAMINATED SOILS AND SEDIMENTS IN PAVLODAR, KAZAKHSTAN  

EPA Science Inventory

There is extensive mercury contamination of soil surrounding a chloralkali plant in Pavlodar, Kazakhstan that operated from 1970 to 1990. High-level mercury contamination exists within the confines of the plant, at nearby off-site waste storage and evaporation ponds, and in Balky...

11

Mercury concentrations in oligohaline wetland vegetation and associated soil biogeochemistry.  

PubMed

Concentrations of mercury were determined in above- and below-ground tissues of dominant plant species, as well as soils, in the wetlands of Lake Maurepas, Louisiana. Indicators of wetland soil biogeochemical status, such as soil redox potential, pore-water nutrient concentrations, and pore-water total sulfides, were also determined. Total mercury concentrations in plant tissues were within the typical range for vegetation not exposed to mercury contamination. Similarly, total mercury concentrations in soils were typical of uncontaminated wetlands within this geographic region. Soil methyl mercury levels in this study are slightly lower than those reported in other studies of nearby wetlands. This may reflect the less extensive geographic sampling in this study, or the low water levels in the Lake Maurepas system immediately prior to and during this study, which would have altered soil biogeochemical status. This is corroborated by measurements of soil redox potential and soil pore-water nitrogen and sulfur constituents conducted during this study that suggest minimal sulfate reduction was occurring in surficial soils. This study indicates that the wetlands surrounding Lake Maurepas are typical of many uncontaminated oligohaline wetlands in the southeastern U.S. in regard to mercury concentrations. PMID:21188507

Willis, Jonathan M; Gambrell, Robert P; Hester, Mark W

2011-10-01

12

Plant Uptake of Mercury from Contaminated Soil, Oxford, Alabama  

NASA Astrophysics Data System (ADS)

Mercury contamination in the Oxford, Alabama, area is well documented in soil tests in the Snow Creek watershed. In this investigation, mercury levels in soils as well as local plant species were examined. The objectives of the study were first determining the amount of mercury in the soil and then to determine to what degree this mercury is taken in by plant tissue from specimens at each survey site. Variation in accumulation within the individual plant species (leaves, stems) was also examined. Protocols developed for this study were used to achieve both objectives and also to ascertain if a particular plant species hyper accumulates this toxin at levels that would make it useful in bioremediation of mercury contamination in the area.

Steffy, D. A.; Nichols, A. C.

2005-12-01

13

Phytoremediation of mercury-contaminated soils by Jatropha curcas.  

PubMed

Jatropha curcas plants species were tested to evaluate their phytoremediation capacity in soils contaminated by different levels of mercury. The experimental treatments consisted of four levels of mercury concentrations in the soil - T0, T1, T5, and T10 (0, 1, 5, and 10?g Hg per g soil, respectively). The total mercury content absorbed by the different plant tissues (roots, stems and leaves) was determined during four months of exposure. The growth behavior, mercury accumulation, translocation (TF) and bioconcentration (BCF) factors were determined. The different tissues in J. curcas can be classified in order of decreasing accumulation Hg as follows: roots>leaves>stems. The highest cumulative absorption of the metal occurred between the second and third month of exposure. Maximum TF was detected during the second month and ranged from 0.79 to 1.04 for the different mercury concentrations. Values of BCF ranged from 0.21 to 1.43. Soils with T1 showed significantly higher BCF (1.43) followed by T10 (1.32) and T5 (0.91), all of them at the fourth month. On the other hand TFs were low (range 0.10-0.26) at the en of the experiment. The maximum reduction of biomass (16.3%) occurred for T10 (10?g Hg g(-1)). In sum, J. curcas species showed high BCFs and low TFs, and their use could be a promising approach to remediating mercury-contaminated soils. PMID:25655698

Marrugo-Negrete, José; Durango-Hernández, José; Pinedo-Hernández, José; Olivero-Verbel, Jesús; Díez, Sergi

2015-05-01

14

Sorption of mercury in soils with different humus content  

Microsoft Academic Search

The strong sorption of mercury to humic matter in soil and water has raised the question about the influence of organic matter of different soil types on the mobilization of mercury from soil. Mercury is normally bound to humic and fulvic acids, which may be released in connection with flooding, draining and ditching. High mercury contents in fish from man-made

Martin Lodenius; Ari Seppänen; Sari Autio

1987-01-01

15

ALTERNATIVE FIELD METHODS TO TREAT MERCURY IN SOIL  

SciTech Connect

U.S. Department of Energy (DOE) used large quantities of mercury in the uranium separating process from the 1950s until the late 1980s in support of national defense. Some of this mercury, as well as other hazardous metals and radionuclides, found its way into, and under, several buildings, soil and subsurface soils and into some of the surface waters. Several of these areas may pose potential health or environmental risks and must be dealt with under current environmental regulations. DOE's National Energy Technology Laboratory (NETL) awarded a contract ''Alternative Field Methods to Treat Mercury in Soil'' to IT Group, Knoxville TN (IT) and its subcontractor NFS, Erwin, TN to identify remedial methods to clean up mercury-contaminated high-clay content soils using proven treatment chemistries. The sites of interest were the Y-12 National Security Complex located in Oak Ridge, Tennessee, the David Witherspoon properties located in Knoxville, Tennessee, and at other similarly contaminated sites. The primary laboratory-scale contract objectives were (1) to safely retrieve and test samples of contaminated soil in an approved laboratory and (2) to determine an acceptable treatment method to ensure that the mercury does not leach from the soil above regulatory levels. The leaching requirements were to meet the TC (0.2 mg/l) and UTS (0.025 mg/l) TCLP criteria. In-situ treatments were preferred to control potential mercury vapors emissions and liquid mercury spills associated with ex-situ treatments. All laboratory work was conducted in IT's and NFS laboratories. Mercury contaminated nonradioactive soil from under the Alpha 2 building in the Y-12 complex was used. This soils contained insufficient levels of leachable mercury and resulted in TCLP mercury concentrations that were similar to the applicable LDR limits. The soil was spiked at multiple levels with metallic (up to 6000 mg/l) and soluble mercury compounds (up to 500 mg/kg) to simulate expected ranges of mercury contamination and to increase the TCLP mercury values. IT/NFS investigated ambient temperature amalgamation/stabilization/fixation of mercury-contaminated soils to meet these objectives. Treatment ranged in size from a few ounces to 10 pounds. The treatability study philosophy was to develop working envelops of formulations where reasonable minimum and maximum amounts of each reagent that would successfully treat the contaminated soil were determined. The dosages investigated were based on ratios of stoichiometric reactions and applications of standard sets of formulations. The approach purposely identified formulations that failed short or longer cure-time performance criteria to define the limits of the envelope. Reagent envelops successfully met the project requirements one day after treatment and after greater than 30-day cures. The use of multiple levels of spikes allowed the establishment of reagent dosages that were successful across a broad range of mercury values, e.g., 50 to 6000 mg/kg mercury. The treatment products were damp to slightly wet material. Enough drying reagent, e.g., Portland cement or lime by-product, were added to some formulations to control the leachability of uranium and other hazardous metals and to ensure the product passed the paint filter test. Cost analyzes and conceptual designs for four alternatives for full-scale treatments were prepared. The alternatives included two in-situ treatments and two ex-situ treatments. The cost estimates were based on the results from the bench-scale study. All four alternatives treatment costs were well below the baseline costs.

Ernest F. Stine Jr; Steven T. Downey

2002-08-14

16

MERCURY RELEASE FROM DISTURBED ANOXIC SOILS  

SciTech Connect

The primary objectives of experiments conducted at the Energy & Environmental Research Center (EERC) were to provide information on the secondary release of mercury from contaminated anoxic sediments to an aqueous environment after disturbance/change of in situ physical conditions and to evaluate its migration and partitioning under controlled conditions, including implications of these processes for treatment of contaminated soils. Experimental work included (1) characterization of the mercury-contaminated sediment; (2) field bench-scale dredging simulation; (3) laboratory column study to evaluate a longer-term response to sediment disturbance; (4) mercury volatilization from sediment during controlled drying; (5) resaturation experiments to evaluate the potential for secondary release of residual mercury after disturbance, transport, drying, and resaturation, which simulate a typical scenario during soil excavation and transport to waste disposal facilities; and (6) mercury speciation and potential for methylation during column incubation experiments.

Jaroslav Solc; Bethany A. Bolles

2001-07-16

17

Mercury  

MedlinePLUS

... crystals. Mercury also combines with carbon to make organic mercury compounds. The most common one, methylmercury, is produced mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the amounts of methylmercury that these ...

18

ABIOLOGICAL METHYLATION OF MERCURY IN SOIL  

EPA Science Inventory

This work defines several factors influencing the methylation of mercuric ion in soil. Two of the most important findings were that it is possible to extract the mercury methylating factor from soil with a solution of 0.5N sodium hydroxide and that this factor is responsible for ...

19

ALTERNATIVE FIELD METHODS TO TREAT MERCURY IN SOIL  

SciTech Connect

The Department of Energy (DOE) currently has mercury (Hg) contaminated materials and soils at the various sites. Figure 1-1 (from http://www.ct.ornl.gov/stcg.hg/) shows the estimated distribution of mercury contaminated waste at the various DOE sites. Oak Ridge and Idaho sites have the largest deposits of contaminated materials. The majorities of these contaminated materials are soils, sludges, debris, and waste waters. This project concerns treatment of mercury contaminated soils. The technology is applicable to many DOE sites, in-particular, the Y-12 National Security Complex in Oak Ridge Tennessee and Idaho National Engineering and Environmental Laboratory (INEEL). These sites have the majority of the soils and sediments contaminated with mercury. The soils may also be contaminated with other hazardous metals and radionuclides. At the Y12 plant, the baseline treatment method for mercury contaminated soil is low temperature thermal desorption (LTTD), followed by on-site landfill disposal. LTTD is relatively expensive (estimated cost of treatment which exclude disposal cost for the collect mercury is greater than $740/per cubic yard [cy] at Y-12), does not treat any of the metal or radionuclides. DOE is seeking a less costly alternative to the baseline technology. As described in the solicitation (DE-RA-01NT41030), this project initially focused on evaluating cost-effective in-situ alternatives to stabilize or remove the mercury (Hg) contamination from high-clay content soil. It was believed that ex-situ treatment of soil contaminated with significant quantities of free-liquid mercury might pose challenges during excavation and handling. Such challenges may include controlling potential mercury vapors and containing liquid mercury beads. As described below, the focus of this project was expanded to include consideration of ex-situ treatment after award of the contract to International Technology Corporation (IT). After award of the contract, IT became part of Shaw E&I. The company will be denoted as ''IT'' for the rest of the document since the original contract was awarded to IT. This report details IT, Knoxville, TN and its subcontractor Nuclear Fuels Services (NFS) study to investigate alternative mercury treatment technology. The IT/NFS team demonstrated two processes for the amalgamation/stabilization/fixation of mercury and potentially Resource Conservation Recovery Act (RCRA) and radionuclide-contaminated soils. This project was to identify and demonstrate remedial methods to clean up mercury-contaminated soil using established treatment chemistries on soil from the Oak Ridge Reservation, Y-12 National Security Complex, the off-site David Witherspoon properties, and/or other similarly contaminated sites. Soil from the basement of Y-12 Plant Alpha 2 Building at the Oak Ridge Reservation was received at IT and NFS on December 20, 2001. Soils from the other locations were not investigated. The soil had background levels of radioactivity and had all eight RCRA metals well below the Toxicity Characteristic (TC) criteria. This project addresses the new DOE Environmental Management Thrust 2 ''Alternative Approaches to Current High Risk/High Cost Baselines''. Successful completion of this project will provide a step-change in DOE's treatment ability.

Ernie F. Stine

2002-08-14

20

FACTORS INFLUENCING THE VOLATILIZATION OF MERCURY FROM SOIL  

EPA Science Inventory

Mercury volatilization from soils amended to 1 ppm mercury with mercuric nitrate ceased within 1 week after application. During the first week, 20% of the applied mercury was lost from a silty clay-loam soil and 43% was lost from a loamy sand soil. Volatilization of Hg from the l...

21

Spatial distribution of mercury and arsenic levels in water, soil and cassava plants in a community with long history of gold mining in Tanzania.  

PubMed

This study examined the spatial distribution of total mercury (THg) and total arsenic (TAs) in water, soil and cassava (Manihot esculenta) (leaves and roots) samples taken from areas in Rwamagasa village in northwestern Tanzania where daily living activities occur in close proximity to extensive artisanal and small scale gold mining. Results indicated that 33.3 % of the water sources had THg levels above the WHO guideline of 1.0 µg/L for safe drinking water, and 12.5 % had TAs levels above 10 µg/L. Cassava leaves were found to have higher THg (ranging from 8.3 to 167 µg/kg) and TAs (ranging from 60 to 1,120 µg/kg) levels than cassava roots, which ranged between 1.2-8.3 µg/kg for THg and 25-310 µg/kg for TAs. Concentrations of THg and TAs in soil samples ranged between 5.8-1,759 and 183-20,298 µg/kg, respectively. Both THg and TAs were found to be distributed throughout Rwamagasa village. PMID:24923470

Nyanza, Elias C; Dewey, Deborah; Thomas, Deborah S K; Davey, Mark; Ngallaba, Sospatro E

2014-12-01

22

Mercury and plants in contaminated soils. 2: Environmental and physiological factors governing mercury flux to the atmosphere  

SciTech Connect

The objective of this study was to evaluate the role of physiological and environmental factors in governing the flux of elemental mercury from plants to the atmosphere. Five species (Lepidium latifolium, Artemisia douglasiana, Caulanthus sp., Fragaria vesca, and Eucalyptus globulus) with different ecological and physiological attributes and growing in soils with high levels of mercury contamination were examined. Studies were conducted in a whole-plant, gas-exchange chamber providing precise control of environmental conditions, and mercury flux was estimated using the mass balance approach. Mercury flux increased linearly as a function of temperature within the range of 20 to 40 C, and the mean temperature coefficient (Q{sub 10}) was 2.04. The temperature dependence of mercury flux was attributed to changes in the contaminant`s vapor pressure in the leaf interior. Mercury flux from foliage increased linearly as a function of irradiance within the range of 500 to 1,500 {micro}mol m/s, and the light enhancement of mercury flux was within a factor of 2.0 to 2.5 for all species. Even though the leaf-to-atmosphere diffusive path for mercury vapor from foliage is similar to that of water vapor, stomatal conductance played a secondary role in governing mercury flux. In a quantitative comparison with other studies in both laboratory and field settings, a strong linear relationship is evident between mercury vapor flux and the natural logarithm of soil mercury concentration, and this relationship may have predictive value in developing regional- and continental-scale mercury budgets. The most critical factors governing mercury flux from plants are mercury concentration in the soil, leaf area index, temperature, and irradiance.

Leonard, T.L.; Gustin, M.S.; Fernandez, G.C.J. [Univ. of Nevada, Reno, NV (United States); Taylor, G.E. Jr. [George Mason Univ., Fairfax, VA (United States). Dept. of Biology

1998-10-01

23

Ammonium thiosulphate enhanced phytoextraction from mercury contaminated soil--results from a greenhouse study.  

PubMed

According to the 'hard and soft' acid-base principle, mercury is a 'soft metal' and will preferentially form soluble chemical complexes with sulphur-containing ligands. In this work mercury uptake by Chenopodium glaucum L. growing on mercury-contaminated soil was promoted using ammonium thiosulphate. The relative geochemical fractionation of mercury in the soil was subsequently investigated as a function of plant growth with and without thiosulphate amendment. The results indicate that the solubility of mercury is significantly increased through the application of thiosulphate to the soil. Substantially higher mercury levels were found in C. glaucum L. treated with 2 g kg(-1) thiosulphate of soil when compared to the non-treated plants. Compared with initial soil, soluble and exchangeable fractions were increased both in planted and planted treated plants. However, no significant difference was observed between the soils of the planted and planted treated plants. The oxide-bound mercury concentration was significantly decreased for the planted soil (treated and non-treated) at the end of the experiment. Moreover, this fraction was highly correlated with the plant tissue mercury concentration. Taken together, thiosulphate assisted phytoextraction could be used to reduce environmental risk apparent for mercury-contaminated soil through reducing the oxide bound fractions, while managing the bioavailable fractions (compared with no treated plant). PMID:21122988

Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Qiu, Guangle; Ping, Li; Bao, Zhengduo

2011-02-15

24

The relationship between mental retardation and developmental delays in children and the levels of arsenic, mercury and lead in soil samples taken near their mother's residence during pregnancy  

PubMed Central

This study was designed to evaluate the association between lead, mercury, and arsenic in the soil near maternal residences during pregnancy and mental retardation or developmental disability (MR/DD) in children. The study was conducted using 6,048 mothers who did not move throughout their pregnancies and lived within six strips of land in South Carolina and were insured by Medicaid between January 1, 1997 and December 31, 2002. The mother child pairs were then followed until June 1, 2008, through their Medicaid reimbursement files, to identify children diagnosed with MR/DD. The soil was sampled for mercury (Hg), lead (Pb), and As based on a uniform grid, and the soil concentrations were Kriged to estimate chemical concentration at individual locations. We identified a significant relationship between MR/DD and As, and the form of the relationship was nonlinear, after controlling for other known risk factors. PMID:20045663

Liu, Yuan; McDermott, Suzanne; Lawson, Andrew; Aelion, C. Marjorie

2010-01-01

25

Mercury  

MedlinePLUS

Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

26

Mercury in soil gas and air--A potential tool in mineral exploration  

USGS Publications Warehouse

The mercury content in soil gas and in the atmosphere was measured in several mining districts to test the possibility that the mercury content in the atmosphere is higher over ore deposits than over barren ground. At Cortez, Nev., the distribution of anorhalous amounts of mercury in the air collected at ground level (soil gas) correlates well with the distribution of gold-bearing rocks that are covered by as much as 100 feet of gravel. The mercury content in the atmosphere collected at an altitude of 200 feet by an aircraft was 20 times background over a mercury posit and 10 times background over two porphyry copper deposits. Measurement of mercury in soil gas and air may prove to be a valuable exploration tool.

McCarthy, Joseph Howard; Vaughn, W.W.; Learned, R.E.; Meuschke, J.L.

1969-01-01

27

Thermal-treated soil for mercury removal: Soil and phytotoxicity tests  

SciTech Connect

Mercury (Hg) contamination of soils and sediments is one of many environmental problems at the Oak Ridge Reservation, Oak Ridge, TN. Mercury-contaminated soil from the Lower East Fork Poplar Creek (LEFPC) at the Oak Ridge Reservation was treated thermally to reduce Hg concentration to a below target level (20 mg kg{sup {minus}1}) as a pilot scale thermal treatment demonstration. As a part of performance evaluation, the soil characteristics and plant growth response of the untreated and treated soil were examined. The soil treated at 350 C retained most of its original soil properties, but the soil treated at 600 C exhibited considerable changes in mineralogical composition and physicochemical characteristics. Growth and physiological response of the three plant species radish (Raphanus sativus L.), fescue (Festuca arundinacea Schreb.), and oat (Avena sativa L.) indicated adverse effects of the thermal treatment. The addition of N fertilizer had beneficial effects in the 350 C treated soil, but had little beneficial effect in the 600 C treated soil. Some changes of soil characteristics induced by thermal treatment cannot be avoided. Soil characteristics and phytotoxicity test results strongly suggest that changes occurring following the 350 C treatment do not limit the use of the treated soil to refill the excavated site for full-scale remediation. The only problem with the 350 C treatment is that small amounts of Hg compounds (<15 mg kg{sup {minus}1}) remain in the soil and a processing cost of $45/Mg.

Roh, Y.; Edwards, N.T.; Lee, S.Y.; Stiles, C.A.; Armes, S.; Foss, J.E.

2000-04-01

28

Mercury transportation in soil via using gypsum from flue gas desulfurization unit in coal-fired power plant.  

PubMed

The mercury flux in soils was investigated, which were amended by gypsums from flue gas desulphurization (FGD) units of coal-fired power plants. Studies have been carried out in confined greenhouses using FGD gypsum treated soils. Major research focus is uptakes of mercury by plants, and emission of mercury into the atmosphere under varying application rates of FGD gypsum, simulating rainfall irrigations, soils, and plants types. Higher FGD gypsum application rates generally led to higher mercury concentrations in the soils, the increased mercury emissions into the atmosphere, and the increased mercury contents in plants (especially in roots and leaves). Soil properties and plant species can play important roles in mercury transports. Some plants, such as tall fescue, were able to prevent mercury from atmospheric emission and infiltration in the soil. Mercury concentration in the stem of plants was found to be increased and then leveled off upon increasing FGD gypsum application. However, mercury in roots and leaves was generally increased upon increasing FGD gypsum application rates. Some mercury was likely absorbed by leaves of plants from emitted mercury in the atmosphere. PMID:24520729

Wang, Kelin; Orndorff, William; Cao, Yan; Pan, Weiping

2013-09-01

29

Micrometeorological methods for measurements of mercury emissions over contaminated soils  

SciTech Connect

As part of a larger study involving development and application of field and laboratory methods (micrometeorological, dynamic enclosure chamber, and controlled laboratory chamber methods) to measure the air/surface exchange of Hg vapor, we performed a series of preliminary measurements over contaminated soils. From March--April 1993, we used the modified Bowen ratio (MBR) method to measure emission rates of mercury over a floodplain contaminated with mercury near Oak Ridge, TN. The mercury emission rates measured from contaminated EFPC soils using the MBR method during early spring show that (1) in all cases, the contaminated soils acted as a source of mercury to the atmosphere with source strengths ranging from 17 to 160 ng m{sup {minus}2} h{sup {minus}1}; and (2) the strengths of mercury emissions can be greatly influenced by the combined effects of surface soil temperature, residence time of air masses over the source area, and turbulence conditions. The mercury fluxes measured in a controlled flow chamber indicate that contaminated soils can exhibit up to an order of magnitude higher emission rates of Hg under conditions of elevated soil temperature, soil structure disturbance, and high turbulence. Mercury emissions from contaminated soils exceeded emissions from background soils by one to two orders of magnitude.

Kim, K.H.; Lindberg, S.E.; Hanson, P.J.; Owens, J. [Oak Ridge National Lab., TN (United States); Myers, T.P. [National Oceanic and Atmospheric Administration, Oak Ridge, TN (United States). Air Resources Lab. Atmospheric Turbulence and Diffusion Div.

1993-12-31

30

Distribution of mercury, methyl mercury and organic sulphur species in soil, soil solution and stream of a boreal forest catchment  

Microsoft Academic Search

Concentrations of methyl mercury, CH3Hg (II), total mercury, Hgtot = CH3Hg (II) + Hg (II), and organic sulphur species were determined in soils, soil solutions and streams of a small (50 ha) boreal forest catchment in northern Sweden. The CH3Hg (II)\\/Hgtot ratio decreased from 1.2–17.2% in the peaty stream bank soils to 0.4–0.8% in mineral and peat soils 20 m

Ulf Skyllberg; Jin Qian; Wolfgang Frech; Kang Xia; William F. Bleam

2003-01-01

31

Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds  

SciTech Connect

The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds.. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl{sub 2}, and Hg(NO{sub 3}){sub 2}, were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots (<65 mg/kg), even though root mercury accumulation is significant (maximum 2298 mg/kg). Consequently, this plant species may not be suitable for mercury phyto-remediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phyto-extraction. During one experiment, Chinese brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 parts-per-million (ppm) and 1000 ppm HgCl{sub 2} powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl{sub 2}, or Hg(NO{sub 3}){sub 2}. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties. (authors)

Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L. [Institute for Clean Energy Technology (ICET), Mississippi State University, 205 Research Blvd, Starkville, MS 39759 (United States)

2007-07-01

32

Occupational exposure to mercury. What is a safe level?  

PubMed Central

QUESTION: One of my pregnant patients, a dental hygienist, uses mercury in her workplace, but appears to have no symptoms of mercury toxicity. She has heard that mercury might affect her fetus. What should I recommend to her? What is a safe level of mercury in the air for pregnant women? ANSWER: Testing for levels of mercury in whole blood and, preferably, urine is useful for confirming exposure. Currently, mercury vapour concentrations greater than 0.01 mg/m3 are considered unsafe. Also, women of childbearing age should avoid contact with mercury salts in the workplace. PMID:10889853

Moienafshari, R.; Bar-Oz, B.; Koren, G.

1999-01-01

33

Engineering tobacco to remove mercury from polluted soil.  

PubMed

Tobacco is an ideal plant for modification to remove mercury from soil. Although several transgenic tobacco strains have been developed, they either release elemental mercury directly into the air or are only capable of accumulating small quantities of mercury. In this study, we constructed two transgenic tobacco lines: Ntk-7 (a tobacco plant transformed with merT-merP-merB1-merB2-ppk) and Ntp-36 (tobacco transformed with merT-merP-merB1-merB2-pcs1). The genes merT, merP, merB1, and merB2 were obtained from the well-known mercury-resistant bacterium Pseudomonas K-62. Ppk is a gene that encodes polyphosphate kinase, a key enzyme for synthesizing polyphosphate in Enterobacter aerogenes. Pcs1 is a tobacco gene that encodes phytochelatin synthase, which is the key enzyme for phytochelatin synthesis. The genes were linked with LP4/2A, a sequence that encodes a well-known linker peptide. The results demonstrate that all foreign genes can be abundantly expressed. The mercury resistance of Ntk-7 and Ntp-36 was much higher than that of the wild type whether tested with organic mercury or with mercuric ions. The transformed plants can accumulate significantly more mercury than the wild type, and Ntp-36 can accumulate more mercury from soil than Ntk-7. In mercury-polluted soil, the mercury content in Ntp-36's root can reach up to 251 ?g/g. This is the first report to indicate that engineered tobacco can not only accumulate mercury from soil but also retain this mercury within the plant. Ntp-36 has good prospects for application in bioremediation for mercury pollution. PMID:25690353

Chang, S; Wei, F; Yang, Y; Wang, A; Jin, Z; Li, J; He, Y; Shu, H

2015-04-01

34

Human and ecological remediation goals for soil mercury at East Fork Poplar Creek, Oak Ridge, TN  

SciTech Connect

Mercury, used in the past production of enriched lithium by the Department of Energy, is the principal chemical of concern in the 14-mile floodplain of East Fork Poplar Creek (EFPC). SAIC has developed risk-based remediation goal options (RGOS) for mercury in EFPC soils to protect the most sensitive human receptors. The existing chronic oral RfD for mercury is based on exposure of laboratory species to mercuric chloride. However, speciation and leaching/availability studies (conducted by EPA EMSL and Oak Ridge National Laboratory) indicated less soluble and less toxic mercury species, principally mercuric sulfide, with measurable quantities of metallic mercury also present, predominate in EFPC floodplain soils. SAIC derived human health RGOs using deterministic and probabilistic methods and incorporated the probability density function for bioavailability of mercury species from leaching/availability data generated by ORNL. Monte Carlo simulation was used in uncertainty analysis and supported the derivation of a protective, but realistic risk-based remediation goal of 400 mg mercury/kg soil. For ecological risk assessment, RGOs were based on risks through food chains from contaminants in soil. The authors describe a terrestrial food-chain model of contaminant transfer to primary producers, first-order consumers, mid-level predators, and top-level predators. The model uses published toxicity data, site-specific contaminant concentrations, and bioaccumulation factors calculated from measured body burdens of floodplain organisms to compute RGOs for various combinations of exposure parameters. Model calculations show that under reasonably conservative conditions, mid-level predators have the highest exposures relative to dietary limits and, therefore, require the lowest soil-mercury RGOs. Mercury concentrations of {approximately}500 mg/kg are protective of the receptor populations exposed through food chains at this site.

Zafran, F.A.; Cornaby, B.W.; Hadden, C.T. [Science Applications International Corp., McLean, VA (United States). Engineering and Environmental Compliance Group; [Science Applications International Corp., Oak Ridge, TN (United States)

1995-12-31

35

The role of natural purified humic acids in modifying mercury accessibility in water and soil  

SciTech Connect

We investigated the influence of different humic acids (HAs, extracted from lignite, compost, and forest soil) on mercury mobility and availability both in a model solution and in soil samples from a mercury-polluted region. The technique of diffusive gradients in thin-films (DGT), which is capable of measuring: (i) free metal in solution: (ii) dissociated metal complexes previously mobilized by HA; (iii) mobilized metal-HA complexes that liberate metals by dissociation or by exchange reaction between the metal-HA complexes and the chelating groups on the resin-gel, was used in solutions and soils. The DGT measurements in solution, together with ultrafiltration, allowed estimation of the lability of Hg-HA complexes. Ultrafiltration results were also compared with predictions made by the windermere humic-aqueous model (WHAM). According to both these different approaches, Hg{sup 2+} resulted nearly 100% complexed by HAs, whereas results from ultrafiltration showed that 32 to 72% of the CH{sub 4}Hg{sup +} was bound to the HAs, with higher values for compost and lower values for forest and Aldrich HA. The DGT-measured mercury in soils was below 0.20 {mu}g L{sup -1}, irrespective of the extent of the contamination. Addition of HA increased the concentration of DGT-measured mercury in soil solution up to 100-fold in the contaminated soil and up to 30-fold in the control soil. The level of the increase also depended on the HA. The smallest increase (about 10 times) was found for lignite HA in both control and contaminated soils. The addition of forest HA gave the largest increases in DGT-measured mercury, in particular for the contaminated soil. Overall, the results demonstrated that DGT can be used for estimating the lability of mercury complexes in solution and for verifying enhanced mercury mobility when HA is added to contaminated soils.

Cattani, I.; Zhang, H.; Beone, G.M.; Del Re, A.A.M.; Boccelli, R.; Trevisan, M. [University of Cattolica Sacro Cuore, Piacenza (Italy)

2009-03-15

36

Removal of Mercury from Clayey Soils Using Electrokinetics  

Microsoft Academic Search

Numerous sites have been polluted with mercury as a result of accidental spills and improper disposal practices, and these mercury-contaminated sites may have adverse effects on human health and the environment. Innovative and cost-effective remediation techniques are urgently needed, and this study was performed to investigate the use of electrokinetics for mercury-contaminated soils. Initially, batch tests were performed on two

Krishna R. Reddy; Carlos Chaparro; Richard E. Saichek

2003-01-01

37

Distribution of mercury species in soil from a mercury-contaminated site  

Microsoft Academic Search

The distribution of mercury species was determined in soil from a site with Hg contamination. Mercury contamination was primarily confined to the top 40 cm of soil, and the concentration of total Hg ranged from 0.5 to 3000 µg Hg g-1. Of total Hg present, we determined that 91% was inorganic, 0.01% organic (as methyl Hg), and 6% elemental Hg.

N. W. Revis; T. R. Osborne; G. Holdsworth; C. Hadden

1989-01-01

38

Impact of gold mining associated with mercury contamination in soil, biota sediments and tailings in Kenya.  

PubMed

This work considered the environmental impact of artisanal mining gold activity in the Migori-Transmara area (Kenya). From artisanal gold mining, mercury is released to the environment, thus contributing to degradation of soil and water bodies. High mercury contents have been quantified in soil (140 ?g kg(-1)), sediment (430 ?g kg(-1)) and tailings (8,900 ?g kg(-1)), as expected. The results reveal that the mechanism for transporting mercury to the terrestrial ecosystem is associated with wet and dry depositions. Lichens and mosses, used as bioindicators of pollution, are related to the proximity to mining areas. The further the distance from mining areas, the lower the mercury levels. This study also provides risk maps to evaluate potential negative repercussions. We conclude that the Migori-Transmara region can be considered a strongly polluted area with high mercury contents. The technology used to extract gold throughout amalgamation processes causes a high degree of mercury pollution around this gold mining area. Thus, alternative gold extraction methods should be considered to reduce mercury levels that can be released to the environment. PMID:24943890

Odumo, Benjamin Okang'; Carbonell, Gregoria; Angeyo, Hudson Kalambuka; Patel, Jayanti Purshottam; Torrijos, Manuel; Rodríguez Martín, José Antonio

2014-11-01

39

Wavelengths, Energy Level Classifications, and Energy Levels for the Spectrum of Neutral Mercury  

E-print Network

Wavelengths, Energy Level Classifications, and Energy Levels for the Spectrum of Neutral Mercury E of neutral mercury Hg I for both the single isotope 198 Hg and for mercury in its natural isotopic abundance of neutral mercury for both 198 Hg and the natural isotopic mixture. Tabular data for 105 classified lines

Magee, Joseph W.

40

Atmospheric emission and plant uptake of mercury from agricultural soils near the Almaden mercury mine  

Microsoft Academic Search

Surface soils collected near the Almaden, Spain, mercury mine reflected increasing concentrations of mercury (Hg) with proximity to the mine due to weathered mineral deposits and to atmospheric deposition of Hg from the smelter. Extractions with NaHCOâ or NHâOAc removed small amounts of Hg from both control (20 km from the mine; total Hg = 2.3 ..mu..g\\/g) and mine site

S. E. Lindberg; D. R. Jackson; J. W. Huckabee; S. A. Janzen; M. J. Levin; J. R. Lund

1979-01-01

41

Mercury in waters, soils, and sediments of the New Jersey Coastal Plain: A comparison of regional distribution and mobility with the mercury contamination at the William J. Hughes Technical Center, Atlantic County, New Jersey  

USGS Publications Warehouse

Mercury in soils, surface water, and groundwater at the William J. Hughes Technical Center , Atlantic County, New Jersey, has been found at levels that exceed established background concentrations in Coastal Plain waters, and, in some cases, New Jersey State standards for mercury in various media. As of 2012, it is not known whether this mercury is part of regional mercury contamination or whether it is related to former military activities. Regionally, groundwater supplying about 700 domestic wells in the New Jersey Coastal Plain is contaminated with mercury that appears to be derived from anthropogenic inputs, such as agricultural pesticide use and atmospheric deposition. High levels of mercury occasionally are found in Coastal Plain soils, but disturbance during residential development on former agricultural land is thought to have mobilized any mercury applied during farming, a hypothesis borne out by experiments leaching mercury from soils. In the unsewered residential areas with mercury-contaminated groundwater, septic-system effluent is believed to create reducing conditions in which mercury sorbed to subsoils is mobilized to groundwater. In comparing the levels of mercury found in soils, sediments, streamwater, and groundwater at the William J. Hughes Technical Center site with those found regionally, mercury concentrations in groundwater in the region are, in some cases, substantially higher than those found in groundwater at the William J. Hughes Technical Center site. Nevertheless, concentrations of mercury in streamwater at the site are, in some instances, higher than most found regionally. The mercury contents in soils and sediment at the William J. Hughes Technical Center site are substantially higher than those found to date (2012) in the region, indicating that a source other than regional sources may be present at the site.

Barringer, Julia L.; Szabo, Zoltan; Reilly, Pamela A.

2012-01-01

42

Binding of mercury in soils and attic dust in the Idrija mercury mine area (Slovenia).  

PubMed

Total Hg concentrations and Hg speciation were determined in soils and attic dust in a 160 km2 area around Idrija mercury mine. Attic dust as well as a sample of soil was collected at 100 locations. Mercury phases were separated into cinnabar and non-cinnabar compounds via a thermo-desorption technique. The amount of the non-cinnabar fraction is important since it is potentially bioavailable and results are needed for further risk assessment studies. The concentrations of Hg in attic dust are many times higher than in surrounding soils and the attic dust/soil ratio changes with distance. The highest concentration ratios were identified at the greatest distance from the source of pollution and the lowest close to the source of pollution. This confirms the impact of air emissions on the wider area around Idrija. Furthermore the spatial mercury distribution in the attic dust shows that the influence of atmospheric emissions caused by the Idrija smelter resulted in impacts on the environment on a regional scale. The portions of non-cinnabar compounds increase with distance from the mercury source in both sampling media. Non-cinnabar fractions were found to be enriched in distant areas where fine grained material was deposited. There were two different transport mechanisms of dust particles and gaseous Hg(0) during the mercury production period. Obviously coarse grained particles, with mostly cinnabar-bound Hg settled in the immediate vicinity of the smokestack of the smelter, whereas the fine grained fraction could be dispersed further ahead. This is represented by the percentage of cinnabar-bound Hg in attic dust and soil decreasing with distance from the smelter. Gaseous Hg(0) is probably bound to fine and ultrafine aerosols with longer residence time against deposition. The consequence is that fine grained material with Hg2+ and Hg0 prevails in remote localities and is bound in soils and dust with matrix and organic matter as non-cinnabar mercury compounds. The distributions of mercury species in attic dust and soils along the Idrijca River show that in the region from Idrija to Spodnja Idrija the portions of cinnabar and non-cinnabar are about equal, while in the upper and in the lower Idrijca valley non-cinnabar bound mercury prevails. The applicability of attic dust for tracing the mercury halo in the Idrija area was successfully shown. PMID:16764912

Gosar, Mateja; Sajn, Robert; Biester, Harald

2006-10-01

43

Forestry, Wildlife and Fisheries Graduate Seminar "Trees Adaptation to Mercury Contaminated Soils  

E-print Network

1 Forestry, Wildlife and Fisheries Graduate Seminar "Trees Adaptation to Mercury Contaminated Soils contaminated soils along EFPC? · What is the primary symbiotic association? · Where is the mercury localized/sand media. · Inoculate with soil cores obtained from mercury contaminated sites along the creek allowed

Gray, Matthew

44

SULFUR POLYMER STABILIZATION/SOLIDIFICATION TREATABILITY STUDY OF MERCURY CONTAMINATED SOIL FROM THE Y-12 SITE  

E-print Network

SULFUR POLYMER STABILIZATION/SOLIDIFICATION TREATABILITY STUDY OF MERCURY CONTAMINATED SOIL FROM of Mercury Contaminated Soil from the Y-12 Site P.D. Kalb, L. Milian, S.P. Yim November 30, 2012 Prepared for-12 Plant) has extensive mercury-contamination in building structures, soils, storm sewer sediments

Johnson, Peter D.

45

Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil  

DOEpatents

The process of treating elemental mercury within the soil is provided by introducing into the soil a heated vapor phase of elemental sulfur. As the vapor phase of elemental sulfur cools, sulfur is precipitated within the soil and then reacts with any elemental mercury thereby producing a reaction product that is less hazardous than elemental mercury.

Looney, Brian B.; Denham, Miles E.; Jackson, Dennis G.

2014-07-08

46

Natural mercury isotope variation in coal deposits and organic soils  

SciTech Connect

There is a need to distinguish among sources of Hg to the atmosphere in order to more fully understand global Hg pollution. In this study we investigate whether coal deposits within the United States, China, and Russia-Kazakhstan, which are three of the five greatest coal-producing regions, have diagnostic Hg isotopic fingerprints that can be used to discriminate among Hg sources. We also investigate the Hg isotopic composition of modern organic soil horizons developed in areas distant from point sources of Hg in North America. Mercury stored in coal deposits displays a wide range of both mass dependent fractionation and mass independent fractionation. {delta}{sup 202}Hg varies in coals by 3{per_thousand} and {Delta}{sup 201}Hg varies by 0.9{per_thousand}. Combining these two Hg isotope signals results in what may be a unique isotopic 'fingerprint' for many coal deposits. Mass independent fractionation of mercury has been demonstrated to occur during photochemical reactions of mercury. This suggests that Hg found in most coal deposits was subjected to photochemical reduction near the Earth's surface prior to deposition. The similarity in MDF and MIF of modern organic soils and coals from North America suggests that Hg deposition from coal may have imprinted an isotopic signature on soils. This research offers a new tool for characterizing mercury inputs from natural and anthropogenic sources to the atmosphere and provides new insights into the geochemistry of mercury in coal and soils. 35 refs., 2 figs., 1 tab.

Abir, Biswas; Joel D. Blum; Bridget A. Bergquist; Gerald J. Keeler; Zhouqing Xie [University of Michigan, Ann Arbor, MI (United States). Department of Geological Sciences

2008-11-15

47

Effects of metal-soil contact time on the extraction of mercury from soils.  

PubMed

To investigate the mercury aging process in soils, soil samples were spiked with inorganic mercury (Hg(II)) or methylated mercury (MeHg) and incubated for 2, 7, 14 or 28 days in the laboratory. Potential availability of mercury, assessed by bovine serum albumin (BSA) or calcium chloride (CaCl2) extraction, decreased by 2-19 times for Hg(II) or 2-6 times for MeHg, when the contact time increased from 2 to 28 days. Decreased Hg(II) extraction could be explained by Hg(II) geochemical fractionation, i.e., Hg(II) migrated from more mobile fractions (water soluble and stomach acid soluble fractions) to refractory ones (organo-complexed, strongly complexed and residual fractions) over time, resulting in more stable association of Hg(II) with soils. In addition, decrease of mercury extraction was more evident in soils with lower organic content in most treatments, suggesting that organic matter may potentially play an important role in mercury aging process. In view of the significant decreased Hg(II) or MeHg extraction with prolonged contact time, mercury aging process should be taken into account when assessing risk of mercury in contaminated soils. PMID:25613855

Ma, Lan; Zhong, Huan; Wu, Yong-Gui

2015-03-01

48

Feather growth influences blood mercury level of young songbirds.  

PubMed

Dynamics of mercury in feathers and blood of free-living songbirds is poorly understood. Nestling eastern bluebirds (Sialia sialis) living along the mercury-contaminated South River (Virginia, USA) had blood mercury levels an order of magnitude lower than their parents (nestling: 0.09 +/- 0.06 mg/kg [mean +/- standard deviation], n = 156; adult: 1.21 +/- 0.57 mg/kg, n = 86). To test whether this low blood mercury was the result of mercury sequestration in rapidly growing feathers, we repeatedly sampled free-living juveniles throughout the period of feather growth and molt. Mean blood mercury concentrations increased to 0.52 +/- 0.36 mg/kg (n = 44) after the completion of feather growth. Some individuals had reached adult blood mercury levels within three months of leaving the nest, but levels dropped to 0.20 +/- 0.09 mg/kg (n = 11) once the autumn molt had begun. Most studies of mercury contamination in juvenile birds have focused on recently hatched young with thousands of rapidly growing feathers. However, the highest risk period for mercury intoxication in young birds may be during the vulnerable period after fledging, when feathers no longer serve as a buffer against dietary mercury. We found that nestling blood mercury levels were not indicative of the extent of contamination because a large portion of the ingested mercury ended up in feathers. The present study demonstrates unequivocally that in songbirds blood mercury level is influenced strongly by the growth and molt of feathers. PMID:18937528

Condon, Anne M; Cristol, Daniel A

2009-02-01

49

Atmospheric deposition of mercury in Atlantic Forest and ecological risk to soil fauna  

NASA Astrophysics Data System (ADS)

The increasing levels of mercury (Hg) found in the atmosphere nowadays has a great contribution from anthropogenic sources and has been a great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. Certainly, the petroleum refineries have significant contribution, seen that 100 million m3 of crude oil are annually processed. These refineries contribute with low generation of solid waste; however, a large fraction of Hg can be emitted to the atmosphere. There are sixteen refineries in Brazil, three of them located in the state of Rio de Janeiro. The Hg is a toxic and hazardous trace element, naturally found in the earth crust. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of great importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transfer to the soil through litterfall, which play an important role as Hg sink. The Atlantic Forest of Brazil is the greater contributor of fauna and flora biodiversity in the world and, according to recent studies, this biome has the highest concentrations of mercury in litter in the world, as well as in China, at Subtropical Forest. Ecotoxicological assessments can predict the potential ecological risk of Hg toxicity in the soil can lead to impact the soil fauna and indirectly other trophic levels of the food chain within one or more ecosystems. This study aims to determine mercury levels that represent risks to diversity and functioning of soil fauna in tropical forest soils. The study is conducted in two forest areas inserted into conservation units of Rio de Janeiro state. One area is located next to an important petroleum refinery in activity since fifty-two years ago, whereas the other one is located next to other refinery under construction (beginning activities in 2015), which will be the largest refinery of Brazil and, consequently, with less anthropogenic influences for the moment. Ecological risk assessments are conducted together with ecotoxicological tests in natural and artificial tropical soils, using exotic and native species of the soil fauna, naturally present in the area of study, in order to determine the risk of mercury in soil and litter in tropical forest. Previous results confirm higher concentrations of mercury in litter and soil of the forest area closest to the operating refinery. The presence of Hg seems to select the size of the organisms as well as the abundance and diversity of the soil fauna that remain in tropical forest.

Cristhy Buch, Andressa; Cabral Teixeira, Daniel; Fernandes Correia, Maria Elizabeth; Vieira Silva-Filho, Emmanoel

2014-05-01

50

Mercury exposure in French Guiana: Levels and determinants  

SciTech Connect

Mercury is used widely for gold extraction in French Guiana and throughout the entire Amazon basin. To evaluate contamination among the general population, the authors chose individuals who attended 13 health centers and maternity hospitals dispersed geographically across the territory and served Guiana`s different populations. Five hundred individuals (109 pregnant women, 255 other adults, and 136 children) who received care at one of the centers were selected randomly for this study. Each individual answered a questionnaire and provided a hair sample. The authors determined mercury in hair with atomic absorption spectrometry. The following mean levels of mercury were observed: 1.6 {micro}g/g among pregnant women; 3.4 {micro}g/g among other adults; and 2.5 {micro}g/g among children. Diet factors contributed the most to mercury levels, especially consumption of freshwater fish and livers from game. Other factors, including age, dental amalgams, use of skin-lightening cosmetics, and residence near a gold-mining community, did not contribute significantly to mercury levels. Overall, 12% of the samples contained mercury levels in excess of 10 {micro}g/g, but in some Amerindian communities up to 79% of the children had hair mercury levels that exceeded 10 {micro}g/g. The results of this study indicated that (a) diet played a predominant role in total mercury burden, and (b) in some communities, mercury contamination exceeded safe levels.

Cordier, S.; Mandereau, L. [Inst. National de Sante et de Recherche Medicale, Villejuif (France); Grasmick, C. [Direction Generale de la Sante, Paris (France); Paquier-Passelaigue, M. [Direction Dept. des Affaires Sanitaires et Sociales, Cayenne (France); Weber, J.P. [Centre de Toxicologie du Quebec (Canada); Jouan, M. [Reseau National de Sante Publique, St. Maurice (France)

1998-07-01

51

Evaluation of mercury in urine as an indicator of exposure to low levels of mercury vapor.  

PubMed Central

We conducted a pooled analysis to investigate the relationship between exposure to elemental mercury in air and resulting urinary mercury levels, specifically at lower air levels relevant for environmental exposures and public health goals (i.e., < 50 microg/m3 down to 1.0 microg/m3). Ten studies reporting paired air and urine mercury data (149 samples total) met criteria for data quality and sufficiency. The log-transformed data set showed a strong correlation between mercury in air and in urine (r = 0.774), although the relationship was best fit by a series of parallel lines with different intercepts for each study R2 = 0.807). Predicted ratios of air to urine mercury levels at 50 microg/m3 air concentration ranged from 1:1 to 1:3, based on the regression line for the studies. Toward the lower end of the data set (i.e., 10 microg/m3), predicted urinary mercury levels encompassed two distinct ranges: values on the order of 20 microg/L and 30-60 microg/L. Extrapolation to 1 microg/m3 resulted in predicted urinary levels of 4-5 and 6-13 microg/L. Higher predicted levels were associated with use of static area air samplers by some studies rather than more accurate personal air samplers. Urinary mercury predictions based primarily on personal air samplers at 1 and 10 microg/m3 are consistent with reported mean (4 microg/L) and upper-bound (20 microg/L) background levels, respectively. Thus, although mercury levels in air and urine are correlated below 50 microg/m3, the impact of airborne mercury levels below 10 microg/m3 is likely to be indistinguishable from background urinary mercury levels. PMID:12676626

Tsuji, Joyce S; Williams, Pamela R D; Edwards, Melanie R; Allamneni, Krishna P; Kelsh, Michael A; Paustenbach, Dennis J; Sheehan, Patrick J

2003-01-01

52

Bioavailability of mercury in East Fork Poplar Creek soils  

SciTech Connect

The initial risk assessment for the East Fork Poplar Creek (EFPC) floodplain in Oak Ridge, Tennessee, a superfund site heavily contaminated with mercury, was based upon a reference dose for mercuric chloride, a soluble mercury compound not expected to be present in the floodplain, which is frequently saturated with water. Previous investigations had suggested mercury in the EFPC floodplain was less soluble and therefore less bioavailable than mercuric chloride, possibly making the results of the risk assessment unduly conservative. A bioavailability study, designed to measure the amount of mercury available for absorption in a child`s digestive tract, the most critical risk endpoint and pathway, was performed on twenty soils from the EFPC floodplain. The average percentage of mercury released during the study for the twenty soils was 5.3%, compared to 100% of the compound mercuric chloride subjected to the same conditions. Alteration of the procedure to test additional conditions possible during soil digestion did not appreciably alter the results. Therefore, use of a reference dose for mercuric chloride in the EFPC risk assessment without inclusion of a corresponding bioavailability factor may be unduly conservative.

Barnett, M.O.; Turner, R.R.

1995-05-01

53

Stability and bioavailability of mercury sulfide in Oak Ridge Soils  

SciTech Connect

During the 1950's and 1960's, a large amount of elemental mercury escaped confinement and is still present in the buildings and grounds of the U.S. Department of Energy's Y-12 National Security Facility and in the Y-12 Watershed in Oak Ridge, Tennessee, USA. Because of the adverse effects of elemental mercury and mercury compounds upon human health, the Oak Ridge Site is engaged in an on-going effort to monitor and remediate the area. In order to more cost effectively implement those extensive remediation efforts, it is necessary now to obtain an improved understanding of the role that mercury and mercury compounds play in the Oak Ridge ecosystem. Specifically, the long-term bioavailability, stability, and mobility of mercury species in contaminated terrestrial and aquatic environments of the Oak Ridge ecosystem under a range of biogeochemical conditions are not well understood. Mercury can be expected to be present in various forms. These species can be transformed from one form into another thus bioavailability, toxicity, and mobility can change as a function of the biogeochemical conditions. The kinetics of these transformations is currently unknown. We have conducted pilot scale experiments to study the bioavailability of mercury sulfide (HgS) in Oak Ridge soils. The effects of plants and incubation time on chemical stability and bioavailability of HgS under simulated conditions of the Oak Ridge ecosystem have been examined, as has the dynamics of the dissolution of HgS by various extractants. The results show that HgS in contaminated Oak Ridge soils was still to some extent bioavailable to plants. (authors)

Han, F.; Shiyab, S.; Su, Y.; Monts, D.L.; Waggoner, C.A. [Mississippi State Univ., Institute for Clean Energy Technology (ICET), Starkville, MS (United States); Matta, F.B. [Mississippi State Univ., Dept. of Plant and Soil Sciences, Mississippi State, MS (United States)

2007-07-01

54

Impact of Wildfire on Levels of Mercury in Forested Watershed Systems - Voyageurs National Park, Minnesota  

USGS Publications Warehouse

Atmospheric deposition of mercury to remote lakes in mid-continental and eastern North America has increased approximately threefold since the mid-1800s (Swain and others, 1992; Fitzgerald and others, 1998; Engstrom and others, 2007). As a result, concerns for human and wildlife health related to mercury contamination have become widespread. Despite an apparent recent decline in atmospheric deposition of mercury in many areas of the Upper Midwest (Engstrom and Swain, 1997; Engstrom and others, 2007), lakes in which fish contain levels of mercury deemed unacceptable for human consumption and possibly unacceptable for fish-consuming wildlife are being detected with increasing frequency. In northern Minnesota, Voyageurs National Park (VNP) (fig. 1) protects a series of southern boreal lakes and wetlands situated on bedrock of the Precambrian Canadian Shield. Mercury contamination has become a significant resource issue within VNP as high concentrations of mercury in loons, bald eagle eaglets, grebes, northern pike, and other species of wildlife and fish have been found. The two most mercury-contaminated lakes in Minnesota, measured as methylmercury in northern pike (Esox lucius), are in VNP. Recent multidisciplinary U.S. Geological Survey (USGS) research demonstrated that the bulk of the mercury in lake waters, soils, and fish in VNP results from atmospheric deposition (Wiener and others, 2006). The study by Wiener and others (2006) showed that the spatial distribution of mercury in watershed soils, lake waters, and age-1 yellow perch (Perca flavescens) within the Park was highly variable. The majority of factors correlated for this earlier study suggested that mercury concentrations in lake waters and age-1 yellow perch reflected the influence of ecosystem processes that affected within-lake microbial production and abundance of methylmercury (Wiener and others, 2006), while the distribution of mercury in watershed soils seemed to be partially dependent on forest disturbance, especially the historic forest fire pattern (Woodruff and Cannon, 2002). Forest fire has an essential role in the forest ecosystems of VNP (Heinselman, 1996). Because resource and land managers need to integrate both natural wildfire and prescribed fire in management plans, the potential influence of fire on an element as sensitive to the environment as mercury becomes a critical part of their decisionmaking. A number of recent studies have shown that while fire does have a significant impact on mercury at the landscape level, the observed effects of fire on aquatic environments are highly variable and unpredictable (Caldwell and others, 2000; Garcia and Carrigan, 2000; Kelly and others, 2006; Nelson and others, 2007). Caldwell and others (2000) described an increase in methylmercury in reservoir sediments resulting from mobilization and transport of charred vegetative matter following a fire in New Mexico. Krabbenhoft and Fink (2000) attributed increases in total mercury concentrations in young-of-the-year fish in the Florida Everglades to release of mercury resulting from peat oxidation following fires. A fivefold increase in whole-body mercury accumulation by rainbow trout (Oncorhynchus mykiss) following a fire in Alberta, Canada, apparently resulted from increased nutrient concentrations that enhanced productivity and restructured the food web of a lake within the fire's burn footprint (Kelly and others, 2006). For this study, we determined the short-term effects of forest fire on mercury concentrations in terrestrial and aquatic environments in VNP by comparing and contrasting mercury concentrations in forest soils, lake waters, and age-1 yellow perch for a burned watershed and an adjacent lake, with similar samples from watersheds and lakes with no fire activity (control watersheds and lakes). The concentration of total mercury in whole, 1-year-old yellow perch serves as a good biological indicator for monitoring trends in methylmercury conce

Woodruff, Laurel G.; Sandheinrich, Mark B.; Brigham, Mark E.; Cannon, William F.

2009-01-01

55

Remediation of Mercury Contaminated Soils at the Miramas Site - 12243  

SciTech Connect

Beneficial 'new' use of the Miramas Site is the remediation objective for a former light isotope manufacturing facility. Remediation operations will remove contaminated soils and materials and deconstruct facilities. The remediation objective is faced with project challenges and regulatory requirements that dictate/influence the outcome. The operation consists of the remediation of approximately 100,000 cubic meters of soil and the decommissioning of facilities. The types and ranges of waste are the result of historical processing activities (chemical facilities, pyrotechnic components storage, mining component treatment and light isotope manufacturing activities). Mercury is the primary component of the waste, but metals and organic compounds are also possible waste components. A thermal desorption process is used to remove Mercury from the polluted soil while a biological treatment is considered to the organic nitrate compound removal. A focus is done on the technologies used to remediate the Mercury contaminated soil. After few months of operation, the first results confirm that the technology choices were relevant and the soil remediation project is a success. The first successful month of operation at an industrial scale demonstrate that the Thermal Desorption is an efficient and relevant process to remediate large quantity of mercury contaminated soils. The project is on cost and the mercury removal should be end by 2014. The scrubbing is a good way to limit the volume of material to be treated with the Thermal Desorption Unit. The biological treatment is a promising process for the organic nitrate compound removal and testing at a pilot scale will be done in 2012. (authors)

Potier, G.; Chambon, F. [AREVA NC (France)

2012-07-01

56

Mercury speciation in contaminated soils by thermal release analysis  

Microsoft Academic Search

Thermal release analysis of mercury species in contaminated soils was performed by temperature controlled continuous heating of the samples in a furnace coupled to an Atomic Absorption Spectrophotometer (AAS). It was shown that this method allows the identification of different redox states of Hg-species through their characteristic releasing temperature ranges. The method was applied to Hg-contaminated samples from an inactive

Cláudia Carvalhinho Windmöller; Rolf-Dieter Wilken; Wilson De Figueiredo Jardim

1996-01-01

57

Mercury release from deforested soils triggered by base cation enrichment  

E-print Network

considerable colonization in the last few decades. Family agriculture based on slash- and-burn enables millions-rich ashes from the burning of the vegetation biomass for cultivation to be successful, which leads to forest ecosystem degradation, soil erosion and mercury contamination. While recent studies have suggested

Long, Bernard

58

Evaluation of treatment options for mercury/PCB contaminated soil  

SciTech Connect

The purpose of this project was to evaluate treatment alternatives for soil contaminated with mercury and polychlorinated biphenyl (PCB) aroclor 1268 at the LCP site, a former chlor-alkali plant, in Brunswick, GA. The site was operated as a petroleum refinery from 1919 to 1930. Based on past experience and a literature search, soil washing and thermal desorption were deemed to be the most promising technologies. A bulk soil sample was collected from the south process area and analyzed to have 190 mg/kg mercury and 405 mg/kg of PCB aroclor 1268. The soil was screened to {1/4} treatability tests. Testing was performed in three parts consisting of a round of geophysical and chemical analyses to determine matrix characteristics; thermal desorption tests at temperatures ranging from 100 C to 700 C to determine the volatility of mercury and PCB aroclor 1268; and a soil-washing study matrix to evaluate the effect of chemical additives such as acids, oxidizers, and surfactants to physically and chemically remove contaminants from the soil matrix.

Camacho, J.M. [EPA/Environmental Response Team Center, Edison, NJ (United States); Tobia, R.J. [Roy F. Weston, Inc./REAC, Edison, NJ (United States); Peronard, P. [EPA/Region IV, Atlanta, GA (United States)

1996-12-31

59

Mercury in terrestrial biomass and soils and factors determining atmospheric mercury sequestration  

NASA Astrophysics Data System (ADS)

Terrestrial carbon (C) pools play an important role in uptake, deposition, sequestration, and emission of atmospheric mercury (Hg). The objective of this study is to assess atmospheric Hg sequestration associated with vegetation and soil C pools in forest ecosystems. As part of an ongoing EPA STAR project, we are systematically evaluating Hg pools and fluxes associated with terrestrial C pools in all major ecosystem compartments (i.e., leaves, branches, bole, litter, soils) across selected US forest ecosystems. Results from the first five sites located in the remote western United States show that the dominant above-ground pool of mercury is associated with surface litter with smaller pools associated with leaves and branches. Mass concentrations greatly increase in the following order: green leaves, dry leaves, initial litter, partially decomposed litter, humus. Based on detailed comparison of stochiometric relationships (e.g., Hg/C and Hg/N ratios) we conclude that these concentration increases are dominated by additional atmospheric deposition retained in the decomposing plant material while exposed to the environment rather than by organic C losses during decomposition. The large majority of total ecosystem mercury, up to 98 percent, however, is sequestered belowground in the soils. Soil Hg accumulation across all sites is greatly determined by the availability of organic matter in these systems, with soil C and soil N explaining more than 90 percent of the variability in observed soil Hg stocks. Our results suggest that the availability of soil organic matter is the main determinant for retention of atmospheric inputs in soils and hence in terrestrial ecosystems. Ecosystem structure and soil organic accumulation hence determine the resilience of Hg in terrestrial ecosystems with important implication for the stability and runoff of atmospheric Hg deposition to surrounding waterbodies.

Obrist, D.; Johnson, D. W.; Lindberg, S.; Luo, Y.

2008-12-01

60

Mercury contamination in sandy soils surrounding an industrial emission source (Estarreja, Portugal)  

Microsoft Academic Search

This study reports the degree and the extent of mercury contamination in sandy soils surrounding a chloralkali plant at Estarreja, Portugal. Total mercury concentration in the soils studied is at a maximum in the upper 5 cm, ranging from 117 to 49,233 ?g kg?1. The profile distribution pattern for total mercury together with the results of a sequential extraction suggest

M. M. Inácio; V. Pereira; M. S. Pinto

1998-01-01

61

Studies of Mercury in High Level Waste Systems  

Microsoft Academic Search

Historically, mercury was added to the nuclear weapons processing as a catalyst for the dissolution of aluminum metal. After neutralization the mercury was disposed to the High Level Waste tanks where its speciation led to mercuric oxides\\/hydroxides in the sludge and a small soluble mercuric ion concentration in the alkaline supernate. This report in its original revision described a three-pronged

2004-01-01

62

STATE FISH SURVEY FINDS MERCURY LEVELS DOWN By Alex Breitler  

E-print Network

they do not accumulate as much mercury. Salmon also were relatively free of contamination, sinceNews STATE FISH SURVEY FINDS MERCURY LEVELS DOWN By Alex Breitler May 25, 2013 Record Staff Writer downstream you go the more likely fish will be contaminated. For example, the Delta remains a hot spot

63

Mercury contamination in agricultural soils from abandoned metal mines classified by geology and mineralization.  

PubMed

This survey aimed to compare mercury concentrations in soils related to geology and mineralization types of mines. A total of 16,386 surface soils (0~15 cm in depth) were taken from agricultural lands near 343 abandoned mines (within 2 km from each mine) and analyzed for Hg by AAS with a hydride-generation device. To meaningfully compare mercury levels in soils with geology and mineralization types, three subclassification criteria were adapted: (1) five mineralization types, (2) four valuable ore mineral types, and (3) four parent rock types. The average concentration of Hg in all soils was 0.204 mg kg(-1) with a range of 0.002-24.07 mg kg(-1). Based on the mineralization types, average Hg concentrations (mg kg(-1)) in the soils decreased in the order of pegmatite (0.250) > hydrothermal vein (0.208) > hydrothermal replacement (0.166) > skarn (0.121) > sedimentary deposits (0.045). In terms of the valuable ore mineral types, the concentrations decreased in the order of Au-Ag-base metal mines ? base metal mines > Au-Ag mines > Sn-W-Mo-Fe-Mn mines. For parent rock types, similar concentrations were found in the soils derived from sedimentary rocks and metamorphic rocks followed by heterogeneous rocks with igneous and metamorphic processes. Furthermore, farmland soils contained relatively higher Hg levels than paddy soils. Therefore, it can be concluded that soils in Au, Ag, and base metal mines derived from a hydrothermal vein type of metamorphic rocks and pegmatite deposits contained relatively higher concentrations of mercury in the surface environment. PMID:21814815

Kim, Han Sik; Jung, Myung Chae

2012-01-01

64

Phyto extraction and accumulation of mercury in selected plant species grown in soil contaminated with different mercury compounds  

SciTech Connect

The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy's (DOE) Oak Ridge Site, where mercury contamination is a major concern in the Y-12 Watershed area. In order to cost effectively implement those remediation efforts currently planned for FY09, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds from the Oak Ridge ecosystem. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal accumulating wild plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl{sub 2} and Hg(NO{sub 3}){sub 2}, were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation; and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots (<65 mg/kg), even though root mercury accumulation is significant (maximum 2298 mg/kg). Consequently, this plant species may not be suitable for mercury phyto-remediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phyto-extraction. During one experiment, brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 ppm and 1000 ppm HgCl{sub 2} powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contaminated HgS, HgCl{sub 2}, and Hg(NO{sub 3}){sub 2}. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in Oak Ridge flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. (authors)

Su, Y.; Han, F.; Shiyab, S.; Monts, D.L. [Mississippi State Univ., Institute for Clean Energy Technology (ICET), Starkville, MS (United States)

2007-07-01

65

Mercury isotope compositions in North American forest soils and litters  

NASA Astrophysics Data System (ADS)

Soils represent one of the largest reservoirs of mercury on Earth, playing a critical role in the natural cycle of mercury by acting as both a sink and source. However, it is not well understood how soils sequestrate and remobilize Hg. Natural variations in stable Hg isotopes are being explored as a promising tool in studying the transformation and transport of Hg. However, Hg isotopic data in soils is scarce. In addition, the limited isotopic data that exists is significantly different from those of atmospheric Hg, which is one of the major sources of Hg to soils. For example, Hg mass independent fractionation (MIF, typically reported as ?199Hg) is positive in atmospheric wet deposition, but most soils display negative ?199Hg. MIF on 200Hg (?200Hg) is also observed in atmospheric wet deposition, but not in soils. The discrepancy between soils and atmospheric samples is still unexplained. In this study, we surveyed the Hg isotope compositions in soil profiles, litters and fresh vegetation from four different forest sites across United States (Thompson forest, WA, Truckee, CA, Niwot Ridge, CO and Howland, MA). The current results from the WA site show that soils primarily display negative mass dependent fractionation for the even isotopes (MDF, reported as ?202Hg) with values for ?202Hg of up to -2.0‰. Significant MIF for both odd isotopes is also observed in all WA soil samples and ?199Hg is mostly negative (up to -0.4‰). No MIF on 200Hg is observed in these soils. The negative ?199Hg in soils is inconsistent with the positive ?199Hg reported in atmospheric wet deposition, suggesting that either Hg transformations within or on the surface of soils and/or plants alter its isotope composition after deposition or other types of Hg deposition (e.g., Hg(0) or Hg(II) dry deposition) is more predominant. The ?199Hg/?201Hg ratio is close to 1 in the soils, which is consistent with the results of laboratory photochemical reduction of inorganic Hg(II), indicating that photochemical reduction (either on the surface of soils and vegetations, in surface water or in the atmosphere) is the plausible cause of the MIF in the soils. We are currently studying samples from the other three sites to determine the variation of Hg isotope composition in soils formed in different geological and climatic settings. We will also evaluate the correlation between Hg isotope composition in soils and organic carbon, precipitation and clay content in order to determine the key environmental factors that shape the Hg isotope composition in soils.

Zheng, W.; Obrist, D.; Bergquist, B. A.

2013-12-01

66

Mercury levels in high-end consumers of fish.  

PubMed Central

Consumption of food containing mercury has been identified as a health risk. The U.S. Environmental Protection Agency (U.S. EPA) and the National Academy of Sciences recommend keeping the whole blood mercury level < 5.0 microg/L or the hair level < 1.0 microg/g. This corresponds to a reference dose (RfD) of 0.1 microg/kg body weight per day. All patients in a 1-year period (n = 720) who came for an office visit in a private internal medicine practice in San Francisco, California, were evaluated for mercury excess using the current RfD. One hundred twenty-three patients were tested (93 females, 30 males). Of these, data were statistically analyzed for 89 subjects. Mercury levels ranged from 2.0 to 89.5 microg/L for the 89 subjects. The mean for 66 women was 15 microg/L [standard deviation (SD) = 15], and for 23 men was 13 microg/L (SD = 5); 89% had levels exceeding the RfD. Subjects consumed 30 different forms or types of fish. Swordfish had the highest correlation with mercury level. Sixty-seven patients with serial blood levels over time after stopping fish showed a decline in mercury levels; reduction was significant (p < 0.0001). A substantial fraction of patients had diets high in fish consumption; of these, a high proportion had blood mercury levels exceeding the maximum level recommended by the U.S. EPA and National Academy of Sciences. The mean level for women in this survey was 10 times that of mercury levels found in a recent population survey by the U.S. Centers for Disease Control and Prevention. Some children were > 40 times the national mean. PMID:12676623

Hightower, Jane M; Moore, Dan

2003-01-01

67

Sources and remediation techniques for mercury contaminated soil.  

PubMed

Mercury (Hg) in soils has increased by a factor of 3 to 10 in recent times mainly due to combustion of fossil fuels combined with long-range atmospheric transport processes. Other sources as chlor-alkali plants, gold mining and cement production can also be significant, at least locally. This paper summarizes the natural and anthropogenic sources that have contributed to the increase of Hg concentration in soil and reviews major remediation techniques and their applications to control soil Hg contamination. The focus is on soil washing, stabilisation/solidification, thermal treatment and biological techniques; but also the factors that influence Hg mobilisation in soil and therefore are crucial for evaluating and optimizing remediation techniques are discussed. Further research on bioremediation is encouraged and future study should focus on the implementation of different remediation techniques under field conditions. PMID:25454219

Xu, Jingying; Bravo, Andrea Garcia; Lagerkvist, Anders; Bertilsson, Stefan; Sjöblom, Rolf; Kumpiene, Jurate

2015-01-01

68

[Characteristics of mercury exchange flux between soil and atmosphere under the snow retention and snow melting control].  

PubMed

Jiapigou gold mine, located in the upper Songhua River, was once the largest mine in China due to gold output, where gold extraction with algamation was widely applied to extract gold resulting in severe mercury pollution to ambient environmental medium. In order to study the characteristics of mercury exchange flux between soil (snow) and atmosphere under the snow retention and snow melting control, sampling sites were selected in equal distances along the slope which is situated in the typical hill-valley terrain unit. Mercury exchange flux between soil (snow) and atmosphere was determined with the method of dynamic flux chamber and in all sampling sites the atmosphere concentration from 0 to 150 cm near to the earth in the vertical direction was measured. Furthermore, the impact factors including synchronous meteorology, the surface characteristics under the snow retention and snow melting control and the mercury concentration in vertical direction were also investigated. The results are as follows: During the period of snow retention and melting the air mercury tends to gather towards valley bottom along the slope and an obvious deposit tendency process was found from air to the earth's surface under the control of thermal inversion due to the underlying surface of cold source (snow surface). However, during the period of snow melting, mercury exchange flux between the soil and atmosphere on the surface of the earth with the snow being melted demonstrates alternative deposit and release processes. As for the earth with snow covered, the deposit level of mercury exchange flux between soil and atmosphere is lower than that during the period of snow retention. The relationship between mercury exchange flux and impact factors shows that in snow retention there is a remarkable negative linear correlation between mercury exchange flux and air mercury concentration as well as between the former and the air temperature. In addition, in snow melting mercury exchange flux is remarkably negatively linearly correlated to air mercury concentration and positively linearly correlated to air temperature. Furthermore, there is a general positive linear correlation between mercury exchange flux and soil temperature on the surface of earth after snow melting. PMID:23668111

Zhang, Gang; Wang, Ning; Ai, Jian-Chao; Zhang, Lei; Yang, Jing; Liu, Zi-Qi

2013-02-01

69

Trace-level mercury removal from surface water  

SciTech Connect

Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water.

Klasson, K.T.; Bostick, D.T.

1998-06-01

70

Mercury in the surface soil and cassava, Manihot esculenta (flesh, leaves and peel) near goldmines at Bogoso and Prestea, Ghana.  

PubMed

Mercury amalgamation is used indiscriminately in the recovery of gold by small-scale native gem winners in Ghana. Mercury is released into the environment in the form of wastewater, tailing and vapor from the roasting of amalgam to separate gold. The study looked at the levels of total mercury concentration in surface soil and cassava crop from farms located within the vicinities of Bogoso and Prestea Goldmines. The surface soil total mercury concentrations ranged between 125.29 and 352.52 ?g/kg whiles cassava had between 66.60 and 195.47 ?g/kg. The results showed proportionately more deposits at higher distances in 15-30 cm soil zone and less deposits at higher distances on leaves with relatively high uptake of the metal occurred at higher distances from the mines into the peels. These results suggest serious mercury pollution to the surface soil and the cassava crop but the speciation exercise showed that mercury is not in the free state, rather bound to hydroxides and organic compounds as complexes. PMID:23052587

Adjorlolo-Gasokpoh, A; Golow, A A; Kambo-Dorsa, J

2012-12-01

71

Comparison of immunoassay field tests and laboratory results for PCB, PAH, BTEX, and mercury contaminated soils  

SciTech Connect

Immunoassay tests were used as in situ field screening tools for simultaneous assessment and remediation of soil contaminated with mercury and organics (polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and BTEX). Soil samples from approximately 200 sites including metering and compressor stations were investigated along gas pipelines. The suspected contamination originated from formerly used mercury manometers and pipeline liquids. An enzyme-linked immunosorbent assay (ELISA) was used for the detection of organic and mercury contaminants. ELISA combines selective antibodies with sensitive enzyme reactions to produce semiquantitative analytical systems capable of detecting very low levels of chemicals. Color sample tubes were compared to the color of standard tubes to semiquantitate the amount of mercury, PCB, PAH, and BBTEX present in the samples. Two standards were tested in order to eliminate the effects of false negatives (e.g., contaminant not detected when present) or false positives (e.g., contamination detected when not present). For verification purposes, selected samples that were determined to be below action level with the immunoassay tests were sent to the laboratory.

Hammes, U. [IT Corp., Houston, TX (United States)

1995-09-01

72

Mercury Exposure Levels in Children with Dental Amalgam Fillings  

PubMed Central

ABSTRACT% Objectives: Mercury combined with other metals to form solid amalgams has long been used in reconstructive dentistry but its use has been controversial since at least the middle of the 19th century. The exposure and body burden of mercury reviews have consistently stated that there is a deficiency of adequate epidemiological studies addressing this issue. Fish and dental amalgam are two major sources of human exposure to organic (MeHg) and inorganic Hg respectively. Materials and methods: A total of 150 subjects aged between 9 and 14 years were divided into two groups of 75 subjects each depending on their diet, i.e. seafood or nonseafood consuming. Each category was subdivided into three groups based on number of restorations. Scalp hair and urine samples were collected at baseline and 3 months later to assess the organic and inorganic levels of mercury respectively by atomic absorption spectrophotometer (AAS). Results: The mean values of urinary mercury (inorganic mercury) in the group of children with restorations were 1.5915 ?g/l as compared to 0.0130 ?g/l in the groups with no amalgam restorations (p < 0.001) (Wilcoxon sign rank test and paired t-test). The hair mercury levels (organic mercury) varied signi-ficantly between the fsh-eating group and nonfsh-eating group, the average values being 1.03 ?g/l and 0.84 ?g/l respectively (p < 0.001) (Mann-Whitney U-test and paired t-test). Conclusion and significance: The notion about the mercury being released from the amalgam restorations as a sole exposure source needs to be put to a rest, as environmental factors collectively overpower the exposure levels from restorations alone. How to cite this article: Varkey IM, Shetty R, Hegde A. Mercury Exposure Levels in Children with Dental Amalgam Fillings. Int J Clin Pediatr Dent 2014;7(3):180-185. PMID:25709298

Miriam Varkey, Indu; Shetty, Rajmohan; Hegde, Amitha

2014-01-01

73

Hair mercury levels in Amazonian populations: spatial distribution and trends  

PubMed Central

Background Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 ?g/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian populations can be considered exposed to methylmercury contamination. The situation for many of these traditional communities is very complex because of their high dependence on fish nutrients. It remains difficult to conclude on the Public Health implication of mercury exposure in this context. PMID:20025776

2009-01-01

74

Mercury poisoning dentistry: high-level indoor air mercury contamination at selected dental sites.  

PubMed

Mercury (Hg), also known as quick silver, is an essential constituent of dental amalgam. It is a toxic substance of global concern. Children are more at risk from mercury poisoning which affects their neurological development and brain. In the past, a number of studies at dental sites in many countries have been carried out and reported. The present report briefly describes and discusses our recent investigations carried out at 34 dental sites (teaching institutions, hospitals and private clinics) in Pakistan. It is evident from the data that at many sites the indoor mercury vapor levels exceed far above the permissible limit recommended for safe physical and mental health. At these sites, public in general and the medical, paramedical staff and vulnerable population in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. To minimize such risk, some of the recommendations are, best in-house environmental practices for occupational health and safety, mercury contaminated waste reduction at source, mercury specific legislation and ratification of Minamata convention on mercury by Pakistan and other world governments at the earliest time possible. PMID:24552960

Khwaja, Mahmood A; Abbasi, Maryam Shabbir

2014-01-01

75

[Determination of trace mercury species in water and soil samples with atomic fluorescence spectrometry].  

PubMed

With hydride generation-cold atomic fluorescence spectrometry (HG-AFS), the method of determining trace mercury species in water and soil samples in Jimei, Xiamen city, China was established. The content of inorganic mercury in water was measured by sample direct injection, while the total mercury was measured after digestion with the reagents of KBrO3-KBr. The soil samples were digested with microwave for total mercury measurement. Sequential extraction procedure was carried out for determining different mercuric species in soil samples. The results indicated that the mercury concentration of wastewater from chemical laboratory exceeded the limit of the integrated wastewater discharge standard of China (GB 8978-1996). It is one of the serious pollution sources of mercury in environment. The mercury contents from soil samples including the sideward soil of highway, the sea sediment and the garden soil were under the limits of relative national standards of China. However, attention should be paid to the accumulation of mercury in garden soil due to the artificial pollution. Meanwhile, the average recoveries for water and soil samples tested with adding standards were 93.7% and 93.8%, respectively. Meanwhile, the detection limits estimated with 3-fold standard deviation were 0.000 8 microg x L(-1) for water and 0.072 3 microg x kg(-1) for soil, respectively. The results indicated that the established method, with the merits of high sensitivity and precision, was suitable for the measurement of trace mercury species in environmental samples. PMID:18260432

Huang, Zhi-Yong; Huang, Zhi-Tao; Zhang, Qiang; Zhuang, Zhi-Xia

2007-11-01

76

Mercury  

SciTech Connect

Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury.

Vilas, F.; Chapman, C.R.; Matthews, M.S.

1988-01-01

77

Dry deposition of gaseous elemental mercury to plants and soils using mercury stable isotopes in a controlled environment  

Microsoft Academic Search

Uptake of gaseous elemental mercury (Hg0(g)) by three plant species and two soil types was measured using mercury vapor enriched in the 198 isotope (198Hg0(g)). The plant species and soil types were: White Ash (Fraxinus Americana; WA); White Spruce (Picea Glauca; WS); Kentucky Bluegrass (Poa Partensis; KYBG); Plano Silt Loam (4% organic matter; PSL); and Plainfield Sand\\/Sparta Loamy Sand (1.25–1.5%

Andrew P. Rutter; James J. Schauer; Martin M. Shafer; Joel E. Creswell; Michael R. Olson; Michael Robinson; Ryan M. Collins; Andrew M. Parman; Tanya L. Katzman; Justin L. Mallek

2011-01-01

78

Studies of Mercury in High Level Waste Systems  

SciTech Connect

During nuclear weapons production, nuclear reactor target and fuel rods were processed in F- and H-Canyons. For the target rods, a caustic dissolution of the aluminum cladding was performed prior to nitric acid dissolution of the uranium metal targets in the large canyon dissolvers. To dissolve the aluminum cladding and the U-Al fuel, mercury in the form of soluble mercury (II) nitrate was added as a catalyst to accelerate the dissolution of the aluminum. F-Canyon began to process plutonium-containing residues that were packaged in aluminum cans and thus required the use of mercury as a dissolution catalyst. Following processing to remove uranium and plutonium using the solvent extraction process termed the Plutonium-Uranium Recovery by Extraction (PUREX) process, the acidic waste solutions containing fission products and other radionuclides were neutralized with sodium hydroxide. The mercury used in canyon processing is fractionated between the sludge and supernate that is transferred from the canyons to the tank farm. The sludge component of the waste is currently vitrified in the Defense Waste Processing Facility (DWPF). The vitrified waste canisters are to be sent to the federal repository for High Level Waste. The mercury in the sludge, presumably in an oxide or hydroxide form is reduced to elemental mercury by the chemical additions and high temperatures, steam stripped and collected in the Mercury Collection Tank. The mercury in the dilute supernate is in the form of mercuric ion and is soluble. During evaporation, the mercuric ion is reduced to elemental mercury, vaporizes into the overheads system and is collected as a metallic liquid in the Mercury Removal Tank.

Wilmarth, W.R.

2003-09-03

79

The role of humic substances in the aqueous mobilization of mercury from contaminated floodplain soils  

Microsoft Academic Search

The water-mobilizability of mercury from contaminated floodplain soils of the river Elbe in Northern Germany was evaluated by batch extraction experiments. It was shown that only a small amount of the total mercury present (about 1% per extraction) can be mobilized by water. This mercury is transported entirely in the form of a complex bound to humic acids (HA); particulates

Dirk Wallschläger; Madhukar V. M. Desai; Rolf-Dieter Wilken

1996-01-01

80

MERCURY IN THE ENVIRONMENT  

EPA Science Inventory

Mercury is released from a variety of sources and exhibits a complicated chemistry. According to the Mercury Study Report to Congress, mercury fluxes and budgets in water, soil, and other media have increased by a factor of two to five over pre-industrial levels. The primary expo...

81

Potential bioremediation of mercury-contaminated substrate using filamentous fungi isolated from forest soil.  

PubMed

The use of filamentous fungi in bioremediation of heavy metal contamination has been developed recently. This research aims to observe the capability of filamentous fungi isolated from forest soil for bioremediation of mercury contamination in a substrate. Six fungal strains were selected based on their capability to grow in 25 mg/L Hg(2+)-contaminated potato dextrose agar plates. Fungal strain KRP1 showed the highest ratio of growth diameter, 0.831, thus was chosen for further observation. Identification based on colony and cell morphology carried out by 18S rRNA analysis gave a 98% match to Aspergillus flavus strain KRP1. The fungal characteristics in mercury(II) contamination such as range of optimum pH, optimum temperature and tolerance level were 5.5-7 and 25-35°C and 100 mg/L respectively. The concentration of mercury in the media affected fungal growth during lag phases. The capability of the fungal strain to remove the mercury(II) contaminant was evaluated in 100 mL sterile 10 mg/L Hg(2+)-contaminated potato dextrose broth media in 250 mL Erlenmeyer flasks inoculated with 10(8) spore/mL fungal spore suspension and incubation at 30°C for 7 days. The mercury(II) utilization was observed for flasks shaken in a 130 r/min orbital shaker (shaken) and non-shaken flasks (static) treatments. Flasks containing contaminated media with no fungal spores were also provided as control. All treatments were done in triplicate. The strain was able to remove 97.50% and 98.73% mercury from shaken and static systems respectively. A. flavus strain KRP1 seems to have potential use in bioremediation of aqueous substrates containing mercury(II) through a biosorption mechanism. PMID:25079829

Kurniati, Evi; Arfarita, Novi; Imai, Tsuyoshi; Higuchi, Takaya; Kanno, Ariyo; Yamamoto, Koichi; Sekine, Masahiko

2014-06-01

82

Mercury exposure may suppress baseline corticosterone levels in juvenile birds.  

PubMed

Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (<3 days) and blood of older (15-37 days) Forster's tern (Sterna forsteri) chicks in San Francisco Bay, California. Baseline fecal corticosterone metabolite concentrations were negatively correlated with mercury concentrations in blood of older chicks (decreasing by 81% across the range of observed mercury concentrations) while accounting for positive correlations between corticosterone concentrations and number of fledgling chicks within the colony and chick age. In recently hatched chicks, baseline fecal corticosterone metabolite concentrations were weakly negatively correlated with mercury concentrations in down feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis. PMID:22578153

Herring, Garth; Ackerman, Joshua T; Herzog, Mark P

2012-06-01

83

Mercury Exposure May Suppress Baseline Corticosterone Levels in Juvenile Birds.  

USGS Publications Warehouse

Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (Sterna forsteri) chicks in San Francisco Bay, California. Baseline fecal corticosterone metabolite concentrations were negatively correlated with mercury concentrations in blood of older chicks (decreasing by 81% across the range of observed mercury concentrations) while accounting for positive correlations between corticosterone concentrations and number of fledgling chicks within the colony and chick age. In recently hatched chicks, baseline fecal corticosterone metabolite concentrations were weakly negatively correlated with mercury concentrations in down feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis.

Herring, Garth; Ackerman, Joshua T.; Herzog, Mark P.

2012-01-01

84

Mercury distribution in the soil-plant-air system at the Wanshan mercury mining district in Guizhou, Southwest China.  

PubMed

The level of mercury bioaccumulation in wild plants; the distribution of bioavailable Hg, elemental Hg, and total Hg in soil; and the concentration of total gaseous Hg (TGM) in ambient air was studied at three different mining sites (SiKeng [SK], WuKeng [WK], and GouXi [GX]) in the Wanshan mercury mining district of China. Results of the present study showed that the distribution of soil total Hg, elemental Hg, bioavailable Hg, and TGM varies across the three mining sites. Higher soil total Hg (29.4-1,972.3 mg/kg) and elemental Hg (19.03-443.8 mg/kg) concentrations were recorded for plots SK and WK than for plot GX. Bioavailable Hg was lower at plot SK and GX (SK, 3-12 ng/g; GX, 9-14 ng/g) than at plot WK (11-1,063 ng/g), although the TGM concentration in the ambient air was significantly higher for plot GX (52,723 ng/m(3) ) relative to WK (106 ng/m(3) ) and SK (43 ng/m(3)). Mercury in sampled herbage was elevated and ranged from 0.8 to 4.75 mg/kg (SK), from 2.17 to 34.38 mg/kg (WK), and from 47.45 to 136.5 mg/kg (GX). Many of the sampled plants are used as fodder or for medicinal purposes. High shoot Hg concentrations may therefore pose an unacceptable human health risk. Statistical analysis of the recorded data showed that the Hg concentration in plant shoots was positively correlated with TGM and that the Hg concentration in roots was positively correlated with the bioavailable Hg concentration in the soil. The bioaccumulation factor (BAF) in the present study was defined with reference to the concentration of bioavailable Hg in the soil (Hg([root]) /Hg([bioavail])). Three plant species, Macleaya cordata L., Achillea millefolium L., and Pteris vittata L., showed enhanced accumulation of Hg and therefore may have potential for use in the phytoremediation of soils of the Wanshan mining area. PMID:21935979

Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Zhu, Wei; Yin, Runsheng; Wang, Heng

2011-12-01

85

Comparison of Adsorbed Mercury Screening Method With Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil  

NASA Technical Reports Server (NTRS)

A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.

Easterling, Donald F.; Hovanitz, Edward S.; Street, Kenneth W.

2000-01-01

86

Mercury emission and dispersion models from soils contaminated by cinnabar mining and metallurgy.  

PubMed

The laboratory flux measurement system (LFMS) and dispersion models were used to investigate the kinetics of mercury emission flux (MEF) from contaminated soils. Representative soil samples with respect to total Hg concentration (26-9770 ?g g(-1)) surrounding a decommissioned mercury-mining area (Las Cuevas Mine), and a former mercury smelter (Cerco Metalúrgico de Almadenejos), in the Almadén mercury mining district (South Central Spain), were collected. Altogether, 14 samples were analyzed to determine the variation in mercury emission flux (MEF) versus distance from the sources, regulating two major environmental parameters comprising soil temperature and solar radiation. In addition, the fraction of the water-soluble mercury in these samples was determined in order to assess how MEF from soil is related to the mercury in the aqueous soil phase. Measured MEFs ranged from less than 140 to over 10,000 ng m(-2) h(-1), with the highest emissions from contaminated soils adjacent to point sources. A significant decrease of MEF was then observed with increasing distance from these sites. Strong positive effects of both temperature and solar radiation on MEF was observed. Moreover, MEF was found to occur more easily in soils with higher proportions of soluble mercury compared to soils where cinnabar prevails. Based on the calculated Hg emission rates and with the support of geographical information system (GIS) tools and ISC AERMOD software, dispersion models for atmospheric mercury were implemented. In this way, the gaseous mercury plume generated by the soil-originated emissions at different seasons was modeled. Modeling efforts revealed that much higher emissions and larger mercury plumes are generated in dry and warm periods (summer), while the plume is smaller and associated with lower concentrations of atmospheric mercury during colder periods with higher wind activity (fall). Based on the calculated emissions and the model implementation, yearly emissions from the "Cerco Metalúrgico de Almadenejos" decommissioned metallurgical precinct were estimated at 16.4 kg Hg y(-1), with significant differences between seasons. PMID:22037967

Llanos, Willians; Kocman, David; Higueras, Pablo; Horvat, Milena

2011-12-01

87

In vitro penetration of soil-aged mercury through pig skin.  

PubMed

The dermal bioavailability of mercury "aged" in soil for 3 mo was compared to that of pure mercury (without soil) and to mercury in brief contact with soil (16 h). Studies were conducted in vitro with [203Hg]mercuric chloride on dermatomed male pig skin by flow-through diffusion cell methodology. Less than 0.5% of the initial mercury dose penetrated through skin into receptor fluid after each treatment. The majority of pure mercury became covalently bound to skin. However, a short contact time with either an Atsion (sandy) or Keyport (clay) soil significantly decreased the total penetration of mercury (sum of receptor fluid and skin) by 40%. After aging, a 95% reduction in total penetration was observed for the compound relative to chemical without soil. Both soils bind mercury more strongly with time, as evidenced by larger quantities of radioactivity in soil and smaller amounts in skin decontaminate after aging than in soil for 16 h. Decreased mercury bioavailability with aging indicates lower health risk and reduced need for soil cleanup. PMID:11036507

Skowronski, G A; Turkall, R M; Abdel-Rahman, M S

2000-10-13

88

Mercury levels in avian feathers from different trophic levels of eight families collected from the northern region of Iran.  

PubMed

Mercury levels were determined in feathers from 83 birds belonging to 18 species (eight families), all collected from the northern region of Iran. Mercury levels were evaluated in relation to taxonomic affiliation and feeding strategies. Mercury levels in the feathers were between 0.05?±?0.01 and 1.10?±?0.15 ?g g(-1) dry weight, and there was a significant effect of taxonomic groups (p?mercury levels were found in Accipitridae, and mercury was not detected in the family Upupidae. The pattern for mercury levels was Accipitridae > Pelecanidae > Sternidae > Ardeidae > Anatidae > Rallidae > Phasianidae (p?mercury levels were found among species as a function of feeding method and trophic level. Mercury levels were highest in the carnivorous species and lowest in the herbivorous species. Mercury levels in feathers of birds in this study were generally below the thresholds reported to affect reproduction. PMID:25893758

Mashroofeh, Abdulreza; Bakhtiari, Alireza Riyahi; Ghobeishavi, Ahmad; Ahmadpour, Mohsen; Asadi, Asad; Ahmadpour, Mousa; Hosseini, Sayyed Hamid; Eskandari, Tahereh; Burger, Joanna

2015-05-01

89

MERCURY RESIDUES IN SOIL AROUND A LARGE COAL-FIRED POWER PLANT  

EPA Science Inventory

Seventy soil samples were collected on a radial grid around the Four Corners power plant. The soil samples were analyzed for total mercury using a Zeeman atomic absorption spectrophotometer. Even though the plant emits 1-2% of all the mercury released by U.S. coal-fired utilities...

90

Mercury  

Microsoft Academic Search

New findings on the environmental fate of Hg indicate that lakes can be contaminated by long distance transport on mercury vapor in the atmosphere and that higher levels of Me Hg in fish are associated with acidification of lakes and with the creation of hydroelectric reservoirs. Considerable progress has been made in the understanding of the disposition and metabolism of

Thomes W. Clarkson

1989-01-01

91

Phytoremediation of Mercury and Methylmercury-Polluted Soils Using Genetically Engineered Plants  

Microsoft Academic Search

Inorganic mercury in contaminated soils and sediments is relatively immobile, though biological and chemical processes can transform it to more toxic and bioavailable methylmercury. Methylmercury is neurotoxic to vertebrates and is biomagnified in animal tissues as it is passed from prey to predator. Traditional remediation strategies for mercury contaminated soils are expensive and site-destructive. As an alternative we propose the

Andrew C. P. Heaton; Clayton L. Rugh; Nian-jie Wang; Richard B. Meagher

1998-01-01

92

Anthropogenic impacts on global storage and emissions of mercury from terrestrial soils: Insights from a new global model  

Microsoft Academic Search

We develop a mechanistic global model of soil mercury storage and emissions that ties the lifetime of mercury in soils to the lifetime of the organic carbon pools it is associated with. We explore the implications of considering terrestrial mercury cycling in the framework of soil carbon cycling and suggest possible avenues of future research to test our assumptions and

Nicole V Smith-Downey; Elsie M. Sunderland; Daniel J. Jacob

2010-01-01

93

Egg mercury levels decline with the laying sequence in charadriiformes  

SciTech Connect

Whereas pollutants do not differ in concentration among eggs of one clutch in some bird species, in gulls, terns and grebes several organochlorines show intraclutch variation: Concentrations increase with the laying sequence. Heavy metals, however, are not so intensively studied with respect to intraclutch variation. In contrast to lead and cadmium, mercury is accumulated in great quantities in eggs. Variation in mercury levels between the eggs of one clutch were low compared to interclutch variability in the White-tailed Sea Eagle (Haliaeetus albicilla) and the Peregrine (Falco peregrinus). In gulls, however, intraclutch variation was significant and characterized by higher mercury levels in the first than in subsequently laid eggs, which is the opposite to the trend in organochlorine levels. In this paper, the author reports on investigations of intraclutch variation in mercury levels in three Charadriiform-species, Herring Gull, Common Tern and Oystercatcher (Haematopus ostralegus). The results confirm those previously reported in gulls and point to the importance of the egg in reducing the females' mercury burden. 23 refs, 2 tabs.

Becker, P.H. (Institut fuer Vogelforschung, Wilhelmshaven (Germany))

1992-05-01

94

Subtask 1.17 - Subcritical Water Extraction of Mercury From Soils and Sediments  

SciTech Connect

The U.S. Environmental Protection Agency (EPA) "National Sediment Quality Survey" lists the top pollutants responsible for toxicity in watersheds as 1) PCBS (polychlorinated biphenyls), 2) mercury, and 3) other organics such as PAHs polycyclic aromatic hydrocarbons) and pesticides. In addition, these same pollutants are major contributors to chemical pollution on U.S. Department of Energy (DOE) and other contaminated sites (e.g., industrial sites and harbors). An ideal remediation method would allow cost-effective removal of both organic and mercury contamination using a single process. The Energy & Environmental Research Center (EERC) has demonstrated that controlling the temperature (and to a lesser extent, the pressure) of water can dramatically change its ability to extract organics and inorganic from matrices ranging from soils and sediments to waste sludges and coal. The dielectric constant of water can be changed from ca. 80 (a very polar solvent) to <5 (similar to a nonpolar organic solvent) by controlling the temperature (from ca. ambient to ca. 400oC) and pressure (from ea. 5 to 350 bar). The EERC has shown that hazardous organic pollutants such as pesticides, PAHs, and PCBS can be completely removed from soils, sludges, and sediments at temperatures (250"C) and pressures ( c 50 atrn) that are much milder than typically used for supercritical water processes (temperature > 374oC, pressure >221 atm). In addition, the process has been demonstrated to be particularly effective for samples containing very high levels of contaminants (e.g., parts per thousand). The EERC has also demonstrated that mercury can be extracted using supercritical water at much harsher conditions (400"C, and >300 atm). However, the removal of mercury from contaminated solids at the lower temperature and pressure conditions (e. g., 250"C, 50 atm) has not been investigated. If successful, this project will provide the basis for using hot/liquid water to extract both organic contaminants and mercury from contaminated solids in a single-step process.

Steven B. Hawthorne

1997-08-01

95

Self-Transmissible Mercury Resistance Plasmids with Gene-Mobilizing Capacity in Soil Bacterial Populations: Influence of Wheat Roots and Mercury Addition  

PubMed Central

A set of mercury resistance plasmids was obtained from wheat rhizosphere soil amended or not amended with mercuric chloride via exogenous plasmid isolation by using Pseudomonas fluorescens R2f, Pseudomonas putida UWC1, and Enterobacter cloacae BE1 as recipient strains. The isolation frequencies were highest from soil amended with high levels of mercury, and the isolation frequencies from unamended soil were low. With P. putida UWC1 as the recipient, the isolation frequency was significantly enhanced in wheat rhizosphere compared to bulk soil. Twenty transconjugants were analyzed per recipient strain. All of the transconjugants contained plasmids which were between 40 and 50 kb long. Eight selected plasmids were distributed among five groups, as shown by restriction digestion coupled with a similarity matrix analysis. However, all of the plasmids formed a tight group, as judged by hybridization with two whole-plasmid probes and comparisons with other plasmids in dot blot hybridization analyses. The results of replicon typing and broad-host-range incompatibility (Inc) group-specific PCR suggested that the plasmid isolates were not related to any previously described Inc group. Although resistance to copper, resistance to streptomycin, and/or resistance to chloramphenicol was found in several plasmids, catabolic sequences were generally not identified. One plasmid, pEC10, transferred into a variety of bacteria belonging to the ? and ? subdivisions of the class Proteobacteria and mobilized as well as retromobilized the IncQ plasmid pSUP104. A PCR method for detection of pEC10-like replicons was used, in conjunction with other methods, to monitor pEC10-homologous sequences in mercury-polluted and unpolluted soils. The presence of mercury enhanced the prevalence of pEC10-like replicons in soil and rhizosphere bacterial populations. PMID:9546155

Smit, Eric; Wolters, Anneke; van Elsas, Jan Dirk

1998-01-01

96

The Relationship between Adirondack Lake pH and Levels of Mercury in Yellow Perch  

Microsoft Academic Search

Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and

Donald Brown; Alexey Goncharov; Eric Paul; Howard Simonin; David O. Carpenter

2010-01-01

97

Sulfur Polymer Stabilization/Solidification Treatability Study of Mercury Contaminated Soil from the Y-12 Site  

SciTech Connect

As a result of past operations, the Department of Energy’s (DOE) Oak Ridge Y-12 National Security Complex (Y-12 Plant) has extensive mercury-contamination in building structures, soils, storm sewer sediments, and stream sediments, which are a source of pollution to the local ecosystem. Because of mercury’s toxicity and potential impacts on human health and the environment, DOE continues to investigate and implement projects to support the remediation of the Y-12 site.URS and #9122;CH2M Oak Ridge LLC (UCOR) under its prime contract with DOE has cleanup responsibilities on the DOE Oak Ridge Reservation and is investigating potential mercury-contaminated soil treatment technologies through an agreement with Babcock and Wilcox (B and W) Y-12, the Y-12 operating contractor to DOE. As part of its investigations, UCOR has subcontracted with Brookhaven National Laboratory (BNL) to conduct laboratory-scale studies evaluating the applicability of the Sulfur Polymer Stabilization/Solidification (SPSS) process using surrogate and actual mixed waste Y-12 soils containing mercury (Hg) at 135, 2,000, and 10,000 ppm.SPSS uses a thermoplastic sulfur binder to convert Hg to stable mercury sulfide (HgS) and solidifies the chemically stable product in a monolithic solid final waste form to reduce dispersion and permeability. Formulations containing 40 – 60 dry wt% Y-12 soil were fabricated and samples were prepared in triplicate for Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP) testing by an independent laboratory. Those containing 50 and 60 wt% soil easily met the study criteria for maximum allowable Hg concentrations (47 and 1 ppb, respectively compared with the TCLP limit of 200 ppb Hg). The lowest waste loading of 40 wt% yielded TCLP Hg concentrations slightly higher (240 ppb) than the allowable limit. Since the Y-12 soil tended to form clumps, the improved leaching at higher waste loadings was probably due to reduction in particle size from friction of the soil mixing, which creates more surface area for chemical conversion. This was corroborated by the fact that the same waste loading pre-treated by ball milling to reduce particle size prior to SPSS processing yielded TCLP concentrations almost 30 times lower, and at 8.5 ppb Hg was well below EPA limits. Pre-treatment by ball milling also allowed a reduction in the time required for stabilization, thus potentially reducing total process times by 30%.Additional performance testing was conducted including measurement of compressive strength to confirm mechanical integrity and immersion testing to determine the potential impacts of storage or disposal under saturated conditions. For both surrogate and actual Y-12 treated soils, waste form compressive strengths ranged between 2,300 and 6,500 psi, indicating very strong mechanical integrity (a minimum of greater than 40 times greater than the NRC guidance for low-level radioactive waste). In general, compressive strength increases with waste loading as the soil acts as an aggregate in the sulfur concrete waste forms. No statistically significant loss in strength was recorded for the 30 and 40 wt% surrogate waste samples and only a minor reduction in strength was measured for the 43 wt% waste forms. The 30 wt% Y-12 soil did not show a significant loss in strength but the 50 wt% samples were severely degraded in immersion due to swelling of the clay soil. The impact on Hg leaching, if any, was not determined.

Kalb P.; Milian, L.; Yim, S. P.

2012-11-30

98

Immediate and long-term fire effects on total mercury in forests soils of northeastern Minnesota.  

PubMed

Within the Boundary Waters Canoe Area Wilderness in northeastern Minnesota, soils were collected from 116 sites in areas of primarily virgin forest with fire-origin stand years (year of last recognizable stand-killing wildfire) that range from the 1759 to 1976. Median concentrations for total mercury in soils for this span of 217 years range from 0.28 +/- 0.088 ppm (1759) to 0.09 +/- 0.047 ppm (1976) for A-horizon soils and from 0.23 +/- 0.062 ppm (1759) to 0.09 +/- 0.018 ppm (1976) for O-horizon soils. A separate study of soils collected from 30 sites within an area that burned in a 2004 wildfire at Voyageurs National Park, northern Minnesota, suggested that high soil burn severity resulted in significant mercury loss from both organic and mineral soils. Integrated data from these two studies and additional regional soil data demonstrate that older forests have progressively higher mercury concentrations in O-horizon soils (r(2) = 0.423) and A-horizon soils (r(2) = 0.456). These results support the hypotheses that an important factor for mercury concentrations in forest soils is time since stand-replacing fire and that high soil burn severity has the potential to reduce the concentration of mercury in burned soils for tens to hundreds of years. PMID:20553021

Woodruff, Laurel G; Cannon, William F

2010-07-15

99

Orthogonal array design (OAD) for the optimization of mercury extraction from soils by dilute acid with microwave heating.  

PubMed

The use of dilute acid for mercury extraction from geological samples with microwave assisted heating was investigated. An orthogonal array design OA(16)(4(1)x2(12)) was applied to select the optimum conditions. The effects of the concentration of HNO(3), the additions of HCl and H(2)S0(4), the extraction time and their interactions were evaluated by the mixed-level orthogonal array design (OAD). The results indicated that the addition of small amount of HCl would improve significantly the extraction of mercury from soil matrices. From the study, it is seen that the mercury in the soil matrices could be extracted completely by 14% (v/v) HNO(3) with small quantity of HCl. The effects of the pressure within the digestion vessel and the sample mass were studied under the optimum conditions derived from the OAD. The extraction methods with optimum conditions were evaluated by determining mercury in NIST SRM 1645 River Sediment, NIES CRM No. 2 Pond Sediment and NRCC BCSS-1 Marine Sediment. Recoveries of 78-109% were achieved. Good mean recoveries of 95-98% were also obtained from real soil samples spiked with different species of mercury. PMID:18967226

Gu, W; Zhou, C Y; Wong, M K; Gan, L M

1998-08-01

100

Mercury Deposition Through Litterfall and Subsequent Accumulation in Soils: Influence of Forest Community Type  

NASA Astrophysics Data System (ADS)

We investigated the influence of community type on mercury deposition to forest soils, more precisely to the Oi, Oe, Oa, and A soil horizons. Studies have estimated that roughly half the mercury deposition in forests occurs through litterfall. Because of the importance of litterfall in the mercury deposition process, the presence or absence of forest and the type of forest may have a large impact on the magnitude of the deposition fluxes and the accumulation in soils. Eighteen sites were sampled in 2008 and 2009, throughout Vermont. The sites were located in three distinct Northern Forest community types: Northern Hardwoods, Enriched Northern Hardwoods, and Lowland Spruce-Fir. This poster will present total mercury (THg) concentration in the upper soil horizons at nine sites sampled in 2008 (THg: 59-300 ng/g, n=100), as well as mercury concentration in leaves at five of these sites, for each major tree species present (THg: 23-104 ng/g, n=25). Results were consistent within soil horizons and within tree species. Total leaf mass at senescence was measured at these five sites and an estimate of total mercury mass per hectare deposited yearly through litterfall will be presented for each site. Research has shown that mercury in soils relates to the retention of organic carbon; mercury to carbon ratio has previously been suggested for assessing Hg mobility. Mercury to carbon ratios was calculated for each soil horizon sampled and will be compared. Earthworms are invasive in Vermont and may greatly influence the depth of organic horizons and thus have the potential to affect the ability of soils to act as sink for mercury. Earthworms were detected at some but not all of the sites sampled. The detection or non-detection of earthworms and the associated forest floor depth will be discussed.

Juillerat, J. I.; Ross, D. S.

2009-12-01

101

Canadian soil quality criteria for lead, copper, arsenic, cadmium and mercury  

SciTech Connect

National soil quality criteria for the protection of ecological receptors, including livestock and wildlife, are currently under development in Canada. Based on an evaluation of direct soil contact and soil and food ingestion pathways for sensitive species, soil quality criteria for lead, copper, arsenic, cadmium and mercury for three land use categories have been derived. The draft values, in mg/kg soil, for agricultural, residential/parkland, commercial/industrial land uses are: mercury, 4, 4, 30; copper, 62, 62, 100; cadmium, 10, 10, 27; lead, 70, 250, 400; arsenic, 17, 17, 26. Critical data requirements in developing soil quality criteria are also reviewed.

Gaudet, C.; Milne, D.; Teed, S.; Lin, J.; Raju, G.S.; Ouellet, S. [Environment Canada, Hull, Quebec (Canada)

1995-12-31

102

Vertical variations in the concentration of mercury in soils around Sakurajima Volcano, Southern Kyushu, Japan.  

PubMed

In an effort to estimate the influence of mercury emitted from Sakurajima Volcano, Southern Kyushu, Japan, on the accumulation of mercury in soil, the vertical distribution of total mercury in soils was investigated together with organic matter content and grain size. The soils were sampled at a thickness of 1 cm from the surface to depth of 1 m at five locations on Sakurajima and two control locations, i.e. Takatoge approximately 11 km southeast and Suzuyama 22 km southwest of the volcano. The concentration in soils increased with the distance from the volcano and was 6.5+/-1.9 ngg(-1) (n=335), 29.0+/-15.6 ngg(-1) (n=100) and 229+/-105 ngg(-1) (n=103) for Sakurajima, Takatoge and Suzuyama, respectively. The concentration of mercury correlated with the amount of organic matter, but not with grain size distribution. The sedimentation rate for Sakurajima, Takatoge and Suzuyama was estimated from geological data to be approximately 1.3, 0.083 and 0.0048 cmyear(-1), respectively. The relatively fast sedimentation of Sakurajima soil was caused by the frequent precipitation of volcanic ash. The annual deposition of mercury estimated for Sakurajima, Takatoge and Suzuyama from the mercury concentration, sedimentation rate and soil density was 9 x 10(4), 3 x 10(4) and 2 x 10(4) ngm(-2)year(-1), respectively. Although the soil of Sakurajima had the lowest concentration among the three sites, it received the largest amount of mercury. PMID:12663186

Tomiyasu, Takashi; Okada, Morimichi; Imura, Ryusuke; Sakamoto, Hayao

2003-03-20

103

Soil geochemistry and digestive solubilization control mercury bioaccumulation in the earthworm Pheretima guillemi.  

PubMed

Mercury presents a potential risk to soil organisms, yet our understanding of mercury bioaccumulation in soil dwelling organisms is limited. The influence of soil geochemistry and digestive processes on both methylmercury (MeHg) and total mercury (THg) bioavailability to earthworms (Pheretima guillemi) was evaluated in this study. Earthworms were exposed to six mercury-contaminated soils with geochemically contrasting properties for 36 days, and digestive fluid was concurrently collected to solubilize soil-associated mercury. Bioaccumulation factors were 7.5-31.0 and 0.2-0.6 for MeHg and THg, respectively, and MeHg accounted for 17-58% of THg in earthworm. THg and MeHg measured in soils and earthworms were negatively associated with soil total organic carbon (TOC). Earthworm THg and MeHg also increased with increasing soil pH. The proportion of MeHg and THg released into the digestive fluid (digestive solubilizable mercury, DSM) was 8.3-18.1% and 0.4-1.3%, respectively. The greater solubilization of MeHg by digestive fluid than CaCl2, together with a biokinetic model-based estimate of dietary MeHg uptake, indicated the importance of soil ingestion for MeHg bioaccumulation in earthworms. PMID:25781374

Dang, Fei; Zhao, Jie; Greenfield, Ben K; Zhong, Huan; Wang, Yujun; Yang, Zhousheng; Zhou, Dongmei

2015-07-15

104

Survey of helium in soils and soil gases and mercury in soils at Roosevelt Hot Springs Known Geothermal Resource Area, Utah  

Microsoft Academic Search

The concentrations of helium and mercury in soils and of helium in soil gases were surveyed in part of the Roosevelt Hot Springs Known Geothermal Resource Area to see what relationship helium and mercury concentrations might have to geothermal features of the area. High concentrations of helium occurred over the producing geothermal field, in an area of high temperature gradients.

Hinkle

1980-01-01

105

Mercury and plants in contaminated soils. 1: Uptake, partitioning, and emission to the atmosphere  

SciTech Connect

The uptake, distribution, and subsequent emission of mercury to the atmosphere were investigated in five plant species (Lepidium latifolium [L.], Artemisia douglasiana [Bess in Hook], Caulanthus sp. [S. Watson], Fragaria vesca [L.], and Eucalyptus globulus [Labill]) with different ecological and physiological attributes. Transfer coefficients for mercury in the soil-plant system were calculated. Plant-to-atmosphere emissions of mercury were determined using a controlled environment gas-exchange system and ranged from 10 to 93 mg/m{sup 2}/h in the light; emissions in the dark were an order of magnitude less. Transfer coefficients for mercury within the soil-plant system increased acropetally (root-to-leaf axis) by orders of magnitude. Estimated mercury emissions from plants in the Carson River Drainage Basin of Nevada over the growing season (0.5 mg/m{sup 2}) add to the previously reported soil mercury emissions (8.5 mg/m{sup 2}), resulting in total landscape emissions of 9 mg/m{sup 2}. For L. latifolium, 70% of the mercury taken up by the roots during the growing season was emitted to the atmosphere. For every one molecule of mercury retained in foliage of L. latifolium, 12 molecules of mercury were emitted. Within this arid ecosystem, mercury emissions are a dominant pathway of the mercury cycle. Plants function as conduits for the interfacial transport of mercury from the geosphere to the atmosphere, and this role is undervalued in models of the behavior of mercury in terrestrial exosystems and in the atmosphere on a global scale.

Leonard, T.L.; Gustin, M.S.; Fernandez, G.C.J. [Univ. of Nevada, Reno, NV (United States); Taylor, G.E. Jr. [George Mason Univ., Fairfax, VA (United States). Dept. of Biology

1998-10-01

106

Efficiency of solvent extraction methods for the determination of methyl mercury in forest soils.  

PubMed

Methyl mercury was determined by gas chromatography, microwave induced plasma, atomic emission spectrometry (GC-MIP-AES) using two different methods. One was based on extraction of mercury species into toluene, pre-concentration by evaporation and butylation of methyl mercury with a Grignard reagent followed by determination. With the other, methyl mercury was extracted into dichloromethane and back extracted into water followed by in situ ethylation, collection of ethylated mercury species on Tenax and determination. The accuracy of the entire procedure based on butylation was validated for the individual steps involved in the method. Methyl mercury added to various types of soil samples showed an overall average recovery of 87.5%. Reduced recovery was only caused by losses of methyl mercury during extraction into toluene and during pre-concentration by evaporation. The extraction of methyl mercury added to the soil was therefore quantitative. Since it is not possible to directly determine the extraction efficiency of incipient methyl mercury, the extraction efficiency of total mercury with an acidified solution containing CuSO4 and KBr was compared with high-pressure microwave acid digestion. The solvent extraction efficiency was 93%. For the IAEA 356 sediment certified reference material, mercury was less efficiently extracted and determined methyl mercury concentrations were below the certified value. Incomplete extraction could be explained by the presence of a large part of inorganic sulfides, as determined by x-ray absorption near-edge structure spectroscopy (XANES). Analyses of sediment reference material CRM 580 gave results in agreement with the certified value. The butylation method gave a detection limit for methyl mercury of 0.1 ng g(-1), calculated as three times the standard deviation for repeated analysis of soil samples. Lower values were obtained with the ethylation method. The precision, expressed as RSD for concentrations 20 times above the detection limit, was typically 5%. PMID:11227478

Qian, J; Skyllberg, U; Tu, Q; Bleam, W F; Frech, W

2000-07-01

107

Mercury and plants in contaminated soils. 1: Uptake, partitioning, and emission to the atmosphere  

Microsoft Academic Search

The uptake, distribution, and subsequent emission of mercury to the atmosphere were investigated in five plant species (Lepidium latifolium [L.], Artemisia douglasiana [Bess in Hook], Caulanthus sp. [S. Watson], Fragaria vesca [L.], and Eucalyptus globulus [Labill]) with different ecological and physiological attributes. Transfer coefficients for mercury in the soil-plant system were calculated. Plant-to-atmosphere emissions of mercury were determined using a

Todd L. Leonard; M. S. Gustin; G. C. J. Fernandez; G. E. Jr. Taylor

1998-01-01

108

Speciation of mercury in soil and sediment by selective solvent and acid extraction.  

PubMed

In order to characterize the mercury hazard in soil, a sequential extraction scheme has been developed to classify mercury species based on their environmental mobility and/or toxicity for either routine lab analysis or on-site screening purposes. The alkyl mercury species and soluble inorganic species that contribute to the major portion of potential mercury toxicity in the soil are extracted by an acidic ethanol solution (2% HCl+10% ethanol solution) from soil matrices as "mobile and toxic" species. A High-Performance Liquid Chromatography (HPLC) system coupled with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) detection has been developed to further resolve the species information into soluble inorganic species (Hg(2+)), methylmercury(II) (MeHg(+)) and ethylmercury(II) (EtHg(+)) species. Alternatively, these species can be separated into "soluble inorganic mercury" and "alkyl mercury" sub-categories by Solid-Phase Extraction (SPE). A custom Sulfydryl Cotton Fiber (SCF) material is used as the solid phase medium. Optimization of the SCF SPE technique is discussed. Combined with a direct mercury analyzer (DMA-80), the SCF SPE technique is a promising candidate for on-site screening purposes. Following the ethanol extraction, the inorganic mercury species remaining in soil are further divided into "semi-mobile" and "non-mobile" sub-categories by sequential acid extractions. The "semi-mobile" mercury species include mainly elemental mercury (Hg) and mercury-metal amalgams. The non-mobile mercury species mainly include mercuric sulfide (HgS) and mercurous chloride (Hg(2)Cl(2)). PMID:12589509

Han, Y; Kingston, H M; Boylan, H M; Rahman, G M M; Shah, S; Richter, R C; Link, D D; Bhandari, S

2003-02-01

109

High altitude artisanal small-scale gold mines are hot spots for Mercury in soils and plants.  

PubMed

Mercury releases from artisanal and small-scale gold mines (ASGM) condense and settle on plants, soils and water bodies. We collected soil and plant samples to add knowledge to the likely transfer of Hg from soils into plants and eventually predict Hg accumulation in livestock around ASGM in Bolivia. Mean contents of Hg in soils range from 0.5 to 48.6 mg Hg kg(-1) soil (5× to 60× more compared to control sites) and exceeded the soil Hg threshold levels in some European countries. The Hg contents ranged from 0.6 to 18 and 0.2 to 28.3 mg Hg kg(-1) leaf and root, respectively. The high Hg in Poaceae and Rosaceae may elevate Hg accumulation into the food chain because llama and alpaca solely thrive on these plants for food. Erosion of soils around ASGM in Bolivia contributes to the Hg contamination in lower reaches of the Amazon basin. PMID:23202639

Terán-Mita, Tania A; Faz, Angel; Salvador, Flor; Arocena, Joselito M; Acosta, Jose A

2013-02-01

110

Atmospheric mercury inputs in montane soils increase with elevation: evidence from mercury isotope signatures  

PubMed Central

The influence of topography on the biogeochemical cycle of mercury (Hg) has received relatively little attention. Here, we report the measurement of Hg species and their corresponding isotope composition in soil sampled along an elevational gradient transect on Mt. Leigong in subtropical southwestern China. The data are used to explain orography-related effects on the fate and behaviour of Hg species in montane environments. The total- and methyl-Hg concentrations in topsoil samples show a positive correlation with elevation. However, a negative elevation dependence was observed in the mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) signatures of Hg isotopes. Both a MIF (?199Hg) binary mixing approach and the traditional inert element method indicate that the content of Hg derived from the atmosphere distinctly increases with altitude. PMID:24270081

Zhang, Hua; Yin, Run-sheng; Feng, Xin-bin; Sommar, Jonas; Anderson, Christopher W. N.; Sapkota, Atindra; Fu, Xue-wu; Larssen, Thorjørn

2013-01-01

111

Mercury Source Zone Identification using Soil Vapor Sampling and Analysis  

SciTech Connect

Development and demonstration of reliable measurement techniqes that can detect and help quantify the nature and extent of elemental mercury (Hg(0)) in the subsurface are needed to reduce certainties in the decision making process and increase the effectiveness of remedial actions. We conducted field tests at the Y-12 National Security Complex (NSC) in Oak Ridge, TN, to determine if sampling and analysis of Hg(0) vapors in the shallow subsurface (<0.3 m depth) can be used to as an indicator of the location and extent of Hg(0) releases in the subsurface. We constructed a rigid PVC pushprobe assembly, which was driven into the ground. Soil gas samples were collected through a sealed inner tube of the assembly and analyzed immediately in the field with a Lumex and/or Jerome Hg(0) analyzer. Time-series sampling showed that Hg vapor concentrations were fairly stable over time suggesting that the vapor phase Hg(0) was not being depleted and that sampling results were not dependent on the soil gas purge volume. Hg(0) vapor data collected at over 200 pushprobe locations at 3 different release sites correlated well to areas of known Hg(0) contamination. Vertical profiling of Hg(0) vapor concentrations conducted at 2 locations provided information on the vertical distribution of Hg(0) contamination in the subsurface. We concluded from our studies that soil gas sampling and analysis can be conducted rapidly and inexpensively at a large scale to help identify areas contaminated with Hg(0).

Watson, David B [ORNL] [ORNL; Miller, Carrie L [ORNL] [ORNL; Lester, Brian P [ORNL] [ORNL; Lowe, Kenneth Alan [ORNL] [ORNL; Southworth, George R [ORNL] [ORNL; Bogle, Mary Anna [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Pierce, Eric M [ORNL] [ORNL

2014-01-01

112

Influence of soil mercury concentration and fraction on bioaccumulation process of inorganic mercury and methylmercury in rice (Oryza sativa L.).  

PubMed

Recent studies showed that rice is the major pathway for methylmercury (MeHg) exposure to inhabitants in mercury (Hg) mining areas in China. There is, therefore, a concern regarding accumulation of Hg in rice grown in soils with high Hg concentrations. A soil pot experimental study was conducted to investigate the effects of Hg-contaminated soil on the growth of rice and uptake and speciation of Hg in the rice. Our results imply that the growth of rice promotes residual fraction of Hg transforming to organic-bound fraction in soil and increased the potential risks of MeHg production. Bioaccumulation factors deceased for IHg but relatively stabilized for MeHg with soil total mercury (THg) increasing. IHg in soil was the major source of Hg in the root and stalk, but leaf was contributed by Hg from both atmosphere and soil. Soluble and exchangeable Hg fraction can predict the bioavailability of IHg and MeHg in soils, and that can provide quantitative description of the rate of uptake of the bioavailable Hg. Soluble and exchangeable Hg fraction in paddy soil exceeding 0.0087 mg kg(-1) may cause THg concentration in rice grain above the permissible limit standard, and MeHg concentration in paddy soil more than 0.0091 mg kg(-1) may have the health risks to humans. PMID:25398217

Zhou, Jun; Liu, Hongyan; Du, Buyun; Shang, Lihai; Yang, Junbo; Wang, Yusheng

2015-04-01

113

Phytoremediation of mercury in pristine and crude oil contaminated soils: Contributions of rhizobacteria and their host plants to mercury removal  

Microsoft Academic Search

The rhizospheric soils of three tested legume crops: broad beans (Vicia faba), beans (Phaseolus vulgaris) and pea (Pisum sativum), and two nonlegume crops: cucumber (Cucumis sativus) and tomato, (Lycopersicon esculentum) contained considerable numbers (the magnitude of 105g?1 soil) of bacteria with the combined potential for hydrocarbon-utilization and mercury-resistance. Sequencing of the 16S rRNA coding genes of rhizobacteria associated with broad

N. A. Sorkhoh; N. Ali; H. Al-Awadhi; N. Dashti; D. M. Al-Mailem; M. Eliyas; S. S. Radwan

2010-01-01

114

Mercury levels in fish in the La Grande River area, Northern Quebec  

Microsoft Academic Search

High mercury levels in organisms in inland waters have usually been attributed to pollution (e.g. FIMREITE et al. 1971). But there is evidence that high mercury content im rocks in some regions (CAMERON and JONASSON 1972) may be responsible for high mercury levels in organisms. It has been known for some time that fish in the southern James Bay region

Eric C. Smith; Fikret Berkes; John A. Spence

1975-01-01

115

Strong positive associations between seafood, vegetables, and alcohol with blood mercury and urinary arsenic levels in the Korean adult population.  

PubMed

Blood mercury and urinary arsenic levels are more than fivefold greater in the Korean population compared with those of the United States. This may be related to the foods people consumed. Therefore, we examined the associations between food categories and mercury and arsenic exposure in the Korean adult population. Data regarding nutritional, biochemical, and health-related parameters were obtained from a cross-sectional study, the 2008-2009 Korean National Health and Nutrition Examination Survey (3,404 men and women age ? 20 years). The log-transformed blood mercury and urinary arsenic levels were regressed against the frequency tertiles of each food group after covariate adjustment for sex, age, residence area, education level, smoking status, and drinking status using food-frequency data. Blood mercury levels in the high consumption groups compared to the low consumption groups were elevated by about 20 percents with salted fish, shellfish, whitefish, bluefish, and alcohol, and by about 9-14 percents with seaweeds, green vegetables, fruits and tea, whereas rice did not affect blood mercury levels. Urinary arsenic levels were markedly increased with consumption of rice, bluefish, salted fish, shellfish, whitefish, and seaweed, whereas they were moderately increased with consumption of grains, green and white vegetables, fruits, coffee, and alcohol. The remaining food categories tended to lower these levels only minimally. In conclusion, the typical Asian diet, which is high in rice, salted fish, shellfish, vegetables, alcoholic beverages, and tea, may be associated with greater blood mercury and urinary arsenic levels. This study suggests that mercury and arsenic contents should be monitored and controlled in soil and water used for agriculture to decrease health risks from heavy-metal contamination. PMID:23011092

Park, Sunmin; Lee, Byung-Kook

2013-01-01

116

Electrokinetic remediation of mercury-contaminated soils using iodine\\/iodide lixiviant  

Microsoft Academic Search

In-situ remediation of mercury-contaminated soils, by electrokinetic or other means, is difficult because of the low solubility of mercury and its compounds. In this research, enhanced electrokinetic remediation of HgS-contaminated soils using Iâ\\/I⁻ lixiviant was investigated using bench-scale electrokinetic cells. The thermodynamic conditions under which the lixiviant could be effective were determined by constructing a pE-pH diagram for the Hg-S-I

Chris D. Cox; Matthew A. Shoesmith; Mriganka M. Ghosh

1996-01-01

117

Binding and mobility of mercury in soils contaminated by emissions from chlor-alkali plants  

Microsoft Academic Search

Chlor-alkali plants are known to be an important source of Hg emissions to the atmosphere and related contamination of soils in their vicinity. In the present study, the results of Hg speciation and mobility of Hg in soils affected by Hg emissions from three chlor-alkali plants are compared. Solid phase mercury speciation analyses was carried out using a mercury–thermo-desorption technique

H. Biester; G. Muller; H. F. Scholer

2002-01-01

118

An evaluation of mercury levels in Louisiana fish: Trends and public health issues  

Microsoft Academic Search

To characterize statewide fish tissue mercury levels in edible finfish the first comprehensive analysis of Louisiana's fish tissue mercury database was conducted. Analyses were based on fifteen years of fish tissue mercury data collected from 368 waterbodies between 1994 and 2008 (n=14,344). The overall objectives of this study were to establish baseline fish tissue mercury levels; and evaluate species-specific temporal

Adrienne Katner; Mei-Hung Sun; Mel Suffet

2010-01-01

119

Lead and mercury levels in raccoons from Macon County, Alabama  

SciTech Connect

Heavy metal contamination in the environment has become a major concern of the scientific community. The ubiquitous present of heavy metals such as lead, mercury, and cadmium in wildlife animals has been reported. Although the understanding of the full significance of these metals is incomplete, it is known that some species contain concentrations of metals proportional to the levels present in their environments. Thus, wild animals can be used as biological indicators of environmental concentrations of metals. The behavior, omnivorous feeding habits, and adaptability of raccoons (Procyon lotor) qualify this animal as a useful indicator of environmental pollution. The purpose of this paper was to report some preliminary observations on lead and mercury levels in raccoons from Macon County, Alabama, a potential indicator species for wildlife. 19 refs., 3 tabs.

Khan, A.T.; Thompson, S.J. [Tuskegee Univ., AL (United States); Mieike, H.W. [Xavier Univ. of Louisiana, New Orleans, LA (United States)

1995-06-01

120

Simultaneous determination of mercury and organic carbon in sediment and soils using a direct mercury analyzer based on thermal decomposition-atomic absorption spectrophotometry.  

PubMed

The purpose of this work was to study the feasibility of using a direct mercury analyzer (DMA) to simultaneously determine mercury (Hg) and organic matter content in sediment and soils. Organic carbon was estimated by re-weighing the sample boats post analysis to obtain loss-on-ignition (LOI) data. The DMA-LOI results were statistically similar (p<0.05) to the conventional muffle furnace approach. A regression equation was developed to convert DMA-LOI data to total organic carbon (TOC), which varied between 0.2% and 13.0%. Thus, mercury analyzers based on combustion can provide accurate estimates of organic carbon content in non-calcareous sediment and soils; however, weight gain from moisture (post-analysis), measurement uncertainty, and sample representativeness should all be taken into account. Sediment cores from seasonal wetland and open water areas from six oxbow lakes in the Mississippi River alluvial flood plain were analyzed. Wetland sediments generally had higher levels of Hg than open water areas owing to a greater fraction of fine particles and higher levels of organic matter. Annual loading of Hg in open water areas was estimated at 4.3, 13.4, 19.2, 20.7, 129, and 135ngcm(-2)yr(-1) for Beasley, Roundaway, Hampton, Washington, Wolf and Sky Lakes, respectively. Generally, the interval with the highest Hg flux was dated to the 1960s and 1970s. PMID:25847156

Chen, Jingjing; Chakravarty, Pragya; Davidson, Gregg R; Wren, Daniel G; Locke, Martin A; Zhou, Ying; Brown, Garry; Cizdziel, James V

2015-04-29

121

Effects of intensive fishing on the structure of zooplankton communities and mercury levels.  

PubMed

Following the impoundment of hydroelectric reservoirs, a small fraction of the mercury (Hg) in the flooded soils is transformed and released into the ecosystem. This causes an increase in the mercury level in the food chain, particularly in piscivorous fish, and represents a potential risk for human health. In 1998, Hydro-Québec carried out an intensive fishing campaign to examine the feasibility of using intensive fishing as a mitigation tool. The goal of this particular part of the project was to evaluate the impact of intensive fishing on the zooplanktonic communities' structure and mercury levels. Specifically, the effects of intensive fishing on: (1) total biomass and zooplankton size structure (>500, 200-500, 100-200 and 53-100 microm); (2) species composition; and (3) total mercury and methylmercury (MeHg) concentrations in zooplankton of different size fractions were studied. Although important decreases were observed in total zooplankton biomass or its size structure, it cannot be related to the intensive fishing. The results, however, show major changes in the dominance of macrozooplanktonic species in fished lakes as opposed to reference lakes. Similarly, in contrast to the reference lakes, mercury and MeHg concentrations in the four size fractions of the zooplanktonic communities changed from 1998 to 2000 in the fished lakes. The MeHg concentration increased from approximately 20 to 200 ng/gdw from the 53 to 500 microm mesh size fraction, showing a biomagnification in the food chain. The canonical correspondence analysis showed that lakes dominated by Holopedium gibberum presented higher concentrations of Hg and MeHg than lakes dominated by Daphnia spp. PMID:12663198

Masson, Stéphane; Tremblay, Alain

2003-03-20

122

Aqueous and Gas Phase Sorption Properties of Mercury in Burned Soils  

NASA Astrophysics Data System (ADS)

Wildfires are a common occurrence in the Mediterranean climate of Southern California. Many studies have focused on the post-fire physical impacts however; there is a lack of studies on the potential for post-fire metal transport, in particular mercury (Hg). Inorganic Hg contamination is present even in pristine areas due to atmospheric deposition, which can be microbially transformed to methylmercury (a bioaccumulative neurotoxin) in aquatic systems. In order to model the transport of mercury in burned soils, we need to understand the sorption properties of mercury in soils exposed to fire. To test the hypothesis that burned soils have different sorption properties than unburned ones, we have collected samples of unburned soils, and burned them in a controlled setting at different temperatures to simulate several fire intensities. Then, we applied traditional aqueous sorption techniques to determine the binding properties of mercury to each burned soil. Experimental data were fitted with FITEQL to derive constants for sorption reactions, which were in agreement with values observed in literature. Since Southern California does not receive much rain, most of the atmospheric mercury deposition is in form of dry deposition. Thus, we have designed and applied a novel sorption technique to determine the binding of mercury in the gas phase to the burned soils. Trends in sorption affinity and capacity with burning temperature are discussed, as well as a comparison between aqueous and gas phase sorption properties is made.

Jay, J.; Ferreira, M.; Burke, M.; Hogue, T.

2008-12-01

123

Green waste compost as an amendment during induced phytoextraction of mercury-contaminated soil.  

PubMed

Phytoextraction of mercury-contaminated soils is a new strategy that consists of using the higher plants to make the soil contaminant nontoxic. The main problem that occurs during the process is the low solubility and bioavailability of mercury in soil. Therefore, some soil amendments can be used to increase the efficiency of the Hg phytoextraction process. The aim of the investigation was to use the commercial compost from municipal green wastes to increase the efficiency of phytoextraction of mercury-contaminated soil by Lepidium sativum L. plants and determine the leaching of Hg after compost amendment. The result of the study showed that Hg can be accumulated by L. sativum L. The application of compost increased both the accumulation by whole plant and translocation of Hg to shoots. Compost did not affect the plant biomass and its biometric parameters. Application of compost to the soil decreased the leaching of mercury in both acidic and neutral solutions regardless of growing medium composition and time of analysis. Due to Hg accumulation and translocation as well as its potential leaching in acidic and neutral solution, compost can be recommended as a soil amendment during the phytoextraction of mercury-contaminated soil. PMID:25245260

Smolinska, Beata

2015-03-01

124

Methyl Mercury Production In Tropical Hydromorphic Soils: Impact Of Gold Mining.  

NASA Astrophysics Data System (ADS)

Artisanal alluvial gold mining is important in many tropical developing countries and several million people are involved worldwide. The dominant use of mercury for gold amalgamation in this activity leads to mercury accumulation in soils, to sediment contamination and to methyl mercury (MMHg) bioaccumulation along the food chain. In this presentation we will present recent data on methyl mercury production in hydromorphic soils and tailing ponds from a former gold mining area located in French Guiana (South America). Comparison of specific fluxes between a pristine sub watershed and the contaminated watershed shows that former mining activities lead to a large enhancement of dissolved and particulate MMHg emissions at least by a factor of 4 and 6, respectively. MMHg production was identified in sediments from tailing ponds and in surrounding hydromorphic soils. Moreover, interstitial soil water and tailing pond water profiles sampled in an experimental tailing pond demonstrate the presence of a large MMHg production in the suboxic areas. Both tailing ponds and hydromorphic soils present geochemical conditions that are favorable to bacterial mercury methylation (high soil Hg content, high aqueous ferric iron and dissolved organic carbon concentrations). Although sulfate-reducing bacteria have been described as being the principal mercury methylating bacteria, the positive correlation between dissolved MMHg and ferrous iron concentrations argue for a significant role of iron-reducing bacteria. Identifications by sequencing fragments of 16S rRNA from total soil DNA support these interpretations. This study demonstrates that current and past artisanal gold mining in the tropics lead to methyl mercury production in contaminated areas. As artisanal activities are increasing with increasing gold prices, the bio- magnification of methyl mercury in fish presents an increasing threat to local populations whose diet relies on fish consumption.

Guedron, S.; Charlet, L.; Harris, J.; Grimaldi, M.; Cossa, D.

2007-12-01

125

Mercury Levels in Common (Actitis hypoleucos) and Green (Tringa ochropus) Sandpipers from West-Central Iran.  

PubMed

Mercury concentrations were examined in the liver, kidneys, and tail and breast feathers of common and green sandpipers from Zayanderud Dam in west-central Iran. The aim was to provide indirect information about habitat contamination. Tail feathers of both species had higher mercury levels compared to other tissues. Moreover, tissues of common sandpipers had significantly higher mercury concentrations compared to tissues of green sandpipers. Male specimens of both species had higher values of mercury compared to females. The pattern of larger body size-higher mercury body burden was not completely true in the current study. Smaller and shorter common sandpipers had higher mercury concentrations compared to taller and heavier green sandpipers. At the intraspecific level, body weight was positively correlated with mercury concentrations in tissues of common sandpipers. Based on the data presented here, it appears that these sandpipers, especially common sandpipers, are at potential risk from the toxic effects of mercury. PMID:25851218

Malekian, Mansoureh; Hosseinpour-Mohamadabadi, Zahra

2015-05-01

126

Risk, Mercury Levels, and Birds: Relating Adverse Laboratory Effects to Field Biomonitoring  

Microsoft Academic Search

There is an abundance of field data on levels of mercury in a variety of organisms and there are a number of studies that demonstrate the adverse effects of mercury on laboratory animals, but few studies examine the relationship between the two. Thus it is often difficult to determine the ecological relevance of mercury concentrations found in nature, or to

Joanna Burger; Michael Gochfeld

1997-01-01

127

Mercury level in fish caught in Indian River Lagoon higher than it should be?  

E-print Network

Mercury level in fish caught in Indian River Lagoon higher than it should be? Harbor Branch at the idea he might ingest too much mercury. "I ain't dead yet," said Justin Baird, who stopped, figured he would gobble it up in two days. Chances are, all the fish contained some mercury. As the poor

Belogay, Eugene A.

128

REMOVAL OF MERCURY FROM CONTAMINATED SOILS AT THE PAVLODAR CHEMICAL PLANT.  

SciTech Connect

Soils beneath and adjacent to the Pavlodar Chemical Plant in Kazakhstan have been contaminated with elemental mercury as a result of chlor alkali processing using mercury cathode cell technology. The work described in this paper was conducted in preparation for a demonstration of a technology to remove the mercury from the contaminated soils using a vacuum assisted thermal distillation process. The process can operate at temperatures from 250-500 C and pressures of 0.13kPa-1.33kPa. Following vaporization, the mercury vapor is cooled, condensed and concentrated back to liquid elemental mercury. It will then be treated using the Sulfur Polymer Stabilization/Solidification process developed at Brookhaven National Laboratory as described in a companion paper at this conference. The overall project objectives include chemical and physical characterization of the contaminated soils, study of the influence of the soil's physical-chemical and hydro dynamical characteristics on process parameters, and laboratory testing to optimize the mercury sublimation rate when heating in vacuum. Based on these laboratory and pilot-scale data, a full-scale production process will be designed for testing. This paper describes the soil characterization. This work is being sponsored by the International Science and Technology Center.

KHRAPUNOV, V. YE.; ISAKOVA, R.A.; LEVINTOV, B.L.; KALB, P.D.; KAMBEROV, I.M.; TREBUKHOV, A.

2004-09-25

129

Mercury  

NSDL National Science Digital Library

This lithograph shows mosaic images of Mercury, captured by the Mariner 10 spacecraft. The images are accompanied by a brief description and history, some statistical facts, and a list of significant dates in the exploration of Mercury.

130

Mercury  

MedlinePLUS

... Data and Publications Grants and Funding Science and Technology The Mercury Study Report to Congress About Mercury Basic Information Frequent Questions Human Exposure Health Effects Environmental Effects Protecting Yourself Where You Live Releases and ...

131

Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils  

NASA Astrophysics Data System (ADS)

Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed.

Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P.

2013-09-01

132

Monitoring of arsenic, boron and mercury by lichen and soil analysis in the Mt. Amiata geothermal area (central Italy)  

SciTech Connect

Epiphytic lichens and top-soils from the Mt. Amiata geothermal field (central Italy) were analyzed for their As, B and Hg content. Three areas were selected: (1) Abbadia S. Salvatore, where a large Hg mine with smelting and roasting plant was located; (2) Piancastagnaio, where there are geothermal power plants; (3) a remote site far from mines and geothermal power plants. The results showed that the geothermal power plants do not represent a macroscopic source of arsenic and boron contamination in the area. As far as mercury is concerned, at the Hg mining area of Abbadia S. Salvatore concentrations were extremely high both in soil and epiphytic lichens, and the anomalous content in these organisms was due to the uptake of elemental mercury originating from soil degassing. At the geothermal area of Piancastagnaio, soil mercury was not different from that in the control area, but Hg in lichens was almost twice the control levels, suggesting that the gaseous emissions from the geothermal power plants are an important source of air contamination.

Loppi, S. [Universita di Siena Via P.A. Mattioli (Italy)

1997-12-31

133

Mercury Levels in Premature and Low Birth Weight Newborns after Receipt of Thimerosal-Containing Vaccines  

PubMed Central

Objective We conducted a population-based pharmacokinetic study to assess blood levels and elimination of mercury following vaccination of premature infants born at ? 32 and < 37 weeks of gestation and with birth weight ? 2000 but < 3000 grams. Study design Blood, stool, and urine samples were obtained pre-vaccination and 12 hours to 30 days post-vaccination from 72 premature newborns. Total mercury levels were measured by atomic absorption. Results The mean ± standard deviation (SD) birth weight was 2.4 ±0.3 Kg for the study population. Maximal mean ± SD blood mercury levels was 3.6 ± 2.1 ng/mL occurring at 1 day after vaccination, maximal mean ± SD stool mercury levels were 35.4 ± 38.0 ng/g, occurring on day 5 after vaccination, and urine mercury levels were mostly non-detectable. The blood mercury half-life was calculated to be 6.3 (95% CI:3.85-8.77) days and mercury levels returned to pre-vaccination levels by day 30. Conclusions The blood half-life of intramuscular ethyl mercury from thimerosal in vaccines given to premature infants is substantially shorter than that of oral methyl mercury in adults. Because of the differing pharmacokinetics, exposure guidelines based on oral methyl mercury in adults may not be accurate for children who receive thimerosal-containing vaccines. PMID:19560158

Pichichero, Michael E.; Gentile, Angela; Giglio, Norberto; Alonso, Margarita Martin; Fernandez Mentaberri, Maria Veronica; Zareba, Grazyna; Clarkson, Thomas; Gotelli, Carlos; Gotelli, Mariano; Yan, Lihan; Treanor, John

2009-01-01

134

Hg contents in soils and olive-tree (Olea Europea, L.) leaves from an area affected by elemental mercury pollution (Jódar, SE Spain).  

NASA Astrophysics Data System (ADS)

Data from soil and olive tree leaves around a decommissioned chlor-alkali plant are presented in this communication. The factory was active in the period 1977-1991, producing during these years a heavily pollution of Guadalquivir River and hydrargyrism in more than local 45 workers. It is located at 7 km South of Jódar, a locality with some 12,120 inhabitants. Mercury usage was general in this type of plants, but at present it is being replaced by other types of technologies, due to the risks of mercury usage in personal and environment. A soil geochemistry survey was carried out in the area, along with the analysis of olive-tree leaves (in the plots with this culture) from the same area. 73 soil samples were taken at two different depths (0-15 cm and 15-30 cm), together with 41 olive tree samples. Mercury content of geologic and biologic samples was determined by means of Atomic Absorption Spectrometry with Zeeman Effect, using a Lumex RA-915+ device with the RP-91C pyrolysis attachment. Air surveys were carried our using a RA-915M Lumex portable analytical device. Soil mercury contents were higher in topsoil than in the deeper soil samples, indicating that incorporation of mercury was due to dry and wet deposition of mercury vapors emitted from the plant. Average content in topsoil is 564.5 ng g-1. Hg contents in olive-tree leaves were in the range 46 - 453 ng g-1, with an average of 160.6 ng g-1. This level is slightly lower than tolerable level for agronomic crops established by Kabata-Pendias (2001) in 200 ng g-1. We have also compared soil and leaf contents for each sampling site, finding a positive and significant correlation (R=0.49), indicating that Hg contents in the leaves are linked to Hg contents in the soils. BAC (Bioaccumulation Absorption Coefficient, calculated as ratio between soil and leaf concentration) is 0.28 (consistent with world references, BAC = 0.7), considered "medium" in comparison with other mineral elements. Main conclusions of this research work are the following: i) The Jódar decommissioned chlor-alkali plant is still a mercury source 20 years after its cease of activities without any reclamation measures; ii) The activity of the plant has produced an important dissemination of mercury in the surrounding environment; and iii) The corresponding pollution levels, in particular in soils, may suppose a risk to the main crops of the area (olive trees present significant accumulation of Hg in leaf).

López-Berdonces, Miguel Angel; María Esbrí, José; Amorós, José Angel; Lorenzo, Saturnino; Fernández-Calderón, Sergio; Higueras, Pablo; Perez-de-los-Reyes, Caridad

2014-05-01

135

Mercury  

NASA Astrophysics Data System (ADS)

Mercury has always held the distinction of being the terrestrial planet most unlike the others. On 18 March 2011, after three successful flybys of Mercury, the MESSENGER spacecraft entered orbit around Mercury. Essential to the payload of MESSENGER are three instruments designed to measure the geochemistry of the surface - an x-ray spectrometer, a gamma-ray spectrometer, and a neutron spectrometer. Together, the data returned by these three instruments - coupled with insights about planetary structure gained from tracking the spacecraft, spectral data measured in orbit, and a new and complete view of the geology of the surface - have begun to revolutionize the people's understanding of Mercury. In this chapter, the authors first review the pre-MESSENGER views of Mercury, followed by the first results from the MESSENGER mission. The authors then discuss the implications of these first results in constraining the origin of Mercury, followed by looking forward to future work.

McCoy, T. J.; Nittler, L. R.

136

USEPA'S RESEARCH PROGRAM ON REMEDIATION AND CONTAINMENT OF ARSENIC AND MERCURY IN SOILS, INDUSTRIAL WASTES, AND GROUNDWATER  

EPA Science Inventory

In the U.S. and around the world, mercury and arsenic contaminated soils, industrial wastes, and groundwater are difficult to effectively and cheaply remediate and contain. Mercury is a serious health concern and has been identified as a contaminant in the air, soil, sediment, su...

137

Review: Interpreting Hair Mercury Levels in Individual Patients  

Microsoft Academic Search

Evaluation of mercury exposure in an individual patient ideally includes the presenting history, physical examination, consideration of the differential diagnosis, and mercury analysis of blood and urine specimens. Analysis of mercury in hair specimens may supply useful supplemental information about exposure to organic compounds such as methylmercury, particularly to help reconstruct the pattern of prior exposure. The most appropriate specimen

Kern L. Nuttall

2006-01-01

138

The sorption characteristics of mercury as affected by organic matter content and/or soil properties  

NASA Astrophysics Data System (ADS)

The determination and description of the mercury sorption extend on soil is significant for potential environmental toxic effects. The aim of this study was to assess the effectiveness of mercury sorption at different soil samples and vermicomposts. Mercury interactions with soil organic matter were studied using three soils with different physical-chemical properties - fluvisol, cambisol, and chernozem. Moreover, three different vermicomposts based on various bio-waste materials with high organic matter content were prepared in special fermentors. First was a digestate, second was represented by a mixture of bio-waste from housing estate and woodchips, and third was a garden bio-waste. In the case of vermicompost, the fractionation of organic matter was executed primarily using the resin SuperliteTM DAX-8. Therefore, the representation of individual fractions (humic acid, fulvic acid, hydrophilic compounds, and hydrophobic neutral organic matter) was known. The kinetics of mercury sorption onto materials of interest was studied by static sorption experiments. Samples were exposed to the solution with known Hg concentration of 12 mg kg-1 for the time from 10 minutes to 24 hours. Mercury content in the solutions was measured by the inductively coupled plasma mass spectrometry (ICP-MS). Based on this data, the optimum conditions for following sorption experiments were chosen. Subsequently, the batch sorption tests for all soil types and vermicomposts were performed in solution containing variable mercury concentrations between 1 and 12 mg kg-1. Equilibrium concentration values measured in the solution after sorption and calculated mercury content per kilogram of the soil or the vermi-compost were plotted. Two basic models of sorption isotherm - Langmuir and Freundlich, were used for the evaluation of the mercury sorption properties. The results showed that the best sorption properties from studied soil were identified in chernozem with highest cation exchange capacity. The highest amount of mercury was adsorbed by the vermicompost from garden bio-waste. This vermicompost contained the most humic acids and the least amount of other fractions of organic matter. Acknowledgements: Financial support for these investigations was provided by the Grant Agency of the Czech Republic; Project No. 503/12/0682 and Czech University of Life Science Prague; Project No. 21140/1313/3130.

Šípková, Adéla; Šillerová, Hana; Száková, Ji?ina

2014-05-01

139

Effects of low dietary levels of methyl mercury on mallard reproduction  

USGS Publications Warehouse

Mallard ducks were fed a control diet or a diet containing 0.5 ppm or 3 ppm mercury (as methylmercury dicyandiamide). Health of adults and reproductive success were studied. The dietary level of 3 ppm mercury had harmful effects on reproduction, although it did not appear to affect the health of the adults during the 12 months of dosage. Ducks that were fed the diet containing 0.5 ppm mercury reproduced as well as controls, and ducklings from parents fed 0.5 ppm mercury grew faster in the first week of life than did controls....The greatest harm to reproduction associated with the diet containing 3 ppm mercury was an increase in duckling mortality, but reduced egg laying and increased embryonic mortality also occurred....During the peak of egg laying, eggs laid by controls tended to be heavier than eggs laid by ducks fed either level of mercury; however, there seemed to be no eggshell thinning associated with mercury treatment. Levels of mercury reached about 1 ppm in eggs from ducks fed a dietary dosage of 0.5 ppm mercury and between 6 and 9 ppm in the eggs from ducks fed 3 ppm mercury.

Heinz, G.

1974-01-01

140

An evaluation of mercury levels in Louisiana fish: trends and public health issues.  

PubMed

To characterize statewide fish tissue mercury levels in edible finfish the first comprehensive analysis of Louisiana's fish tissue mercury database was conducted. Analyses were based on fifteen years of fish tissue mercury data collected from 368 waterbodies between 1994 and 2008 (n=14,344). The overall objectives of this study were to establish baseline fish tissue mercury levels; and evaluate species-specific temporal and spatial trends in fish tissue mercury levels. Fish tissue mercury levels ranged from 0.001 ppm (the detection limit) to 5.904 ppm for king mackerel; with an overall geometric mean of 0.218 ppm. Ninety-five percent of samples had mercury levels below the FDA's action level of 1.0 ppm for methylmercury in commercial food. Forty-four percent of all samples had mercury levels above the U.S. EPA's methylmercury fish tissue criterion of 0.3 ppm for sportfish. Species of potential concern include cobia, king mackerel, blackfin tuna, greater amberjack, spotted bass, bowfin, largemouth bass and freshwater drum. There was a significant but small decline in statewide length-adjusted largemouth bass mercury levels between 1994-1999 to 2003-2008 (p<0.05). The highest fish mercury levels were observed in Pearl, Calcasieu, Mermentau, Ouachita, Pontchartrain and Sabine basins. Length-adjusted largemouth bass mercury levels were significantly higher in wetlands and rivers/streams vs. lakes; and in wetlands vs. estuaries (p<0.05). Data were analyzed from a public health perspective to make recommendations for optimizing monitoring and outreach. PMID:20855108

Katner, Adrienne; Sun, Mei-Hung; Suffet, Mel

2010-11-01

141

Volcanism and soil mercury on Mars - Consequences for terrestrial microorganisms  

NASA Technical Reports Server (NTRS)

An earth-Mars depletion formula proposed by Anders and Owen for volatiles is used to calculate a range of putative Hg levels for Martian volcanic soils based upon analyzed samples from Hawaii. The range is about 50-150 microgram per kg. When applied either in conventional or special media (e.g., basalt powder), these levels of Hg are effective inhibitors of the growth of earth microorganisms. Taken together with other hostile chemical and physical factors, volcanic toxicants would appear to provide a further deterrent to the accidental establishment of terrestrial microbiota on Mars.

Siegel, B. Z.; Siegel, S. M.

1978-01-01

142

Lead, cadmium and mercury levels in the 2010 Korean diet.  

PubMed

This study analysed the level of contamination of harmful heavy metals in 3820 food samples available in Korea in 2010. A total of 119 types of samples were collected, including corns, vegetables, fruits, fishes, mollusks, shellfish, crustaceans, seaweed, bean products, meats and eggs from seven major cities. These samples were analysed using ICP-MS after pre-treatment with a microwave-digestion system. Results of lead, cadmium and mercury analyses were compared with the standard specifications of Korea Food Standards Codex. As a result, high levels of Pb, Cd and Hg were detected in "cockle," "dried-squid" and "shark-meat." Acceptable intake for consumers was checked using provisional tolerable weekly intake values. Such results will be utilised as data on the exposure of human body through foods. In addition, satisfactory results were obtained through purchase and analysis of National Institute of Science and Technology-certified reference materials to obtain reliability on analysis results. PMID:24786406

Kim, Jae Hoon; Lee, Ji Yeon; Seo, Joo Ee; Jeong, Ji Yoon; Jung, Ki Kyung; Yoon, Hae Jung; Park, Kyung Su

2012-01-01

143

An Assessment of health risk associated with mercury in soil and sediment from East Fork Poplar Creek, Oak Ridge, Tennessee. Final report  

SciTech Connect

This report presents results from a study conducted to determine the toxicity of Mercury in soils sediments samples. Mice were fed via diet, soils and sediment, from various locations along the East Fork Poplar creek. Tissue distribution of pollutants was determined at various intervals. The tissue level relative to toxicity was used to determine the effect of a complex matrix on the gastrointestinal absorption and tissue distribution of the pollutants (other pollutants included cadmium and selenium).

Revis, N.; Holdsworth, G.; Bingham, G.; King, A.; Elmore, J.

1989-04-01

144

Mercury in mushrooms and soil of the Tarnobrzeska Plain, south-eastern Poland.  

PubMed

Mercury was quantified in the fruiting bodies of 15 species of higher mushrooms and underlying soil substrate collected from the Tarnobrzeska Plain in south-eastern part of Poland in 1995. In total, 405 samples each of caps, stalks or whole fruiting bodies and 221 samples of soil (0 10cm layer) were examined. The area under investigation can be considered generally as unpolluted with mercury since the mean concentrations in underlying soil substrate of 14 mushroom species were between 21 +/- 9 and 58 +/- 31 ng/g dry wt. (total range between 4.5-240). Somewhat elevated concentrations, of 630 +/- 80 ng/g dry wt., were noted for underlying soil substrate of Livid Entoloma (Entoloma sinuatum). Among the mushroom species examined, King Bolete (Boletus edulis), Livid Entoloma, and Red-capped Scaber Stalk (Leccinum rufum) contained the greatest mercury concentrations both in the caps (between 1,800 +/- 600 and 3,500 +/- 1,100 ng/g dry wt.) and stalks (between 900 +/- 400 and 2,300 +/- 1,000 ng/g dry wt.). Because of the relatively great bioconcentration factors (BCF) of mercury, which averaged between 73 +/- 44 and 220 +/- 270 in the caps, and between 37 +/- 28 and 170 +/- 240 in the stalks, King Bolete, Bay Bolete (Xerocomus badius) and Red-capped Scaber Stalk can be considered as good mercury accumulators. Nevertheless, apart from the Common Earth Ball (Scleroderma citrinum), that can be considered as an excluder of mercury due to the BCF value of less than 1, other species examined were characterised by BCFs greater than 1. The caps were usually characterised with greater mercury content than the stalks (Hg(Cap)/Hg(stalk) quotients > 1) and the reverse was noted only for Bay Bolete. Due to a statistically significant relationship between mercury content of the caps/stalks and underlying soil substrate (p<0.001) in Filamentous Pax (Paxilus filamentosus), and in the stalks of Red-capped Scaber (p < 0.05) and Brick Tops (Hypholoma sublateritium) (caps; p < 0.05), these species can be suggested to exhibit bioindication potential for soil mercury contamination. PMID:11929073

Falandysz, Jerzy

2002-03-01

145

[Characteristics of mercury pollution in soil and atmosphere in Songhua River upstream Jia-pi-gou gold mining area].  

PubMed

In the studied area of Jia-pi-gou at the upstream area of Songhua River, algamation process has been applied as a dominant method to extract gold for more than one hundred and eighty years, resulting in severe mercury environmental pollution. The total mercury contents in the atmosphere and soil have been determined by mercury analyzer (Zeeman RA915+) and cold atomic absorption spectrophotometry (GB/T 17136-1997), respectively. To study the pollution characteristics of mercury in the soil and atmosphere, the mercury flux at the interface between the soil and the atmosphere of 4 sampling sites Lao-jin-chang, Er-dao-gou, Er-dao-cha and community of Jia-pi-gou have been determined with the method of dynamic flux chamber. Furthermore, linear regression analyses on the total mercury contents between soil and atmosphere have been carried out and the correlation coefficient of mercury exchange flux between soil and atmosphere and meteorological factors has been studied. The results are as follows: (1) The mean value of mercury content in the atmosphere is (71.08 +/- 38.22) ng x m(-3). (2) The mean value of mercury content in the soil is (0.913 1 +/- 0.040 8) mg x kg(-1); it shows remarkably positive correlation between the mercury contents in soil and in the atmosphere. (3) The mercury exchange flux between soil and atmosphere in different locations are Lao-jin-chang [(129.13 +/- 496.07) ng (m2 x h)(-1)], Er-dao-gou [(98.64 +/- 43.96) ng x (m2 x h)(-1)], Er-dao-cha [(23.17 +/- 171.23) ng x (m2 x h)(-1)], and community of Jia-pi-gou [(7.12 +/- 46.33) ng x (m2 x h)(-1)]. (4) Solar radiation is the major influential factor in the mercury exchange flux between the soil and atmosphere in Lao-jin-chang, Er-dao-cha and community of Jia-pi-gou. Solar radiation, air temperature and soil temperature jointly influence the process of the mercury exchange flux between the soil and atmosphere in Er-dao-gou. Under the disturbance of terrain, three noticeably distinctive trend features of daily change of mercury exchange flux between the soil and atmosphere have been formed. PMID:23243844

Zhang, Gang; Wang, Ning; Wang, Yuan; Liu, Te; Ai, Jian-Chao

2012-09-01

146

Fate and transport of ambient mercury and applied mercury isotope in terrestrial upland soils: insights from the METAALICUS watershed.  

PubMed

The fate of mercury (Hg) deposited on forested upland soils depends on a wide array of biogeochemical and hydrological processes occurring in the soil landscape. In this study, Hg in soil, soilwater, and streamwater were measured across a forested upland subcatchment of the METAALICUS watershed in northwestern Ontario, Canada, where a stable Hg isotope (spike Hg) was applied to distinguish newly deposited Hg from Hg already resident in the watershed (ambient Hg). In total, we were able to account for 45% of the total mass of spike Hg applied to the subcatchment during the entire loading phase of the experiment, with approximately 22% of the total mass applied now residing in the top 15 cm of the mineral soil layer. Decreasing spike Hg/ambient Hg ratios with depth in the soil and soilwater suggest that spike Hg is less mobile than ambient Hg over shorter time scales. However, the transport of spike Hg into the mineral soil layer is enhanced in depressional areas where water table fluctuation is more extreme. While we expect that this pool of Hg is now effectively sequestered in the mineral horizon, future disturbance of the soil profile could remobilize this stored Hg in runoff. PMID:24383823

Oswald, Claire J; Heyes, Andrew; Branfireun, Brian A

2014-01-21

147

Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report  

SciTech Connect

Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies.

Looney, B.B.

2000-08-18

148

Unified Science Information Model for SoilSCAPE using the Mercury Metadata Search System  

NASA Astrophysics Data System (ADS)

SoilSCAPE (Soil moisture Sensing Controller And oPtimal Estimator) introduces a new concept for a smart wireless sensor web technology for optimal measurements of surface-to-depth profiles of soil moisture using in-situ sensors. The objective is to enable a guided and adaptive sampling strategy for the in-situ sensor network to meet the measurement validation objectives of spaceborne soil moisture sensors such as the Soil Moisture Active Passive (SMAP) mission. This work is being carried out at the University of Michigan, the Massachusetts Institute of Technology, University of Southern California, and Oak Ridge National Laboratory. At Oak Ridge National Laboratory we are using Mercury metadata search system [1] for building a Unified Information System for the SoilSCAPE project. This unified portal primarily comprises three key pieces: Distributed Search/Discovery; Data Collections and Integration; and Data Dissemination. Mercury, a Federally funded software for metadata harvesting, indexing, and searching would be used for this module. Soil moisture data sources identified as part of this activity such as SoilSCAPE and FLUXNET (in-situ sensors), AirMOSS (airborne retrieval), SMAP (spaceborne retrieval), and are being indexed and maintained by Mercury. Mercury would be the central repository of data sources for cal/val for soil moisture studies and would provide a mechanism to identify additional data sources. Relevant metadata from existing inventories such as ORNL DAAC, USGS Clearinghouse, ARM, NASA ECHO, GCMD etc. would be brought in to this soil-moisture data search/discovery module. The SoilSCAPE [2] metadata records will also be published in broader metadata repositories such as GCMD, data.gov. Mercury can be configured to provide a single portal to soil moisture information contained in disparate data management systems located anywhere on the Internet. Mercury is able to extract, metadata systematically from HTML pages or XML files using a variety of methods including OAI-PMH [3]. The Mercury search interface then allows users to perform simple, fielded, spatial and temporal searches across a central harmonized index of metadata. Mercury supports various metadata standards including FGDC, ISO-19115, DIF, Dublin-Core, Darwin-Core, and EML. This poster describes in detail how Mercury implements the Unified Science Information Model for Soil moisture data. References: [1]Devarakonda R., et al. Mercury: reusable metadata management, data discovery and access system. Earth Science Informatics (2010), 3(1): 87-94. [2]Devarakonda R., et al. Daymet: Single Pixel Data Extraction Tool. http://daymet.ornl.gov/singlepixel.html (2012). Last Accesses 10-01-2013 [3]Devarakonda R., et al. Data sharing and retrieval using OAI-PMH. Earth Science Informatics (2011), 4(1): 1-5.

Devarakonda, Ranjeet; Lu, Kefa; Palanisamy, Giri; Cook, Robert; Santhana Vannan, Suresh; Moghaddam, Mahta Clewley, Dan; Silva, Agnelo; Akbar, Ruzbeh

2013-12-01

149

Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: a field manipulation experiment.  

PubMed

Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m(-2)d(-1)) were significantly greater than both the traditional clearcut plot (-40 ± 60 ng m(-2)d(-1)) and the un-harvested reference plot (-180 ± 115 ng m(-2)d(-1)) during July. This difference was likely a result of enhanced Hg(2+) photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest soils will increase, although it is not yet clear for how long such an effect will persist. PMID:24993512

Mazur, M; Mitchell, C P J; Eckley, C S; Eggert, S L; Kolka, R K; Sebestyen, S D; Swain, E B

2014-10-15

150

Sorption of inorganic mercury and monomethyl mercury in an iron–humus podzol soil of southern Norway studied by batch experiments  

Microsoft Academic Search

Considerable fractions of the Hg content of lake and river systems in Scandinavia are discharged from the soil of the catchments.\\u000a An important soil type in Scandinavia is the iron–humus podzol. The sorption characteristics of this soil type for inorganic\\u000a Hg(II) and monomethyl mercury were investigated by batch experiments. The solubility of Hg2+ and CH3Hg+ in the soil horizons containing

K. Schlüter

1997-01-01

151

Arsenic, cadmium, lead, and mercury in surface soils, Pueblo, Colorado: Implications for population health risk  

USGS Publications Warehouse

Decades of intensive industrial and agricultural practices as well as rapid urbanization have left communities like Pueblo, Colorado facing potential health threats from pollution of its soils, air, water and food supply. To address such concerns about environmental contamination, we conducted an urban geochemical study of the city of Pueblo to offer insights into the potential chemical hazards in soil and inform priorities for future health studies and population interventions aimed at reducing exposures to inorganic substances. The current study characterizes the environmental landscape of Pueblo in terms of heavy metals, and relates this to population distributions. Soil was sampled within the city along transects and analyzed for arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb). We also profiled Pueblo's communities in terms of their socioeconomic status and demographics. ArcGIS 9.0 was used to perform exploratory spatial data analysis and generate community profiles and prediction maps. The topsoil in Pueblo contains more As, Cd, Hg and Pb than national soil averages, although average Hg content in Pueblo was within reported baseline ranges. The highest levels of As concentrations ranged between 56.6 and 66.5 ppm. Lead concentrations exceeded 300 ppm in several of Pueblo's residential communities. Elevated levels of lead are concentrated in low-income Hispanic and African-American communities. Areas of excessively high Cd concentration exist around Pueblo, including low income and minority communities, raising additional health and environmental justice concerns. Although the distribution patterns vary by element and may reflect both industrial and non-industrial sources, the study confirms that there is environmental contamination around Pueblo and underscores the need for a comprehensive public health approach to address environmental threats in urban communities. ?? Springer 2006.

Diawara, D.M.; Litt, J.S.; Unis, D.; Alfonso, N.; Martinez, L.A.; Crock, J.G.; Smith, D.B.; Carsella, J.

2006-01-01

152

Gold nanoparticle-based miniaturized nanomaterial surface energy transfer probe for rapid and ultrasensitive detection of mercury in soil, water, and fish.  

PubMed

Contamination of the environment with mercury has been an important concern throughout the world for decades. Exposure to high Hg levels can be harmful to the brain, heart, kidneys, lungs, and immune system of humans of all ages. Driven by the need to detect trace amounts of mercury in environmental samples, here we present a miniaturized, inexpensive, and battery-operated ultrasensitive gold nanoparticle-based nanomaterial surface energy transfer probe for screening mercury levels in contaminated soil, water, and fish which has excellent sensitivity (2 ppt) and selectivity for Hg(II) over competing analytes, with the largest fluorescence enhancement to date for sensing Hg(II) in environmental samples (1100-fold). The sensitivity of our probe to detect mercury level in soil, water, and fish is about 2-3 orders of magnitude higher than the EPA standard limit. We demonstrate that our probe is suitable to screen the amount of mercury in different fish, shellfish, and water samples from various commercial sources. PMID:19206651

Darbha, Gopala Krishna; Ray, Anandhi; Ray, Paresh Chandra

2007-10-01

153

Chapter A5. Section 6.4.B. Low-Level Mercury  

USGS Publications Warehouse

Collecting and processing water samples for analysis of mercury at a low (subnanogram per liter) level requires use of ultratrace-level techniques for equipment cleaning, sample collection, and sample processing. Established techniques and associated quality-assurance (QA) procedures for the collection and processing of water samples for trace-element analysis at the part-per-billion level (NFM 3-5) are not adequate for low-level mercury samples. Modifications to the part-per-billion procedures are necessary to minimize contamination of samples at a typical ambient mercury concentration, which commonly is at the subnanogram-per-liter level.

Lewis, Michael Edward; Brigham, Mark E.

2004-01-01

154

Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals  

SciTech Connect

Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black-Right-Pointing-Pointer Accumulation of Hg in hair following exposure from fish was modified by genotype. Black-Right-Pointing-Pointer GSTP1, GSS, and SEPP1 polymorphisms influenced Hg accumulation in hair.

Goodrich, Jaclyn M.; Wang, Yi [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Gillespie, Brenda [Department of Biostatistics, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Biostatistics, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Werner, Robert [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States) [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Department of Physical Medicine and Rehabilitation, University of Michigan, 325 E. Eisenhower Parkway Suite 100, Ann Arbor, MI 48108 (United States); Franzblau, Alfred [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Basu, Niladri, E-mail: niladri@umich.edu [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)

2011-12-15

155

Mercury Reduction and Removal from High Level Waste at the Defense Waste Processing Facility - 12511  

SciTech Connect

The Defense Waste Processing Facility processes legacy nuclear waste generated at the Savannah River Site during production of enriched uranium and plutonium required by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. One of the constituents in the nuclear waste is mercury, which is present because it served as a catalyst in the dissolution of uranium-aluminum alloy fuel rods. At high temperatures mercury is corrosive to off-gas equipment, this poses a major challenge to the overall vitrification process in separating mercury from the waste stream prior to feeding the high temperature melter. Mercury is currently removed during the chemical process via formic acid reduction followed by steam stripping, which allows elemental mercury to be evaporated with the water vapor generated during boiling. The vapors are then condensed and sent to a hold tank where mercury coalesces and is recovered in the tank's sump via gravity settling. Next, mercury is transferred from the tank sump to a purification cell where it is washed with water and nitric acid and removed from the facility. Throughout the chemical processing cell, compounds of mercury exist in the sludge, condensate, and off-gas; all of which present unique challenges. Mercury removal from sludge waste being fed to the DWPF melter is required to avoid exhausting it to the environment or any negative impacts to the Melter Off-Gas system. The mercury concentration must be reduced to a level of 0.8 wt% or less before being introduced to the melter. Even though this is being successfully accomplished, the material balances accounting for incoming and collected mercury are not equal. In addition, mercury has not been effectively purified and collected in the Mercury Purification Cell (MPC) since 2008. A significant cleaning campaign aims to bring the MPC back up to facility housekeeping standards. Two significant investigations are being undertaken to restore mercury collection. The SMECT mercury pump has been removed from the tank and will be functionally tested. Also, research is being conducted by the Savannah River National Laboratory to determine the effects of antifoam addition on the behavior of mercury. These path forward items will help us better understand what is occurring in the mercury collection system and ultimately lead to an improved DWPF production rate and mercury recovery rate. (authors)

Behrouzi, Aria [Savannah River Remediation, LLC (United States); Zamecnik, Jack [Savannah River National Laboratory, Aiken, South Carolina, 29808 (United States)

2012-07-01

156

Latent Effect of Soil Organic Matter Oxidation on Mercury Cycling within a Southern Boreal Ecosystem  

EPA Science Inventory

The focus of this study is to investigate processes causing the observed spatial variation of total mercury (THg) in the soil O horizon of watersheds within the Superior National Forest (Minnesota) and to determine if results have implications toward understanding long-term chang...

157

Soil and Sediment Properties Affecting the Transport and Accumulations of Mercury in a Flood Control Reservoir  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mercury accumulations in some fish species from Grenada Lake in north Mississippi exceed the Food and Drug Administration standards for human consumption. This large flood control reservoir serves as a sink for the Skuna and Yalobusha River watersheds whose highly erodible soils contribute to exces...

158

The bioaccessibility of soil-based mercury as determined by physiological based extraction tests and human biomonitoring in children.  

PubMed

Environmental contaminants associated with soil particles are generally less bioavailable than contaminants associated with other exposure media where chemicals are often found in more soluble forms. In vitro methods, such as Physiological Based Extraction Tests (PBET), can provide estimates of bioaccessibility for soil-based contaminants. The results of these tests can be used to predict exposure to contaminants from soil ingestion pathways within human health risk assessment (HHRA). In the current investigation, an HHRA was conducted to examine the risks associated with elevated concentrations of mercury in soils in the northern Canadian smelter community of Flin Flon, Manitoba. A PBET was completed for residential soils and indicated mean bioaccessibilities of 1.2% and 3.0% for total mercury using gastric phase and gastric+intestinal phase methodologies, respectively. However, as many regulators only allow for the consideration of in vitro results for lead and arsenic in the HHRA process, in vitro bioaccessibility results for mercury were not utilized in the current HHRA. Based on the need to assume 100% bioaccessibility for inorganic mercury in soil, results from the HHRA indicated the need for further assessment of exposure and risk. A biomonitoring study was undertaken for children between 2 and 15years of age in the community to examine urinary inorganic mercury concentrations. Overall, 375 children provided valid urine samples for analysis. Approximately 50% of urine samples had concentrations of urinary inorganic mercury below the limit of detection (0.1?g/L), with an average creatinine adjusted concentration of 0.11?g/g. Despite high variability in mercury soil concentrations within sub-communities, soil concentrations did not appear to influence urinary mercury concentrations. The results of the current investigation indicate that mercury bioaccessibility in residential soils in the Flin Flon area was likely limited and that HHRA estimates would have been better approximated through inclusion of the in vitro study results. PMID:25777960

Safruk, Adam M; Berger, Robert G; Jackson, Blair J; Pinsent, Celine; Hair, Alan T; Sigal, Elliot A

2015-06-15

159

Elevated mercury levels in pregnant woman linked to skin cream from Mexico.  

PubMed

Mercury exposure during pregnancy can have serious health effects for a developing fetus including impacting the child's neurologic and cognitive development. Through biomonitoring in a low-income Latina population in California, we identified a patient with high levels of mercury and traced the source to face creams purchased in a pharmacy in Mexico. PMID:23685000

Dickenson, Carrie A; Woodruff, Tracey J; Stotland, Naomi E; Dobraca, Dina; Das, Rupali

2013-08-01

160

Mercury Levels along the Food Chain and Risk for Exposed Populations  

Microsoft Academic Search

Mercury was not regarded as a pollutant of primary importance until many deaths due to mercury poisoning occurred in the 1950s. More recently, adverse health effects have been documented at relatively low exposure levels, and monitoring data must now be interpreted in this light. The Mediterranean basin has been studied in great detail over the past 20 years because of

A. Renzoni; F. Zino; E. Franchi

1998-01-01

161

Studies of Mercury in High Level Waste Systems  

Microsoft Academic Search

During nuclear weapons production, nuclear reactor target and fuel rods were processed in F- and H-Canyons. For the target rods, a caustic dissolution of the aluminum cladding was performed prior to nitric acid dissolution of the uranium metal targets in the large canyon dissolvers. To dissolve the aluminum cladding and the U-Al fuel, mercury in the form of soluble mercury

Wilmarth

2003-01-01

162

Hair mercury levels in Amazonian populations: spatial distribution and trends  

Microsoft Academic Search

BACKGROUND: Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial

Flavia L Barbieri; Jacques Gardon

2009-01-01

163

Mercury Intoxication: Lack of Correlation Between Symptoms and Levels  

Microsoft Academic Search

The incidence of mercury intoxication has decreased considerably because of stricter public health regulations. However, it has not been completely eliminated and should be considered in a child with unexplained tachycardia, hypertension, mood changes, weight loss, and acrodynia. Mercury intoxication can be difficult to differentiate from pheochromocytoma and Kawasaki's disease. Here, the authors report the case of an 8-year-old boy

Jyothsna Gattineni; Susan Weiser; Amy M. Becker; Michel Baum

2007-01-01

164

Spatial and vertical distribution of mercury in upland forest soils across the northeastern United States  

PubMed Central

Assessing current Hg pools in forest soils of the northeastern U.S. is important for monitoring changes in Hg cycling. The forest floor, upper and lower mineral horizons were sampled at 17 long-term upland forest sites across the northeastern U.S. in 2011. Forest floor Hg concentration was similar across the study region (274 ± 13 ?g kg?1) while Hg amount at northern sites (39 ± 6 g ha?1) was significantly greater than at western sites (11 ± 4 g ha?1). Forest floor Hg was correlated with soil organic matter, soil pH, latitude and mean annual precipitation and these variables explained approximately 70% of the variability when multiple regressed. Mercury concentration and amount in the lower mineral soil was correlated with Fe, soil organic matter and latitude, corresponding with Bs horizons of Spodosols (Podzols). Our analysis shows the importance of regional and soil properties on Hg accumulation in forest soils. PMID:23911621

Richardson, Justin B.; Friedland, Andrew J; Engerbretson, Teresa R.; Kaste, James M.; Jackson, Brian P.

2013-01-01

165

Complexation of mercury(II) ions with humic acids in tundra soils  

NASA Astrophysics Data System (ADS)

The interaction mechanisms of mercury(II) ions with preparations of humic acids (HAs) isolated from organic horizons of surface-gleyed soils (Haplic Stagnosol (Gelic, Siltic)) of shrub tundra and hydromorphic peat gley soils (Histic Cryosol (Reductaquic, Siltic)) of moss-lichen tundra have been studied. The particular features of the interactions between the mercury(II) ions and the HAs are related to the molecular structure of the HAs, the mercury concentration range, and the environmental parameters. The fixation of mercury(II) ions into stable coordination compounds is most efficient in the pH range of 2.5-3.5. At the element concentrations below 0.50 ?mol/dm3, the main complexing sites of HAs are their peripheral aminoacid functional groups. Pyrocatechol, salicylate, and phenolic groups from the nuclear moiety of molecules interact in the concentration range of 0.0005-0.50 mmol/dm3; the physical sorption of mercury hydroxo complexes by the surface of HAs is the main process occurring in the system.

Vasilevich, R. S.; Beznosikov, V. A.; Lodygin, E. D.; Kondratenok, B. M.

2014-03-01

166

Dietary Predictors of Maternal Prenatal Blood Mercury Levels in the ALSPAC Birth Cohort Study  

PubMed Central

Background: Very high levels of prenatal maternal mercury have adverse effects on the developing fetal brain. It has been suggested that all possible sources of mercury should be avoided. However, although seafood is a known source of mercury, little is known about other dietary components that contribute to the overall levels of blood mercury. Objective: Our goal was to quantify the contribution of components of maternal diet to prenatal blood mercury level. Methods: Whole blood samples and information on diet and sociodemographic factors were collected from pregnant women (n = 4,484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The blood samples were assayed for total mercury using inductively coupled plasma dynamic reaction cell mass spectrometry. Linear regression was used to estimate the relative contributions of 103 dietary variables and 6 sociodemographic characteristics to whole blood total mercury levels (TBM; untransformed and log-transformed) based on R2 values. Results: We estimated that maternal diet accounted for 19.8% of the total variation in ln-TBM, with 44% of diet-associated variability (8.75% of the total variation) associated with seafood consumption (white fish, oily fish, and shellfish). Other dietary components positively associated with TBM included wine and herbal teas, and components with significant negative associations included white bread, meat pies or pasties, and french fries. Conclusions: Although seafood is a source of dietary mercury, seafood appeared to explain a relatively small proportion of the variation in TBM in our UK study population. Our findings require confirmation, but suggest that limiting seafood intake during pregnancy may have a limited impact on prenatal blood mercury levels. Citation: Golding J, Steer CD, Hibbeln JR, Emmett PM, Lowery T, Jones R. 2013. Dietary predictors of maternal prenatal blood mercury levels in the ALSPAC birth cohort study. Environ Health Perspect 121:1214–1218;?http://dx.doi.org/10.1289/ehp.1206115 PMID:23811414

Steer, Colin D.; Hibbeln, Joseph R.; Emmett, Pauline M.; Lowery, Tony; Jones, Robert

2013-01-01

167

Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA  

PubMed Central

A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn; Gochfeld, Michael

2015-01-01

168

Vertical profile measurements of soil air suggest immobilization of gaseous elemental mercury in mineral soil.  

PubMed

Evasion of gaseous elemental Hg (Hg(0)g) from soil surfaces is an important source of atmospheric Hg, but the volatility and solid-gas phase partitioning of Hg(0) within soils is poorly understood. We developed a novel system to continuously measure Hg(0)g concentrations in soil pores at multiple depths and locations, and present a total of 297 days of measurements spanning 14 months in two forests in the Sierra Nevada mountains, California, U.S. Temporal patterns showed consistent pore Hg(0)g concentrations below levels measured in the atmosphere (termed Hg(0)g immobilization), ranging from 66 to 94% below atmospheric concentrations throughout multiple seasons. The lowest pore Hg(0)g concentrations were observed in the deepest soil layers (40 cm), but significant immobilization was already present in the top 7 cm. In the absence of sinks or sources, pore Hg(0)g levels would be in equilibrium with atmospheric concentrations due to the porous nature of the soil matrix and gas diffusion. Therefore, we explain decreases in pore Hg(0)g in mineral soils below atmospheric concentrations--or below levels found in upper soils as observed in previous studies--with the presence of an Hg(0)g sink in mineral soils possibly related to Hg(0)g oxidation or other processes such as sorption or dissolution in soil water. Surface chamber measurements showing daytime Hg(0)g emissions and nighttime Hg(0)g deposition indicate that near-surface layers likely dominate net atmospheric Hg(0)g exchange resulting in typical diurnal cycles due to photochemcial reduction at the surface and possibly Hg(0)g evasion from litter layers. In contrast, mineral soils seem to be decoupled from this surface exchange, showing consistent Hg(0)g uptake and downward redistribution--although our calculations indicate these fluxes to be minor compared to other mass fluxes. A major implication is that once Hg is incorporated into mineral soils, it may be unlikely subjected to renewed Hg(0)g re-emission from undisturbed, background soils emphasizing the important role of soils in sequestering past and current Hg pollution loads. PMID:24428735

Obrist, Daniel; Pokharel, Ashok K; Moore, Christopher

2014-02-18

169

Mercury levels in Great Lakes herring gull eggs, 1972--1992  

SciTech Connect

Since 1971, the herring gull (Larus argentatus) has been used as a sentinel species for monitoring the levels of persistent contaminants in the Great Lakes ecosystem. In this study, 21 herring gull colonies in the Great Lakes and connecting channels were sampled for years 1972--1976, 1981--1983, 1985 and 1992. For each year, 10 eggs (usually) were collected from each colony site and analyzed for total mercury (ppm, wet weight). Results indicated that eggs from Lake Ontario displayed the highest mercury levels, mean = 0.28 (s.d. = 0.08) to 0.73 (0.23). Lake Erie typically displayed the lowest egg mercury levels, 0.18 (0.08) to 0.24 (0.11). Overall, mercury levels ranged from 0.12 (0.02) in 1985 to 0.88 (0.23) in 1982 for Channel-Shelter Island (Lake Huron) and Pigeon Island (Lake Ontario), respectively. Generally, all colony sites showed peak mercury levels in 1982. A significant decline in egg mercury levels was observed in six colony sites between 1972 and 1992 and in three colony sites between 1981 and 1992. The mean herring gull egg mercury levels observed in the early and mid 1970s and in 1982 for some colony sites were within the range found which potentially reduces hatchability in other fish-eating bird species.

Weseloh, D.V.; Koster, M.D.; Ryckman, D.P.; Struger, J. [Canadian Wildlife Service, Burlington, Ontario (Canada). Canada Centre for Inland Waters

1995-12-31

170

Mercury contamination study for flight system safety  

NASA Technical Reports Server (NTRS)

The effects and prevention of possible mercury pollution from the failure of solar electric propulsion spacecraft using mercury propellant were studied from tankage loading of post launch trajector injection. During preflight operations and initial flight mode there is little danger of mercury pollution if proper safety precautions are taken. Any spillage on the loading, mating, transportation, or launch pad areas is obvious and can be removed by vacuum cleaning soil and chemical fixing. Mercury spilled on Cape Kennedy ground soil will be chemically complexed and retained by the sandstone subsoil. A cover layer of sand or gravel on spilled mercury which has settled to the bottom of a water body adjacent to the system operation will control and eliminate the formation of toxic organic mercurials. Mercury released into the earth's atmosphere through leakage of a fireball will be diffused to low concentration levels. However, gas phase reactions of mercury with ozone could cause a local ozone depletion and result in serious ecological hazards.

Gorzynski, C. S., Jr.; Maycock, J. N.

1972-01-01

171

Blood mercury levels among fish consumers residing in areas with high environmental burden.  

PubMed

Mercury is a ubiquitous, persistent toxicant found in the environment. In water, mercury bioaccumulates up the food chain and leads to high concentrations in fish. Consumption of contaminated fish is the major source of exposure to mercury in the US. The objective of this study was to enroll persons living in areas selected by the Environmental Protection Agency (EPA) to have high mercury concentrations and who consume at least 6o z of locally caught fish per week to determine the feasibility of monitoring future trends among a population identified as highly exposed. Blood samples were collected at time of interview and analyzed for mercury. Participants (n=287) were enrolled from North Carolina, Maryland, and South Dakota. Participants reported eating an average of five servings of fish per week. The overall geometric mean for total mercury was 0.75 ?g L(-1), with North Carolina having the highest mean level (2.02 ?g L(-1)). Overall, 42% of the study population had levels greater than the US geometric mean 0.83 ?g L(-1). The number of servings of fish consumed was not found to be associated with blood mercury levels. We were able to identify some persons with elevated mercury concentrations living in areas identified by EPA; however, identifying and monitoring a highly exposed population over time would be challenging. PMID:22153999

Wolkin, Amy; Hunt, Danielle; Martin, Colleen; Caldwell, Kathleen L; McGeehin, Michael A

2012-03-01

172

Fish consumption and hair mercury levels in women of childbearing age, Martin County, Florida.  

PubMed

The health effects of mercury in humans are mostly on the developing nervous system. Pregnant women and women who are breastfeeding must be targeted in order to decrease mercury exposure to the populations at highest risk-infants, unborn fetuses, and young children. This purpose of this study is to understand the demographics of fish-consumption patterns among women of childbearing age (including pregnant women) in Martin County, Florida, and to analyze the associations of mercury levels in participants' hair with socio-demographic variables in order to better design prevention messages and campaigns. Mercury concentrations in hair samples of 408 women ages 18-49 were assessed. Data on demographic factors, pregnancy status, fish consumption, and awareness of fish advisories were collected during personal interviews. Data were analyzed using descriptive statistics and multivariate logistic regression. The geometric and arithmetic means of hair mercury concentration were 0.371 and 0.676 µg/g of hair. One-fourth of the respondents had a concentration ?1 µg/g of hair. Consuming a higher number of fish meals per month, consumption of commercially purchased or locally caught fish higher in mercury, White race and income ?$75,000 were positively associated with the likelihood of having higher hair mercury levels. This study confirms the existence of a higher overall mean hair mercury level and a higher percentage of women with ?1 µg/g hair mercury level than those reported at the national level and in other regional studies. This suggests the need for region-specific fish consumption advisories to minimize mercury exposure in humans. PMID:24807406

Nair, Anil; Jordan, Melissa; Watkins, Sharon; Washam, Robert; DuClos, Chris; Jones, Serena; Palcic, Jason; Pawlowicz, Marek; Blackmore, Carina

2014-12-01

173

Field analytical techniques for mercury in soils technology evaluation. Topical report, November 1994--March 1997  

SciTech Connect

This report presents the evaluation of the four field analytical techniques for mercury detection in soils, namely (1) an anodic stripping voltametry technique (ASV) developed and tested by General Electric Corporation; (2) a static headspace analysis (SHSA) technique developed and tested by Dr. Ralph Turner of Oak Ridge National Laboratory; (3) the BiMelyze{reg_sign} Mercury Immunoassay (Bio) developed and tested by BioNebraska, Inc.; and (4) a transportable x-ray fluorescence (XRF) instrument/technique developed and tested by Spectrace, Inc.

Solc, J.; Harju, J.A.; Grisanti, A.A.

1998-02-01

174

Comparative Analysis for Polluted Agricultural Soils with Arsenic, Lead, and Mercury in Mexico  

SciTech Connect

The use of mercury in Mexico has been associated with the mining industry of Zacatecas. This activity has polluted several areas currently used for agriculture. The main objective of this study was to investigate the heavy metal concentration (Hg, As and Pb) in soil of Guadalupe Zacatecas in order to justify a further environmental risk assessment in the site. A 2X3 km grid was used for the sampling process and 20 soil samples were taken. The analysis was developed using EPA SW 846: 3050B/6010B method for arsenic and metals and EPA SW 846: 7471A for total mercury. It was concluded that there are heavy metals in agricultural soils used for corn and bean farming. For this it is required to make an environmental risk assessment and a bioavailability study in order to determine if there's a risk for heavy metals bioaccumulation in animals or human beings or metal lixiviation to aquifers.

Yarto-Ramirez, Mario; Santos-Santos, Elvira; Gavilan-Garcia, Arturo; Castro-Diaz, Jose; Gavilan-Garcia, Irma Cruz; Rosiles, Rene; Suarez, Sara

2004-03-31

175

MERCURY LEVELS IN HAWAIIAN PREDATORY PEI-AGIC FISHES AND THEIR PREY ASA FUNCTION OF DEPTH AND ECOLOGY  

E-print Network

MERCURY LEVELS IN HAWAIIAN PREDATORY PEI-AGIC FISHES AND THEIR PREY ASA FUNCTION OF DEPTH Gregory F,. P.av:.zza N{argaretA. N.,Icl\\{anus #12;ABSTRACT Mercury is drstributedthroughout the Earth in plants and animals. Inter- and intra-specific variations in mercury levels of predatory pelagic fish have

Luther, Douglas S.

176

Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen  

PubMed Central

Background and Aim. Although mercury is involved in several immunological diseases, nothing is known about its implication in celiac disease. Our aim was to evaluate blood and urinary levels of mercury in celiac patients. Methods. We prospectively enrolled 30 celiac patients (20 treated with normal duodenal mucosa and 10 untreated with duodenal atrophy) and 20 healthy controls from the same geographic area. Blood and urinary mercury concentrations were measured by means of flow injection inductively coupled plasma mass spectrometry. Enrolled patients underwent dental chart for amalgam fillings and completed a food-frequency questionnaire to evaluate diet and fish intake. Results. Mercury blood/urinary levels were 2.4 ± 2.3/1.0 ± 1.4, 10.2 ± 6.7/2.2 ± 3.0 and 3.7 ± 2.7/1.3 ± 1.2 in untreated CD, treated CD, and healthy controls, respectively. Resulting mercury levels were significantly higher in celiac patients following a gluten-free diet. No differences were found regarding fish intake and number of amalgam fillings. No demographic or clinical data were significantly associated with mercury levels in biologic samples. Conclusion. Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism. PMID:25802516

Elli, Luca; Rossi, Valentina; Conte, Dario; Ronchi, Anna; Tomba, Carolina; Passoni, Manuela; Bardella, Maria Teresa; Roncoroni, Leda; Guzzi, Gianpaolo

2015-01-01

177

Dry deposition of gaseous elemental mercury to plants and soils using mercury stable isotopes in a controlled environment  

NASA Astrophysics Data System (ADS)

Uptake of gaseous elemental mercury (Hg 0(g)) by three plant species and two soil types was measured using mercury vapor enriched in the 198 isotope ( 198Hg 0(g)). The plant species and soil types were: White Ash ( Fraxinus Americana; WA); White Spruce ( Picea Glauca; WS); Kentucky Bluegrass ( Poa Partensis; KYBG); Plano Silt Loam (4% organic matter; PSL); and Plainfield Sand/Sparta Loamy Sand (1.25-1.5% organic matter: PS). The plants and soils were exposed to isotopically enriched Hg 0(g) in a 19 m 3 controlled environment room for 7 days under optimal plant growth conditions (20 °C, 140 Wm -2 between 300 nm and 700 nm; 70% RH) and atmospherically relevant Hg 0(g) concentrations. Mercury was recovered from the samples using acidic digestions and surface leaches, and then analyzed for enrichments in 198Hg by ICPMS. The method was sensitivity enough that statistically significant enrichments in 198Hg were measured in the plant foliage at the end of Day 1. Whole leaf digestions and surface-selective leaches revealed that accumulative uptake was predominantly to the interior of the leaf under the conditions studied. Uptake fluxes for WA increased between the first and third days and remained constant thereafter (WA; Day 1 = 7 ± 2 × 10 -5 ng m -2 s -1; Days 3-7 = 1.3 ± 0.1 × 10 -4 ng m -2 s -1; where m 2 refers to one sided leaf area). KYBG demonstrated similar behavior although no Day 3 measurement was available (Day 1 = 7.5 ± 0.5 × 10 -5 ng m -2 s -1; Day 7 = 1.2 ± 0.1 × 10 -4 ng m -2 s -1). Fluxes to White Spruce were lower, with little difference between Days 1 and 3 followed by a decrease at Day 7 (WS; Days 1-3 = 5 ± 2 × 10 -5 ng m -2 s -1; Day 7 = 2.4 ± 0.2 × 10 -5 ng m -2 s -1). Uptake of Hg to soils was below the method detection limit for those media (PSL = 3 × 10 -2 ng m -2 s -1; PS = 3 × 10 -3 ng m -2 s -1) over the 7 day study period. Foliar resistances calculated for each species compared well to previous studies.

Rutter, Andrew P.; Schauer, James J.; Shafer, Martin M.; Creswell, Joel E.; Olson, Michael R.; Robinson, Michael; Collins, Ryan M.; Parman, Andrew M.; Katzman, Tanya L.; Mallek, Justin L.

2011-02-01

178

Mercury  

NSDL National Science Digital Library

This NASA (National Aeronautics and Space Administration) planet profile provides data and images of the planet Mercury. These data include planet size, distance from the Sun, rotation and revolution times, temperature, atmospheric composition, density, and albedo. Images of the planet include general surface features such as crater basins, the Caloris Basin, and other images taken by the Mariner 10 spacecraft.

179

Effects of mercury contamination on the culturable heterotrophic, functional and genetic diversity of the bacterial community in soil  

Microsoft Academic Search

This study investigates the effect of mercury contamination on the culturable heterotrophic, functional and genetic diversity of the bacterial community in soil. The changes in diversity were monitored in soil microcosms, enriched with 25 ?g Hg(II) g?1 soil, over a period of 3 months. The culturable heterotrophic diversity was investigated by colony morphology and colony appearance on solid LB medium.

Lasse D Rasmussen; Søren J Sørensen

2001-01-01

180

Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping  

SciTech Connect

The overall objective of this work is to develop a reasonable and cost-effective approach to meet the emerging mercury standards, especially for high volume outfalls with concentrations below the drinking water standard.

Looney, B.B.

2001-02-23

181

Gaseous mercury emissions from soil following forest loss and land use changes: Field experiments in the United States and Brazil  

NASA Astrophysics Data System (ADS)

Forest ecosystems are a sink of atmospheric mercury, trapping the metal in the canopy, and storing it in the forest floor after litter fall. Fire liberates a portion of this mercury; however, little is known about the long-term release of mercury post deforestation. We conducted two large-scale experiments to study this phenomenon. In upstate New York, gaseous mercury emissions from soil were monitored continually using a Teflon dynamic surface flux chamber for two-weeks before and after cutting of the canopy on the edge of a deciduous forest. In Brazil, gaseous mercury emissions from soil were monitored in an intact Ombrophilous Open forest and an adjacent field site both before and after the field site was cleared by burning. In the intact forest, gaseous mercury emissions from soil averaged -0.73 ± 1.84 ng m-2 h-1 (24-h monitoring) at the New York site, and 0.33 ± 0.09 ng m-2 h-1 (daytime-only) at the Brazil site. After deforestation, gaseous mercury emissions from soil averaged 9.13 ± 2.08 ng m-2 h-1 in New York and 21.2 ± 0.35 ng m-2 h-1 at the Brazil site prior to burning. Gaseous mercury emissions averaged 74.9 ± 0.73 ng m-2 h-1 after burning of the cut forest in Brazil. Extrapolating our data, measured over several weeks to months, to a full year period, deforested soil is estimated to release an additional 2.30 g ha-1 yr-1 of gaseous mercury to the atmosphere in the Brazilian experiment and 0.41 g ha-1 yr-1 in the New York experiment. In Brazil, this represents an additional 50% of the mercury load released during the fire itself.

Carpi, Anthony; Fostier, Anne H.; Orta, Olivia R.; dos Santos, Jose Carlos; Gittings, Michael

2014-10-01

182

Health effects in the Flemish population in relation to low levels of mercury exposure: from organ to transcriptome level.  

PubMed

Due to possible health risks, quantification of mercury accumulation in humans was included in the Flemish biomonitoring programmes FLEHS I (2002-2006) and FLEHS II (2007-2011). The general objective of FLEHS I was to assess regional exposure levels in order to link possible differences in these internal exposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmercury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercury concentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (reference group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of the FLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess relations between mercury exposure and possible sources like fish consumption; (3) to assess dose-effect relations between mercury exposure and health effect markers. The results showed that mercury concentrations in the Flemish population were rather low compared to other studies. Mercury levels in the Flemish populations were strongly related to the age of the participants and consumption of fish. Significant negative associations were observed between mercury in hair and asthma, having received breast feeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significant correlations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) and HLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls). PMID:23920476

Croes, Kim; De Coster, Sam; De Galan, Sandra; Morrens, Bert; Loots, Ilse; Van de Mieroop, Els; Nelen, Vera; Sioen, Isabelle; Bruckers, Liesbeth; Nawrot, Tim; Colles, Ann; Den Hond, Elly; Schoeters, Greet; van Larebeke, Nicolas; Baeyens, Willy; Gao, Yue

2014-03-01

183

Mercury concentrations and distribution in soil, water, mine waste leachates, and air in and around mercury mines in the Big Bend region, Texas, USA.  

PubMed

Samples of soil, water, mine waste leachates, soil gas, and air were collected from areas mined for mercury (Hg) and baseline sites in the Big Bend area, Texas, to evaluate potential Hg contamination in the region. Soil samples collected within 300 m of an inactive Hg mine contained elevated Hg concentrations (3.8-11 µg/g), which were considerably higher than Hg in soil collected from baseline sites (0.03-0.05 µg/g) distal (as much as 24 km) from mines. Only three soil samples collected within 300 m of the mine exceeded the probable effect concentration for Hg of 1.06 µg/g, above which harmful effects are likely to be observed in sediment-dwelling organisms. Concentrations of Hg in mine water runoff (7.9-14 ng/L) were generally higher than those found in springs and wells (0.05-3.1 ng/L), baseline streams (1.1-9.7 ng/L), and sources of drinking water (0.63-9.1 ng/L) collected in the Big Bend region. Concentrations of Hg in all water samples collected in this study were considerably below the 2,000 ng/L drinking water Hg guideline and the 770 ng/L guideline recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic wildlife from chronic effects of Hg. Concentrations of Hg in water leachates obtained from leaching of mine wastes varied widely from <0.001 to 760 µg of Hg in leachate/g of sample leached, but only one leachate exceeded the USEPA Hg industrial soil screening level of 31 µg/g. Concentrations of Hg in soil gas collected at mined sites (690-82,000 ng/m(3)) were highly elevated compared to soil gas collected from baseline sites (1.2-77 ng/m(3)). However, air collected from mined areas at a height of 2 m above the ground surface contained concentrations of Hg (4.9-64 ng/m(3)) that were considerably lower than Hg in soil gas from the mined areas. Although concentrations of Hg emitted from mine-contaminated soils and mine wastes were elevated, persistent wind in southwest Texas disperses Hg in the air within a few meters of the ground surface. PMID:24974151

Gray, John E; Theodorakos, Peter M; Fey, David L; Krabbenhoft, David P

2015-02-01

184

Temporal characterization of mercury accumulation at different trophic levels and implications for metal biomagnification along a coastal food web.  

PubMed

The main goal of this study was to assess temporal mercury variations along an estuarine food web to evaluate the mercury contamination level of the system and the risks that humans are exposed to, due to mercury biomagnification. The highest mercury concentrations in the sediments and primary producers (macrophytes) were observed during winter sampling. Instead, the highest mercury concentrations in the water, suspended particulate matter as well as in the zooplanktonic and suprabenthic communities were observed during summer sampling. Evidences of mercury biomagnification along the food web were corroborated by the positive biomagnification factors, particularly for omnivorous macrobenthic species. Comparing the mercury levels at distinct components with several environmental quality criteria it suggests that sediments, water and edible species (e.g., bivalve Scrobicularia plana and the crustacean Carcinus maenas) presented higher mercury levels than the values accepted by legislation which represent a matter of concern for the environment and human health. PMID:25172612

Cardoso, P G; Pereira, E; Duarte, A C; Azeiteiro, U M

2014-10-15

185

Study on the reduction of atmospheric mercury emissions from mine waste enriched soils through native grass cover in the Mt. Amiata region of Italy.  

PubMed

Atmospheric mercury emissions from mine-waste enriched soils were measured in order to compare the mercury fluxes of bare soils with those from other soils covered by native grasses. Our research was conducted near Mt. Amiata in central Italy, an area that was one of the largest and most productive mining centers in Europe up into the 1980s. To determine in situ mercury emissions, we used a Plexiglas flux chamber connected to a portable mercury analyzer (Lumex RA-915+). This allowed us to detect, in real time, the mercury vapor in the air, and to correlate this with the meteorological parameters that we examined (solar radiation, soil temperature, and humidity). The highest mercury flux values (8000ngm(-2)h(-1)) were observed on bare soils during the hours of maximum insulation, while lower values (250ngm(-2)h(-1)) were observed on soils covered by native grasses. Our results indicate that two main environmental variables affect mercury emission: solar radiation intensity and soil temperature. The presence of native vegetation, which can shield soil surfaces from incident light, reduced mercury emissions, a result that we attribute to a drop in the efficiency of mercury photoreduction processes rather than to decreases in soil temperature. This finding is consistent with decreases in mercury flux values down to 3500ngm(-2)h(-1), which occurred under cloudy conditions despite high soil temperatures. Moreover, when the soil temperature was 28°C and the vegetation was removed from the experimental site, mercury emissions increased almost four-fold. This increase occurred almost immediately after the grasses were cut, and was approximately eight-fold after 20h. Thus, this study demonstrates that enhancing wild vegetation cover could be an inexpensive and effective approach in fostering a natural, self-renewing reduction of mercury emissions from mercury-contaminated soils. PMID:23477569

Fantozzi, L; Ferrara, R; Dini, F; Tamburello, L; Pirrone, N; Sprovieri, F

2013-08-01

186

Bench- and pilot-scale demonstration of thermal desorption for removal of mercury from the Lower East Fork Poplar Creek floodplain soils  

SciTech Connect

Thermal desorption is an innovative technology that has seen significant growth in applications to organically contaminated soils and sludges for the remediation of hazardous, radioactive and mixed waste sites. This paper will present the results of a bench and pilot-scale demonstration of this technology for the removal of mercury from the Lower East Fork Poplar Creek floodplain soil. Results demonstrate that the mercury in this soil can be successfully removed to the target treatment levels of 10 milligrams per kilogram (mg/kg) and that all process residuals could be rendered RCRA-nonhazardous as defined by the Resource Conservation and Recovery Act. Sampling and analyses of the desorber off-gas before and after the air pollution control system demonstrated effective collection of mercury and organic constituents. Pilot-scale testing was also conducted to verify requirements for material handling of soil into and out of the process. This paper will also present a conceptual design and preliminary costs of a full-scale system, including feed preparation, thermal treatment, and residuals handling for the soil.

Morris, M.I. [Oak Ridge National Lab., TN (United States); Sams, R.J.; Gillis, G. [Oak Ridge Y-12 Plant, TN (United States); Helsel, R.W.; Alperin, E.S.; Geisler, T.J.; Groen, A.; Root, D. [IT Corp., Knoxville, TN (United States)

1995-04-01

187

Mercury levels of small fishes: influence of size and catch area  

Microsoft Academic Search

In the present study, we assessed small fishes as potential feed fishes with the lowest mercury levels. The mercury levels\\u000a of four small pelagic fishes and a benthic fish from the Pacific Ocean and the Sea of Japan, i.e., spotted chub mackerel Scomber australasicus, chub mackerel Scomber japonicus, horse mackerel Trachurus trachurus, round scad Decapterus punctatus, and bastard halibut Paralichthys

Wen Jye Mok; MokManabu Seoka; Yasuyuki Tsukamasa; Ken-ichi Kawasaki; Masashi Ando

188

Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon  

Microsoft Academic Search

The mercury rejected in the water system, from mining operations and lixiviation of soils after deforesta- tion, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with

MARÚCIA I. M. AMORIM; DONNA MERGLER; MARCELO O. BAHIA; HÉLÈNE DUBEAU; DANIELA MIRANDA; JEAN LEBEL; ROMMEL R. BURBANO; MARC LUCOTTE

2000-01-01

189

Mercury  

NASA Technical Reports Server (NTRS)

Prior to the flight of the Mariner 10 spacecraft, Mercury was the least investigated and most poorly known terrestrial planet (Kuiper 1970, Devine 1972). Observational difficulties caused by its proximity to the Sun as viewed from Earth caused the planet to remain a small, vague disk exhibiting little surface contrast or details, an object for which only three major facts were known: 1. its bulk density is similar to that of Venus and Earth, much greater than that of Mars and the Moon; 2. its surface reflects electromagnetic radiation at all wavelengths in the same manner as the Moon (taking into account differences in their solar distances); and 3. its rotation period is in 2/3 resonance with its orbital period. Images obtained during the flyby by Mariner 10 on 29 March 1974 (and the two subsequent flybys on 21 September 1974 and 16 March 1975) revealed Mercury's surface in detail equivalent to that available for the Moon during the early 1960's from Earth-based telescopic views. Additionally, however, information was obtained on the planet's mass and size, atmospheric composition and density, charged-particle environment, and infrared thermal radiation from the surface, and most significantly of all, the existence of a planetary magnetic field that is probably intrinsic to Mercury was established. In the following, this new information is summarized together with results from theoretical studies and ground-based observations. In the quantum jumps of knowledge that have been characteristic of "space-age" exploration, the previously obscure body of Mercury has suddenly come into sharp focus. It is very likely a differentiated body, probably contains a large Earth-like iron-rich core, and displays a surface remarkably similar to that of the Moon, which suggests a similar evolutionary history.

Gault, D. E.; Burns, J. A.; Cassen, P.; Strom, R. G.

1977-01-01

190

Low-Cost Options for Moderate Levels of Mercury Control  

SciTech Connect

On March 15, 2005, EPA issued the Clean Air Mercury Rule, requiring phased-in reductions of mercury emissions from electric power generators. ADA-ES, Inc., with support from DOE/NETL and industry partners, is conducting evaluations of EPRI's TOXECON II{trademark} process and of high-temperature reagents and sorbents to determine the capabilities of sorbent/reagent injection, including activated carbon, for mercury control on different coals and air emissions control equipment configurations. DOE/NETL targets for total mercury removal are {ge}55% (lignite), {ge}65% (subbituminous), and {ge}80% (bituminous). Based on work done to date at various scales, meeting the removal targets appears feasible. However, work needs to progress to more thoroughly document and test these promising technologies at full scale. This is the final site report for tests conducted at MidAmerican's Louisa Station, one of three sites evaluated in this DOE/NETL program. The other two sites in the program are MidAmerican's Council Bluff Station and Entergy's Independence Station. MidAmerican's Louisa Station burns Powder River Basin (PRB) coal and employs hot-side electrostatic precipitators with flue gas conditioning for particulate control. This part of the testing program evaluated the effect of reagents used in the existing flue gas conditioning on mercury removal.

Sharon Sjostrom

2006-03-31

191

An Exploration of Mercury Soils Treatment Technologies for the Y-12 Plant - 13217  

SciTech Connect

There are a number of areas at the Y-12 National Security Complex (Y-12) that have been contaminated with mercury due to historical mercury use and storage. Remediation of these areas is expected to generate large volumes of waste that are Resource Conservation and Recovery Act (RCRA) characteristically hazardous. These soils will require treatment to meet RCRA Land Disposal Restrictions (LDR) prior to disposal. URS - CH2M Oak Ridge LLC (UCOR) performed a feasibility assessment to evaluate on-site and off-site options for the treatment and disposal of mercury-contaminated soil from the Y-12 Site. The focus of the feasibility assessment was on treatment for disposal at the Environmental Management Waste Management Facility (EMWMF) located on the Oak Ridge Reservation. A two-phase approach was used in the evaluation process of treatment technologies. Phase 1 involved the selection of three vendors to perform treatability studies using their stabilization treatment technology on actual Y-12 soil. Phase II involved a team of waste management specialists performing an in-depth literature review of all available treatment technologies for treating mercury contaminated soil using the following evaluation criteria: effectiveness, feasibility of implementation, and cost. The result of the treatability study and the literature review revealed several viable on-site and off-site treatment options. This paper presents the methodology used by the team in the evaluation of technologies especially as related to EMWMF waste acceptance criteria, the results of the physical treatability studies, and a regulatory analysis for obtaining regulator approval for the treatment/disposal at the EMWMF. (authors)

Wrapp, John [UCOR, P.O. Box 4699, Oak Ridge, TN 37831 (United States)] [UCOR, P.O. Box 4699, Oak Ridge, TN 37831 (United States); Julius, Jonathon [DOE Oak Ridge (United States)] [DOE Oak Ridge (United States); Browning, Debbie [Strata-G, LLC, 2027 Castaic Lane, Knoxville, TN, 37932 (United States)] [Strata-G, LLC, 2027 Castaic Lane, Knoxville, TN, 37932 (United States); Kane, Michael [RSI, P.O. Box 4699, Oak Ridge, TN 37831 (United States)] [RSI, P.O. Box 4699, Oak Ridge, TN 37831 (United States); Whaley, Katherine [RSI, P.O. Box 4699, Oak Ridge, TN 37831 (United States)] [RSI, P.O. Box 4699, Oak Ridge, TN 37831 (United States); Estes, Chuck [EnergySolutions, P.O. Box 4699, Oak Ridge, TN 37831 (United States)] [EnergySolutions, P.O. Box 4699, Oak Ridge, TN 37831 (United States); Witzeman, John [RSI, P.O. Box 4699, Oak Ridge, TN, 37831 (United States)] [RSI, P.O. Box 4699, Oak Ridge, TN, 37831 (United States)

2013-07-01

192

Study on the reduction of atmospheric mercury emissions from mine waste enriched soils through native grass cover in the Mt. Amiata region of Italy  

SciTech Connect

Atmospheric mercury emissions from mine-waste enriched soils were measured in order to compare the mercury fluxes of bare soils with those from other soils covered by native grasses. Our research was conducted near Mt. Amiata in central Italy, an area that was one of the largest and most productive mining centers in Europe up into the 1980s. To determine in situ mercury emissions, we used a Plexiglas flux chamber connected to a portable mercury analyzer (Lumex RA-915+). This allowed us to detect, in real time, the mercury vapor in the air, and to correlate this with the meteorological parameters that we examined (solar radiation, soil temperature, and humidity). The highest mercury flux values (8000 ng m{sup ?2} h{sup ?1}) were observed on bare soils during the hours of maximum insulation, while lower values (250 ng m{sup ?2} h{sup ?1}) were observed on soils covered by native grasses. Our results indicate that two main environmental variables affect mercury emission: solar radiation intensity and soil temperature. The presence of native vegetation, which can shield soil surfaces from incident light, reduced mercury emissions, a result that we attribute to a drop in the efficiency of mercury photoreduction processes rather than to decreases in soil temperature. This finding is consistent with decreases in mercury flux values down to 3500 ng m{sup ?2} h{sup ?1}, which occurred under cloudy conditions despite high soil temperatures. Moreover, when the soil temperature was 28 °C and the vegetation was removed from the experimental site, mercury emissions increased almost four-fold. This increase occurred almost immediately after the grasses were cut, and was approximately eight-fold after 20 h. Thus, this study demonstrates that enhancing wild vegetation cover could be an inexpensive and effective approach in fostering a natural, self-renewing reduction of mercury emissions from mercury-contaminated soils. -- Highlights: ? Mercury air/surface exchange from grass covered soil is different from bare soil. ? Light enhances mercury emissions and is the main parameter driving the process. ? The presence of wild vegetation covering the soil reduces mercury emission. ? Vegetative covers could be a solution to reduce atmospheric mercury pollution.

Fantozzi, L., E-mail: l.fantozzi@iia.cnr.it [CNR-Institute of Atmospheric Pollution Research, c/o: UNICAL-Polifunzionale, 87036 Rende (Italy); Ferrara, R., E-mail: romano.ferrara@pi.ibf.cnr.it [CNR-Institute of Biophysics, San Cataldo Research Area, Via G. Moruzzi 1, 56124 Pisa (Italy); Dini, F., E-mail: fdiniprotisti@gmail.com [University of Pisa, Department of Biology, Via A. Volta 4, 56126 Pisa (Italy); Tamburello, L., E-mail: ltamburello@biologia.unipi.it [University of Pisa, Department of Biology, Via Derna 1, I-56126 Pisa (Italy); Pirrone, N.; Sprovieri, F. [CNR-Institute of Atmospheric Pollution Research, c/o: UNICAL-Polifunzionale, 87036 Rende (Italy)] [CNR-Institute of Atmospheric Pollution Research, c/o: UNICAL-Polifunzionale, 87036 Rende (Italy)

2013-08-15

193

Increased mercury in forest soils under elevated carbon dioxide  

SciTech Connect

Fossil fuel combustion is the primary anthropogenic source of both CO2 and Hg to the atmosphere. On a global scale, most Hg that enters ecosystems is derived from atmospheric Hg that deposits onto the land surface. Increasing concentrations of atmospheric CO2 may affect Hg deposition to terrestrial systems and storage in soils through CO2-mediated changes in plant and soil properties. We show, using free-air CO2 enrichment (FACE) experiments, that soil Hg concentrations are almost 30% greater under elevated atmospheric CO2 in two temperate forests. There were no direct CO2 effects, however, on litterfall, throughfall or stemflow Hg inputs. Soil Hg was positively correlated with percent soil organic matter (SOM), suggesting that CO2-mediated changes in SOM have influenced soil Hg concentrations. Through its impacts on SOM, elevated atmospheric CO2 may increase the Hg storage capacity of soils and modulate the movement of Hg through the biosphere. Such effects of rising CO2, ones that transcend the typically studied effects on C and nutrient cycling, are an important next phase for research on global environmental change.

Natali, Susan M. [State University of New York, Stony Brook; Sa_udo-Wilhelmy, Sergio A. [University of Southern California; Norby, Richard J [ORNL; Finzi, Adrien C [Boston University; Lerdau, Manuel T. [University of Virginia

2008-01-01

194

Total mercury and methylmercury levels in commercially important fishes in Japan  

Microsoft Academic Search

The distribution of mercury in the muscle and other tissues was determined in 23 species of fishes and invertebrates. This\\u000a study reveals species-specific patterns of mercury accumulation in the muscle of tuna and alfonsino. Consistently high levels\\u000a of total mercury were found in Beryx splendens (0.78±0.56 ?g\\/g), Atlantic Thunnus thynnus (0.42±0.06 ?g\\/g), Pacific T. thynnus (0.59±0.34 ?g\\/g), Thunnus obesus (0.98±0.34

Yumiko Yamashita; Yuji Omura; Emiko Okazaki

2005-01-01

195

Mercury levels of Nelson's and saltmarsh sparrows at wintering grounds in Virginia, USA.  

PubMed

Nelson's and saltmarsh sparrows (Ammodramus nelsoni and A. caudacutus) have recently been recognized as separate species, and because of their limited distributions and the susceptibility of their wetland habitats to climate change, these two new species are of conservation concern. Both species are known to bioaccumulate mercury at breeding sites in New England, USA where their ranges overlap, with the saltmarsh sparrow reported to have twice the concentration of blood total mercury. In this study we sampled both species on their shared wintering grounds, and documented that mercury exposure is lower than that reported for the breeding range, with saltmarsh sparrow blood mercury 2.6 times higher than in Nelson's sparrow. Feather mercury, which is incorporated on the breeding grounds, confirmed that saltmarsh sparrows had incorporated 2.3 times more mercury than Nelson's sparrows during the previous breeding season. A comparison of stable isotopes of nitrogen and carbon suggests that the higher exposure of saltmarsh sparrows may be not due to feeding at a higher trophic level, as previously hypothesized, but rather could be related to a difference in the carbon source at the base of each species' food chain. This study, along with recently published data from both species on additional breeding and wintering grounds, provides a more complete picture of relative mercury exposure. Saltmarsh sparrows are exposed to mercury levels that warrant concern, with the highest exposure being during the breeding season. Areas set aside for the long-term conservation of this species should be carefully assessed for mercury bioaccumulation. PMID:21698442

Cristol, Daniel A; Smith, Fletcher M; Varian-Ramos, Claire W; Watts, Bryan D

2011-11-01

196

Mercury levels in tissues of Giant otters (Pteronura brasiliensis) from the Rio Negro, Pantanal, Brazil.  

PubMed

This research reports the first data on mercury levels found in Giant otters (Pteronura brasiliensis) from South America. Mercury concentrations were analyzed from different organs/tissues of two animals found dead floating on the water of the Rio Negro in the Pantanal, Brazil. The mean mercury concentration ranged from 2.94 to 3.68 microg/g in hair, from 1.52 to 4.3 microg/g in liver, and from 1.11 to 4.59 microg/g in kidney and was 0.17 microg/g in muscle samples. In comparison with other research, there is no evidence of contamination in these animals and mercury concentrations in tissues appeared to be at levels below those associated with toxicity. PMID:15910792

Dias Fonseca, Fabrizio Rafael; Malm, Olaf; Francine Waldemarin, Helen

2005-07-01

197

The Effect of Wildfire on Soil Mercury Concentrations in Southern California Watersheds  

PubMed Central

Mercury (Hg) stored in vegetation and soils is known to be released to the atmosphere during wildfires, increasing atmospheric stores and altering terrestrial budgets. Increased erosion and transport of sediments is well-documented in burned watersheds, both immediately post-fire and as the watershed recovers; however, understanding post-fire mobilization of soil Hg within burned watersheds remains elusive. The goal of the current study is to better understand the impact of wildfire on soil-bound Hg during the immediate post-fire period as well as during recovery, in order to assess the potential for sediment-driven transport to and within surface waters in burned watersheds. Soils were collected from three southern California watersheds of similar vegetation and soil characteristics that experienced wildfire. Sampling in one of these watersheds was extended for several seasons (1.5 years) in order to investigate temporal changes in soil Hg concentrations. Laboratory analysis included bulk soil total Hg concentrations and total organic carbon of burned and unburned samples. Soils were also fractionated into a subset of grain sizes with analysis of Hg on each fraction. Low Hg concentrations were observed in surface soils immediately post-fire. Accumulation of Hg coincident with moderate vegetative recovery was observed in the burned surface soils 1 year following the fire, and mobilization was also noted during the second winter (rainy) season. Hg concentrations were highest in the fine-grained fraction of unburned soils; however, in the burned soils, the distribution of soil-bound Hg was less influenced by grain size. The accelerated accumulation of Hg observed in the burned soils, along with the elevated risk of erosion, could result in increased delivery of organic- or particulate-bound Hg to surface waters in post-fire systems. PMID:20936165

Ferreira, Marcia; Mendez, Carolina B.; Navarro, Bridget; Lopez, Sonya; Jay, Jennifer A.

2010-01-01

198

LEVEL AND EXTENT OF MERCURY CONTAMINATION IN OREGON LOTIC FISH  

EPA Science Inventory

As part of the U.S. EPA's EMAP Oregon Pilot project, we conducted a probability survey of 154 Oregon streams and rivers to assess the spatial extent of mercury (Hg) contamination in fish tissue across the state. Samples consisted of whole fish analyses of both small (< 120 mm) a...

199

Response of rice to soil phosphorus levels  

E-print Network

RESPORSE OF RICE TO SOIL PHOSPHORUS LEVELS MOHJQRiD JL ~ QUDDUS Submitted te the Graduate Sohool of the kgrloultural and Mechanical College of Texas im partial fulfillment of the requirements for the legree of IGLSTER OF SCIENCE Luguet~ 1962... Eager Sub)cot& Agronomy RESPONSE OF RICE TO SOIL PHOSPHORUS LEVELS A Thesis KIHAMNAD Ae QUDDUS Approwed as to style and content by& Chairman of Committee Cpt r Head of Department August, 1962 ACKNOWLEDGMENTS The author wishes to express his...

Quddus, Mohammad Abdul

1962-01-01

200

The relationship between Adirondack lake pH and levels of mercury in yellow perch.  

PubMed

Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and water chemistry data were analyzed from eight Adirondack lakes. Four lakes (Halfmoon Lake, Sand Pond, Rock Pond, and Upper Sister Lake) had pH values of less than 5.0. Four other lakes (Lake Adirondack, Kings Flow, Harris Lake, and Lake Kushaqua) had pH values of more than 7.0. The acidic lakes also had high levels of aluminum and low acid-neutralizing capacity relative to the neutral lakes. Yellow perch (n = 100) from the acidic lakes had significantly higher levels of mercury than did those (n = 102) from the neutral lakes (P < 0.001), and the total mercury concentration increased with both length and weight of the fish. We conclude that the pH of the lake water is a major factor in determining the concentration of methylmercury in yellow perch. PMID:21413513

Brown, Donald; Goncharov, Alexey; Paul, Eric; Simonin, Howard; Carpenter, David O

2010-12-01

201

Potential cultivation of Hordeum vulgare L. in soils with high mercury background concentrations.  

PubMed

Experimental work was carried out under close-to-real conditions to study mercury uptake by Hordeum vulgare L. cultivated in lysimeter experiments. The soil in the lysimeter experiment was obtained from a test plot located near Almadén (Spain) and had a mean mercury content of 22.9 mg kg(-1). A sequence of four crops was sown starting in autumn 2000 and repeated on a yearly basis until 2004. The first crop was grown in the field prior to the extraction of 5 one-cubic-meter lysimeters. The succeeding crops were sown in the lysimeter experiments at the CIEMAT Research Centre (Madrid, Spain). Samples of root and shoot were obtained during the four seasons. Concentrations of mercury at plant maturity in roots vary between I and 3 mg kg(-1) and in straw and grain the concentrations range from 72 to 480 microg kg(-1) and from 5 to 257 microg kg(-1), respectively. In order to assess the potential risk for human health and animal feed, an evaluation of the mercury content in the edible part of the crop has been carried out. According to legislation, there is no human health intoxication risk with a balanced consumption; otherwise, the forage use would have to be controlled. PMID:21972517

Sierra, M J; Millán, R; Cardona, A I; Schmid, T

2011-09-01

202

Low-Cost Options for Moderate Levels of Mercury Control  

SciTech Connect

This is the final technical report for a three-site project that is part of an overall program funded by the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL) and industry partners to obtain the necessary information to assess the feasibility and costs of controlling mercury from coal-fired utility plants. This report summarizes results from tests conducted at MidAmerican's Louisa Generating Station and Entergy's Independence Steam Electric Station (ISES) and sorbent screening at MidAmerican's Council Bluffs Energy Center (CBEC) (subsequently renamed Walter Scott Energy Center (WSEC)). Detailed results for Independence and Louisa are presented in the respective Topical Reports. As no full-scale testing was conducted at CBEC, screening updates were provided in the quarterly updates to DOE. ADA-ES, Inc., with support from DOE/NETL, EPRI, and other industry partners, has conducted evaluations of EPRI's TOXECON II{trademark} process and of high-temperature reagents and sorbents to determine the capabilities of sorbent/reagent injection, including activated carbon, for mercury control on different coals and air emissions control equipment configurations. An overview of each plant configuration is presented: (1) MidAmerican's Louisa Generating Station burns Powder River Basin (PRB) coal in its 700-MW Unit 1 and employs hot-side electrostatic precipitators (ESPs) with flue gas conditioning for particulate control. This part of the testing program evaluated the effect of reagents used in the existing flue gas conditioning on mercury removal. (2) MidAmerican's Council Bluffs Energy Center typically burns PRB coal in its 88-MW Unit 2. It employs a hot-side ESP for particulate control. Solid sorbents were screened for hot-side injection. (3) Entergy's Independence Steam Electric Station typically burns PRB coal in its 880-MW Unit 2. Various sorbent injection tests were conducted on 1/8 to 1/32 of the flue gas stream either within or in front of one of four ESP boxes (SCA = 542 ft{sup 2}/kacfm), specifically ESP B. Initial mercury control evaluations indicated that although significant mercury control could be achieved by using the TOXECON II{trademark} design, the sorbent concentration required was higher than expected, possibly due to poor sorbent distribution. Subsequently, the original injection grid design was modeled and the results revealed that the sorbent distribution pattern was determined by the grid design, fluctuations in flue gas flow rates, and the structure of the ESP box. To improve sorbent distribution, the injection grid and delivery system were redesigned and the effectiveness of the redesigned system was evaluated. This project was funded through the DOE/NETL Innovations for Existing Plants program. It was a Phase II project with the goal of developing mercury control technologies that can achieve 50-70% mercury capture at costs 25-50% less than baseline estimates of $50,000-$70,000/lb of mercury removed. Results from testing at Independence indicate that the DOE goal was successfully achieved. Further improvements in the process are recommended, however. Results from testing at Louisa indicate that the DOE goal was not achievable using the tested high-temperature sorbent. Sorbent screening at Council Bluffs also indicated that traditional solid sorbents may not achieve significant mercury removal in hot-side applications.

Sharon Sjostrom

2008-02-09

203

40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans  

Code of Federal Regulations, 2014 CFR

...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

2014-07-01

204

40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans  

Code of Federal Regulations, 2012 CFR

...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

2012-07-01

205

40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans  

Code of Federal Regulations, 2013 CFR

...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

2013-07-01

206

40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans  

Code of Federal Regulations, 2011 CFR

...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

2011-07-01

207

40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans  

Code of Federal Regulations, 2010 CFR

...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

2010-07-01

208

Potential risks of natural mercury levels to wild predator fish in an Amazon reservoir.  

PubMed

Mercury (Hg) is a toxic metal that bioaccumulates in aquatic organisms and along food chain. Many studies have reported the problem of mercury exposure in aquatic systems from Amazon basin, but very few have focused on the potential risks to wild fish. The present study reports the bioaccumulation of mercury and alterations in target organs of the predator fish Hoplias malabaricus (traíra) from Samuel reservoir, Amazon basin, Northern Brazil. About 18% of fish had mercury levels in muscle exceeding the safe limit for ingestion through food, established by WHO (0.5 ?g Hg g(-1)). Fish were separated in two groups according to mercury bioaccumulation in liver (<0.2 ?g Hg g(-1)-group I and >0.2 ?g Hg g(-1)-group II) for biomarker comparisons. Catalase activity and number of macrophage centers were statistically higher in group II, confirming the potential of Hg to interfere with redox balance and to recruit defense cells to the liver. Conversely, erythrocyte nuclear alterations were less frequent in group II, indicating a more rigorous selection of erythrocytes or hormesis pattern of response. Glutathione S-transferase activity, lipid peroxidation, and histopathological analyses were not statistically different in the liver and gills of both groups. Comparison of lipid peroxidation levels of these fish with others captured in Southern Brazil during another study and the high incidence of morphological alterations in the liver and gills suggest that the bioaccumulation of mercury during continuous exposure is posing potential risks to the species. PMID:21927790

da Silva, Grazyelle Sebrenski; Filipak Neto, Francisco; Silva de Assis, Helena Cristina; Bastos, Wanderley Rodrigues; de Oliveira Ribeiro, Ciro Alberto

2012-08-01

209

Low-Cost Options for Moderate Levels of Mercury Control  

Microsoft Academic Search

This is the final technical report for a three-site project that is part of an overall program funded by the U.S. Department of Energy's National Energy Technology Laboratory (DOE\\/NETL) and industry partners to obtain the necessary information to assess the feasibility and costs of controlling mercury from coal-fired utility plants. This report summarizes results from tests conducted at MidAmerican's Louisa

Sharon Sjostrom

2008-01-01

210

Water and soil biotic relations in Mercury distribution  

NASA Technical Reports Server (NTRS)

The distribution of Hg is considered both in terms of its availability in soil fractions and the relationship between Hg in plant samples and Hg in ambient soils or other supportive media. The plants were grouped by habitat into epipedic-epiphytic (mosses, lichens) and endopedic-aquatic-marine (Basidiomycetes and algae) samples; nonvascular and vascular forms were also distinguished. Sources included Alaska, Hawaii, New England and Iceland. Brief consideration was also given to Hg distribution in a plant-animal-soil community. Data were expressed in terms of plant Hg content and plant substratum concentration ratio. Average Hg contents and concentration ratios, and modal ranges for the ratios were determined. The results showed similar average Hg contents in all groups (126 to 199 ppb) but a low value (84 ppb) in the lichens; terrestrial forms had ratios of 3.5 to 7.6 whereas the marine algae yielded a figure of 78.7. A secondary mode in the range 0 to 0.1 appeared only in the Alaska-New England Group, over 500 km distant from active thermal sites. Evidence for both exclusion and concentration behavior was obtained.

Siegel, S. M.; Siegel, B. Z.; Puerner, N.; Speitel, T.; Thorarinsson, F.

1975-01-01

211

Chronic effects of low-level mercury and cadmium to goldfish (Carassius Auratus)  

SciTech Connect

During this five and one half year investigation, experiments were performed to determine the effects of nanogram levels of cadmium and mercury on reproductive performance, growth, and tissue residues of goldfish. In addition, embryo-larval bioassays were conducted on these metals to compare the effects of a short-term exposure to a sensitive life-cycle stage (i.e., eggs and larvae) with a sustained exposure to a relatively insensitive life-cycle period (i.e., adult). Reproduction was blocked by the long-term exposure to 0.25 ..mu..g/l mercury and 0.27 ..mu..g/l cadmium. Over the 1972 days, the control fish spawned on eleven occasions, but the experimentals failed to spawn. The metal-induced reproductive impairment continued in the experimentals even after six months in clean water. Growth of the populations exposed to mercury and cadmium was significantly less than that of the control population (P < 0.001). The mercury, cadmium and control populations grew by 229%, 232% and 353%, respectively. Mercury and cadmium continuously accumulated in fish tissues over the entire 1789 days of whole body exposure. Despite exposure to mercury as inorganic metal, organomercury also accumula

Westerman, A.G.

1984-01-01

212

Comparative observations on levels of mercury in scalp hair of humans from different Islands  

NASA Astrophysics Data System (ADS)

Following the Minamata events, an extraordinary number of studies concerning mercury toxicity and human health have been undertaken. Particular attention has been given to the evaluation of the dose-response relationship, i.e., the body burden at which (evaluated through the mercury analyses in blood or hair) the risk of poisoning begins. The results of a comparative study concerning levels of mercury in the hair of fishermen living in small islands who eat seafood more than four times per week show that in two areas only, and only in a few cases in these areas, the mercury in the hair exceeds the limit at which a possible risk could exist. In fact, the limit of 50 mg/g of total mercury in the hair (indicated as the lower limit above which a possible risk could occur) is surpassed by nine fishermen out of a total of 39 at station 1 and by four fishermen out of a total of 26 at station 3. The average value at station 1 is 36.38 mg/g and that at station 3 is 30.31 mg. Many countries have set legal limits of mercury for seafood, but evidently the system does not offer a true protection for man. Only the provisional tolerable weekly intake (PTWI), as repeatedly suggested by WHO, should be considered the best guideline to prevent possibly harmful consequences.

Renzoni, Aristeo

1992-09-01

213

Achieving very low mercury levels in refinery wastewater by membrane filtration.  

SciTech Connect

Microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes were evaluated for their ability to achieve the world's most stringent Hg discharge criterion (<1.3 ng/L) in an oil refinery's wastewater. The membrane processes were operated at three different pressures to demonstrate the potential for each membrane technology to achieve the targeted effluent mercury concentrations. The presence of mercury in the particulate form in the refinery wastewater makes the use of MF and UF membrane technologies more attractive in achieving very low mercury levels in the treated wastewater. Both NF and RO were also able to meet the target mercury concentration at lower operating pressures (20.7 bar). However, higher operating pressures ({ge}34.5 bar) had a significant effect on NF and RO flux and fouling rates, as well as on permeate quality. SEM images of the membranes showed that pore blockage and narrowing were the dominant fouling mechanisms for the MF membrane while surface coverage was the dominant fouling mechanism for the other membranes. The correlation between mercury concentration and particle size distribution was also investigated to understand mercury removal mechanisms by membrane filtration. The mean particle diameter decreased with filtration from 1.1 {+-} 0.0 {micro}m to 0.74 {+-} 0.2 {micro}m after UF.

Urgun Demirtas, M.; Benda, P.; Gillenwater, P. S.; Negri, M. C.; Xiong, H.; Snyder, S. W. (Center for Nanoscale Materials); ( ES)

2012-05-15

214

Influence of Methylmercury from Tributary Streams on Mercury Levels in Savannah River Asiatic Clams  

SciTech Connect

Average methylmercury levels in five Savannah River tributary streams sampled 11 times over two years were nearly twice as high as in the Savannah River. Total mercury levels in the tributaries did not differ significantly from the river. All of the tributaries drained extensive wetlands that would be expected to support comparatively high rates of methylation. Mercury concentrations in Asiatic clams (Corbicula fluminea) collected from the discharge plumes of Savannah River tributaries were significantly higher than in Asiatic clams collected from the Savannah River upstream from the tributary mouths . These results indicate that streams draining wetlands into coastal plain rivers can create localized areas of elevated methylmercury with resulting increases in the mercury levels of river biota.

Paller, M.H.

2004-03-01

215

Relating Land Cover Characteristics and Common Loon Mercury Levels Using Geographic Information Systems  

Microsoft Academic Search

This effort models the relationship between mercury (Hg) levels in the common loon (Gavia immer) and land cover types as defined by the National Land Cover Database (NLCD). We constructed the model within the framework of a GIS to analyze the spatial relationships between land cover types and blood Hg levels in male common loons. Thiessan polygons were used to

David Kramar; Wing M. Goodale; L. M. Kennedy; L. W. Carstensen; Taranjat Kaur

2005-01-01

216

Electronic Characterization of Defects in Narrow Gap Semiconductors-Comparison of Electronic Energy Levels and Formation Energies in Mercury Cadmium Telluride, Mercury Zinc Telluride, and Mercury Zinc Selenide  

NASA Technical Reports Server (NTRS)

We have used a Green's function technique to calculate the energy levels and formation energy of deep defects in the narrow gap semiconductors mercury cadmium telluride (MCT), mercury zinc telluride (MZT) and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total energy with an impurity cluster and the total energy for the perfect crystal. Substitutional (including antisite), interstitial (self and foreign), and vacancy deep defects are considered. Relaxation effects are calculated (with molecular dynamics). By use of a pseudopotential, we generalize the ideal vacancy model so as to be able to consider relaxation for vacancies. Different charge states are considered and the charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that due to relaxation. Different charged states for vacancies were not calculated to have much effect on the formation energy. For all cases we find deep defects in the energy gap only for cation site s-like orbitals or anion site p-like orbitals, and for the substitutional case only the latter are appreciably effected by relaxation. For most cases for MCT, MZT, MZS, we consider x (the concentration of Cd or Zn) in the range appropriate for a band gap of 0.1 eV. For defect energy levels, the absolute accuracy of our results is limited, but the precision is good, and hence chemical trends are accurately predicted. For the same reason, defect formation energies are more accurately predicted than energy level position. We attempt, in Appendix B, to calculate vacancy formation energies using relatively simple chemical bonding ideas due to Harrison. However, these results are only marginally accurate for estimating vacancy binding energies. Appendix C lists all written reports and publications produced for the grant. We include abstracts and a complete paper that summarizes our work which is not yet available.

Patterson, James D.

1996-01-01

217

Barium Levels in Soils and Centella asiatica.  

PubMed

In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [?g/g dry weight (dw)] was 63.72 to 382.01 ?g/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 ?g/g for roots, 3.31 to 11.22 ?g/g for leaves and 2.37 to 6.14 ?g/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution. PMID:24575242

Ong, Ghim Hock; Yap, Chee Kong; Mahmood, Maziah; Tan, Soon Guan; Hamzah, Suhaimi

2013-08-01

218

Barium Levels in Soils and Centella asiatica  

PubMed Central

In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [?g/g dry weight (dw)] was 63.72 to 382.01 ?g/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 ?g/g for roots, 3.31 to 11.22 ?g/g for leaves and 2.37 to 6.14 ?g/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution. PMID:24575242

Ong, Ghim Hock; Yap, Chee Kong; Mahmood, Maziah; Tan, Soon Guan; Hamzah, Suhaimi

2013-01-01

219

Risk, mercury levels, and birds: relating adverse laboratory effects to field biomonitoring.  

PubMed

There is an abundance of field data on levels of mercury in a variety of organisms and there are a number of studies that demonstrate the adverse effects of mercury on laboratory animals, but few studies examine the relationship between the two. Thus it is often difficult to determine the ecological relevance of mercury concentrations found in nature, or to predict the ecosystem consequences of current levels. In this paper we review the levels in tissues that are associated with adverse effects in birds from laboratory studies and compare these with levels found in wild bird populations in the New York Bight to provide a basis for interpreting values in avian populations. We use feathers from fledgling birds which would have been fed on locally obtained food to eliminate the problem of where toxic burdens were acquired by more mobile adult birds. Laboratory studies indicate that in some species mercury levels of 1.5 ppm in eggs and/or 5 to 40 ppm in the feathers of birds are associated with adverse effects, including impaired reproduction. We report egg levels in birds that range as high as 3.8 ppm and feather levels that range as high as 10.3 ppm, although means are much lower. The levels in eggs of some wild birds in the New York Bight are within the range known to lower hatchability, embryo and chick survival, and chick weight, all variables that reduce reproductive success. Species with high egg levels include Forster's tern (Sterna forsteri) and black skimmer (Rynchops niger). Levels in feathers of some young wild birds from the New York Bight are within the range associated with reduced hatchability of eggs, behavioral abnormalities of adults, and infertility. Species with dangerously elevated mercury levels in feathers include great egret (Ardea [=Egretta] alba), snowy egret [Egretta thula), and black skimmers. PMID:9417847

Burger, J; Gochfeld, M

1997-11-01

220

Patterns of bacterial diversity along a long-term mercury-contaminated gradient in the paddy soils.  

PubMed

Mercury (Hg) pollution is usually regarded as an environmental stress in reducing microbial diversity and altering bacterial community structure. However, these results were based on relatively short-term studies, which might obscure the real response of microbial species to Hg contamination. Here, we analysed the bacterial abundance and community composition in paddy soils that have been potentially contaminated by Hg for more than 600 years. Expectedly, the soil Hg pollution significantly influenced the bacterial community structure. However, the bacterial abundance was significantly correlated with the soil organic matter content rather than the total Hg (THg) concentration. The bacterial alpha diversity increased at relatively low levels of THg and methylmercury (MeHg) and subsequently approached a plateau above 4.86 mg kg(-1) THg or 18.62 ng g(-1) MeHg, respectively. Contrasting with the general prediction of decreasing diversity along Hg stress, our results seem to be consistent with the intermediate disturbance hypotheses with the peak biological diversity under intermediate disturbance or stress. This result was partly supported by the inconsistent response of bacterial species to Hg stress. For instance, the relative abundance of Nitrospirae decreased, while that of Gemmatimonadetes increased significantly along the increasing soil THg and MeHg concentrations. In addition, the content of SO(4)(2-), THg, MeHg and soil depth were the four main factors influencing bacterial community structures based on the canonical correspondence analysis (CCA). Overall, our findings provide novel insight into the distribution patterns of bacterial community along the long-term Hg-contaminated gradient in paddy soils. PMID:24827389

Liu, Yu-Rong; Wang, Jian-Jun; Zheng, Yuan-Ming; Zhang, Li-Mei; He, Ji-Zheng

2014-10-01

221

Characterization of soils from an industrial complex contaminated with elemental mercury  

SciTech Connect

Historical use of liquid elemental mercury (Hg(0){sub l}) at the Y-12 National Security Complex in Oak Ridge, TN, USA, resulted in large deposits of Hg(0){sub l} in the soils. The fate and distribution of the spilled Hg(0) are not well characterized. In this study we evaluated analytical tools for characterizing the speciation of Hg in the contaminated soils and then used the analytical techniques to examine the speciation of Hg in two soil cores collected at the site. These include x-ray fluorescence (XRF), soil Hg(0) headspace analysis, and total Hg determination by acid digestion coupled with cold vapor atomic absorption (HgT). XRF was not found to be suitable for evaluating Hg concentrations in heterogeneous soils containing low concentration of Hg or Hg(0) because Hg concentrations determined using this method were lower than those determined by HgT analysis and the XRF detection limit is 20 mg/kg. Hg(0){sub g} headspace analysis coupled with HgT measurements yielded good results for examining the presence of Hg(0){sub l} in soils and the speciation of Hg. The two soil cores are highly heterogeneous in both the depth and extent of Hg contamination, with Hg concentrations ranging from 0.05 to 8400 mg/kg. In the first core, Hg(0){sub l} was distributed throughout the 3.2 m depth, whereas the second core, from a location 12 m away, contained Hg(0){sub l} in a 0.3 m zone only. Sequential extractions showed organically associated Hg dominant at depths with low Hg concentration. Soil from the zone of groundwater saturation showed reducing conditions and the Hg is likely present as Hg-sulfide species. At this depth, lateral Hg transport in the groundwater may be a source of Hg detected in the soil at the deeper soil depths. Overall, characterization of soils containing Hg(0){sub l} is difficult because of the heterogeneous distribution of Hg within the soils. This is exacerbated in industrial facilities where fill materials make up much of the soils and historical and continued reworking of the subsurface has remobilized the Hg. -- Highlights: • Presence of Hg(0) and chemical transformations control the Hg speciation in soil. • Redox reactions can result in the mobilization and sequestration of Hg in soils. • Analysis of soils containing Hg(0) is complex due to sample heterogeneity.

Miller, Carrie L., E-mail: millercl@ornl.gov; Watson, David B.; Lester, Brian P.; Lowe, Kenneth A.; Pierce, Eric M.; Liang, Liyuan

2013-08-15

222

Effects of infiltration chemistry on the mobilization potential of mercury (Hg) in soils from the New Jersey Coastal Plain  

SciTech Connect

Mercury concentrations in ground water exceeding the USEPA maximum contaminant level of 2 [mu]g/l have been found in wells 60 to 100 feet deep in the Kirkwood-Cohansey Aquifer System of the New Jersey Coastal Plain. The aquifer is a sand and gravel aquifer consisting primarily of quartz with minor amounts of biotite, plagioclase feldspars and ilmenite. This is the shallowest aquifer system in the NJ Coastal Plain and is unconfined over much of central and southern NJ. Soils on these aquifer sediments are quartz-rich with poorly developed A[sub 0] and B horizons. These are weakly-buffered acid soils with a pH ranging from 4.0 to 5.5, and little or no capacity for metal retention. Mercury contaminated soils from Gloucester County, NJ were used to determine the mobilization potential of Hg by run-off solutions containing 0.02M NaCl and 0.02M CaCl[sub 2] salt solutions that approximate diluted highway de-icing salts; and by a simulated acid rain solution of pH 4.0. These experimental data are in agreement with previous studies suggesting that chlorides from de-icing salts are capable of mobilizing Hg. However, the mobilization potential of Hg in coastal plain soils attributable to acid rain is much greater (approx. 1 to 2 orders of magnitude) than that estimated for de-icing salts. These data also indicate that in NJ Coastal Plain soils Hg mobilization may be controlled by colloidal movement during an infiltration event. Mobilization of Hg by the simulated acid rain solution was found to coincide with the resuspension of Fe and Al colloids, while no colloidal movement was found with either of the salt solutions. Thus Hg sorbed to Fe and Al colloids in NJ Coastal Plain soils is more likely to be mobilized by infiltration of acidic rain water or fluctuating acidic ground water than by highway de-icing salts.

MacLeod, C.; Taylor, E. (Princeton Univ., NJ (United States). Dept. of Geological and Geophysical Sciences)

1992-01-01

223

Effect of soil organic carbon level on the erodibility of a U.S. Piedmont soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Intensive soil cultivation and high soil erosion has impoverished levels of soil organic carbon (SOC) in the southeastern U.S. Piedmont region. Sound soil management practices that build SOC levels are needed to reduce soil erodibility and restore soil quality. We studied the relationship of SOC con...

224

Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study  

SciTech Connect

Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levels to those in the pituitary gland of AD and control subjects.

Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States)

1996-12-31

225

Projections of atmospheric mercury levels and their effect on air quality in the United States  

NASA Astrophysics Data System (ADS)

The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the United States are investigated by using the global climate-chemistry model, CAM-Chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected by using dynamic schemes. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1-4.0 ng m-3 for the eastern US and 1.4-3.0 ng m-3 for the western US. This spatial difference corresponds to potential increases in wet deposition of 10-14 ?g m-2 for the eastern US and 2-4 ?g m-2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystem. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this finding indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses show that changes in anthropogenic emissions contribute 32-53% of projected changes in mercury air concentration, while the independent contribution by climate change and its induced natural emissions change accounts for 47-68%.

Lei, H.; Wuebbles, D. J.; Liang, X.-Z.; Tao, Z.; Olsen, S.; Artz, R.; Ren, X.; Cohen, M.

2014-01-01

226

Mercury in the soil of two contrasting watersheds in the eastern United States.  

PubMed

Soil represents the largest store of mercury (Hg) in terrestrial ecosystems, and further study of the factors associated with soil Hg storage is needed to address concerns about the magnitude and persistence of global environmental Hg bioaccumulation. To address this need, we compared total Hg and methyl Hg concentrations and stores in the soil of different landscapes in two watersheds in different geographic settings with similar and relatively high methyl Hg concentrations in surface waters and biota, Fishing Brook, Adirondack Mountains, New York, and McTier Creek, Coastal Plain, South Carolina. Median total Hg concentrations and stores in organic and mineral soil samples were three-fold greater at Fishing Brook than at McTier Creek. Similarly, median methyl Hg concentrations were about two-fold greater in Fishing Brook soil than in McTier Creek soil, but this difference was significant only for mineral soil samples, and methyl Hg stores were not significantly different among these watersheds. In contrast, the methyl Hg/total Hg ratio was significantly greater at McTier Creek suggesting greater climate-driven methylation efficiency in the Coastal Plain soil than that of the Adirondack Mountains. The Adirondack soil had eight-fold greater soil organic matter than that of the Coastal Plain, consistent with greater total Hg stores in the northern soil, but soil organic matter - total Hg relations differed among the sites. A strong linear relation was evident at McTier Creek (r(2)?=?0.68; p<0.001), but a linear relation at Fishing Brook was weak (r(2)?=?0.13; p<0.001) and highly variable across the soil organic matter content range, suggesting excess Hg binding capacity in the Adirondack soil. These results suggest greater total Hg turnover time in Adirondack soil than that of the Coastal Plain, and that future declines in stream water Hg concentrations driven by declines in atmospheric Hg deposition will be more gradual and prolonged in the Adirondacks. PMID:24551042

Burns, Douglas A; Woodruff, Laurel G; Bradley, Paul M; Cannon, William F

2014-01-01

227

Characterization of soils from an industrial complex contaminated with elemental mercury  

SciTech Connect

Historic use of liquid elemental mercury (Hg(0)l) at the Y-12 National Security Complex in Oak Ridge, TN, USA resulted in large deposits of Hg(0)l in the soils. An evaluation of analytical tools for characterizing the speciation of Hg in the soils at the Y-12 facility was conducted and these tequniques were used to examine the speciation of Hg in two soil cores collect at the site. These include X-ray fluorescence (XRF), soil Hg(0) headspace analysis, and total Hg determination by acid digestion coupled with cold vapor atomic absorption. Hg concentrations determined using XRF, a tool that has been suggestions for quick onsite characterization of soils, were lower than concentrations determined by HgT analysis and as a result this technique is not suitable for the evaluation of Hg concentrations in heterogeneous soils containing Hg(0)l. Hg(0)g headspace analysis can be used to examine the presence of Hg(0)l in soils and when coupled with HgT analysis an understanding of the speciation of Hg in soils can be obtained. Two soil cores collected within the Y-12 complex highlight the heterogeneity in the depth and extent of Hg contamination, with Hg concentrations ranging from 0.05 to 8400 mg/kg. At one location Hg(0)l was distributed throughout 3.2 meters of core whereas the core from a location only 12 meters away only contained Hg(0)l in 0.3 m zone of the core. Sequential extractions, used to examine the forms of Hg in the soils, indicated that at depths within the core that have low Hg concentrations organically associated Hg is dominant. Soil from the zone of groundwater inundation showed reduced characteristics and the Hg is likely present as Hg-sulfide species. At this location it appears that Hg transported within the groundwater is a source of Hg to the soil. Overall the characterization of Hg in soils containing Hg(0) l is difficult due to the heterogeneous distribution within the soils and this challenge is enhanced in industrial facilities in which fill material comprise most of the soils and historical and continuing reworking of the subsurface has remobilized the Hg.

Miller, Carrie L [ORNL; Watson, David B [ORNL; Liang, Liyuan [ORNL; Lester, Brian P [ORNL; Lowe, Kenneth Alan [ORNL; Pierce, Eric M [ORNL

2013-01-01

228

Mercury in the Soil of Two Contrasting Watersheds in the Eastern United States  

PubMed Central

Soil represents the largest store of mercury (Hg) in terrestrial ecosystems, and further study of the factors associated with soil Hg storage is needed to address concerns about the magnitude and persistence of global environmental Hg bioaccumulation. To address this need, we compared total Hg and methyl Hg concentrations and stores in the soil of different landscapes in two watersheds in different geographic settings with similar and relatively high methyl Hg concentrations in surface waters and biota, Fishing Brook, Adirondack Mountains, New York, and McTier Creek, Coastal Plain, South Carolina. Median total Hg concentrations and stores in organic and mineral soil samples were three-fold greater at Fishing Brook than at McTier Creek. Similarly, median methyl Hg concentrations were about two-fold greater in Fishing Brook soil than in McTier Creek soil, but this difference was significant only for mineral soil samples, and methyl Hg stores were not significantly different among these watersheds. In contrast, the methyl Hg/total Hg ratio was significantly greater at McTier Creek suggesting greater climate-driven methylation efficiency in the Coastal Plain soil than that of the Adirondack Mountains. The Adirondack soil had eight-fold greater soil organic matter than that of the Coastal Plain, consistent with greater total Hg stores in the northern soil, but soil organic matter – total Hg relations differed among the sites. A strong linear relation was evident at McTier Creek (r2?=?0.68; p<0.001), but a linear relation at Fishing Brook was weak (r2?=?0.13; p<0.001) and highly variable across the soil organic matter content range, suggesting excess Hg binding capacity in the Adirondack soil. These results suggest greater total Hg turnover time in Adirondack soil than that of the Coastal Plain, and that future declines in stream water Hg concentrations driven by declines in atmospheric Hg deposition will be more gradual and prolonged in the Adirondacks. PMID:24551042

Burns, Douglas A.; Woodruff, Laurel G.; Bradley, Paul M.; Cannon, William F.

2014-01-01

229

Assessment of Mercury in Soils, Crops, Earthworms, and Water when Soil is Treated with Gypsum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flue gas desulfurization (FGD) gypsum from fossil fuel combustion has many potential uses in agriculture, but there is concern about the potential environmental effects of its elevated mercury (Hg) concentration. The wet limestone scrubbing process that removes sulfur from flue gas (and produces gyp...

230

Population correlates of circulating mercury levels in Korean adults: the Korea National Health and Nutrition Examination Survey IV  

PubMed Central

Background Prior studies focused on bioaccumulation of mercury (Hg) and on large, long-lived fish species as the major environmental source of Hg, but little is known about consumption of small-sized fish or about non-dietary determinants of circulating Hg levels. The purpose of this study was to evaluate whole blood mercury concentration (WBHg) and its major dietary and non-dietary correlates in Korean adults. Methods We analyzed cross-sectional data from 3,972 (male?=?1,994; female?=?1,978) participants who completed the Korean National Health and Nutrition Examination Survey IV, 2008 to 2009. Relevant factors included diet, geographic location of residence, demographics, and lifestyle. WBHg concentration was measured using cold-vapor atomic absorption spectrometry. Multivariable linear models assessed independent correlates of dietary and non-dietary factors for WBHg levels. Results Median levels of WBHg were 5.1 ?g/L in men and 3.7 ?g/L in women. Higher levels of fish/shellfish intake were associated with higher levels of WBHg. Higher consumption of small-sized fish was linked to higher levels of WBHg. Non-dietary predictors of higher WBHg were being male, greater alcohol consumption, higher income and education, overweight/obesity, increasing age, and living in the southeast region. Conclusions Both dietary and non-dietary factors were associated with WBHg levels in the Korean population. There is significant geographic variation in WBHg levels; residents living in the mid-south have higher WBHg levels. We speculate that uncontrolled geographic characteristics, such as local soil/water content and specific dietary habits are involved. PMID:24884916

2014-01-01

231

Projections of atmospheric mercury levels and their effect on air quality in the United States  

NASA Astrophysics Data System (ADS)

The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the US are investigated by using the global climate-chemistry model, CAM-chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected using dynamic schemes. The zonal mean surface total gaseous mercury (TGM) concentrations in the tropics and mid-latitudes of the Southern Hemisphere are projected to increase by 0.5-1.2 ng m-3 in 2050. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1-4.0 ng m-3 for the eastern US and 1.4-3.0 ng m-3 for the western US. This pattern corresponds to potential increases in wet deposition of 10-14 ?g m-2 for the eastern US and 2-4 ?g m-2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystems. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses presented show that anthropogenic emissions changes contribute 32-53% of projected mercury air concentration changes, while the independent contribution by climate change accounts for 47-68%. In summary, global climate change could have a comparable effect on mercury pollution in the US to that caused by global emissions changes.

Lei, H.; Wuebbles, D. J.; Liang, X.-Z.; Tao, Z.; Olsen, S.; Artz, R.; Ren, X.; Cohen, M.

2013-08-01

232

Mercury accumulation in soils and plants in the Almadén mining district, Spain: one of the most contaminated sites on Earth.  

PubMed

Although mercury (Hg) mining in the Almadén district ceased in May 2002, the consequences of 2000 years of mining in the district has resulted in the dissemination of Hg into the surrounding environment where it poses an evident risk to biota and human health. This risk needs to be properly evaluated. The uptake of Hg has been found to be plant-specific. To establish the different manners in which plants absorb Hg, we carried out a survey of Hg levels in the soils and plants in the most representative habitats of this Mediterranean area and found that the Hg concentrations varied greatly and were dependent on the sample being tested (0.13-2,695 microg g(-1) Hg). For example, the root samples had concentrations ranging from 0.06 (Oenanthe crocata, Rumex induratus) to 1095 (Polypogon monspeliensis) microg g(-1) Hg, while in the leaf samples, the range was from 0.16 (Cyperus longus) to 1278 (Polypogon monspeliensis) microg g(-1) Hg. There are four well-differentiated patterns of Hg uptake: (1) the rate of uptake is constant, independent of Hg concentration in the soil (e.g., Pistacia lentiscus, Quercus rotundifolia); (2) after an initial linear relationship between uptake and soil concentration, no further increase in Hg(plant) is observed (e.g., Asparagus acutifolius, Cistus ladanifer); (3) no increase in uptake is recorded until a threshold is surpassed, and thereafter a linear relationship between Hg(plant) and Hg(soil) is established (e.g., Rumex bucephalophorus, Cistus crispus); (4) there is no relationship between Hg(plant) and Hg(soil )(e.g., Oenanthe crocata and Cistus monspeliensis). Overall, the Hg concentrations found in plants from the Almadén district clearly reflect the importance of contamination processes throughout the study region. PMID:17013679

Molina, José Antonio; Oyarzun, Roberto; Esbrí, José María; Higueras, Pablo

2006-10-01

233

Hair mercury levels in relation to fish consumption in a community of the Moroccan Mediterranean coast.  

PubMed

Coastal populations with high seafood consumption in the Mediterranean have a significant exposure to dietary methylmercury, and areas where environmental mercury pollution is an issue due to industrial activities are of special concern. The study was undertaken with the aim of assessing methylmercury exposure through fish consumption in a community of north Morocco and characterizing the relevant health risk. Concentrations of total mercury were determined in human hair, a biomarker of methylmercury exposure, and in locally consumed fish by cold vapour atomic absorption spectrophotometry. Based on consumption frequencies reported by the 108 subjects included in the study the weekly intake of methylmercury was estimated and biomarker data were evaluated in relation to the estimated intake and the sociodemographic characteristics of the population. Multiple regression analysis was employed for the interpretation of hair mercury data in relation to fish consumption frequency, gender and the age of individuals. Mercury concentrations in hair ranged from 0.22 to 9.56 microg g(-1) (geometric mean = 1.79 microg g(-1)) and were closely related to fish intake. Fisherman and their families consumed fish three to five times per week and were the most exposed population subgroup. A high proportion of women of child-bearing age (50%) had relatively high levels of mercury in their hair (3.08-7.88 microg g(-1)). PMID:17852400

Elhamri, Hecham; Idrissi, Larbi; Coquery, Marina; Azemard, Sabine; El Abidi, Abdellah; Benlemlih, Mohamed; Saghi, Mohamed; Cubadda, Francesco

2007-11-01

234

Bioaccumulation of trace mercury in trophic levels of benthic, benthopelagic, pelagic fish species, and sea birds from Arvand River, Iran.  

PubMed

In this study, concentration of mercury was determined in the trophic levels of benthic, benthopelagic, pelagic fish species, and river birds from Arvand River, located in the Khuzestan province in the lowlands of southwestern Iran at the head of the Persian Gulf. The order of mercury concentrations in tissues of the fish species was as follows: liver>gill>muscle and in tissues of the kingfisher species was as follows: feather>liver>kidney>muscle. Therefore, liver in fish and feather in kingfisher exhibited higher mercury concentration than the other tissues. There was a positive correlation between mercury concentrations in fish and kingfisher species with size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. The results of this study show that the highest mean mercury level were found in the kingfisher (Anas crecca), followed by benthic (Epinephelus diacanthus), benthopelagic (Chanos chanos), and pelagic fish (Strongylura strongylura). Mean value of mercury in fish species, S. strongylura were (0.61 ?g g(-1) dry weight), C. chanos (0.45 ?g g(-1) dry weight), E. diacanthus (0.87 ?g g(-1) dry weight), and in kingfisher species A. crecca was (2.64 ?g g(-1) dry weight). Significant correlation between mercury concentration in fish and kingfisher may be related to high variability of mercury in the fish. PMID:24174062

Hosseini, Mehdi; Nabavi, Seyed Mohammad Bagher; Parsa, Yaghob

2013-12-01

235

A gravimetric approach to providing SI traceability for concentration measurement results of mercury vapor at ambient air levels  

NASA Astrophysics Data System (ADS)

Current measurement and calibration capabilities for mercury vapor in air are maintained at levels of 0.2–40??g?Hg?m?3. In this work, a mercury vapor generator has been developed to establish metrological traceability to the international system of units (SI) for mercury vapor measurement results ?15?ng?Hg?m?3, i.e. closer to realistic ambient air concentrations (1–2?ng?Hg?m?3) [1]. Innovations developed included a modified type of diffusion cell, a new measurement method to weigh the loss in (mercury) mass of these diffusion cells during use (ca. 6–8??g mass difference between successive weighings), and a new housing for the diffusion cells to maximize flow characteristics and to minimize temperature variations and adsorption effects. The newly developed mercury vapor generator system was tested by using diffusion cells generating 0.8 and 16?ng?Hg?min?1. The results also show that the filter system, to produce mercury free air, is working properly. Furthermore, and most importantly, the system is producing a flow with a stable mercury vapor content. Some additional improvements are still required to allow the developed mercury vapor generator to produce SI traceable mercury vapor concentrations, based upon gravimetry, at much lower concentration levels and reduced measurement uncertainties than have been achieved previously. The challenges to be met are especially related to developing more robust diffusion cells and better mass measurement conditions. The developed mercury vapor generator will contribute to more reliable measurement results of mercury vapor at ambient and background air levels, and also to better safety standards and cost reductions in industrial processes, such as the liquefied natural gas field, where aluminum main cryogenic heat exchangers are used which are particularly prone to corrosion caused by mercury.

Ent, Hugo; van Andel, Inge; Heemskerk, Maurice; van Otterloo, Peter; Bavius, Wijnand; Baldan, Annarita; Horvat, Milena; Brown, Richard J. C.; Quétel, Christophe R.

2014-11-01

236

Molecular field analysis of trophic relationships in soil-dwelling invertebrates to identify mercury, lead and cadmium transmission through forest ecosystems.  

PubMed

Contamination pathways in complex food chains in soil ecosystems can be difficult to elucidate. Molecular analysis of predator gut content can, however, rapidly reveal previously unidentified trophic interactions between invertebrates and thereby uncover pathways of pollutant spread. Here, we measured concentrations of the toxic metals lead, cadmium and mercury in carabid beetle predators and their prey. Invertebrates were sampled at one control and four heavy metal-polluted sites to reveal the impact of diet composition and seasonal variation in prey availability on metal burden in carabids and metal transfer pathways through forest ecosystems. This is the first report, to our knowledge, of carabid diet composition based on PCR analysis of gut contents at the forest community level, rather than in cultivated fields. Extensive screening using group- and species-specific primers revealed that carabids ate primarily earthworms and slugs, as well as smaller numbers of woodlice and springtails. Metal concentrations in carabids correlated with seasonal changes in diet. Mercury accumulated in beetle predators more than in their slug prey. As earthworms, slugs and carabid beetles are the major prey of many birds and mammals, prey-predator transfer and associated toxicity are major risks at mercury-contaminated sites. Carabids may be useful bioindicators for assessing the impact of pollutants on soil ecosystems, as long as species and seasonal factors are taken into account. PMID:24138157

Šeri? Jelaska, Lucija; Jurasovi?, Jasna; Brown, David S; Vaughan, Ian P; Symondson, William O C

2014-08-01

237

The precise measurement of concentration gradients of mercury in air over soils: A review of past and recent measurements  

Microsoft Academic Search

Measurements of the atmospheric concentration gradients of mercury (Hg) vapor over soils can be used to determine the direction and magnitude of exchange rates of Hg if certain assumptions are met. However, these gradients are quite small and require highly precise sampling to achieve accurate data. We have developed a sampling and analysis procedure which allows quantification of gradients over

S. E. Lindberg; K.-H. Kim; J. Munthe

1995-01-01

238

Variation and distribution of total mercury in water, sediment and soil from northern Lake Victoria, East Africa  

Microsoft Academic Search

Lake Victoria, the world's largest tropical freshwater lake, is an important resource, ecologi- cally and economically. THg distribution in the northern parts of the lake are not well known, so to answer this gap, patterns in total mercury (THg) in water, soil and two dated sediment cores from north- ern Lake Victoria were determined. Water THg concentrations ranged from 0.7

L. M. CAMPBELL; R. E. HECKY; R. MUGGIDE; D. G. DIXON

2003-01-01

239

Variation and distribution of total mercury in water, sediment and soil from northern Lake Victoria, East Africa  

Microsoft Academic Search

Lake Victoria, the world's largest tropical freshwater lake, is an important resource, ecologically and economically. THg distribution in the northern parts of the lake are not well known, so to answer this gap, patterns in total mercury (THg) in water, soil and two dated sediment cores from northern Lake Victoria were determined. Water THg concentrations ranged from 0.7 to 5.8

L. M. Campbell; R. E. Hecky; R. Muggide; D. G. Dixon; P. S. Ramlal

2003-01-01

240

Contaminated Soils (II): In Vitro Dermal Absorption of Nickel (Ni63) and Mercury (Hg203) in Human Skin  

Microsoft Academic Search

Dermal absorption of heavy metal soil contaminants was tested in vitro with chloride salts of radioactive nickel (Ni-63) and mercury (Hg-203). Aqueous soil suspensions, spiked with either Ni-63 or Hg-203, were applied to fresh viable human breast skin tissue in Bronaugh diffusion cells perfused with Hanks HEPES buffered (pH 7.4) receptor containing 4% bovine serum albumin (BSA). Receptor fractions were

Richard P. Moody; Julie Joncas; Mark Richardson; Sanya Petrovic; Ih Chu

2009-01-01

241

MERCURY FLUX MEASUREMENTS OVER AIR AND WATER IN KEJIMKUJIK NATIONAL PARK, NOVA SCOTIA  

E-print Network

MERCURY FLUX MEASUREMENTS OVER AIR AND WATER IN KEJIMKUJIK NATIONAL PARK, NOVA SCOTIA F. S. BOUDALA. Mercury flux measurements were conducted at two lakes and three soil sites in Kejimkujik National Park, located in the eastern Canadian province of Nova Scotia. One of the lakes had high levels of both mercury

Folkins, Ian

242

Estimation and Mapping of Wet and Dry Mercury Deposition Across Northeastern North America  

Microsoft Academic Search

Whereas many ecosystem characteristics and processes influence mercury accumulation in higher trophic-level organisms, the mercury flux from the atmosphere to a lake and its watershed is a likely factor in potential risk to biota. Atmospheric deposition clearly affects mercury accumulation in soils and lake sediments. Thus, knowledge of spatial patterns in atmospheric deposition may provide information for assessing the relative

Eric K. Miller; Alan Vanarsdale; Gerald J. Keeler; Ann Chalmers; Laurier Poissant; Neil C. Kamman; Raynald Brulotte

2005-01-01

243

[Mercury poisoning].  

PubMed

Mercury is a widespread heavy metal with potential severe impacts on human health. Exposure conditions to mercury and profile of toxicity among humans depend on the chemical forms of the mercury: elemental or metallic mercury, inorganic or organic mercury compounds. This article aims to reviewing and synthesizing the main knowledge of the mercury toxicity and its organic compounds that clinicians should know. Acute inhalation of metallic or inorganic mercury vapours mainly induces pulmonary diseases, whereas chronic inhalation rather induces neurological or renal disorders (encephalopathy and interstitial or glomerular nephritis). Methylmercury poisonings from intoxicated food occurred among some populations resulting in neurological disorders and developmental troubles for children exposed in utero. Treatment using chelating agents is recommended in case of symptomatic acute mercury intoxication; sometimes it improves the clinical effects of chronic mercury poisoning. Although it is currently rare to encounter situations of severe intoxication, efforts remain necessary to decrease the mercury concentration in the environment and to reduce risk on human health due to low level exposure (dental amalgam, fish contamination by organic mercury compounds…). In case of occupational exposure to mercury and its compounds, some disorders could be compensated in France. Clinicians should work with toxicologists for the diagnosis and treatment of mercury intoxication. PMID:20579784

Bensefa-Colas, L; Andujar, P; Descatha, A

2011-07-01

244

Air-surface exchange of mercury with soils amended with ash materials.  

PubMed

Air-surface exchange of mercury (Hg) was measured from soil low in Hg (0.013 mg/kg) amended with four different ash materials: a wood ash containing -10% coal ash (0.070 mg/kg Hg), a mixture of two subbituminous coal fly ashes (0.075 mg/kg Hg), a subbituminous coal ash containing -10% petroleum coke ash (1.2 mg/kg Hg), and an ash from incinerated municipal sewage sludge (4.3 mg/kg Hg) using a dynamic flux chamber. Ash was added to soil to simulate agricultural supplements, soil stabilization, and pad layers used in livestock areas. For the agricultural amendment, -0.4% ash was well mixed into the soil. To make the stabilized soil that could be used for construction purposes, -20% ash was mixed into soil with water. The pad layer consisted of a wetted 1-cm layer of ash material on the soil surface. Diel trends of Hg flux were observed for all of the substrates with significantly higher Hg emissions during the day and negligible flux or deposition of Hg during the night. Hg fluxes, which were measured in the summer months, were best correlated with solar radiation, temperature, and air O3 concentrations. Mean Hg fluxes measured outdoors for unamended soils ranged from 19 to 140 ng/m2 day, whereas those for soil amended with ash to simulate an agricultural application ranged from 7.2 to 230 ng/m2 day. Fluxes for soil stabilized with ash ranged from 77 to 530 ng/m2 day and for soil with pads constructed of ash ranged from -50 to 90 ng/m2 day. Simple analytical tests (i.e., total Hg content, synthetic precipitation leaching procedure, heating, and indoor gas-exchange experiments) were performed to assess whether algorithms based on these tests could be used to predict Hg fluxes observed outdoors using the flux chamber. Based on this study, no consistent relationships could be developed. More work is needed to assess long-term and seasonal variations in Hg flux from (intact and disturbed) substrates before annual estimates of emissions can be developed. PMID:16878589

Ericksen, Jody; Gustin, Mae Sexauer

2006-07-01

245

Immobilization of mercury in field soil and sediment using carboxymethyl cellulose stabilized iron sulfide nanoparticles.  

PubMed

Mercury (Hg) is one of the most pervasive and bio-accumulative metals in the environment. Yet, effective in situ remediation technologies have been lacking. This study investigated the effectiveness of a class of soil-deliverable FeS nanoparticles for in situ immobilization of Hg in two field-contaminated soils from a New Jersey site and one sediment from an Alabama site. The nanoparticles were prepared using sodium carboxymethyl cellulose (CMC) as a stabilizer. Transmission electron microscopy measurements revealed a particle size of 34.3 ± 8.3 nm (standard deviation), whereas dynamic light scattering gave a hydrodynamic diameter of 222.5 ± 3.2 nm. Batch tests showed that at an FeS-to-Hg molar ratio of 28:1-118:1, the nanoparticles reduced water-leachable Hg by 79%-96% and the TCLP (toxicity characteristic leaching procedure) based leachability by 26%-96%. Column breakthrough tests indicated that the nanoparticles were deliverable in the sediment/soil columns under moderate injection pressure. However, once the external pressure was removed, the delivered nanoparticles remained virtually mobile under typical groundwater flow conditions. When the Hg-contaminated soil and sediment were treated with 52-95 pore volumes of a 500 mg l(-1) FeS nanoparticle suspension, water-leachable Hg was reduced by 90%-93% and TCLP-leachable Hg was reduced by 65%-91%. The results warrant further field demonstration of this promising in situ remediation technology. PMID:22743738

Gong, Yanyan; Liu, Yuanyuan; Xiong, Zhong; Kaback, Dawn; Zhao, Dongye

2012-07-27

246

Mercury concentrations in forest soils and stream waters in northeast and south China.  

PubMed

Atmospheric deposition of mercury (Hg) is generally higher in China than in North America and Europe. Transport and methylation of Hg deposited in forest ecosystems may cause health risks to humans. We collected water samples from 117 small streams, and soil samples from 25 sites in forested areas in northeast and south China during 2011-2013 to investigate the spatial distribution of Hg. Results showed that Hg concentration in surface soil (0-5 cm in depth) was generally higher in south China (97.8 ± 36.0 ?g/kg) than that in the northeast (44.0 ± 14.1 ?g/kg). In contrast, the Hg concentration in stream water was higher in northeast China (17.2 ± 11.0 ng/L) than that in the south (6.2 ± 6.4 ng/L). Hg concentrations in surface soil were positively correlated with Hg concentrations in the overlying litter Oe/Oa horizon (r(2)=0.84). Hg concentrations in stream water were positively correlated to DOC (dissolved organic carbon) concentrations (r(2)=0.43) and to the Hg concentration in the litter Oe/Oa horizon (r(2)=0.69). Because the litter Oe/Oa horizon represents Hg accumulated by foliage, the positive correlations indicate that atmospheric Hg deposition was an important factor affecting Hg concentrations in soils and stream water. PMID:25063712

Luo, Yao; Duan, Lei; Wang, Long; Xu, Guangyi; Wang, Shuxiao; Hao, Jiming

2014-10-15

247

Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): importance of atmospheric deposition and ecosystem factors.  

PubMed

Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercuryto interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination of lacustrine food webs. Geologic sources of mercury were small, based on analyses of underlying bedrock and C-horizon soils, and nearly all mercury in the 0- and A-horizon soils was derived from atmospheric deposition. Analyses of dated sediment cores from five lakes showed that most (63% +/- 13%) of the mercury accumulated in lake sediments during the 1900s was from anthropogenic sources. Contamination of food webs was assessed by analysis of whole, 1-year-old yellow perch (Perca flavescens), a regionally important prey fish. The concentrations of total mercury in yellow perch and of methylmercury in lake water varied substantially among lakes, reflecting the influence of ecosystem processes and variables that affect the microbial production and abundance of methylmercury. Models developed with the information-theoretic approach (Akaike Information Criteria) identified lake water pH, dissolved sulfate, and total organic carbon (an indicator of wetland influence) as factors influencing methylmercury concentrations in lake water and fish. We conclude that nearly all of the mercury in fish in this seemingly pristine PMID:17120551

Wiener, J G; Knights, B C; Sandheinrich, M B; Jeremiason, J D; Brigham, M E; Engstrom, D R; Woodruff, L G; Cannon, W F; Balogh, S J

2006-10-15

248

Determination of mercury in microwave-digested soil by laser-excited atomic fluorescence spectrometry with electrothermal atomization.  

PubMed

A sample digestion procedure was developed which employs microwave heating of soil and sediment in concentrated nitric acid in a high-pressure closed vessel. Complete dissolution of mercury into the sample solution occurs within 5 min at 59 W/vessel without loss of analyte through overpressurization. Laser-excited atomic fluorescence spectrometry with electrothermal atomization (LEAFS-ETA) was used as the detection method. The scheme uses a two-step excitation, with lambda(1) = 253.7 nm and lambda(2) = 435.8 nm. Direct line fluorescence was measured at 546.2 nm. The absolute instrumental limit of detection was 14 fg; 1.4 pg/ml with a 10 mul sample injection. The recoveries of mercury in two spiked samples were 94 and 98%. The SRM 8406 (Mercury in River Sediment) was digested and analyzed for mercury, and the results (58.4 +/- 1.8 ng/g) agreed well with the reference value of 60 ng/g. The results obtained by LEAFS-ETA with microwave sample digestion are in good agreement with those found by cold vapor atomic absorption spectrometry with EPA Series Method 245.5 sample digestion, which is one of the most commonly used methods for the determination of mercury in soil. PMID:18966173

Pagano, S T; Smith, B W; Winefordner, J D

1994-12-01

249

Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): Importance of atmospheric deposition and ecosystem factors  

USGS Publications Warehouse

Concentrations of methylmercury in game fish from many interior lakes in Voyageurs National Park (MN, U.S.A.) substantially exceed criteria for the protection of human health. We assessed the importance of atmospheric and geologic sources of mercury to interior lakes and watersheds within the Park and identified ecosystem factors associated with variation in methylmercury contamination of lacustrine food webs. Geologic sources of mercury were small, based on analyses of underlying bedrock and C-horizon soils, and nearly all mercury in the O- and A-horizon soils was derived from atmospheric deposition. Analyses of dated sediment cores from five lakes showed that most (63% ?? 13%) of the mercury accumulated in lake sediments during the 1900s was from anthropogenic sources. Contamination of food webs was assessed by analysis of whole, 1-year-old yellow perch (Perca flavescens), a regionally important prey fish. The concentrations of total mercury in yellow perch and of methylmercury in lake water varied substantially among lakes, reflecting the influence of ecosystem processes and variables that affect the microbial production and abundance of methylmercury. Models developed with the information-theoretic approach (Akaike Information Criteria) identified lake water pH, dissolved sulfate, and total organic carbon (an indicator of wetland influence) as factors influencing methylmercury concentrations in lake water and fish. We conclude that nearly all of the mercury in fish in this seemingly pristine landscape was derived from atmospheric deposition, that most of this bioaccumulated mercury was from anthropogenic sources, and that both watershed and lacustrine factors exert important controls on the bioaccumulation of methylmercury. ?? 2006 American Chemical Society.

Wiener, J.G.; Knights, B.C.; Sandheinrich, M.B.; Jeremiason, J.D.; Brigham, M.E.; Engstrom, D.R.; Woodruff, L.G.; Cannon, W.F.; Balogh, S.J.

2006-01-01

250

Hair mercury levels in pregnant women in Mahshahr, Iran: fish consumption as a determinant of exposure.  

PubMed

MeHg is a well-documented neurotoxicant even at low levels of exposure. Developing brain, in particular, is vulnerable to that. Through bioaccumulating to differing degrees in various fish species, it can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Therefore, the purpose of this study was to investigate mercury concentration in hair samples of pregnant women living in Mahshahr located in Khuzestan province, Iran. It assessed the association between fish consumption and specific characteristics that can influence exposure. From April to June 2008, 149 pregnant women were invited to participate in this study. An interview administered questionnaire was used to collect information about age, body weight, height, fish (fresh, canned and shrimp) consumption, pregnancy stage, residence duration, education level, family income and number of dental amalgam fillings. The obtained results showed that the geometric mean and range for hair total Hg concentration was 3.52 microg/g (0.44-53.56 microg/g). About 5.4% of mothers had hair total Hg levels in excess of 10 microg/g. Maternal hair mercury level was less than threshold level of WHO (5 microg/g). As expected, there was a clear increase in hair Hg with reported fresh marine fish consumption (p=0.04). The highest mean for hair mercury level in a group who consumed fish several times per week, was 4.93 microg/g. Moreover, a significant effect of age and residential time on Hg concentration in the hair of the women was found. Pregnant women in Mahshahr consumed large amounts of fish; consequently, most of their offspring were prenatally exposed to moderately high levels of mercury. The results found suggest that pregnant women should decrease their fish consumption. PMID:20655095

Salehi, Zohreh; Esmaili-Sari, Abbas

2010-09-15

251

Risks associated with the transfer of toxic organo-metallic mercury from soils into the terrestrial feed chain.  

PubMed

Although the transfer of organo-metallic mercury (OrgHg) in aquatic food webs has long been studied, it has only been recently recognized that there is also accumulation in terrestrial systems. There is still however little information about the exposure of grazing animals to OrgHg from soils and feed as well as on risks of exposure to animal and humans. In this study we collected 78 soil samples and 40 plant samples (Lolium perenne and Brassica juncea) from agricultural fields near a contaminated industrial area and evaluated the soil-to-plant transfer of Hg as well as subsequent trophic transfer. Inorganic Hg (IHg) concentrations ranged from 0.080 to 210mgkg(-1) d.w. in soils, from 0.010 to 84mgkg(-1) d.w. in roots and from 0.020 to 6.9mgkg(-1) d.w. in shoots. OrgHg concentrations in soils varied between 0.20 and 130?gkg(-1) d.w. representing on average 0.13% of the total Hg (THg). In root and shoot samples OrgHg comprised on average 0.58% (roots) and 0.66% (shoots) of THg. Average bioaccumulation factors (BAFs) for OrgHg in relation to soil concentrations were 3.3 (for roots) and 1.5 (for shoots). The daily intake (DI) of THg in 33 sampling sites exceeded the acceptable daily intake (ADI) of THg of both cows (ADI=1.4mgd(-1)) and sheep (ADI=0.28mgd(-1)), in view of food safety associated with THg in animal kidneys. Estimated DI of OrgHg for grazing animals were up to 220?gd(-1) (for cows) and up to 33?gd(-1) (for sheep). This study suggested that solely monitoring the levels of THg in soils and feed may not allow to adequately taking into account accumulation of OrgHg in feed crops and properly address risks associated with OrgHg exposure for animals and humans. Hence, the inclusion of limits for OrgHg in feed quality and food safety legislation is advised. PMID:23917441

Henriques, Bruno; Rodrigues, S M; Coelho, C; Cruz, N; Duarte, A C; Römkens, P F A M; Pereira, E

2013-09-01

252

Mercury Contamination of Aquatic Ecosystems  

NSDL National Science Digital Library

This United States Geological Survey (USGS) factsheet contains information about US mercury contamination. Issues discussed include how mercury becomes a toxicological problem through bioaccumulation, human effects of mercury toxicity, and levels of atmospheric mercury. Mercury levels in fish are examined to determine how mercury gets into the environment and into the food chain.

D.P. Krabbenhoft

253

Wild Boar Tissue Levels of Cadmium, Lead and Mercury in Seven Regions of Continental Croatia  

PubMed Central

Concentrations of cadmium, mercury and lead were analysed by atomic absorption spectrometry in the kidney and muscle of free-living wild boar (n = 169) from hunting grounds in seven counties of continental Croatia. Mean levels of metals (mg/kg) in muscle and kidney of boars ranged as follows: Cd: 0.005–0.016 and 0.866–4.58, Pb: 0.033–0.15 and 0.036–0.441, Hg: 0.004–0.012 and 0.04–0.152. In all seven regions, concentrations exceeded the permitted values (muscle and kidney mg/kg: cadmium 0.05/1; lead 0.1/0.5; mercury 0.03/0.1) in 13.6% and 71.6% of samples (muscle and kidney, respectively) for cadmium; 13.6% and 8.9% for lead; 19.5% and 2.4% for mercury. There were significant differences among the regions. Vukovar-Srijem and Virovitica-Podravina Counties were highly contaminated with cadmium, Sisak-Moslavina and Virovitica-Podravina Counties with lead and Brod-Posavina County had highest mercury concentrations. These results suggest a detailed investigation of physiological and environmental factors contributing to accumulation of metals in boars. PMID:20405101

Sedak, Marija; ?oki?, Maja; Šimi?, Branimir

2010-01-01

254

Surveying Mercury Levels in Hair, Blood and Urine of under 7-Year Old Children from a Coastal City in China  

PubMed Central

Aim: The average mercury load in children under 7-years old was determined in a populated but not overly industrial coastal area in China. Methods: 395 blood samples, 1072 urine samples, and 581 hair samples were collected from 1076 children, aged 0 to 6 years, from eight representative communities of Xiamen, China. Mercury levels in the samples were surveyed. Results: The 95% upper limits of mercury in blood, urine, and hair for the children were 2.30, 1.50 and 2100.00 ?g/kg, respectively. Levels tended to increase with age. Correlation analyses showed that mercury levels in blood and urine correlated with those in hair (n = 132), r = 0.49, p < 0.0001 and r = 0.20, p = 0.0008; however, blood mercury levels did not correlate with urine levels (n = 284), r = 0.07, p = 0.35. Conclusions: Surveying the average mercury load in children 0 to 6 years, and the 95% upper limit value of mercury in their blood, urine, and hair should help guide risk assessment and health management for children. PMID:25419876

Chen, Guixia; Chen, Xiaoxin; Yan, Chonghuai; Wu, Xingdong; Zeng, Guozhang

2014-01-01

255

Multifractal analysis of soil porosity based on mercury porosimetry and nitrogen adsorption  

NASA Astrophysics Data System (ADS)

The soil pore space is composed of a continuum of pores extremely variable in size which include structures smaller than nanometres and as large as macropores > 20 mm in diameter, i.e. with an upper size limit of the order of centimetres. Thus, a ratio of at least 106 is displayed in soil pore sizes. Soil pore size distribution directly influences many soil physical, chemical and biological properties. Characterization of soil structure may be achieved by pore size distribution analysis. There is not a unique method for determining soil pore size distributions all over the size scale. Mercury injection porosimetry and N2 adsorption isotherms are techniques commonly used for assessing equivalent pore size diameters in selected ranges. The Hg injection technique provides pore size distributions in the range from about 50 nm to 100 m, whereas N2 adsorption isotherms may be used for finer pores ranging in size from about 2 to 500 nm. In this work, multifractal formalism has been used to describe Hg injection porosimetry and N2 adsorption isotherms measured in a Mollisol and in a Vertisol with four different soil use intensities, ranging from native, never cultivated, land to continuous cropping. Three samples per treatment were analyzed resulting in a total of twelve samples per soil. All the Hg injection curves and N2 adsorption isotherms exhibited multifractal behaviour as shown by singularity spectra and Rényi dimension spectra. The capacity dimension, D0, for both Hg injection and N2 adsorption data sets was not significantly different from 1.00. However, significantly different values of entropy dimension, D1, and correlation dimension, D2, were obtained for mercury injection and nitrogen adsorption experimental data. For instance, entropy dimension, D1, values extracted from multifractal spectra of Hg intrusion porosimetry were on average 0.913 and varied from 0.889 to 0.939. However, the corresponding figures for N2 adsorption isotherms were on average 0.507 with a range from 0.401 to 0.666. The entropy dimension D1 is a measure of diversity and in our study case gauges the concentration degree of the pore size distribution on a specific pore size range. Values of D1 for Hg injection curves were close to 1.00 and consequently they indicate more or less homogeneous pore size distribution pattern distributed over the range of pore sizes measured with this method. In opposite D1 values for N2 adsorption isotherms were much lower, which reflects clustering and indicates that most of the measure concentrates in a small size domain for finer pore scales. The use of multifractal indixes as indicators for characterizing soil structure and as well as for deriving soil physical properties is discussed. Acknowledgements. This work was financed by by MEC (Spain) under project CGL2005-08219-C02-01.

Paz-Ferreiro, J.; Vidal Vázquez, E.; Miranda, J. G. V.

2009-04-01

256

Mercury levels in sediments and mangrove oysters, Crassostrea rizophorae, from the north coast of Villa Clara, Cuba.  

PubMed

Total mercury levels were quantified in sediments and oyster tissues (Crassostrea rizophorae) from the Sagua la Grande River estuary and offshore mangrove keys 19 km downstream of a chlor-alkali plant (CAP) in Villa Clara, Cuba. Relatively elevated total mercury levels were found in sediments from the estuary itself, ranging from 0.507 to 1.81 ?g g(-1) dry weight. However, levels were lower in sediments from the keys farther from the estuary. Oyster mercury levels were always acceptable for human consumption, although levels significantly correlated in sediments and oysters across sampling sites (p < 0.05), which suggests that mercury from the CAP is impacting coastal water quality conditions. PMID:22323046

Olivares-Rieumont, S; Lima, L; Rivero, S; Graham, D W; Alonso-Hernandez, C; Bolaño, Y

2012-04-01

257

Growth response and tissue accumulation trends of herbaceous wetland plant species exposed to elevated aqueous mercury levels.  

PubMed

The impacts of elevated aqueous mercury levels (0, 2, and 4 ppm) on the growth status and mercury tissue concentrations of Eleocharis parvula, Saururus cernuus, Juncus effuses, Typha latifolia, and Panicum hemitomon were determined. Both short-term (net CO2 assimilation) and long-term (biomass) indicators of plant growth status suggest that Eleocharis parvula, Saururus cernuus, and Juncus effuses were relatively unimpacted by elevated mercury levels, whereas Typha latifolia and Panicum hemitomon were somewhat impacted at elevated mercury levels. Eleocharis parvula, Panicum hemitomon, and Typha latifolia generally had the greatest overall belowground tissue concentrations of mercury (2 ppm treatment: 7.21, 7.32, and 9.64 ppm respectively; 4 ppm treatment: 16.23, 18.23, and 13.98 ppm, respectively) and aboveground tissue concentrations of mercury (2 ppm treatment: 0.01, 0.04, 0.02; 4 ppm treatment: 0.26; 0.11; 0.17 ppm, respectively). However, the species investigated in this study demonstrated lower levels of mercury accumulation into tissues when compared with similar investigations of other aquatic plants, suggesting that the above species are not optimal for phytoremediation efforts. PMID:21166283

Willis, Jonathan M; Gambrell, Robert P; Hester, Mark W

2010-08-01

258

National Resources Conservation Service: Soils: College Level Teaching Resources  

NSDL National Science Digital Library

Students and educators looking for resources on the world of soil science will want to bookmark this useful site. Created by the United States Department of Agriculture's (USDA) Natural Resources Conservation Service, the site includes college-level appropriate material on soil biology, soil risks, soil quotations, and urban soil issues. The "Soil Risks & Hazards" area contains two key documents that can be best used by students seeking to understand potential soil-related hazards in and around different parts of the US. Moving along, "The Twelve Soil Orders" leads to a page created by the University of Idaho about the soil taxonomy created by the USDA in 1975. The "Soil Quotations" area has some rather compelling quotes from biologists, soil scientists, and poets about the nature and importance of soil. The site is rounded out by the "Agriculture in the Classroom" link, which leads to state agricultural profiles created by the USDA.

259

Atmospheric Deposition and Fate of Mercury in High-altitude Watersheds of the Rocky Mountains.  

NASA Astrophysics Data System (ADS)

Despite the potential for cold high-altitude ecosystems to act as sinks in the global mercury cycle, atmospheric deposition and fate of mercury have not been measured extensively at mountain sites in the Western United States. At Buffalo Pass in northwestern Colorado (the highest site in the national Mercury Deposition Network at 3234 m elevation), mercury in wet deposition was 9 ? gm-2 in 2000, comparable to many sites in the upper Midwestern United States where fish consumption advisories are widespread because of elevated levels of mercury from atmospheric deposition. Similar levels of mercury deposition were measured about 90 km east of Buffalo Pass at Loch Vale in Rocky Mountain National Park (RMNP) during 2002. Concentrations of total mercury in headwater streams in RMNP averaged 2-4 ngL-1 during spring and summer of 2001-2002. Higher concentrations were observed during snowmelt and rainfall events. Dissolved mercury was generally greater than particulate mercury in these clear mountain streams. Mercury and dissolved organic carbon peaked as soils were flushed during early snowmelt and rainy summer periods. Overall, mercury deposition was greater than mercury export, indicating accumulation in alpine/subalpine ecosystems; however, the mercury exported in streamflow may contribute substantially to mercury loading in downstream lakes and reservoirs where fish consumption advisories have increased. Methyl mercury concentrations measured in the streams in 2002 were generally near or less than detection limits, however, extreme drought conditions limited hydrologic flushing of soils and wetlands that may be sources of methyl mercury. In 2003, surface and ground water from various alpine and subalpine landscapes were sampled to determine sources and transport of total and methyl mercury. The elevated levels of mercury in atmospheric deposition indicate a need for better understanding of mercury cycling and transport in high-altitude ecosystems of Western North America.

Campbell, D. H.; Mast, M. A.; Ingersoll, G. P.; Manthorne, D. J.; Krabbenhoft, D. P.; Taylor, H. E.; Aiken, G. R.; Schuster, P. F.; Reddy, M. M.

2003-12-01

260

FIELD MEASUREMENT TECHNOLOGY FOR MERCURY IN SOIL AND SEDIMENT OHIO LUMEX'S RA-915+/RP-91C MERCURY ANALYZER  

EPA Science Inventory

Ohio Lumex's RA915+/91 C mercury analyzer was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in May 2003, at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the Demonstration was to c...

261

FIELD MEASUREMENT TECHNOLOGY FOR MERCURY IN SOIL AND SEDIMENT MILESTONE INC.'S DIRECT MERCURY ANALYZER (DMA)-80  

EPA Science Inventory

Milestone's Direct Mercury Analyzer (DMA-80) was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in May 2003 at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the Demonstration was to...

262

The influence of sample drying procedures on mercury concentrations analyzed in soils.  

PubMed

Methods commonly used for soil sample preparation may be unsuitable for measuring Hg concentrations due to the possible loss of volatile Hg species when drying at higher temperatures. Here, the effects of freeze-drying, air drying at 25°C and oven-drying at 105°C on Hg concentrations in two soil types and three standard reference materials were tested. Two soils with different levels of Hg contamination and three reference materials were examined. A systematic decrease of Hg concentrations was observed in air-dried (24 %) and oven-dried (3 %) contaminated upland soils in comparison to freeze-dried control samples. The 105°C oven drying also led to loss of Hg from reference materials (5 %-8 % in comparison with the certified Hg concentration). Different results from the drying of sterilized reference materials and natural soils were probably related to the extent of microbiological activity, demonstrating the importance of this parameter in sample preparation for Hg analysis. PMID:25786366

Hojdová, Maria; Rohovec, Jan; Chrastný, Vladislav; Penížek, Vít; Navrátil, Tomáš

2015-05-01

263

Mercury levels in fish from the upper peninsula of Michigan (ElS Subregion 2B) in relation to lake acidity  

Microsoft Academic Search

The accumulation of mercury by fish and the potential human health effects of eating mercury-contaminated fish have been well documented. However, elevated mercury concentrations in fish from dilute, low-pH lakes have only recently been associated with increased lake acidity. Nevertheless, there now is ample evidence to document that elevated levels of mercury are found in fish from lakes in remote

D. Landers; S. P. Gloss; T. M. Grieb; C. T. Driscoll; C. L. Schofield

1990-01-01

264

Fate and transport of mercury in soil systems : a numerical model in HP1 and sensitivity analysis  

NASA Astrophysics Data System (ADS)

Mercury (Hg) poses threats for human health and the environment, notably due to its persistence and its ability to bioaccumulate in ecosystems. Anthropogenic activities are major contributors of mercury release to soils. Main sources of contamination include manufacturing (chlor-alkali plants, manometer spill), mine tailings from mercury, gold and silver mining industries, wood preservation. The objective of this study was to develop a reactive transport model for simulating mercury fate and transport in the unsaturated zone, and to gain insight in the fate and transport of Hg following anthropogenic soil contamination. The present work is done in the framework of the IMaHg project, which aims at providing recommendations to improve management of sites contaminated by mercury within the SNOWMAN funding framework. A model of mercury fate and transport in soil systems was developed using the reactive transport code HP1 (Jacques and Šim?nek, 2010). The geochemical database THERMODDEM (Blanc et al., 2012) is used, augmented with some speciation data from (Skyllberg, 2012). The main processes accounted for in the model are : Hg aqueous speciation (including complexation with dissolved organic matter (DOM) - humic and fulvic acids, and thiol groups), Hg sorption to solid organic matter (SOM), dissolution of solid phase Hg (e.g. cinnabar HgS(s)), dissolution of Hg non-aqueous liquid phase (NAPL), sunlight-driven Hg(II) reduction to Hg(0), Hg(0) diffusion in the gas phase and volatilization, DOM sorption to soil minerals. Colloid facilitated transport is implicitly accounted for by solute transport of Hg-DOM complexes. Because we focused on soil systems having a high Hg contamination, some processes showing relatively smaller Hg fluxes could be neglected such as vegetation uptake and atmospheric wet and dry deposition. NAPL migration and entrapment is not modelled, as pollution is assumed to be historical and only residual NAPL to be present. Mercury methylation and demethylation was not implemented, because it could be neglected in an oxidising environment. However, if the model is to be tested in more reducing conditions (e.g. shallow groundwater table), methyl- and dimethylmercury formation can be non negligible. Using 50 year time series of daily weather observations in Dessel (Belgium) and a typical sandy soil with deep groundwater (free drainage, oxic conditions), a sensitivity analysis was performed to assess the relative importance of processes and parameters within the model. We used the elementary effects method (Morris, 1991; Campolongo et al., 2007), which draws trajectories across the parameter space to derive information on the global sensitivity of the selected input parameters. The impact of different initial contamination phases (solid, NAPL, aqueous and combinations of these) was also tested. Simulation results are presented in terms of (i) Hg volatilized to the atmosphere; (ii) Hg leached out of the soil profile; (iii) Hg still present in the soil horizon originally polluted; and (iv) Hg still present in the soil profile but below the original contaminated horizon. Processes and parameters identified as critical based on the sensitivity analysis differ from one scenario to the other ; depending on pollution type (cinnabar, NAPL, aqueous Hg), on the indicator assessed and on time (after 5, 25 or 50 years). However, in general DOM in soil water was the most critical parameter. Other important parameters were those related to Hg sorption on SOM (thiols, and humic and fulvic acids), and to Hg complexation with DOM. Initial Hg concentration was also often identified as a sensitive parameter. Interactions between factors and non linear effects as measured by the elementary effect method were generally important, but also dependent on the type of contamination and on time. No model calibration was performed until now. The numerical tool could greatly benefit from partial model calibration and/or validation. Ideally, detailed speciation data on a contaminated sites would be required, together with a good characteriz

Leterme, Bertrand; Jacques, Diederik

2013-04-01

265

Soil organic carbon buffers heavy metal contamination on semiarid soils: Effects of different metal threshold levels on soil microbial activity  

Microsoft Academic Search

Traditionally, three threshold levels have been accepted for heavy metal concentrations in agricultural soils, depending on soil pH. The aim of this work was to ascertain how the three threshold values proposed for Cd (3, 6.5, and 12.5 mg kg?1) and Zn (300, 650, and 1300 mg kg?1) really affect soil microbial activity. Two soils, a scrubland soil and a forest soil, differing widely

J. L. Moreno; F. Bastida; M. Ros; T. Hernández; C. García

2009-01-01

266

Application of a renewable silver based mercury film electrode to the determination of Cr(VI) in soil samples  

Microsoft Academic Search

The design and experimental results of the application of a renewable mercury film silver based electrode to the determination\\u000a of Cr(VI) in soil samples are presented. The main feature of this procedure is that it can be used in field measurements.\\u000a The procedure is based on the extraction of total Cr(VI) exploiting the complexation property of diethylenetriaminepentaacetic\\u000a acid (DTPA) followed

Malgorzata Grabarczyk; Bogus?aw Ba?; Mieczys?aw Korolczuk

2009-01-01

267

Water-air and soil-air exchange rate of total gaseous mercury measured at background sites  

Microsoft Academic Search

In order to evaluate and understand the processes of water-air and soil-air exchanges involved at background sites, an intensive field measurement campaign has been achieved during the summer of 1995 using high-time resolution techniques (10 min) at two sites (land and water) in southern Québec (Canada). Mercury flux was measured using a dynamic flux chamber technique coupled with an automatic

Laurier Poissant; Alain Casimir

1998-01-01

268

Mercury Air\\/Surface Exchange Kinetics of Background Soils of the Tahquamenon River Watershed in the Michigan Upper Peninsula  

Microsoft Academic Search

Air\\/surface exchange of mercury was investigated over background soils at five sites in the Tahquamenon River watershed in the Michigan Upper Peninsula in the summer of 1998. Measurements of Hg fluxes were performed during middayperiods using the ORNL Teflon dynamic flux chamber. Mean Hg emission fluxes were 1.4±0.3–2.4±1.0 ng m-2 hr-1 for three shaded forest sites and 7.6±1.7 ng m-2

H. Zhang; S. E. Lindberg; F. J. Marsik; G. J. Keeler

2001-01-01

269

Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway  

SciTech Connect

Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anesthetized individuals at Svalbard, Norway, were analyzed for cadmium and total mercury. The mean level of cadmium was 0.860 {+-} 0.321 {micro}g/g dry weight and the mean level of mercury was 0.235 {+-} 0.100 {micro}g/g dry weight. Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels of Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anesthetized individuals or at the haul-out sites during molt, to monitor heavy metal levels of the population.

Wiig, O. [Univ. of Oslo (Norway). Zoological Museum] [Univ. of Oslo (Norway). Zoological Museum; Renzoni, A. [Univ. degli Studi di Siena (Italy). Dept. di Biologia Ambientale] [Univ. degli Studi di Siena (Italy). Dept. di Biologia Ambientale; Gjertz, I. [Norwegian Polar Inst., Tromsoe (Norway)] [Norwegian Polar Inst., Tromsoe (Norway)

1999-08-01

270

Behavior of mercury in a soil-plant system as affected by inoculation with the arbuscular mycorrhizal fungus Glomus mosseae.  

PubMed

Effects of inoculation with the arbuscular mycorrhizal (AM) fungus Glomus mosseae on the behavior of Hg in soil-plant system were investigated using an artificially contaminated soil at the concentrations of 0, 1.0, 2.0, and 4.0 mg Hg kg(-1). Mercury accumulation was lower in mycorrhizal roots than in nonmycorrhizal roots when Hg was added at the rates of 2.0 and 4.0 mg kg(-1), while no obvious difference in shoot Hg concentration was found between mycorrhizal and nonmycorrhizal treatments. Mycorrhizal inoculation significantly decreased the total and extractable Hg concentrations in soil as well as the ratio of extractable to total Hg in soil. Equilibration sorption of Hg by soil was investigated, and the results indicated that mycorrhizal treatment enhanced Hg sorption on soil. The uptake of Hg was lower by mycorrhizal roots than by nonmycorrhizal roots. These experiments provide further evidence for the role of mycorrhizal inoculation in increasing immobilization of Hg in soil and reducing the uptake of Hg by roots. Calculation on mass balance of Hg in soil suggests the presence of Hg loss from soil presumably through evaporation, and AM inoculation enhanced Hg evaporation. This was evidenced by a chamber study to detect the Hg evaporated from soil. PMID:20077122

Yu, Yang; Zhang, Shuzhen; Huang, Honglin

2010-08-01

271

Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs  

NASA Astrophysics Data System (ADS)

Before adopting modern corn-and-grain-based western processed diets, circumpolar people had a high fat and protein subsistence diet and exhibited a low incidence of obesity, diabetes and cardiovascular disease. Some health benefits are attributable to a subsistence diet that is rich in omega-3 fatty acids and antioxidants. Pollution, both global and local, is a threat to wild foods, as it introduces contaminants into the food system. Northern indigenous people and their sled dogs are exposed to a variety of contaminants, including mercury, that accumulate in the fish and game that they consume. The sled dogs in Alaskan villages are maintained on the same subsistence foods as their human counterparts, primarily salmon, and therefore they can be used as a food systems model for researching the impact of changes in dietary components. In this study, the antioxidant status and mercury levels were measured for village sled dogs along the Yukon River. A reference kennel, maintained on a nutritionally balanced commercial diet, was also measured for comparison. Total antioxidant status was inversely correlated with the external stressor mercury.

Dunlap, Kriya L.; Reynolds, Arleigh J.; Gerlach, S. Craig; Duffy, Lawrence K.

2011-10-01

272

Mercury levels in mink (Mustela vison) and river otter (Lontra canadensis) from northeastern North America.  

PubMed

Aquatic ecosystems have received mercury released from anthropogenic sources. The northeast region of North America is at especially high risk because of local and regional emission sources, prevailing wind patterns, and certain hydrological and biogeochemical features. Here we examine regional variation in total mercury (Hg) in brain, liver, and fur from otter and mink collected across New York, New England, and Nova Scotia. Gender and age are examined as factors potentially affecting Hg tissue levels. In addition, temporal relationships are analyzed for New York as well as correlative relationships for tissues from Maine. Animals were collected from 1982 to 2003, mostly from licensed trappers. Liver was the only tissue from otter that exhibited significant regional variation (New York versus Maine) in Hg concentration. Mercury concentration was significantly related to age but not to gender for otter. All tissues in mink exhibited significant, but inconsistent, regional variation in total Hg concentration, with the highest mean Hg concentration in liver samples from Massachusetts/Connecticut. Female mink had significantly greater Hg concentrations in liver than males. Total Hg concentration in the liver of both otter and mink from New York decreased significantly with time. Correlations among tissues for Hg concentration were stronger for male and female mink and male otter than female otter from Maine. PMID:15931971

Yates, David E; Mayack, David T; Munney, Kenneth; Evers, David C; Major, Andrew; Kaur, Taranjit; Taylor, Robert J

2005-03-01

273

Growth Response and Tissue Accumulation Trends of Herbaceous Wetland Plant Species Exposed to Elevated Aqueous Mercury Levels  

Microsoft Academic Search

The impacts of elevated aqueous mercury levels (0, 2, and 4 ppm) on the growth status and mercury tissue concentrations of Eleocharis parvula, Saururus cernuus, Juncus effuses, Typha latifolia, and Panicum hemitomon were determined. Both short-term (net CO2 assimilation) and long-term (biomass) indicators of plant growth status suggest that Eleocharis parvula, Saururus cernuus, and Juncus effuses were relatively unimpacted by

Jonathan M. Willis; Robert P. Gambrell; Mark W. Hester

2010-01-01

274

The Effect of Fire on Mercury Cycling in the Soils of Forested Watersheds: Acadia National Park, Maine, U.S.A  

Microsoft Academic Search

This study compares mercury (Hg) and methylmercury (MeHg) distribution in the soils of two forested stream watersheds at Acadia National Park, Maine, U.S.A. Cadillac Brook watershed, which burned in 1947, has thin soils and predominantly deciduous vegetation. It was compared to the unburned Hadlock Brook watershed, with thicker soil and predominantly coniferous vegetation. Soils in both watersheds were primarily well

Aria Amirbahman; Philip L. Ruck; Ivan J. Fernandez; Terry A. Haines; Jeffery S. Kahl

2004-01-01

275

The effects of endosulfan and fertilizer source on soil fertility 2. Available soil nutrient levels and soil organic matter  

Microsoft Academic Search

A lab incubation study was conducted on three Quebec soils over 29 months. Soils amended with either inorganic or organic fertilizer (composted manure) were sprayed 0, 2, 4, 8 or 16 times per year with endosulfan as Thiodan (2.2 kg\\/ha). Application of the endosulfan affected extractable soil levels of Ca and P in two of the above soils, but the

P. R. Warman; G. Fairchild

1984-01-01

276

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season.  

PubMed

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3-0.5 ppm, 3 species), medium (0.14-0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

Burger, Joanna; Gochfeld, Michael

2011-03-15

277

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season  

PubMed Central

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

Burger, Joanna; Gochfeld, Michael

2014-01-01

278

Applications of Organic and Inorganic Amendments Induce Changes in the Mobility of Mercury and Macro- and Micronutrients of Soils  

PubMed Central

Both soil organic matter and sulfur (S) can reduce or even suppress mercury (Hg) mobility and bioavailability in soil. A batch incubation experiment was conducted with a Chernozem and a Luvisol artificially contaminated by 440?mg·kg?1?Hg showing wide differences in their physicochemical properties and available nutrients. The individual treatments were (i) digestate from the anaerobic fermentation of biowaste; (ii) fly ash from wood chip combustion; and (iii) ammonium sulfate, and every treatment was added with the same amount of S. The mobile Hg portion in Chernozem was highly reduced by adding digestate, even after 1 day of incubation, compared to control. Meanwhile, the outcome of these treatments was a decrease of mobile Hg forms as a function of incubation time whereas the contents of magnesium (Mg), potassium (K), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), and phosphorus (P) were stimulated by the addition of digestate in both soils. The available calcium (Ca) contents were not affected by the digestate addition. The experiment proved digestate application as the efficient measure for fast reduction of mobile Hg at extremely contaminated soils. Moreover, the decrease of the mobile mercury portion was followed by improvement of the nutrient status of the soils. PMID:25401138

García-Sánchez, Mercedes; Šípková, Adéla; Száková, Ji?ina; Kaplan, Lukáš; Ochecová, Pavla; Tlustoš, Pavel

2014-01-01

279

Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades  

USGS Publications Warehouse

As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While ??15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. ?? 2002 Elsevier Science B.V. All rights reserved.

Rumbold, D.G.; Fink, L.E.; Laine, K.A.; Niemczyk, S.L.; Chandrasekhar, T.; Wankel, S.D.; Kendall, C.

2002-01-01

280

Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades.  

PubMed

As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While delta15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. PMID:12389795

Rumbold, D G; Fink, L E; Laine, K A; Niemczyk, S L; Chandrasekhar, T; Wankel, S D; Kendall, C

2002-10-01

281

Mercury in seabird feathers: insight on dietary habits and evidence for exposure levels in the western Indian Ocean.  

PubMed

Breast feathers were used to estimate mercury levels in six marine birds nesting in the tropical western Indian Ocean, i.e. Sooty Tern (Sterna fuscata), Brown Noddy (Anous stolidus), Lesser Noddy (Anous tenuirostris), Audubon Shearwater (Puffinus lherminieri bailloni), Barau's Petrel (Pterodroma baraui) and the White-tailed Tropicbird (Phaethon lepturus). Juveniles consistently showed lower plumage mercury than adults. The lowest mean level was noted in juvenile Sooty Terns from the Glorioso Archipelago (0.05 microg g(-1)). The highest levels were obtained for adult Barau's Petrels from Reunion Island (0.96 microg g(-1)). An inter-site analysis of Sooty Tern showed higher mercury levels in birds nesting on Juan de Nova Island. Levels were low in comparison with values reported in the plumage of seabirds worldwide. The potential impacts of the size, the type (fish/cephalopod) and the origin (epi-/meso-pelagic) of prey on mercury intake in birds are discussed. Although the diet composition of individuals within a species appeared to be quite variable, combining results on mercury levels with common knowledge of each species allowed additional information on their dietary and foraging habits to be unraveled. PMID:17659323

Kojadinovic, Jessica; Bustamante, Paco; Churlaud, Carine; Cosson, Richard P; Le Corre, Matthieu

2007-10-01

282

Catchment Area Composition and Water Chemistry Heavily Affects Mercury Levels in Perch ( Perca Fluviatilis L.) in Circumneutral Lakes  

Microsoft Academic Search

The environmental impact on the mercury level in perch (Perca fluviatilis L.) is examined using Partial Least Squareregression (PLS) on 48 environmental descriptors assessingland use, various catchment area and lake characteristics,lake water chemistry, and fish stock. The lake specificintercepts of Hg content vs. fish length regressions are usedto describe the Hg level in the fish. The Hg levels in perchfrom

Lars Sonesten

2003-01-01

283

Long-term changes in fish mercury levels in the historically impacted English-Wabigoon River system (Canada).  

PubMed

The English-Wabigoon River system in Northwestern Ontario, Canada, was one of the most heavily mercury-contaminated waterways in the world due to historical discharges in the 1960s from a chlor-alkali plant. This study examines long-term (1970-2010) monitoring data to assess temporal trends in mercury contamination in Walleye, Northern Pike and Lake Whitefish, three species important for sport and subsistence fishing in this region, using dynamic linear modeling and piecewise regression. For all lakes and species, there is a significant decline (36-94%) in mercury concentrations through time; however, there is evidence that this decline is either slowing down or levelling off. Concentrations in the English-Wabigoon fish are elevated, and may still present a potential health risk to humans consuming fish from this system. Various biotic and abiotic factors are examined as possible explanations to slowing rates of decline in mercury concentrations observed in the mid-1980s. PMID:22785387

Neff, Margaret R; Bhavsar, Satyendra P; Arhonditsis, George B; Fletcher, Rachael; Jackson, Donald A

2012-09-01

284

Targeting geothermal exploration sites in the Mount St. Helens area using soil mercury surveys  

SciTech Connect

The background mercury level was determined for the areas studied, providing preliminary information for future work. Identification of areas which might merit more intensive sampling was also accomplished. The clusters of samples with high Hg concentrations in both areas may indicate high heat flow and should be investigated further. Problems involving the use of this method in the Cascades were also identified. Both areas north and south of the mountain had approximately the same standard deviation (expressed as a percentage of the mean), even though the sampling horizons seemed much more consistent and less disturbed in the Marble Mountain area than in the Green River Soda Springs area. This may indicate that for these areas, secondary controls are more important, or that Hg anomalies are much smaller than indicated in studies of other areas.

Holmes, J.; Waugh, K.

1983-11-01

285

Atmospheric mercury emissions from mine wastes and surrounding geologically enriched terrains  

USGS Publications Warehouse

Waste rock and ore associated with Hg, precious and base metal mining, and their surrounding host rocks are typically enriched in mercury relative to natural background concentrations (<0.1 ??g Hg g-1). Mercury fluxes to the atmosphere from mineralized areas can range from background rates (0-15 ng m-2 h-1) to tens of thousands of ng m-2 h-1. Mercury enriched substrate constitutes a long-term source of mercury to the global atmospheric mercury pool. Mercury emissions from substrate are influenced by light, temperature, precipitation, and substrate mercury concentration, and occur during the day and night. Light-enhanced emissions are driven by two processes: desorption of elemental mercury accumulated at the soil:air interface, and photo reduction of mercury containing phases. To determine the need for and effectiveness of regulatory controls on short-lived anthropogenic point sources the contribution of mercury from geologic non-point sources to the atmospheric mercury pool needs to be quantified. The atmospheric mercury contribution from small areas of mining disturbance with relatively high mercury concentrations are, in general, less than that from surrounding large areas of low levels of mercury enrichment. In the arid to semi-arid west-ern United States volatilization is the primary means by which mercury is released from enriched sites.

Gustin, M.S.; Coolbaugh, M.F.; Engle, M.A.; Fitzgerald, B.C.; Keislar, R.E.; Lindberg, S.E.; Nacht, D.M.; Quashnick, J.; Rytuba, J.J.; Sladek, C.; Zhang, H.; Zehner, R.E.

2003-01-01

286

A new, catchment-scale model for simulating methyl and total mercury in soils and surface waters  

NASA Astrophysics Data System (ADS)

Mercury (Hg) is a potent and persistent neurotoxin. It is subject to long-range atmospheric transport, accumulates in catchment soils, and can pose health risks to humans and animals both at the point of use as well as in remote locations. Elevated concentrations of methyl mercury (MeHg) in fish are related to atmospheric Hg deposition and have resulted in fish consumption advisories in many parts of North America and Fennoscandia. After more than 150 years of elevated Hg deposition in Europe and North America, there remains a large inventory of Hg in the terrestrial catchments of lakes, which continues to be exported to receiving waters despite decreasing atmospheric inputs. While a substantial Hg pool exists in boreal catchment soils, fluxes of Hg from catchments via stream runoff tend to be much lower than atmospheric Hg inputs. Terrestrial catchments receiving similar atmospheric Hg inputs can have markedly different patterns of Hg output in stream water. Considering the importance of catchment processes in determining Hg flux to lakes and subsequent MeHg concentrations in fish, there is a need to characterize Hg cycling and transport in boreal and temperate forest-covered catchments. We present a new, catchment-scale, process-based dynamic model for simulating Hg in soils and surface waters. The Integrated Catchments Model for Mercury (INCA-Hg) simulates transport of gaseous, dissolved and solid Hg and transformations between elemental (Hg0), ionic (Hg(II)) and MeHg in natural and semi-natural landscapes. The mathematical description represents the model as a series of linked, first-order differential equations describing chemical and hydrological processes in catchment soils and waters which control surface water Hg dynamics and subsequent fluxes to lakes and other receiving waters. The model simulates daily time series between one and one hundred years long and can be applied to catchments ranging in size from <1 to ~10000 km2. Here we present applications of the model to two boreal forest headwater catchments in central Canada where we were able to reproduce observed patterns of stream water total mercury (THg) and MeHg fluxes and concentrations. Model performance was assessed using Monte Carlo techniques. Simulated in-stream THg and MeHg concentrations were sensitive to hydrologic controls and terrestrial and aquatic process rates. Our results show the need for new research to better quantify in-situ methylation and demethylation rates in soils and surface waters and for additional surveys of soil Hg concentrations. These data are needed for constraining model simulations of the effects of changing climate, Hg deposition and land management on fluxes of THg and MeHg.

Futter, M. N.; Poste, A. E.; Whitehead, P. G.; Dillon, P. J.

2012-04-01

287

Mercury in municipal solid wastes and New Jersey mercury prevention and reduction program  

SciTech Connect

Mercury is a very toxic heavy metal which accumulates in the brain causing neurological damages involving psychasthenic and vegetative syndrome. At high exposure levels it causes behavioral and personality changes, loss of memory and insomnia. Long-term exposure or exposure during pregnancy to mercury or mercury compounds can permanently damage the kidney and fetus. In addition to potential effects on human health, mercury poisoning can also affect other living organisms. Mercury is different than other heavy metals. It consistently biomagnifies and bioaccumulates within the aquatic food chain. Global sources of mercury release are both natural and anthropogenic. Natural sources include volatilization of gaseous-mercury iron soils ana rocks, volcanic releases, evaporation from the ocean and other water bodies. Anthropogenic sources are fuel and coal combustion, mining, smelting, manufacturing activities, disposal of sludge, pesticides, animal and food waste, and incineration of municipal solid waste. Worldwide combustion of municipal solid waste is the second largest source of atmospheric emission of mercury. In New Jersey, incineration of solid waste is the largest source of atmospheric emission of mercury. The New Jersey Department of Environmental Protection and Energy (NJDEPE) has developed a comprehensive program to control and prevent emission of mercury resulting from combustion municipal solid waste.

Erdogan, H.; Stevenson, E. [New Jersey Department of Environmental Protection, Trenton, NJ (United States). Division of Science and Research

1994-12-31

288

Determination of the potential for release of mercury from combustion product amended soils: Part 2 - Coal fly ash generated stabilized soil and degradation products  

SciTech Connect

The potential for mercury (Hg) releases to the air and water from three soils, two subbituminous coal fly ashes, and mixtures of these materials as stabilized soil was assessed. In addition, the potential for Hg release from crushed stabilized material mixed into soil simulating degradation over time was investigated. In general, atmospheric Hg deposition was measured for the ash and materials made using the ash with the higher Hg concentration, whereas the second ash material and materials generated using this ash exhibited emission as the dominant flux. Fluxes measured from stabilized material were less than that measured for the pure ash material but of the same direction. Although the stabilized and degraded stabilized materials exhibited Hg fluxes that were significantly different from base soils, values were within the range reported for low Hg-containing background soils. Because of limitations of the experimental design (i.e., reduced light exposures and measurement of flux from dry materials) reported fluxes are most likely underestimates of that which would occur in the natural environment. Materials made to simulate degradation of the stabilized material did not exhibit higher releases than the stabilized material alone. Synthetic Precipitation Leaching Procedure (SPLP; EPA method 1312) results showed that the chemistry of a soil, especially pH, may influence the amount of Hg released to soil solutions, with more acidic soils potentially enhancing Hg release. 25 refs., 9 figs., 4 tabs.

Mae Sexauer Gustin; Mei Xin; Jody Ericksen; George C. Fernandez [University of Nevada-Reno, Reno, NV (United States). Department of Natural Resources and Environmental Sciences

2008-11-15

289

Mercury in ground water, septage, leach-field effluent, and soils in residential areas, New Jersey coastal plain  

USGS Publications Warehouse

Water samples were collected from domestic wells at an unsewered residential area in Gloucester County, New Jersey where mercury (Hg) concentrations in well water were known to exceed the USEPA maximum contaminant level (MCL) of 2000 ng/L. This residential area (the CSL site) is representative of more than 70 such areas in southern New Jersey where about 600 domestic wells, sampled previously by State and county agencies, yielded water containing Hg at concentrations that exceed the MCL. Recent studies indicate that background concentrations of Hg in water from this unconfined sand and gravel aquifer system are < 10 ng/L. Additional sampling was conducted at the CSL site in order to better understand sources of Hg and potential Hg transport mechanisms in the areas with Hg-contaminated ground water. At the CSL site, concentrations of Hg were substantially lower (although still exceeding the MCL in some cases) in filtered water samples than in the unfiltered water samples collected previously from the same wells. Surfactants and elevated concentrations of sodium, chloride, nitrate, ammonium, and phosphate in water from domestic and observation wells indicated septic-system effects on water quality; detections of sulfide indicated localized reducing conditions. Hg concentrations in septage and leach-field effluent sampled at several other households in the region were low relative to the contaminant-level Hg concentrations in water from domestic wells. Relations of Hg concentrations in leach-field effluent to iron concentrations indicate that reductive dissolution of iron hydroxides in soils may release Hg to the percolating effluent. ?? 2005 Elsevier B.V. All rights reserved.

Barringer, J.L.; Szabo, Z.; Schneider, D.; Atkinson, W.D.; Gallagher, R.A.

2006-01-01

290

Mercury pollution in fish from South China Sea: levels, species-specific accumulation, and possible sources.  

PubMed

Both total mercury (THg) and methylmercury (MeHg) levels in fish collected from South China Sea (SCS) were studied to understand Hg pollution in Chinese tropical marine ecosystems. The average THg concentrations in fish species ranged from 39.6 ?g/kg for rabbitfish (Siganus fuscessens) to 417 ?g/kg for thornfish (Terapon jarbua), while those of MeHg varied from 13 ?g/kg (rabbitfish) to 176 ?g/kg (thornfish). The median values of MeHg/THg ratios in different fish species ranged from 36 to 85%. Significant inter-species differences of THg and MeHg in fish were observed due to feeding habits and fish sizes. Overall, carnivorous fish had higher levels of THg, MeHg and MeHg/THg ratios than omnivorous and herbivorous fish. High Hg levels in fish of the SCS were probably related to Hg input from atmospheric deposition and anthropogenic activities. PMID:24721134

Liu, Jinling; Xu, Xiangrong; Yu, Shen; Cheng, Hefa; Hong, Yiguo; Feng, Xinbin

2014-05-01

291

Lead, cadmium, arsenic, mercury and copper levels in Chinese Yunnan Pu'er tea.  

PubMed

The Yunnan region of China produces a distinctive variety of Pu'er tea, which is consequently labeled as a Chinese geographic indication product. In this study, the safety of Chinese Yunnan Pu'er tea with regard to heavy metal content was evaluated in 30 different brands of Pu'er tea, including 150 commercial samples. Metal levels in the Pu'er tea samples followed the order: copper (12-22 µg/g) > lead (0.26-3.2 µg/g) > arsenic (0.035-0.24 µg/g) > cadmium (0.0059-0.085 µg/g) > mercury (<0.010 µg/g). Mercury was not detected in 17 of the brands of Pu'er tea. Metal-to-metal correlation studies showed that there were no significant correlation between metal pairs. Based on current safety standards, the low levels of metals detected in these Pu'er tea samples mean they are safe for human consumption. PMID:24779659

Ning, Pengbo; Gong, Chunmei; Zhang, Yanming; Guo, Kangkang; Bai, Juan

2011-01-01

292

LOCATIONAL DIFFERENCES IN MERCURY AND SELENIUM LEVELS IN 19 SPECIES OF SALTWATER FISH FROM NEW JERSEY  

PubMed Central

Individuals who fish, and their families that ingest self-caught fish, make decisions about where to fish, what type of fish to eat, and the quantity of fish to eat. While federal and state agencies often issue consumption advisories for some fish with high mercury (Hg) concentrations, advisories seldom provide the actual metal levels to the general public. There are few data for most saltwater fish, and even less information on variations in Hg levels in fish within a state or geographical region. The objective of this study was to provide Hg concentrations from 19 species of fish caught in different locations in New Jersey to (1) test the hypothesis that mean metal levels vary geographically, (2) provide this information to individuals who fish these coastal waters, and (3) provide a range of values for risk assessors who deal with saltwater fish exposure in the Northeastern United States. Selenium (Se) was also examined because of its purported moderating effect on the toxicity of Hg. Hg levels showed significant geographical variation for 10 of 14 species that were caught in more than one region of New Jersey, but there were significant locational differences for Se in only 5 of the fish. Mercury levels were significantly lower in fish collected from northern New Jersey (except for ling, Molva molva), compared to other regions. As might be expected, locational differences in Hg levels were greatest for fish species with the highest Hg concentrations (shark, Isurus oxyrinchus; tuna, Thunnus thynnus and T. albacares; striped bass, Morone saxatilis; bluefish, Pomatomus saltatrix). Fishers and their families might reduce their risk from Hg exposure not only by selecting fish generally lower in Hg, but by fishing predominantly in some regions over others, further lowering the potential risk. Health professionals might use these data to advise patients on which fish are safest to consume (in terms of Hg exposure) from particular geographical regions. PMID:21598171

Burger, Joanna; Jeitner, Christian; Gochfeld, Michael

2014-01-01

293

MERGANSER- Predicting Mercury Levels in Fish and Loons in New England Lakes  

EPA Science Inventory

MERGANSER (MERcury Geo-spatial AssesmentS for the New England Region) is an empirical least squares multiple regression model using atmospheric deposition of mercury (Hg) and readily obtainable lake and watershed features to predict fish and common loon Hg (as methyl mercury) in ...

294

Mercury contamination in human hair and fish from Cambodia: levels, specific accumulation and risk assessment  

Microsoft Academic Search

Mercury (Hg) concentrations in human hair and fish samples from Phnom Penh, Kien Svay, Tomnup Rolork and Batrong, Cambodia, collected in November 1999 and December 2000 were determined to understand the status of contamination, and age- and sex-dependent accumulation in humans and to assess the intake of mercury via fish consumption. Mercury concentrations in human hair ranged from 0.54 to

Tetsuro Agusa; Takashi Kunito; Hisato Iwata; Touch Seang Tana; Annamalai Subramanian; Shinsuke Tanabe

2005-01-01

295

Projecting the Population-level Effects of Mercury on the Common Loon in the Northeast  

NASA Astrophysics Data System (ADS)

The Common Loon (Gavia immer) is a top-level predator in aquatic systems and is at risk to mercury contamination. This risk is of particular concern in the Northeast, the region of North America in which loons have the highest mean body concentration of methylmercury (MeHg). We used matrix population models to project the population-level effects of mercury on loons in four states in the Northeast (New York, Vermont, New Hampshire, and Maine) exhibiting different levels of risk to MeHg. Four categories of risk to MeHg (low, moderate, high, and extra high) were established based on MeHg levels observed in loons and associated effects observed at the individual and population levels in the field (e.g., behavior and reproductive success). We parameterized deterministic matrix population models using survival estimates from a 12-year band-resight data set and productivity estimates from a 25-year data set of nesting loon observations in NH. The juvenile loon survival rate was 0.55 (minimum) and 0.63 (maximum) (ages 1-3), and the adult loon survival rate was 0.95 (ages 4-30). The mean age at first reproduction was 7. The mean fertility was 0.26 fledgelings per individual at low to moderate risk; there were 53% fewer fledged young per individual at high to extra high risk. Productivity was weighted by risk for each state. The portion of the breeding population at high to extra high risk was 10% in NY, 15% in VT, 17% in NH, and 28% in ME. We also constructed a stochastic model in which productivity was randomly selected in each time step from the 25 estimates in the NH data set. Model results indicated a negative population growth rate for some states. There was a decreasing trend in population growth rate as the percentage of the loon population at high to extra high risk increased. The stochastic model showed that the population growth rate varied over a range of about 0.05 from year to year, and this range decreased as the percentage of the loon population at high to extra high risk increased. These results suggest that an increase in risk to mercury that effects a change in reproductive success may have a negative population-level effect on loons.

Evers, D. C.; Mitro, M. G.; Gleason, T. R.

2001-05-01

296

Determination of the potential for release of mercury from combustion product amended soils: Part 1--Simulations of beneficial use.  

PubMed

This paper describes a project that assessed the potential for mercury (Hg) release to air and water from soil amended with combustion products to simulate beneficial use. Combustion products (ash) derived from wood, sewage sludge, subbituminous coal, and a subbituminous coal-petroleum coke mixture were added to soil as agricultural supplements, soil stabilizers, and to develop low-permeability surfaces. Hg release was measured from the latter when intact and after it was broken up and mixed into the soil. Air-substrate Hg exchange was measured for all materials six times over 24 hr, providing data that reflected winter, spring, summer, and fall meteorological conditions. Dry deposition of atmospheric Hg and emission of Hg to the atmosphere were both found to be important fluxes. Measured differences in seasonal and diel (24 hr) fluxes demonstrated that to establish an annual estimate of air-substrate flux from these materials data on both of these time steps should be collected. Air-substrate exchange was highly correlated with soil and air temperature, as well as incident light. Hg releases to the atmosphere from coal and wood combustion product-amended soils to simulate an agricultural application were similar to that measured for the unamended soil, whereas releases to the air for the sludge-amended materials were higher. Hg released to soil solutions during the Synthetic Precipitation Leaching Procedure for ash-amended materials was higher than that released from soil alone. On the basis of estimates of annual releases of Hg to the air from the materials used, emissions from coal and wood ash-amended soil to simulate an agricultural application could simply be re-emission of Hg deposited by wet processes from the atmosphere; however, releases from sludge-amended materials and those generated to simulate soil stabilization and disturbed low-permeability pads include Hg indigenous to the material. PMID:18512444

Gustin, Mae Sexauer; Ericksen, Jody; Fernandez, George C

2008-05-01

297

Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California  

USGS Publications Warehouse

The water columns of four reservoirs (Almaden, Calero, Guadalupe and Lexington Reservoirs) and an abandoned quarry pit filled by Alamitos Creek drainage for recreational purposes (Lake Almaden) were sampled on September 14 and 15, 2004 to provide the first measurements of mercury accumulation by phytoplankton and zooplankton in lentic systems (bodies of standing water, as in lakes and reservoirs) within the Guadalupe River watershed, California. Because of widespread interest in ecosystem effects associated with historic mercury mining within and downgradient of the Guadalupe Riverwatershed, transfer of mercury to lower trophic-level organisms was examined. The propensity of mercury to bioaccumulate, particularly in phytoplankton and zooplankton at the base of the food web, motivated this attempt to provide information in support of developing trophic-transfer and solute-transport models for the watershed, and hence in support of subsequent evaluation of load-allocation strategies. Both total mercury and methylmercury were examined in these organisms. During a single sampling event, replicate samples from the reservoir water column were collected and processed for dissolved-total mercury, dissolved-methylmercury, phytoplankton mercury speciation, phytoplankton taxonomy and biomass, zooplankton mercury speciation, and zooplankton taxonomy and biomass. The timing of this sampling event was coordinated with sampling and analysis of fish from these five water bodies, during a period of the year when vertical stratification in the reservoirs generates a primary source of methylmercury to the watershed. Ancillary data, including dissolved organic carbon and trace-metal concentrations as well as vertical profiles of temperature, dissolved oxygen, specific conductance and pH, were gathered to provide a water-quality framework from which to compare the results for mercury. This work, in support of the Guadalupe River Mercury Total Maximum Daily Load (TMDL) Study, provides the first measurements of mercury trophic transfer through planktonic communities in this watershed. It is worth reemphasizing that this data set represents a single ?snap shot? of conditions in water bodies within the Guadalupe River watershed to: (1) fill gaps in trophic transfer information, and (2) provide a scientific basis for future process-based studies with enhanced temporal and spatial coverage. This electronic document was unconventionally formatted to enhance the accessibility of information to a wide range of interest groups.

Kuwabara, James S.; Topping, Brent R.; Moon, Gerald E.; Husby, Peter; Lincoff, Andrew; Carter, James L.; Croteau, Marie-Noële

2005-01-01

298

When are fetuses and young children most susceptible to soil metal concentrations of arsenic, lead and mercury?  

PubMed Central

This study was designed to analyze when, during pregnancy and early childhood, the association between soil metal concentrations of arsenic (As), lead (Pb) and mercury (Hg) and the outcome of intellectual disability (ID) is statistically significant. Using cluster analysis, we identified ten areas of land that contained a cluster of ID and areas of average risk for ID. We analyzed soil for As, Pb, and Hg and estimated the soil metal concentration at the residential sites where the woman and children lived during pregnancy and early childhood using a Bayesian Kriging model. Arsenic concentrations were associated with ID during the first trimester of pregnancy and Hg was associated with ID early in pregnancy and the first two years of childhood. The covariates that remained in the final models were also temporally associated with ID. PMID:22749212

McDermott, Suzanne; Bao, Weichao; Aelion, C. Marjorie; Cai, Bo; Lawson, Andrew

2012-01-01

299

Review of State Soil Cleanup Levels for Dioxin (December 2009)  

EPA Science Inventory

This final report summarizes a survey of state soil cleanup levels for dioxin and characterizes the science underlying these values. The objective of this project was to summarize existing state cleanup levels for dioxin in soil, together with their scientific bases where availa...

300

Arsenic and mercury in the soils of an industrial city in the Donets Basin, Ukraine  

USGS Publications Warehouse

Soil and house dust collected in and around Hg mines and a processing facility in Horlivka, a mid-sized city in the Donets Basin of southeastern Ukraine, have elevated As and Hg levels. Surface soils collected at a former Hg-processing facility had up to 1300 mg kg?1 As and 8800 mg kg?1 Hg; 1M HCl extractions showed 74–93% of the total As, and 1–13% of the total Hg to be solubilized, suggesting differential environmental mobility between these elements. In general, lower extractability of As and Hg was seen in soil samples up to 12 km from the Hg-processing facility, and the extractable (1M HCl, synthetic precipitation, deionized water) fractions of As are greater than those for Hg, indicating that Hg is present in a more resistant form than As. The means (standard deviation) of total As and Hg in grab samples collected from playgrounds and public spaces within 12 km of the industrial facility were 64 (±38) mg kg?1 As and 12 (±9.4) mg kg?1 Hg; all concentrations are elevated compared to regional soils. The mean concentrations of As and Hg in dust from homes in Horlivka were 5–15 times higher than dust from homes in a control city. Estimates of possible exposure to As and Hg through inadvertent soil ingestion are provided.

Conko, Kathryn M.; Landa, Edward R.; Kolker, Allan; Kozlov, Kostiantyn; Gibb, Herman J.; Centeno, Jose; Panov, Boris S.; Panov, Yuri B.

2013-01-01

301

Total mercury in fruiting bodies and underlying soil substrate of Poison Pax Paxillus involutus (Batsch Ex. Fr.) Fr. from various sites in Poland  

NASA Astrophysics Data System (ADS)

The total mercury concentrations were quantified in the caps, stalks and underlying soil substrate of Poison Pax Paxillus involutus collected from 19 spatially distant sites in Poland in 1994-2001 to examine the status of mercury pollution, bioconcentration features as well as bioindication potential of this mushroom species. The mushroom and soil samples were collected from the Mierzeja Wi?lana Landscape Park, Wdzydzki Landscape Park, Zaborski Landscape Park, Augustów Forests, Borecka Forests, Wielu?ska Upland, Dar?lubska Forest, Tucholskie Forest and the counties of Gubin. Ko?cierzyna, Morag, Koszalin, Gda?sk, Bydgoszcz, K?trzyn, ?uromin, W?oc?awek, and Starachowice. The mean concentrations of mercury varied, depending on the sampling site, between 15±9 and 410±200 ng/g dry matter for caps and between 14±26 and 200±130 ng/g dry matter for stalks, The mean soil mercury concentrations varied between 8.8±4.5 and 95±84 ng/g. The mean mercury concentration cap to stalk quotients varied between O.6±0.2 and 1.9±1.5, with exception of the site Morag with 4.4±7.2. The mean values of bioconcentration factor of mercury in caps and stalks of Poison Pax varied in relatively narrow range between 0.7 and 10, and 0.5 and 8.5, respectively.

Brzostowski, A.; Falandysz, J.

2003-05-01

302

Elevated mercury concentrations in soils, sediments, water, and fish of the Madeira River basin, Brazilian Amazon: a function of natural enrichments?  

PubMed

Previous site-specific investigations have found that mercury concentrations in water, sediments, and biota of the Brazilian Amazon are elevated above global averages, and that these concentrations are a direct result of widespread mercury amalgamation mining operations conducted by non-organized prospectors. In order to assess the regional impacts of Hg contamination from these non-organized gold mining activities, water, sediments, and fish were systematically collected in 1997 along a 900-km reach of the Madeira River. The sampling program extended from the Amazon River upstream to Porto Velho, the site of historic and ongoing mercury amalgamation mining. Mercury concentrations were found to be elevated above global averages in all sampled media. However, the geochemical data suggest that the high mercury levels are due largely to natural sources and natural biogeochemical processes, and that the impacts of anthropogenically released mercury from mine sites is relatively localized. PMID:11032118

Lechler, P J; Miller, J R; Lacerda, L D; Vinson, D; Bonzongo, J C; Lyons, W B; Warwick, J J

2000-10-01

303

Successful Characterization and Remedial Contour of Highly Contaminated Mercury Soil at the Y-12 National Security Complex - 13593  

SciTech Connect

An area known as the 81-10 pad within the footprint of the Y-12 National Security Complex, suspected to be heavily contaminated with mercury, was slated for characterization in support of a Federal Facilities Agreement (FFA) milestone to be accomplished by September 30, 2012. A full remedial design report (RDR) required the soil in Exposure Unit -9 (EU-9) to be fully characterized for a number of contaminates of concern including mercury. The goal of this characterization effort was to determine what soil, if any, would need to be removed for the protection of industrial workers and impacts to the surface and ground water. Funding for this project was made available using buy-back scope under the American Recovery and Reinvestment Act (ARRA). The EU-9 soil unit involved 3 different classifications which were determined as follows: Class 1: Known to have been impacted, contamination is likely; Class 2: Suspected to have been impacted, contamination is unknown; Class 3: Area not known to have been impacted, contamination unlikely. Due to various sampling and analysis events since the 1980's, significant mercury contamination was expected under the concrete pad of an area known as 81-10. Mercury contamination outside of the boundary of this pad within the EU-9 footprint was not known and therefore an original planned estimate of 1,461 cubic meters of material were expected to be heavily contaminated with mercury requiring removal, treatment and disposal. Through the use of a highly effective nature and extent sampling and analysis design that involved a hybrid of statistically-based and judgmental sampling, the actual remedial contour requiring removal was approximately 717 cubic meters, roughly 12% of the original estimate. This characterization approach was executed in full compliance with the Record of Decision (ROD) [1] documents that were agreed upon by the U.S. Department of Energy, Environmental Protection Agency and Tennessee Department of Environment and Conservation. In addition, the RDR was completed ahead of the FFA milestone date of September 30, 2012. (authors)

White, Aaron; Rigas, Michael [U.S. Department of Energy Oak Ridge Operations, Oak Ridge, TN 37830 (United States)] [U.S. Department of Energy Oak Ridge Operations, Oak Ridge, TN 37830 (United States); Birchfield, Joseph W. III [1528 Paxton Drive Knoxville, TN 37918 (United States)] [1528 Paxton Drive Knoxville, TN 37918 (United States)

2013-07-01

304

Boron Levels in Soils Cropped to Coffee and their Relationships to some Soil Properties in Ghana  

Microsoft Academic Search

Studies on boron levels in soils cropped to coffee were carried out in Ghana due to widespread reports on boron deficiency in soils of some coffee producing countr ies. Leaves and soils were sampled from Cocobod coffee plantations at Bogoso, Suhuma, Manso-Mim, Bunso and Bepong, which represent the main coffee growing areas in the Western, Ashanti and Eastern regions of

A. A. Afrifa; K. Ofori-Frimpong; M. K. Abekoe

305

Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide  

NASA Technical Reports Server (NTRS)

The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

Patterson, James D.; Li, Wei-Gang

1995-01-01

306

Mercury retorting of calcine waste, contaminated soils and railroad ballast at the Idaho National Egineering Laboratory  

SciTech Connect

The Idaho National Engineering Laboratory (INEL) has been involved in nuclear reactor research and development for over 40 years. One of the earliest major projects involved the development of a nuclear powered aircraft engine, a long-term venture which used mercury as a shielding medium. Over the course of several years, a significant amount of mercury was spilled along the railroad tracks where the test engines were transported and stored. In addition, experiments with volume reduction of waste through a calcine process employing mercury as a catalyst resulted in mercury contaminated calcine waste. Both the calcine and Test Area North wastes have been identified in Department of Energy Action Memorandums to be retorted, thereby separating the mercury from the various contaminated media. Lockheed Idaho Technologies Company awarded the Mercury Retort contract to ETAS Corporation and assigned Parsons Engineering Science, Inc. to manage the treatment field activities. The mercury retort process entails a mobile unit which consists of four trailer-mounted subsystems requiring electricity, propane, and a water supply. This mobile system demonstrates an effective strategy for retorting waste and generating minimal secondary waste.

Cotten, G.B.; Rothermel, J.S. [Parsons Engineering Science, Inc., Houston, TX (United States); Sherwood, J. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Heath, S.A.; Lo, T.Y.R. [ETAS Corporation (United States)

1996-02-28

307

Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens).  

PubMed

Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake's watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy-Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content. PMID:25134675

Larson, James H; Maki, Ryan P; Knights, Brent C; Gray, Brian R

2014-10-01

308

Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)  

USGS Publications Warehouse

Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy–Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content.

Larson, James H.; Maki, Ryan P.; Knights, Brent C.; Gray, Brian R.

2014-01-01

309

Seasonal, locational and size variations in mercury and selenium levels in striped bass (Morone saxatilis) from New Jersey.  

PubMed

We examined total mercury and selenium levels in muscle of striped bass (Morone saxatilis) collected from 2005 to 2008 from coastal New Jersey. Of primary interest was whether there were differences in mercury and selenium levels as a function of size and location, and whether the legal size limits increased the exposure of bass consumers to mercury. We obtained samples mainly from recreational anglers, but also by seine and trawl. For the entire sample (n=178 individual fish), the mean (±standard error) for total mercury was 0.39±0.02 ?g/g (=0.39 ppm, wet weight basis) with a maximum of 1.3 ?g/g (=1.3 ppm wet weight). Mean selenium level was 0.30±0.01 ?g/g (w/w) with a maximum of 0.9 ?g/g). Angler-caught fish (n=122) were constrained by legal size limits to exceed 61 cm (24 in.) and averaged 72.6±1.3 cm long; total mercury averaged 0.48±0.021 ?g/g and selenium averaged 0.29±0.01 ?g/g. For comparable sizes, angler-caught fish had significantly higher mercury levels (0.3 vs 0.21 ?g/g) than trawled fish. In both the total and angler-only samples, mercury was strongly correlated with length (Kendall tau=0.37; p<0.0001) and weight (0.38; p<0.0001), but was not correlated with condition or with selenium. In the whole sample and all subsamples, total length yielded the highest r(2) (up to 0.42) of any variable for both mercury and selenium concentrations. Trawled fish from Long Branch in August and Sandy Hook in October were the same size (68.9 vs 70.1cm) and had the same mercury concentrations (0.22 vs 0.21 ppm), but different selenium levels (0.11 vs 0.28 ppm). The seined fish (all from Delaware Bay) had the same mercury concentration as the trawled fish from the Atlantic coast despite being smaller. Angler-caught fish from the North (Sandy Hook) were larger but had significantly lower mercury than fish from the South (mainly Cape May). Selenium levels were high in small fish, low in medium-sized fish, and increased again in larger fish, but overall selenium was correlated with length (tau=0.14; p=0.006) and weight (tau=0.27; p<0.0001). Length-squared contributed significantly to selenium models, reflecting the non-linear relationship. Inter-year differences were explained partly by differences in sizes. The selenium:mercury molar ratio was below 1:1 in 20% of the fish and 25% of the angler-caught fish. Frequent consumption of large striped bass can result in exposure above the EPA's reference dose, a problem particularly for fetal development. PMID:22226733

Gochfeld, Michael; Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2012-01-01

310

Seasonal, locational and size variations in mercury and selenium levels in striped bass (Morone saxatilis) from New Jersey  

PubMed Central

We examined total mercury and selenium levels in muscle of striped bass (Morone saxatilis) collected from 2005 to 2008 from coastal New Jersey. Of primary interest was whether there were differences in mercury and selenium levels as a function of size and location, and whether the legal size limits increased the exposure of bass consumers to mercury. We obtained samples mainly from recreational anglers, but also by seine and trawl. For the entire sample (n = 178 individual fish), the mean (± standard error) for total mercury was 0.39 ± 0.02 ?g/g (= 0.39 ppm, wet weight basis) with a maximum of 1.3 ?g/g (= 1.3 ppm wet weight). Mean selenium level was 0.30 ± 0.01 ?g/g (w/w) with a maximum of 0.9 ?g/g). Angler-caught fish (n = 122) were constrained by legal size limits to exceed 61 cm (24 in.) and averaged 72.6 ± 1.3 cm long; total mercury averaged 0.48 ± 0.021 ?g/g and selenium averaged 0.29 ± 0.01 ?g/g. For comparable sizes, angler-caught fish had significantly higher mercury levels (0.3 vs 0.21 ?g/g) than trawled fish. In both the total and angler-only samples, mercury was strongly correlated with length (Kendall tau = 0.37; p < 0.0001) and weight (0.38; p < 0.0001), but was not correlated with condition or with selenium. In the whole sample and all subsamples, total length yielded the highest r2 (up to 0.42) of any variable for both mercury and selenium concentrations. Trawled fish from Long Branch in August and Sandy Hook in October were the same size (68.9 vs 70.1 cm) and had the same mercury concentrations (0.22 vs 0.21 ppm), but different selenium levels (0.11 vs 0.28 ppm). The seined fish (all from Delaware Bay) had the same mercury concentration as the trawled fish from the Atlantic coast despite being smaller. Angler-caught fish from the North (Sandy Hook) were larger but had significantly lower mercury than fish from the South (mainly Cape May). Selenium levels were high in small fish, low in medium-sized fish, and increased again in larger fish, but overall selenium was correlated with length (tau = 0.14; p = 0.006) and weight (tau = 0.27; p < 0.0001). Length-squared contributed significantly to selenium models, reflecting the non-linear relationship. Inter-year differences were explained partly by differences in sizes. The selenium:mercury molar ratio was below 1:1 in 20% of the fish and 25% of the angler-caught fish. Frequent consumption of large striped bass can result in exposure above the EPA’s reference dose, a problem particularly for fetal development. PMID:22226733

Gochfeld, Michael; Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2014-01-01

311

High levels of mercury in biota of a new Prairie irrigation reservoir with a simplified food web in Southern Alberta, Canada  

Microsoft Academic Search

This study examined mercury levels in northern pike (Esox lucius) from the Twin Valley Reservoir in southern Alberta, 2 years after construction in 2003. The hypothesis was tested that mercury\\u000a concentrations in pike from the reservoir are significantly higher than in pike from the nearby Oldman River. Mercury concentrations\\u000a in muscle tissue (0.37–1.54 ppm) generally exceeded the consumption guideline of 0.5 ppm total

Lars BrinkmannJoseph; Joseph B. Rasmussen

2010-01-01

312

Potential effect of land-leveling on soil fertility in a Brazilian rice soil  

Microsoft Academic Search

Land-leveling to improve water management in lowland rice (Oryza sativa L.) production is becoming common in many countries. This technique exposes subsoil by removal and deposition of surface soil from high- to low-lying areas. The potential effect of land-leveling on soil fertility was studied in samples from an alluvial soil at depths of 0- to 5-, 5- to 15-, and

Ricardo E. Preve; D. C. Martens

1990-01-01

313

Development of novel activated carbon-based adsorbents for the control of mercury emissions from coal-fired power plants  

SciTech Connect

In addition to naturally occurring mercury sources, anthropogenic activities increase the mercury loading to the environment. Although not all produced mercury is dissipated directly into the environment, only minor portions of the total production are stocked or recycled, and the rest of the mercury and its compounds is finally released in some way into atmosphere, surface waters and soil, or ends in landfills dumps, and refuse. Since mercury and its compounds are highly toxic, their presence in the environment constitutes potential impact on all living organisms, including man. The first serious consequence of industrial mercury discharges causing neurological disorder even death occurred in Minimata, Japan in 1953. Systematic studies showed that mercury poisoning is mainly found in fish-eating populations. However, various levels of mercury are also found in food other than fish. During the past several decades, research has been conducted on the evaluation of risks due to exposure to mercury and the development of control technologies for mercury emissions. In 1990, the Clean Air Act Amendments listed mercury, along with 10 other metallic species, as a hazardous air pollutant (HAP). This has further stimulated research for mercury control during the past several years. The impact of mercury on humans, sources of mercury in the environment, current mercury control strategies and the objective of this research are discussed in this section.

Radisav D. Vidic

1999-03-01

314

Soil properties discriminating Araucaria forests with different disturbance levels.  

PubMed

Soil biological, chemical, and physical properties can be important for monitoring soil quality under one of the most spectacular vegetation formation on Atlantic Forest Biome, the Araucaria Forest. Our aim was to identify a set of soil variables capable of discriminating between disturbed, reforested, and native Araucaria forest soils such that these variables could be used to monitor forest recovery and maintenance. Soil samples were collected at dry and rainy season under the three forest types in two state parks at São Paulo State, Brazil. Soil biological, chemical, and physical properties were evaluated to verify their potential to differentiate the forest types, and discriminant analysis was performed to identify the variables that most contribute to the differentiation. Most of physical and chemical variables were sensitive to forest disturbance level, but few biological variables were significantly different when comparing native, reforested, and disturbed forests. Despite more than 20 years following reforestation, the reforested soils were chemically and biologically distinct from native and disturbed forest soils, mainly because of the greater acidity and Al(3+) content of reforested soil. Disturbed soils, in contrast, were coarser in texture and contained greater concentrations of extractable P. Although biological properties are generally highly sensitive to disturbance and amelioration efforts, the most important soil variables to discriminate forest types in both seasons included Al(3+), Mg(2+), P, and sand, and only one microbial attribute: the NO2 (-) oxidizers. Therefore, these five variables were the best candidates, of the variables we employed, for monitoring Araucaria forest disturbance and recovery. PMID:25792021

Bertini, Simone Cristina Braga; Azevedo, Lucas Carvalho Basilio; Stromberger, Mary E; Cardoso, Elke Jurandy Bran Nogueira

2015-04-01

315

Mercury levels in raccoons (Procyon lotor) from the Warta Mouth National Park, northwestern Poland.  

PubMed

This is the first report on mercury (Hg) levels in the liver, kidney, skeletal muscle, and brain of raccoon in Europe. It studied Hg concentration in 24 raccoons from the Warta Mouth National Park, northwestern Poland by atomic absorption spectroscopy (AAS). The highest total Hg concentrations in the raccoon were found in the liver (maximum, 18.45 mg/kg dry weight), while the lowest in the brain (maximum, 0.49 mg/kg dw). In adult raccoons, Hg concentrations in the liver, kidney, and brain were higher than in immature individuals (p<0.001), while similar in skeletal muscle in both age groups. Our results are consistent with studies by other authors conducted in North America in areas with similar environmental conditions. PMID:24736978

Lanocha, Natalia; Kalisinska, Elzbieta; Kosik-Bogacka, Danuta I; Budis, Halina; Podlasinska, Joanna; Jedrzejewska, Ewa

2014-06-01

316

Overview of investigations into mercury in ground water, soils, and septage, New Jersey coastal plain  

USGS Publications Warehouse

Since the early 1980s, investigations by health departments of eight counties in southern New Jersey, by the NJ Department of Environmental Protection (NJDEP), and subsequently by the US Geological Survey (USGS), have shown that Hg concentrations in water tapped by about 600 domestic wells exceed the maximum contaminant level (MCL) of 2 ??g/L. The wells are finished in the areally extensive unconfined Kirkwood-Cohansey aquifer system of New Jersey's Coastal Plain; background concentrations of Hg in water from this system are < 0.01 ??g/L. Evidence of contributions from point sources of Hg, such as landfills or commercial and industrial hazardous-waste sites, is lacking. During 1996-2003, the USGS collected water samples from 203 domestic, irrigation, observation, and production wells using ultraclean techniques; septage, leach-field effluent, soils, and aquifer sediments also were sampled. Elevated concentrations of NH4, B, Cl, NO3, and Na and presence of surfactants in domestic-well water indicate that septic-system effluent can affect water quality in unsewered residential areas, but neither septage nor effluent appears to be a major Hg source. Detections of hydrogen sulfide in ground water at a residential area indicate localized reducing conditions; undetectable SO4 concentrations in water from other residential areas indicate that reducing conditions, which could be conducive to Hg methylation, may be common locally. Volatile organic compounds (VOCs), mostly chlorinated solvents, also are found in ground water at the affected areas, but statistically significant associations between presence of Hg and VOCs were absent for most areas evaluated. Hg concentrations are lower in some filtered water samples than in paired unfiltered samples, likely indicating that some Hg is associated with particles or colloids. The source of colloids may be soils, which, when undisturbed, contain higher concentrations of Hg than do disturbed soils and aquifer sediments. Soil disturbance during residential development and inputs from septic systems are hypothesized to mobilize Hg from soils to ground water. ?? Springer 2006.

Barringer, J.L.; Szabo, Z.

2006-01-01

317

POPULATION-LEVEL RESPONSE OF THE COMMON LOON TO MERCURY IN TWO CANADIAN PROVINCES: A MATRIX MODELING APPROACH  

EPA Science Inventory

We used data collected from Common Loon Gavia immer populations in two Canadian provinces to demonstrate a matrix population modeling approach for evaluating population-level responses to stressors and to understand how these populations may have responded to mercury contaminatio...

318

Recent changes in levels of persistent organochlorines and mercury in eggs of seabirds from the Barents Sea  

Microsoft Academic Search

Eggs of ten seabird species were collected from six regions in North Norway, Svalbard and NW Russia in 1993, and were analyzed for organochlorines (OCs) and mercury. Significant declines in levels of PCBs, p,p?-DDE, HCB, ?-HCH, ?-HCH and oxychlordane were documented in nearly half the data set since a similar study in 1983 in six of the seabird species breeding

R. T. Barrett; J. U. Skaare; G. W. Gabrielsen

1996-01-01

319

Follow-up of mercury levels in fish, human hair and urine in the Madeira and Tapajós basins, Amazon, Brazil  

Microsoft Academic Search

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted

O Malm; JRD Guimarães; MB Castro; WR Bastos; JP Viana; FJP Branches; EG Silveira; WC Pfeiffer

1997-01-01

320

Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function  

SciTech Connect

To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-{beta}-d-glucosaminidase activity (NAG) and {alpha}{sub 1}-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91{mu}g/g in hair, 0.59+/-0.32{mu}g/g in toenail, and 0.86+/-0.66{mu}g/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84{mu}g/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28{mu}g/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury ({mu}g/g)]=2.44x[toenail mercury ({mu}g/g)].

Ohno, Tomoko [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Sakamoto, Mineshi [Department of Epidemiology, National Institute for Minamata Disease, Minamata 867-0008 (Japan); Kurosawa, Tomoko [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Dakeishi, Miwako [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Iwata, Toyoto [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Murata, Katsuyuki [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan)]. E-mail: winestem@med.akita-u.ac.jp

2007-02-15

321

Calcium levels and availabilities in soils  

Microsoft Academic Search

Calcium is a member of the Alkaline Earth Family, members of which have atoms with well?shielded nucleii and two valence electrons which are readily lost thereby forming divalent cations. The basic cation, Ca, neutralizes acids, is essential for plants, and acts as a flocculator and precursor of granular structure of soils. Expressed as the oxide, Ca constitutes 5% of the

E. O. McLean

1975-01-01

322

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield  

USGS Publications Warehouse

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO3--N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman ?? = 0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r = 0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r2 = 0.73, with an overall 10??ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem. ?? 2009 Elsevier B.V.

Gabriel, M.C.; Kolka, R.; Wickman, T.; Nater, E.; Woodruff, L.

2009-01-01

323

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield.  

PubMed

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO(3)(-)-N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman rho=0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r=0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r(2)=0.73, with an overall 10 ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem. PMID:19349066

Gabriel, Mark C; Kolka, Randy; Wickman, Trent; Nater, Ed; Woodruff, Laurel

2009-06-15

324

Atmospheric mercury incorporation in soils of an area impacted by a chlor-alkali plant (Grenoble, France): contribution of canopy uptake.  

PubMed

This study focused on the fluxes of mercury (Hg) and mechanisms of incorporation into soils surrounding a chlor-alkali plant suspected to have emitted up to ~600 kg Hg year(-1) for decades into the atmosphere. Comparison of vertical Hg soil profiles with As, Cu, Ni and Zn (which were not emitted by the plant) support Hg enrichment in surface horizons due to atmospheric Hg inputs from the chlor-alkali plant. Based on chemical extractions and elemental correlations, Hg was found to be weakly leachable and bio-available for plants, and most probably strongly bound to organic matter. In contrast, other trace elements were probably associated with phyllosilicates, iron oxides or with primary minerals. Hg stocks in the surface horizon of a forested soil (1255 mg Hg m(-3)) were two-fold higher than in an agricultural soil (636 mg Hg m(-3)) at a similar distance to the plant. The difference was attributed to the interception of atmospheric Hg by the canopy (most likely gaseous elemental Hg and reactive gaseous Hg) and subsequent litterfall incorporation. Some differences in the ability to trap atmospheric Hg were observed between tree species. The characterization of the litter showed an increasing Hg concentration in the plant material proportional to their degradation stage. In agricultural soils, very low Hg concentrations found in corn leaves and grains suggested a limited uptake via both the foliar and root pathways. Thus, the short-term risk of Hg transfer to agricultural crops and higher levels of the trophic chain appeared limited. A possible risk which remains to be evaluated is the possible transfer of Hg-rich particles from the forest topsoil to downstream aquatic ecosystems during rain and snowmelt events. PMID:23354376

Guédron, Stéphane; Grangeon, Sylvain; Jouravel, Glorianne; Charlet, Laurent; Sarret, Géraldine

2013-02-15

325

The removal of mercury from solid mixed waste using chemical leaching processes  

SciTech Connect

The focus of this research was to evaluate chemical leaching as a technique to treat soils, sediments, and glass contaminated with either elemental mercury or a combination of several mercury species. Potassium iodide/iodine solutions were investigated as chemical leaching agents for contaminated soils and sediments. Clean, synthetic soil material and surrogate storm sewer sediments contaminated with mercury were treated with KI/I{sub 2} solutions. It was observed that these leaching solutions could reduce the mercury concentration in soil and sediments by 99.8%. Evaluation of selected posttreatment sediment samples revealed that leachable mercury levels in the treated solids exceeded RCRA requirements. The results of these studies suggest that KI/I{sub 2} leaching is a treatment process that can be used to remove large quantities of mercury from contaminated soils and sediments and may be the only treatment required if treatment goals are established on Hg residual concentrations in solid matrices. Fluorescent bulbs were used to simulate mercury contaminated glass mixed waste. To achieve mercury contamination levels similar to those found in larger bulbs such as those used in DOE facilities a small amount of Hg was added to the crushed bulbs. The most effective agents for leaching mercury from the crushed fluorescent bulbs were KI/I{sub 2}, NaOCl, and NaBr + acid. Radionuclide surrogates were added to both the EPA synthetic soil material and the crushed fluorescent bulbs to determine the fate of radionuclides following chemical leaching with the leaching agents determined to be the most promising. These experiments revealed that although over 98% of the dosed mercury solubilized and was found in the leaching solution, no Cerium was measured in the posttreatment leaching solution. This finding suggest that Uranium, for which Ce was used as a surrogate, would not solubilize during leaching of mercury contaminated soil or glass.

Gates, D.D.; Chao, K.K.; Cameron, P.A.

1995-07-01

326

Determination of mercury in ash and soil samples by oxygen flask combustion method--cold vapor atomic fluorescence spectrometry (CVAFS).  

PubMed

A simple method was developed for the determination of mercury (Hg) in coal fly ash (CFA), waste incineration ash (WIA), and soil by use of oxygen flask combustion (OFC) followed by cold vapor atomic fluorescence spectrometry (CVAFS). A KMnO4 solution was used as an absorbent in the OFC method, and the sample containing a combustion agent and an ash or soil sample was combusted by the OFC method. By use of Hg-free graphite as the combustion agent, the determination of Hg in ash and soil was successfully carried out; the Hg-free graphite was prepared by use of a mild pyrolysis procedure at 500 degrees C. For six certified reference materials (three CFA samples and three soil samples), the values of Hg obtained by this method were in good agreement with the certified or reference values. In addition, real samples including nine CFAs collected from some coal-fired power plants, five WIAs collected from waste incineration plants, and two soils were analyzed by the present method, and the data were compared to those from microwave-acid digestion (MW-AD) method. PMID:18023528

Geng, Wenhua; Nakajima, Tsunenori; Takanashi, Hirokazu; Ohki, Akira

2008-06-15

327

Effects of infiltration chemistry on the mobilization potential of mercury (Hg) in soils from the New Jersey Coastal Plain  

Microsoft Academic Search

Mercury concentrations in ground water exceeding the USEPA maximum contaminant level of 2 [mu]g\\/l have been found in wells 60 to 100 feet deep in the Kirkwood-Cohansey Aquifer System of the New Jersey Coastal Plain. The aquifer is a sand and gravel aquifer consisting primarily of quartz with minor amounts of biotite, plagioclase feldspars and ilmenite. This is the shallowest

C. MacLeod; E. Taylor

1992-01-01

328

Relating land cover characteristics and common loon mercury levels using geographic information systems.  

PubMed

This effort models the relationship between mercury (Hg) levels in the common loon (Gavia immer) and land cover types as defined by the National Land Cover Database (NLCD). We constructed the model within the framework of a GIS to analyze the spatial relationships between land cover types and blood Hg levels in male common loons. Thiessan polygons were used to generate the territory for each loon. We created 150, 300, and 600-m buffers around the Thiessan polygons and modeled the relationships that existed in each distance class. Within the 150-m buffer, three cover types, crop land, shrub land, and wetland were significantly related to blood Hg levels (r2 = 0.552, p < 0.001), which may indicate that the proximity of these cover types influences Hg availability in loon territories. Cropland exhibited a negative relationship with blood Hg levels and may play a role in reducing the amount of available Hg within the study area while wetlands and shrub lands exhibit a positive relationship. The study area consisted of five major lakes and eleven smaller ponds in northwest Maine, and data included a total of 61 male common loon blood Hg samples. PMID:15931970

Kramar, David; Goodale, Wing M; Kennedy, L M; Carstensen, L W; Kaur, Taranjit

2005-03-01

329

Fish Consumption, Low-Level Mercury, Lipids, and Inflammatory Markers in Children  

PubMed Central

There is considerable evidence that consuming fish has numerous health benefits, including a reduced risk of cardiovascular disease. However, fish is also the primary source of human exposure to mercury (Hg). In a cross-sectional study of 9–11 year old children (N = 100), we measured fish consumption, blood lipids, total blood Hg, diurnal salivary cortisol (4 samples collected throughout the day), and performed a proteomic analysis of serum proteins using spectral count shotgun proteomics. Children that consumed fish had a significantly more atheroprotective lipid profile but higher levels of blood Hg relative to children that did not consume fish. Although the levels of blood Hg were very low in these children (M = 0.77 ?g/L; all but 1 participant had levels below 3.27 ?g/L), increasing blood Hg was significantly associated with blunted diurnal cortisol levels. Blood Hg was also significantly associated with acute-phase proteins suggesting systemic inflammation, and several of these proteins were found to significantly reduce the association between Hg and diminished cortisol when included in the model. This study of a pediatric population is the first to document an association between blood Hg, systemic inflammation, and endocrine disruption in humans, in a pediatric sample. Without a better understanding of the long-term consequences of an atheroprotective lipid profile relative to blunted diurnal cortisol and systemic inflammation, a determination of the risk-benefit ratio for fish consumption by children is not possible. PMID:22030286

Gump, Brooks B.; MacKenzie, James A.; Dumas, Amy K.; Palmer, Christopher D.; Parsons, Patrick J.; Segu, Zaneer M.; Mechref, Yehia S.; Bendinskas, Kestutis

2011-01-01

330

Investigation of increased mercury levels in the fisheries of Lower East Fork Poplar Creek (Lefpc), Oak Ridge Reservation, Tennessee  

SciTech Connect

The DOE Western Environmental Technology Office (WETO) is supporting remediation efforts on the U.S. Department of Energy Oak Ridge Reservation in Oak Ridge, Tennessee by performing this study. MSE Technology Applications, Inc. (MSE) has performed a series of literature reviews and bench-scale testing to further evaluate the mercury problem in the Lower East Fork Poplar Creek (LEFPC) at Oak Ridge. The primary problem is that total mercury (HgT) levels in LEFPC water decrease, while HgT levels in sunfish muscle tissue increase, with distance away from the National Security Complex (NSC), despite extensive source control efforts at the facility and within downstream riparian zones. Furthermore, dissolved methylmercury (d-MeHg) levels increase downstream from the NSC, especially during warm weather and/or high flow events. MSE performed four test series that focused on conversion of aqueous phase elemental mercury (Hg deg. A) to methyl mercury (MeHg) by algal-bacterial bio-films (periphyton) present in the stream-bed of LEFPC. Small (mg/L) quantities of un-sulphured molasses and peptone were added to some of the Hinds Creek samples to stimulate initial bacterial growth. Other Hinds Creek samples either were dosed with glutaraldehyde to preclude microbial growth, or were wrapped in aluminum foil to preclude Hg photochemical redox effects. The bench-scale testing for Phase II was completed August 2006. The final reporting and the planning for Phase III testing are in progress. (authors)

Byrne-Kelly, D.; Cornish, J.; Hart, A. [MSE Technology Applications, Inc., 200 Technology Way, Butte, MT (United States); Southworth, G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Sims, L. [Bechtel Jacobs Company, Oak Ridge, TN (United States)

2007-07-01

331

Perchlorate levels in soil and waters from the Atacama Desert.  

PubMed

Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 ?g/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 ?g/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 ?g/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 ?g/L) for drinking. PMID:24165784

Calderón, R; Palma, P; Parker, D; Molina, M; Godoy, F A; Escudey, M

2014-02-01

332

Fate and aqueous transport of mercury in light of the Clean Air Mercury Rule for coal-fired electric power plants  

NASA Astrophysics Data System (ADS)

Mercury is a hazardous air pollutant emitted to the atmosphere in large amounts. Mercury emissions from electric power generation sources were estimated to be 48 metric tons/year, constituting the single largest anthropogenic source of mercury in the U.S. Settled mercury species are highly toxic contaminants of the environment. The newly issued Federal Clean Air Mercury Rule requires that the electric power plants firing coal meet the new Maximum Achievable Mercury Control Technology limit by 2018. This signifies that all of the air-phase mercury will be concentrated in solid phase which, based on the current state of the Air Pollution Control Technology, will be fly ash. Fly ash is utilized by different industries including construction industry in concrete, its products, road bases, structural fills, monifills, for solidification, stabilization, etc. Since the increase in coal combustion in the U.S. (1.6 percent/year) is much higher than the fly ash demand, large amounts of fly ash containing mercury and other trace elements are expected to accumulate in the next decades. The amount of mercury transferred from one phase to another is not a linear function of coal combustion or ash production, depends on the future states of technology, and is unknown. The amount of aqueous mercury as a function of the future removal, mercury speciation, and coal and aquifer characteristics is also unknown. This paper makes a first attempt to relate mercury concentrations in coal, flue gas, fly ash, and fly ash leachate using a single algorithm. Mercury concentrations in all phases were examined and phase transformation algorithms were derived in a form suitable for probabilistic analyses. Such important parameters used in the transformation algorithms as Soil Cation Exchange Capacity for mercury, soil mercury selectivity sequence, mercury activity coefficient, mercury retardation factor, mercury species soil adsorption ratio, and mercury Freundlich soil adsorption isotherm coefficients were derived. Mercury air-phase removal efficiency was studied as a function of dominant mercury species vapor pressures, the amount of chlorine, sorbent injection rate and adsorption capacities, and process temperature and modifications. A mercury air phase removal algorithm was derived which defines the future removal efficiencies as a function of activated carbon injection rate. Mercury adsorption on soil was studied as a function of Mercury Mass Law incorporating the dominant aquatic mercury species, pH, chlorine and sulfur concentrations, and the amount of complexed hydroxyl groups. Aquatic mercury longitudinal plume delineation was studied using the Domenico and Robbins function. A Monte Carlo simulation was performed using random number series (5000) for all of the variables in the Domenico and Robbins and mercury retardation functions. The probability that the Maximum Contaminant Level for mercury will be exceeded was found to be equal approximately 1 percent of all soil-related fly ash applications.

Arzuman, Anry

333

Soil nutrient levels on grazing farms in the northeast USA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Livestock producers in the northeastern USA rely more on forages, pasture, and grazing management to reduce production costs and remain competitive. Soil nutrient levels are one indicator of the level of nutrient management on farms. Our objective was to gain some insight into the level of various s...

334

Impact of closing Canada's largest point-source of mercury emissions on local atmospheric mercury concentrations.  

PubMed

The Flin Flon, Manitoba copper smelter was Canada's largest point source of mercury emissions until its closure in 2010 after ~80 years of operation. The objective of this study was to understand the variables controlling the local ground-level air mercury concentrations before and after this major point source reduction. Total gaseous mercury (TGM) in air, mercury in precipitation, and other ancillary meteorological and air quality parameters were measured pre- and postsmelter closure, and mercury speciation measurements in air were collected postclosure. The results showed that TGM was significantly elevated during the time period when the smelter operated (4.1 ± 3.7 ng m(-3)), decreased only 20% during the year following its closure, and remained ~2-fold above background levels. Similar trends were observed for mercury concentrations in precipitation. Several lines of evidence indicated that while smelter stack emissions would occasionally mix down to the surface resulting in large spikes in TGM concentrations (up to 61 ng m(-3)), the largest contributor to elevated TGM concentrations before and after smelter closure was from surface-air fluxes from mercury-enriched soils and/or tailings. These findings highlight the ability of legacy mercury, deposited to local landscapes over decades from industrial activities, to significantly affect local air concentrations via emissions/re-emissions. PMID:23978035

Eckley, Chris S; Parsons, Matthew T; Mintz, Rachel; Lapalme, Monique; Mazur, Maxwell; Tordon, Robert; Elleman, Robert; Graydon, Jennifer A; Blanchard, Pierrette; St Louis, Vincent

2013-09-17

335

Singular and combined effects of blowdown, salvage logging, and wildfire on forest floor and soil mercury pools.  

PubMed

A number of factors influence the amount of mercury (Hg) in forest floors and soils, including deposition, volatile emission, leaching, and disturbances such as fire. Currently the impact on soil Hg pools from other widespread forest disturbances such as blowdown and management practices like salvage logging are unknown. Moreover, ecological and biogeochemical responses to disturbances are generally investigated within a single-disturbance context, with little currently known about the impact of multiple disturbances occurring in rapid succession. In this study we capitalize on a combination of blowdown, salvage logging and fire events in the sub-boreal region of northern Minnesota to assess both the singular and combined effects of these disturbances on forest floor and soil total Hg concentrations and pools. Although none of the disturbance combinations affected Hg in mineral soil, we did observe significant effects on both Hg concentrations and pools in the forest floor. Blowdown increased the mean Hg pool in the forest floor by 0.76 mg Hg m(-2) (223%). Salvage logging following blowdown created conditions leading to a significantly more severe forest floor burn during wildfire, which significantly enhanced Hg emission. This sequence of combined events resulted in a mean loss of approximately 0.42 mg Hg m(-2) (68% of pool) from the forest floor, after conservatively accounting for potential losses via enhanced soil leaching and volatile emissions between the disturbance and sampling dates. Fire alone or blowdown followed by fire did not significantly affect the total Hg concentrations or pools in the forest floor. Overall, unexpected consequences for soil Hg accumulation and by extension, atmospheric Hg emission and risk to aquatic biota, may result when combined impacts are considered in addition to singular forest floor and soil disturbances. PMID:22747193

Mitchell, Carl P J; Kolka, Randall K; Fraver, Shawn

2012-08-01

336

Regional differences in mercury levels in aquatic ecosystems: A discussion of possible causal factors with implications for the Tennessee River System and the Northern Hemisphere  

Microsoft Academic Search

Concern about mercury pollution from atmospheric deposition has risen markedly in the last decade because of high levels of mercury in freshwater fish from relatively pristine waters. Whereas high concentrations have been found principally in Canada, the northern United States, and Scandinavia, they have also recently been observed throughout much of Florida. Recent surveys of the Tennessee River system, however,

Joslin

2009-01-01

337

Regional differences in mercury levels in aquatic ecosystems: A discussion of possible causal factors with implications for the Tennessee river system and the Northern Hemisphere  

Microsoft Academic Search

Concern about mercury pollution from atmospheric deposition has risen markedly in the last decade because of high levels of mercury in freshwater fish from relatively pristine waters. Whereas high concentrations have been found principally in Canada, the northern United States, and Scandinavia, they have also recently been observed throughout much of Florida. Recent surveys of the Tennessee River system, however,

J. Devereux Joslin

1994-01-01

338

Mercury Levels in Mink ( Mustela vison ) and River Otter ( Lontra canadensis ) from Northeastern North America  

Microsoft Academic Search

Aquatic ecosystems have received mercury released from anthropogenic sources. The northeast region of North America is at especially high risk because of local and regional emission sources, prevailing wind patterns, and certain hydrological and biogeochemical features. Here we examine regional variation in total mercury (Hg) in brain, liver, and fur from otter and mink collected across New York, New England,

David E. Yates; David T. Mayack; Kenneth Munney; David C. Evers; Andrew Major; Taranjit Kaur; Robert J. Taylor

2005-01-01

339

Relationship between blood mercury levels and components of male song in Nelson's sparrows (Ammodramus nelsoni).  

PubMed

Mercury (Hg) adversely affects the health and behavior of exposed wildlife; however, behavioral effects remain largely unknown. Changes in avian singing behavior may affect a male's fitness because song reveals male quality and thus influences female mate choice and male territory-holding ability. Nelson's sparrows (Ammodramus nelsoni) live exclusively on salt marshes and risk high levels of Hg exposure and bioaccumulation. We recorded songs of male Nelson's sparrows at two locations with different Hg exposure to determine if total blood Hg concentration was related to song characteristics, as previously reported for other species. Males with higher blood Hg levels sang at higher maximum tonal frequency, but blood Hg and site location did not influence low tonal frequency and bout duration, contrary to predictions based on other species. Within the contaminated site, Hg levels were related to bouts per minute and gap duration, such that males at that site sang faster songs. Hg influences hormones and alters brain development, raising questions about specific effects on the brains and singing behavior of male Nelson's sparrows. PMID:22945769

McKay, Jennifer L; Maher, Christine R

2012-11-01

340

DEVELOPMENT AND TEST APPLICATION A SCREENING-LEVEL MERCURY FATE MODEL AND TOOL FOR EVALUATING WILDLIFE EXPOSURE RISK FOR SURFACE WATERS WITH MERCURY-CONTAMINATED SEDIMENTS (SERAFM)  

EPA Science Inventory

Complex chemical cycling of mercury in aquatic ecosystems means that tracing the linkage between anthropogenic and natural loadings of mercury to watersheds and water bodies and associated concentrations in the environment are difficult to establish without the assistance of nume...

341

Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects.  

PubMed

A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6-11 years) and their mothers (? 45 years) living in urban or rural areas of Belgium. The geometric mean levels for mercury in hair were 0.383 ?g/g and 0.204 ?g/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04 ?g/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1 ?g/l for adults), and 9% exceeded the 1 ?g mercury/g hair suggested by the US EPA. PMID:24333995

Pirard, Catherine; Koppen, Gudrun; De Cremer, Koen; Van Overmeire, Ilse; Govarts, Eva; Dewolf, Marie-Christine; Van De Mieroop, Els; Aerts, Dominique; Biot, Pierre; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Angerer, Jürgen; Koch, Holger M; Schindler, Birgit K; Castaño, Argelia; Esteban, Marta; Schoeters, Greet; Den Hond, Elly; Sepai, Ovnair; Exley, Karen; Horvat, Milena; Bloemen, Louis; Knudsen, Lisbeth E; Joas, Reinhard; Joas, Anke; Van Loco, Joris; Charlier, Corinne

2014-02-15

342

Changes in Soil Nitrate-N Levels from Late Summer to Early Spring in Montana  

E-print Network

Changes in Soil Nitrate-N Levels from Late Summer to Early Spring in Montana Clain Jones 1 their N rates based on fall soil sampling. Methods We measured soil nitrate levels in the upper 2 feet (if) and several soil characteristics (organic matter, pH, soil texture and soil water content in the upper 6 and 6

Lawrence, Rick L.

343

Neurobehavioral effects of combined prenatal exposure to low-level mercury vapor and methylmercury.  

PubMed

We evaluated the effects of prenatal exposure to low-level mercury (Hg(0)) or methylmercury (MeHg) as well as combined exposure (Hg(0) + MeHg exposure) on the neurobehavioral function of mice. The Hg(0) exposure group was exposed to Hg(0) at a mean concentration of 0.030 mg/m(3) for 6 hr/day during gestation period. The MeHg exposure was supplied with food containing 5 ppm of MeHg from gestational day 1 to postnatal day 10. The combined exposure group was exposed to both Hg(0) vapor and MeHg according to above described procedure. After delivery, when their offspring reached the age of 8 weeks, behavioral analysis was performed. Open field (OPF) tests of the offspring showed an increase and decrease in voluntary activity in male and female mice, respectively, in the MeHg exposure group. In addition, the rate of central entries was significantly higher in this group than in the control group. The results of OPF tests in the Hg(0) + MeHg exposure group were similar to those in the MeHg exposure group in both males and females. The results in the Hg(0) exposure group did not significantly differ from those in the control group in males or females. Passive avoidance response (PA) tests revealed no significant differences in avoidance latency in the retention trial between the Hg(0), MeHg, or Hg(0) + MeHg exposure group and the control group in males or females. Morris water maze tests showed a delay in the latency to reach the platform in the MeHg and Hg(0) + MeHg exposure groups compared with the control group in males but no significant differences between the Hg(0), MeHg, or Hg(0) + MeHg exposure group and the control group in females. The results of OPF tests revealed only slight effects of prenatal low-level Hg(0) exposure (0.03 mg/m(3)), close to the no-observable-effect level (NOEL) stated by the WHO (0.025 mg/m(3)), on the subsequent neurobehavioral function. However, prenatal exposure to 5 ppm of MeHg affected exploratory activity in the OPF test, and, in particular, male mice were highly sensitive to MeHg. The MeHg and Hg(0) + MeHg exposure groups showed similar neurobehavioral effects. Concerning the effects of prenatal mercury exposure under the conditions of this study, the effects of MeHg exposure may be more marked than those of Hg(0) exposure. PMID:21297343

Yoshida, Minoru; Suzuki, Megumi; Satoh, Masahiko; Yasutake, Akira; Watanabe, Chiho

2011-01-01

344

Mercury in hair and blood from residents of Phnom Penh (Cambodia) and possible effect on serum hormone levels.  

PubMed

High concentration of mercury (Hg) in hair has been reported for Cambodians. To confirm the Hg contamination occurring through intake, Hg concentrations were determined in both hair and blood of residents (n=20) from Phnom Penh, Cambodia. Mercury concentrations in the hair and blood were 0.69-190microg g(-1) dry wt and 5.2-58microg l(-1), respectively, which were lower than those from Hg contaminated or high fish intake regions, but were higher than those from non-contaminated regions. Some female subjects had hair and blood Hg levels exceeding the threshold values for neurotoxic effects. Interestingly, serum estrone and estradiol levels were positively correlated with blood Hg level for both males and females, indicating possible induction of female hormones by Hg exposure in Cambodians. PMID:17292448

Agusa, Tetsuro; Kunito, Takashi; Iwata, Hisato; Monirith, In; Chamnan, Chhoun; Tana, Touch Seang; Subramanian, Annamalai; Tanabe, Shinsuke

2007-06-01

345

Factors influencing blood mercury levels of inhabitants living near fishing areas.  

PubMed

Methylmercury (MeHg), a well-known neuro-toxicant, is usually emitted by industrial and other man-made activities; it is ingested with seafood and shellfish, and accumulates in the human body. The aim of this study was to compare the differences in blood levels of total mercury (T-Hg) and MeHg in residents of 4 coastal sites and 4 inland sites around Taiwan. Meanwhile, the potential question is warranted to find out the association between dietary intake and MeHg accumulation. We found that coastal residents had significantly higher mean blood T-Hg levels (mean: 16.1 ?g/L, range: 0.9-184.9 ?g/L) than inland residents (mean: 11.8 ?g/L, range: 0.8-146.6 ?g/L). The same was for blood MeHg levels: coastal residents (mean: 16.5 ?g/L, range: 0.9-184.9 ?g/L), inland residents (mean: 11.8 ?g/L, range: 2.1-133.4 ?g/L). These elevated levels were positively associated with seafood and shellfish consumption. However, the nature of their residential area may also be an important factor, because the highest T-Hg and MeHg levels were found in residents of a relatively non-industrialized area. To protect vulnerable population-especially children and pregnant women-it is important to know whether locally caught or raised and consumed fish has any source of Hg and MeHg pollution. PMID:22444062

Lee, Ching-Chang; Chang, Jung-Wei; Huang, Hsin-Yi; Chen, Hsiu-Ling

2012-05-01

346

Mercury gas exchanges over selected bare soil and flooded sites in the bay St. François wetlands (Québec, Canada)  

Microsoft Academic Search

In order to evaluate and understand the mercury gas exchange processes in fluvial wetlands, related researches were initiated in a St. Lawrence River wetland (Bay St. François, Qué., Canada). Mercury fluxes were measured using dynamic flux chamber methods, coupled with an automatic mercury vapor analyzer (namely, Tekran, Model 2537A). Mercury air–surface gas exchanges as well as meteorological conditions were measured

Laurier Poissant; Martin Pilote; Philippe Constant; Conrad Beauvais; Hong H Zhang; Xiaohong Xu

2004-01-01

347

Landscape-level patterns of mercury contamination of fish in North Texas, USA.  

PubMed

Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to humans. An emerging conceptual model predicts that the areas of the landscape that have the potential to contain food webs with elevated concentrations of Hg are those that receive high amounts of Hg and sulfate deposition and have high coverage of forests and wetlands and low coverage of agriculture. The objective of the present study was to test this conceptual model using concentrations of Hg in largemouth bass (Micropterus salmoides) from 145 reservoirs in four ecoregions of North Texas. The highest level of Hg contamination in fish was in the South Central Plains, the ecoregion that receives the highest levels of Hg and sulfate deposition and contains extensive forest and wetland habitat and little agriculture. The present study has important implications for other areas of the United States, because the South Central Plains extend into parts of Oklahoma, Louisiana, and Arkansas, covering a total area of 152,132 km(2) of the southern United States. PMID:21647946

Drenner, Ray W; Chumchal, Matthew M; Wente, Stephen P; McGuire, Mandy; Drenner, S Matthew

2011-09-01

348

Heavy metal concentrations in feathers of common loons (Gavia immer) in the Northeastern United States and age differences in mercury levels.  

PubMed

Feathers serve as a useful, non-destructive approach for biomonitoring some aspects of environmental quality. Birds can eliminate over 90% of their body burden of mercury by sequestration in growing feathers, and they molt their feathers at least annually. Thus mercury concentrations should not vary in avian feathers as a function of age. We tested the null hypothesis that there are no age differences in the concentrations of mercury, lead, cadmium, selenium, copper, chromium and manganese in the feathers of immature and adult common loons Gavia immer from the Northeastern United States where the species is declining. Adults had significantly higher mean levels of mercury (20245 ppb) than immature loons (9677 ppb), but there were no age-related differences for other elements. Even with the small number of immatures, females had significantly higher levels of mercury than males, although the gender difference was not significant for adults. PMID:24213705

Burger, J; Pokras, M; Chafel, R; Gochfeld, M

1994-03-01

349

A coupled monitoring network to conduct an assessment of mercury transformation and mobilization in floodplain soils: South River, Virginia  

NASA Astrophysics Data System (ADS)

Mercury (Hg) was used between 1929 and 1950 by the DuPont plant in the production of rayon acetate fiber in Waynesboro, Virginia and released into the South River. The contamination of Hg was discovered in the 1970s and remained elevated in water, soil, sediments, and biota. The primary goal of this study is to investigate the processes that govern biogeochemical transformation and mobilization of Hg in floodplain soils at South River Mile 3.5, characterize geochemical gradients in soils and how they change over time, and to enable targeted sampling at Hg loading hot spots. The biogeochemical data will play a supporting role and be used to further develop our understanding of the processes controlling the leaching of Hg and our conceptual model. Our over-arching hypothesis is to test if leaching of bank soils is a significant source of dissolved or colloidal inorganic Hg. This effort requires an interdisciplinary geochemical approach and sensor technology to understand the interactions between floodplain soil, groundwater, and river. Our investigation will include 10 months' worth data from a number of state-of-the-art in-situ monitoring sensors, such as custom-designed redox probes, soil moisture, temperature, pressure, and conductivity installed at the site. Our preliminary results showed that the concentration of total Hg in soils was up to 900 mg/kg (wet weight).There is a significant redox gradient across the floodplain soil profile. Within the top 40 -70 cm, major changes in redox conditions from oxidizing (Eh ?+600 mV) to very reducing (Eh ?-300 mV) corresponded to heavy rainfall and overbank flooding events. High variations in stream stage may govern the surface water - groundwater exchange facilitating the downward or upward movement of the capillary fringe and saturated zone through the soil horizons, affecting soil redox potential, stability of Hg-bearing minerals and leaching of inorganic Hg into dissolved and colloidal phases. These phases may be directly transported to the South River or methylated within the saturated zone of the bank and subsequently released.

Lazareva, O.; Sparks, D. L.; Landis, R.; Ptacek, C. J.; Hicks, S.; Montgomery, D.

2013-12-01

350

How humic substances dominate mercury geochemistry in contaminated floodplain soils and sediments  

Microsoft Academic Search

The interaction of mercury (Hg) and humic substances (hs) was studied in floodplain topsoils and surface sediments of the contaminated German river Elbe. An intimate coupling exists between the geochemical cycles of Hg and organic carbon (OC) in this ecosystem. Humic substances exert a dominant influence on several important parallel geochemical pathways of Hg, including binding, transformation, and transport processes.

D. Wallschlaeger; Madhukar V. M. Desai; Markus Spengler; C. C. Windmoeller; Rolf-Dieter Wilken

1998-01-01

351

Mercury Concentrations in Plant Tissues as Affected by FGDG Application to Soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flue Gas Desulfurization Gypsum (FGDG) is produced by reducing sulfur dioxide emissions from themo-electric coal-fired power plants. The most common practice of FGDG production may trap some of the Mercury (Hg) present in the coal that normally would escape as vapor in the stack gases. Concern for t...

352

Landscape influence on soil carbon and nutrient levels  

Technology Transfer Automated Retrieval System (TEKTRAN)

Past runoff, erosion, and management practices influence nutrient levels on the landscape. These starting levels affect future nutrient transport due to runoff, erosion, and leaching events. The purpose of this study was to examine closed-depression landscape effects on surface soil organic matter, ...

353

Mercury toxicity in plants  

Microsoft Academic Search

Mercury poisoning has become a problem of current interest as a result of environmental pollution on a global scale. Natural\\u000a emissions of mercury form two-thirds of the input; manmade releases form about one-third. Considerable amounts of mercury\\u000a may be added to agricultural land with sludge, fertilizers, lime, and manures. The most important sources of contaminating\\u000a agricultural soil have been the

Manomita Patra; Archana Sharma

2000-01-01

354

Mercury levels in walleyes from Wisconsin lakes of different water and sediment chemistry characteristics  

Microsoft Academic Search

Forty-three lakes throughout Wisconsin were sampled in 1985-86 to determine the water and sediment chemistry characteristics that were associated with elevated concentrations of mercury in walleyes. Mean mercury concentrations for each of three different length classes of walleyes increased as the parameters lake pH, alkalinity, calcium, conductivity, or chlorophyll-a decreased. Low values for these parameters characterized most lakes in northern

R. C. Lathrop; K. C. Noonan; P. M. Guenther; T. L. Brasino; P. W. Rasmussen

1989-01-01

355

Mercury levels in walleyes from Wisconsin lakes of different water and sediment chemistry characteristics  

SciTech Connect

Forty-three lakes throughout Wisconsin were sampled in 1985-86 to determine the water and sediment chemistry characteristics that were associated with elevated concentrations of mercury in walleyes. Mean mercury concentrations for each of three different length classes of walleyes increased as the parameters lake pH, alkalinity, calcium, conductivity, or chlorophyll-a decreased. Low values for these parameters characterized most lakes in northern Wisconsin. Mean mercury concentrations exceeded the Wisconsin health standard of 0.5 micrograms (ug) Hg/g wet weight of fish for all walleye length classes in lakes with pH values < 6.0, for walleyes > or = to 15.0 inches in lakes with pH 6.0-6.9, and for walleyes > or = 20.0 in. in all lake pH categories. Apparently the older, larger walleyes in hard water as well as soft water lakes can accumulate enough mercury to warrant concern. Sediment mercury concentrations were generally < or = 0.02 ug/g dry weight for all study lakes, but sediment mercury and organic matter were higher in lakes with pH values < 7.0 than in lakes with pH > or = 7.0. Models were developed and tested to predict mercury concentrations in a 17-in. walleye for each lake. The best model derived from the study and tested on an independent dataset used alkalinity and calcium as independent variables. Clearly, walleyes from soft water, poorly buffered, low pH lakes have the highest concentrations of mercury, but the reasons for these higher concentrations require further study. 67 refs., 5 figs., 27 tabs.

Lathrop, R.C.; Noonan, K.C.; Guenther, P.M.; Brasino, T.L.; Rasmussen, P.W.

1989-01-01

356

Estimation and mapping of wet and dry mercury deposition across northeastern North America  

USGS Publications Warehouse

Whereas many ecosystem characteristics and processes influence mercury accumulation in higher trophic-level organisms, the mercury flux from the atmosphere to a lake and its watershed is a likely factor in potential risk to biota. Atmospheric deposition clearly affects mercury accumulation in soils and lake sediments. Thus, knowledge of spatial patterns in atmospheric deposition may provide information for assessing the relative risk for ecosystems to exhibit excessive biotic mercury contamination. Atmospheric mercury concentrations in aerosol, vapor, and liquid phases from four observation networks were used to estimate regional surface concentration fields. Statistical models were developed to relate sparsely measured mercury vapor and aerosol concentrations to the more commonly measured mercury concentration in precipitation. High spatial resolution deposition velocities for different phases (precipitation, cloud droplets, aerosols, and reactive gaseous mercury (RGM)) were computed using inferential models. An empirical model was developed to estimate gaseous elemental mercury (GEM) deposition. Spatial patterns of estimated total mercury deposition were complex. Generally, deposition was higher in the southwest and lower in the northeast. Elevation, land cover, and proximity to urban areas modified the general pattern. The estimated net GEM and RGM fluxes were each greater than or equal to wet deposition in many areas. Mercury assimilation by plant foliage may provide a substantial input of methyl-mercury (MeHg) to ecosystems. ?? 2005 Springer Science+Business Media, Inc.

Miller, E.K.; Vanarsdale, A.; Keeler, G.J.; Chalmers, A.; Poissant, L.; Kamman, N.C.; Brulotte, R.

2005-01-01

357

Is there a chronological record of atmospheric mercury and lead deposition preserved in the mor layer (O-horizon) of boreal forest soils?  

NASA Astrophysics Data System (ADS)

The organic horizon (the mor layer) of podzolized boreal forest soils has accumulated atmospheric fallout of mercury and lead over centuries, resulting in current concentrations close to levels where negative effects on soil biota are thought to occur. To what extent the pollution history is preserved in the stratigraphy of this horizon is not well known. In this study we asses whether the chronology of a large historic pulse of atmospheric pollution emitted from the Rönnskär smelter in northern Sweden, particularly between 1950 and 1980, is preserved within the stratigraphy of the mor layer, which is typically 5-cm thick. Vertical sub-sampling (?5 mm) of five mor profiles sampled along a 100-km pollution gradient away from the smelter are analyzed for mercury and lead concentrations, spheroidal carbonaceous particles from fossil fuel combustion (SCPs) and stable lead isotopes ( 206Pb/ 207Pb and 208Pb/ 207Pb). Their vertical distribution is compared with the temporal variations in atmospheric inputs reconstructed for the last ˜100 years from analyses of an ombrotrophic peat core and a varved lake sediment core sampled within a distance of 50 km of the smelter. The mor profiles situated ?12 km from the smelter record the pollution history of the smelter. There is a 20 to 40-times enrichment of Hg, Pb and SCP at the transition in the O-horizon from the F- to H-layer compared to the basal part and a distinct peak in the 206Pb/ 207Pb ratio (˜1.22) in the F-layer. The mor profiles situated outside the historical contamination range of the smelter (80 and 100 km away) record no obvious influence from the Rönnskär smelter, instead their vertical 206Pb/ 207Pb profiles follow the general regional pollution history in northern Sweden. We conclude that the mor layer preserves a record of atmospheric Hg, Pb and SCP inputs and due to low leaching rates this organic horizon serves as a semi-archive of atmospheric Hg and Pb pollution. We stress the need of including this property in the existing 'black-box' models predicting the fate of Hg and Pb within contaminated boreal forest soils.

Klaminder, Jonatan; Bindler, Richard; Rydberg, Johan; Renberg, Ingemar

2008-02-01

358

IMPACT OF ELIMINATING MERCURY REMOVAL PRETREATMENT ON THE PERFORMANCE OF A HIGH LEVEL RADIOACTIVE WASTE MELTER OFFGAS SYSTEM  

SciTech Connect

The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: (1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; (2) adjust feed rheology; and (3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid pretreatment has been proposed to eliminate the production of hydrogen in the pretreatment systems; alternative reductants would be used to control redox. However, elimination of formic acid would result in significantly more mercury in the melter feed; the current specification is no more than 0.45 wt%, while the maximum expected prior to pretreatment is about 2.5 wt%. An engineering study has been undertaken to estimate the effects of eliminating mercury removal on the melter offgas system performance. A homogeneous gas-phase oxidation model and an aqueous phase model were developed to study the speciation of mercury in the DWPF melter offgas system. The model was calibrated against available experimental data and then applied to DWPF conditions. The gas-phase model predicted the Hg{sub 2}{sup 2-}/Hg{sup 2+} ratio accurately, but some un-oxidized Hg{sup 0} remained. The aqueous model, with the addition of less than 1 mM Cl{sub 2} showed that this remaining Hg{sup 0} would be oxidized such that the final Hg{sub 2}{sup 2+}/Hg{sup 2+} ratios matched the experimental data. The results of applying the model to DWPF show that due to excessive shortage of chloride, only 6% of the mercury fed is expected to be chlorinated, mostly as Hg{sub 2}Cl{sub 2}, while the remaining mercury would exist either as elemental mercury (90%) or HgO (4%).

Zamecnik, J; Alexander Choi, A

2009-03-17

359

Follow-up of mercury levels in fish, human hair and urine in the Madeira and Tapajós basins, Amazon, Brazil  

Microsoft Academic Search

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments\\u000a showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira\\u000a river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted

O. Malm; J. R. D. Guimarães; M. B. Castro; W. R. Bastos; J. P. Viana; F. J. P. Branches; E. G. Silveira; W. C. Pfeiffer

1997-01-01

360

Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils  

Microsoft Academic Search

Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil–earthworm) followed

Gregor Ernst; Stefan Zimmermann; Peter Christie; Beat Frey

2008-01-01

361

INVESTIGATION OF THE LIGHT ENHANCED EMISSION OF MERCURY FROM NATURALLY ENRICHED SUBSTRATES. (R827622E02)  

EPA Science Inventory

Incident radiation has been reported to facilitate mercury release from soils. In this study the influence of light on mercury emissions from substrates amended with pure synthetic mercury species, and from naturally and anthropogenically mercury-enriched substrates were inves...

362

Goldilocks and three factors that make mercury in fish more than just mercury deposition: sulfur, land use and climate (Invited)  

NASA Astrophysics Data System (ADS)

The problem of mercury in fish is often framed as a problem created by anthropogenic emissions of mercury increasing the levels of mercury in the environment. But the methylation step that is crucial to making mercury available for bioaccumulation in the aquatic food web is influenced by more than just the concentration of mercury in the environment. Redox conditions, the quality of organic matter, and, in the case of methylation by sulfur reducing bacteria, the availability of sulfur, have all been shown to influence methylmercury concentrations in surface waters and/or mercury in the biota. This creates many possibilities for human influence on mercury bioaccumulation in freshwater fish. But it also creates possibilities for mitigating those human influences, if we can understand them. Forest harvest is one type of land use with a documented human influence on mercury levels in fish. Atmospheric deposition of sulfur is another potential influence on the mercury cycle, as is warming of the climate. Some for the possibilities for controlling the mercury problem may be overlooked by too much focus on mercury deposition and concentrations of total mercury in the landscape relative to these other factors. A range of field studies in FennoScandia published over the last 15 years were analyzed to explore the relative contribution of these different anthropogenic factors on the cycling of mercury. The studies included synoptic surveys across gradients of atmospheric deposition and land use (clear felling, site preparation and stump harvest) in relation to either fish mercury, sediment mercury, peat methylation potential or methylmercury concentrations in water. Long-term field manipulations (6-15 years) of land use (forest harvest) or combinations of sulphur deposition, nitrogen deposition and well greenhouse warming on peatland were also studied. The results suggest that the variation of total mercury in soils or water is less important than several of the other factors influenced by human activity. Two of the most important of these other factors are sulphur deposition and forest harvest. But these influences can also be neutralized by yet other factors (such as greenhouse warming in the case of sulphur deposition). This helps explain why different types of human influence have been so hard to discern from spatial and temporal patterns of mercury in fish, even though there is good reason to suggestion that forestry and atmospheric sulfur deposition are major factors in the mercury problem with regards to fish in FennoScandia and other high-latitude regions.

Bishop, K. H.; Eklöf, K.; Nilsson, M. B.; Osterwalder, S.; Åkerblom, S.

2013-12-01

363

Relationship between mercury accumulation in young-of-the-year yellow perch and water-level fluctuations  

USGS Publications Warehouse

A three-year (2001 -2003) monitoring effort of 14 northeastern Minnesota lakes was conducted to document relationships between water-level fluctuations and mercury bioaccumulation in young-of-the-year (YOY) yellow perch (Perca flavescens) collected in the fall of each year at fixed locations. Six of those lakes are located within or adjacent to Voyageurs National Park and are influenced by dams on the outlets of Rainy and Namakan lakes. One site on Sand Point Lake coincides with a location that has nine years of previous monitoring suitable for addressing the same issue over a longer time frame. Mean mercury concentrations in YOY yellow perch at each sampling location varied significantly from year to year. For the 12-year monitoring site on Sand Point Lake, values ranged from 38 ng gww-1 in 1998 to 200 ng gww -1 in 2001. For the 14-lake study, annual mean concentrations ranged by nearly a factor of 2, on average, for each lake over the three years of record. One likely factor responsible for these wide variations is that annual water-level fluctuations are strongly correlated with mercury levels in YOY perch for both data sets. ?? 2005 American Chemical Society.

Sorensen, J.A.; Kallemeyn, L.W.; Sydor, M.

2005-01-01

364

Sources of Mercury to East Fork Poplar Creek Downstream from the Y-12 National Security Complex: Inventories and Export Rates  

SciTech Connect

East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee, has been heavily contaminated with mercury (also referred to as Hg) since the 1950s as a result of historical activities at the U.S. Department of Energy (DOE) Y-12 National Security Complex (formerly the Oak Ridge Y-12 Plant and hereinafter referred to as Y-12). During the period from 1950 to 1963, spills and leaks of elemental mercury (Hg{sup 0}) contaminated soil, building foundations, and subsurface drainage pathways at the site, while intentional discharges of mercury-laden wastewater added 100 metric tons of mercury directly to the creek (Turner and Southworth 1999). The inventory of mercury estimated to be lost to soil and rock within the facility was 194 metric tons, with another estimated 70 metric tons deposited in floodplain soils along the 25 km length of EFPC (Turner and Southworth 1999). Remedial actions within the facility reduced mercury concentrations in EFPC water at the Y-12 boundary from > 2500 ng/L to about 600 ng/L by 1999 (Southworth et al. 2000). Further actions have reduced average total mercury concentration at that site to {approx}300 ng/L (2009 RER). Additional source control measures planned for future implementation within the facility include sediment/soil removal, storm drain relining, and restriction of rainfall infiltration within mercury-contaminated areas. Recent plans to demolish contaminated buildings within the former mercury-use areas provide an opportunity to reconstruct the storm drain system to prevent the entry of mercury-contaminated water into the flow of EFPC. Such actions have the potential to reduce mercury inputs from the industrial complex by perhaps as much as another 80%. The transformation and bioaccumulation of mercury in the EFPC ecosystem has been a perplexing subject since intensive investigation of the issue began in the mid 1980s. Although EFPC was highly contaminated with mercury (waterborne mercury exceeded background levels by 1000-fold, mercury in sediments by more than 2000-fold) in the 1980s, mercury concentrations in EFPC fish exceeded those in fish from regional reference sites by only a little more than 10-fold. This apparent low bioavailability of mercury in EFPC, coupled with a downstream pattern of mercury in fish in which mercury decreased in proportion to dilution of the upstream source, lead to the assumption that mercury in fish would respond to decreased inputs of dissolved mercury to the stream's headwaters. However, during the past two decades when mercury inputs were decreasing, mercury concentrations in fish in Lower EFPC (LEFPC) downstream of Y-12 increased while those in Upper EFPC (UEFPC) decreased. The key assumption of the ongoing cleanup efforts, and concentration goal for waterborne mercury were both called into question by the long-term monitoring data. The large inventory of mercury within the watershed downstream presents a concern that the successful treatment of sources in the headwaters may not be sufficient to reduce mercury bioaccumulation within the system to desired levels. The relative importance of headwater versus floodplain mercury sources in contributing to mercury bioaccumulation in EFPC is unknown. A mercury transport study conducted by the Tennessee Valley Authority (TVA) in 1984 estimated that floodplain sources contributed about 80% of the total annual mercury export from the EFPC system (ORTF 1985). Most of the floodplain inputs were associated with wet weather, high flow events, while much of the headwater flux occurred under baseflow conditions. Thus, day-to-day exposure of biota to waterborne mercury was assumed to be primarily determined by the Y-12 source. The objective of this study was to evaluate the results of recent studies and monitoring within the EFPC drainage with a focus on discerning the magnitude of floodplain mercury sources and how long these sources might continue to contaminate the system after headwater sources are eliminated or greatly reduced.

Southworth, George R [ORNL; Greeley Jr, Mark Stephen [ORNL; Peterson, Mark J [ORNL; Lowe, Kenneth Alan [ORNL; Ketelle, Richard H [ORNL; Floyd, Stephanie B [ORNL

2010-02-01

365

Method for fixating sludges and soils contaminated with mercury and other heavy metals  

DOEpatents

The invention relates to a method, composition and apparatus for stabilizing mercury and other heavy metals present in a particulate material such that the metals will not leach from the particulate material. The method generally involves the application of a metal reagent, a sulfur-containing compound, and the addition of oxygen to the particulate material, either through agitation, sparging or the addition of an oxygen-containing compound.

Broderick, Thomas E.; Roth, Rachel L.; Carlson, Allan L.

2005-06-28

366

Mercury Exposure and Children's Health  

Microsoft Academic Search

Acute or chronic mercury exposure can cause adverse effects during any period of development. Mercury is a highly toxic element; there is no known safe level of exposure. Ideally, neither children nor adults should have any mercury in their bodies because it provides no physiological benefit. Prenatal and postnatal mercury exposures occur frequently in many different ways. Pediatricians, nurses, and

Stephan Bose-O'Reilly; Kathleen M. McCarty; Nadine Steckling; Beate Lettmeier

2010-01-01

367

Reactivity and mobility of new and old mercury deposition in a boreal forest ecosystem during the first year of the METAALICUS study  

USGS Publications Warehouse

The METAALICUS (Mercury Experiment To Assess Atmospheric Loading In Canada and the US) project is a whole ecosystem experiment designed to study the activity, mobility, and availability of atmospherically deposited mercury. To investigate the dynamics of mercury newly deposited onto a terrestrial ecosystem, an enriched stable isotope of mercury (202Hg) was sprayed onto a Boreal forest subcatchment in an experiment that allowed us, for the first time, to monitor the fate of "new" mercury in deposition and to distinguish it from native mercury historically stored in the ecosystem. Newly deposited mercury was more reactive than the native mercury with respect to volatilization and methylation pathways. Mobility through runoff was very low and strongly decreased with time because of a rapid equilibration with the large native pool of "bound" mercury. Over one season, only ???8% of the added 202Hg volatilized to the atmosphere and less than 1% appeared in runoff. Within a few months, approximately 66% of the applied 202Hg remained associated with above ground vegetation, with the rest being incorporated into soils. The fraction of 202Hg bound to vegetation was much higher than seen for native Hg (<5% vegetation), suggesting that atmospherically derived mercury enters the soil pool with a time delay, after plants senesce and decompose. The initial mobility of mercury received through small rain events or dry deposition decreased markedly in a relatively short time period, suggesting that mercury levels in terrestrial runoff may respond slowly to changes in mercury deposition rates.

Hintelmann, H.; Harris, R.; Heyes, A.; Hurley, J.P.; Kelly, C.A.; Krabbenhoft, D.P.; Lindberg, S.; Rudd, J.W.M.; Scott, K.J.; St. Louis, V.L.

2002-01-01

368

Effects of reservoir drawdown and refill on mercury levels in fish and other biota  

SciTech Connect

Mercury bioavailability from contaminated sediments is controlled by methylation, related to bacterial activity and degradable organic material. These variables may be affected by large changes in water level and chemistry in a reservoir. At Par Pond, a 1,200 ha impoundment on the USDOE Savannah River Site, South Carolina, potential failure of an earthen dam prompted lowering the reservoir by 3 meters over a two month period in 1991, decreasing water volume about 70%. The reservoir was refilled over a two month period in 1995. Largemouth bass (Micropterus salmoides) were sampled at quarterly intervals before, during and after the drawdown. Length and weight were determined, and liver and muscle analyzed for total Hg. Hg was also measured in top level predators (alligators), forage fish, macrophytes and invertebrates. From Fall 1991 Winter 1994--5, Hg ranged from 0.05 to 2.0 ug/g wet mass in bass muscle, and was strongly related to fish size, based on about 400 fish. Condition factor rose soon after drawdown, then declined as forage populations collapsed. Using fish size as covariate, bass muscle Hg was greater in spring 1992 than all other sampling dates. However, after 3 years of drawdown, there was no overall trend in bass Hg. Forage species differed in Hg, with highest concentrations in brook silversides (0.13 {micro}g Hg/g wet mass in 2 g fish). Alligators contained up to 20 {micro}g Hg/g dry mass in liver. Refill caused inundation of terrestrial plants on exposed sediments, and microbial action associated with the decay of these may enhance Hg methylation. Experiments with caged fish are underway to measure uptake rates.

Jagoe, C.H.; Salice, C.; Yabnochko, G.; Grasman, B.T.; Youngblood, T. [Savannah River Ecology Lab., Aiken, SC (United States)

1995-12-31

369

New Jersey mercury regulations  

SciTech Connect

Mercury, or quicksilver, and its major ore cinnabar (HgS) have been known for thousands of years. Health effects from mercury such as dementia were known as early as the late 19th century ({open_quotes}mad as a hatter{close_quotes}). In the 1960`s and 1970`s, reported levels of mercury in tuna reawakened public awareness of mercury pollution. In the 1970`s, major epidemics of acute mercury poisoning were reported in Japan and Iraq. These incidents highlighted the extreme health risks, such as kidney damage, birth defects, and death, associated with severe mercury poisoning. Fetuses and young children are particularly vulnerable since mercury poisoning can damage growing neural tissues. Recently, the perception of mercury as a dangerous pollutant has been on the rise. Advisories warning the public to avoid or reduce the consumption of freshwater fish caught in specific waterbodies due to mercury contamination have been issued in numerous states. The discovery of mercury in {open_quotes}pristine{close_quotes} lakes in the United States, Canada, and Scandinavia, remote from industry and any known mercury sources, has focused attention on atmospheric emissions of mercury as potential significant sources of mercury.

Elias, D.F.; Corbin, W.E. [RTP Environmental Associates, Inc., Green Brook, NJ (United States)

1996-12-31

370

Relationship between Blood Mercury Level and Risk of Cardiovascular Diseases: Results from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) 2008–2009  

PubMed Central

Limited epidemiologic data is available regarding the cardiovascular effects of mercury exposure. The purpose of this study was to determine the relationship between mercury exposure from fish consumption and cardiovascular disease in a nationally representative sample of Korean adults using the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV 2008~2009). Survey logistic regression models accounting for the complex sampling were used to estimate the odds ratios (OR) adjusted for fish consumption frequency, age, education, individual annual income, household annual income, body mass index (BMI), waist circumference (WC), alcohol consumption status, and smoking status. The mean blood mercury level in the population was 5.44 ?g/L. Trends toward increased blood mercury levels were seen for increased education level (P=0.0011), BMI (P<0.0001), WC (P<0.0001), and fish (i.e., anchovy) consumption frequency (P=0.0007). The unadjusted OR for hypertension in the highest blood mercury quartile was 1.450 [95% confidential interval (CI): 1.106~1.901] times higher than that of the lowest quartile. The fish consumption-adjusted OR for hypertension in the highest blood mercury quartile was 1.550 (95% CI: 1.131~2.123) times higher than that of the lowest quartile, and the OR for myocardial infarction or angina in the highest blood mercury quartile was 3.334 (95% CI: 1.338~8.308) times higher than that of the lowest quartile. No associations were observed between blood mercury levels and stroke. These findings suggest that mercury in the blood may be associated with an increased risk of hypertension and myocardial infarction or angina in the general Korean population. PMID:25580399

Kim, Young-Nam; Kim, Young A; Yang, Ae-Ri; Lee, Bog-Hieu

2014-01-01

371

13. Mercury speciation in biological matrices  

Microsoft Academic Search

In nature, mercury occurs in several forms, e.g.metallic mercury, inorganic mercury and organic mercury compounds. All forms of mercury are considered poisonous, but methyl-mercury is of particular concern since it is extremely toxic and is frequently found in the environment. Through a very effective biomagnification mechanism, methyl-mercury is enriched in food chains which results in high levels in top predators,

I. Drabæk; Á. Iverfeldt

1995-01-01

372

Comparison of mercury levels in various tissues of albino and pigmented mice treated with two different brands of mercury skin-lightening creams  

Microsoft Academic Search

The use of mercury containing skin-lightening creams are becoming increasingly popular among dark-skinned women. The long term use of certain brands may cause serious health effects over the years. In the present study, we investigated the dermal absorption of mercury and its accumulation in the tissues of albino and pigmented mice treated with two brands of mercury containing skin-lightening creams

Iman Al-Saleh; Neptune Shinwari; Inaam El-Doush; Grisellhi Billedo; Mona Al-Amodi; Fathia Khogali

2004-01-01

373

Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands  

SciTech Connect

The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean {+-}SE 4.29{+-}0.30 {mu}g/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161{+-}36.7 ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910{+-}386 ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249{+-}44.7 ng/g) and eggs (161{+-}36.7 ng/g) may pose a risk if consumed frequently by humans. Mill Creek, the site with the most documented prior contamination, had significantly elevated cadmium, chromium, mercury, and lead in goose tissues. - Highlights: {yields} The NJ Meadowlands include extensive wetlands in the urban NYC metropolitan area. {yields} We analyzed eggs, feathers, muscle, and liver of Canada geese at 4 Meadowlands sites. {yields} As, Cd, and Hg were low in all tissues sampled, while Cr was high in feathers. {yields} Pb was higher in goose eggs and feathers than in other Meadowlands bird species. {yields} Pb in muscle and liver was lower and within the range seen in waterfowl elsewhere.

Tsipoura, Nellie [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)] [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States); Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States) [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Newhouse, Michael [NJ Meadowlands Commission, One DeKorte Park Plaza, Lyndhurst, NJ 07071 (United States)] [NJ Meadowlands Commission, One DeKorte Park Plaza, Lyndhurst, NJ 07071 (United States); Jeitner, Christian [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States) [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Gochfeld, Michael [Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States) [Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Environmental and Occupational Medicine. Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Mizrahi, David [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)] [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)

2011-08-15

374

Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands.  

PubMed

The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean ±SE 4.29±0.30?g/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161±36.7ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249±44.7ng/g) and eggs (161±36.7ng/g) may pose a risk if consumed frequently by humans. Mill Creek, the site with the most documented prior contamination, had significantly elevated cadmium, chromium, mercury, and lead in goose tissues. PMID:21679937

Tsipoura, Nellie; Burger, Joanna; Newhouse, Michael; Jeitner, Christian; Gochfeld, Michael; Mizrahi, David

2011-08-01

375

Phytoremediation of Ionic and Methyl Mercury P  

SciTech Connect

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and degrade it to less toxic ionic mercury. They grow on concentrations of methylmercury that kill normal plants and accumulate low levels of ionic mercury. (2) Transgenic plants expressing merA (mercuric ion reductase) extract and electrochemically reduce toxic, reactive ionic mercury to much less toxic and volatile metallic mercury. This metal transformation is driven by the powerful photosynthetic reducing capacity of higher plants that generates excess NADPH using solar energy. MerA plants grow vigorously on levels of ionic mercury that kill control plants. Plants expressing both merB and merA degrade high levels of methylmercury and volatilize metallic mercury. These properties were shown to be genetically stable for several generations in the two plant species examined. Our work demonstrates that native trees, shrubs, and grasses can be engineered to remediate the most abundant toxic mercury pollutants. Building on these data our working hypothesis for the next grant period is that transgenic plants expressing the bacterial merB and merA genes will (a) remove mercury from polluted soil and water and (b) prevent methylmercury from entering the food chain. Our specific aims center on understanding the mechanisms by which plants process the various forms of mercury and volatilize or transpire mercury vapor. This information will allow us to improve the design of our current phytoremediation strategies. As an alternative to volatilizing mercury, we are using several new genes to construct plants that will hyperaccumulate