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G11 Mercury monitoring and risk assessment

Thursday, 28 July, 2011

RG11-P1 — 11:00-12:00 and 17:30-18:30
DISTRIBUTION OF MERCURY IN FISH, SEDIMENT AND WATER FROM THE BLACK VOLTA RIVER AT BUI BEFORE THE CONSTRUCTION OF THE HYDROELECTRIC RESERVOIR
Authors: VOEGBORLO, Ray Bright1, ANKAMAH DANSO, Solomon2, MOMADE, Francis, F. Y.2, AGORKU, Selorm, E1
(1) Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana., raybrightv@yahoo.com; (2) Department of Materials Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.;

The risk of elevated Hg concentration in fish has become one of the most important issues in assessing the environmental impact of hydroelectric reservoirs. Total mercury (Hg) concentrations were determined in fish, sediment and water from the Black Volta River at Bator and Dam site at Bui to understand its distribution and partitioning prior to the construction of the Hydroelectric Dam. One hundred and eighty-five (185) fish samples comprising twenty-one (21) species; one hundred and twenty (120) sediment samples and twelve (12) water samples were collected and analysed for total mercury.

Mercury concentration (µg/g wet weight) in the muscle tissue of fish from Bator ranged from 0.014 to 0.209µg/g. Hg levels in sediment and water from Bator ranged from 0.043 to 0.115 µg/g and 2x10-6 to 1.3x10-5µg/L. In general, mercury concentration in fish from Dam site ranged between 0.035 to 0.346µg/g. Hydrocynus forkali recorded the highest level of 0.346µg/g whilst the lowest recorded Hg concentration of 0.035µg/g was in Brycinus imberi. Hg concentration in sediment and water were also found to be 0.052µg/g and 0.04ng/L respectively.

All the fish samples studied showed mercury concentrations below the Word Health organization (WHO) limit of 0.5µg/g wet weight. The results obtained from this study therefore showed that fish from the Black Volta River Basin are unlikely to constitute a significant mercury exposure to the public through consumption before the construction of the hydroelectric reservoir.

RG11-P2 — 11:00-12:00 and 17:30-18:30
BIOACCUMULATION OF MERCURY IN FISH IN U.S. NATIONAL PARKS OF THE WESTERN GREAT LAKES REGION
Authors: BAILEY, Sean W.1, HARO, Roger J.1, ROLFHUS, Kristofer R.1, SANDHEINRICH, Mark B.1, WIENER, James G.1
(1) University of Wisconsin-La Crosse, bailey.sean@uwlax.edu

We are assessing the bioaccumulation of methylmercury in six national parks of the western Great Lakes region (USA). The parks, which are managed by the U.S. National Park Service, range from human-impacted landscapes (Indiana Dunes National Lakeshore) to relatively pristine wilderness (Isle Royale National Park). Analyses of dated sediment cores and regional forest soils have shown that atmospheric deposition is the dominant source of mercury to the parks—derived mostly from anthropogenic sources. The parks contain abundant aquatic resources (perennial streams, inland lakes, wetlands, and near-shore areas in lakes Michigan and Superior) that support diverse assemblages of warm, cool, and coldwater fishes. Many fishes—including walleye, northern pike, smallmouth bass, and lake trout—are harvested recreationally in the parks, providing a potential pathway for dietary exposure of park visitors to methylmercury. Whole prey fish and axial muscle of predatory fish, as well as other components of the pelagic and benthic food webs, are being sampled and analyzed to (1) assess spatiotemporal patterns in contamination, (2) identify parks and surface waters where methylmercury poses the greatest ecological risk to fish and wildlife, (3) identify water bodies and species for which fish-consumption advisories should be posted, and (4) identify lacustrine, watershed, and trophic factors influencing bioaccumulation of methylmercury. Fish from some of the parks are bioaccumulating methylmercury to toxicologically significant concentrations. Mercury levels in axial muscle of piscivorous fish from several lakes substantially exceeded 0.3 µg/g wet weight, the US Environmental Protection Agency tissue residue criterion for methylmercury (established to protect the health of persons who eat noncommercial fish). Concentrations in many predatory fish exceeded 0.5 µg/g wet weight, an estimated threshold level associated with altered biochemical processes, damage to cells and tissues, and reduced reproduction in fish. In some lakes, concentrations of mercury in whole prey fish may be high enough to adversely affect production of nesting common loons. We conclude that mercury contamination is a significant threat to fish and wildlife in certain national park units of the western Great Lakes region.

RG11-P3 — 11:00-12:00 and 17:30-18:30
MERCURY DETERMINATION IN GROUNDWATER SAMPLES FROM CAPITÃO GERVÁSIO MUNICIPALITY, PIAUÍ STATE (NORTHEASTERN BRAZIL)
Authors: CESAR, Ricardo1, CASTILHOS, Zuleica2, LESSA, Aline2, ARAUJO, Patricia3, BIDONE, Edison4
(1) Federal Fluminense University (UFF), Niterói, RJ, Brazil., geo_ricardocesar@yahoo.com.br; (2) Centre for Mineral Technology (CETEM), Rio de Janeiro, RJ, Brazil; (3) Centre for Mineral Technology (CETEM), RJ, Brazil; (4) Federal Fluminense University (UFF), Niterói, RJ, Brazil.

Capitão Gervásio Municipality (PiauíState) is located at a semi-arid and economically underdeveloped region (“dried polygon”) in the northeastern Brazil, where the availability of potable groundwater is extremely important for maintaining economic activities and providing basic conditions of surveillance for local populations. This paper proposes the assessment of mercury contents in groundwater samples from Capital Gervásio, in order to identify possible risks associated with human health. Total mercury concentration was determined in 15 sampling points along the Municipality. Mercury determination was performed by ICP-OES. A preliminary human health risk assessment was performed according to USEPA (1989) procedures, considering 3 x 10-4mg/kg x day as reference dose for water ingestion and the consumption 2L of water/day. Administrated doses were calculated for the exposure of adults and children and compared with the reference dose. Hidrochemical characterization was executed by quantifying pH, eletric conductivity, Ca, Mg, Na, Cl- and F-. The results revealed the occurrence of some saline waters. As expected, positive and significant correlations were found among Ca, Mg, Na and Cl- concentrations. Mean mercury concentration was 0.0020 ± 0.0011 mg/L. More than 80% of the samples presented contents higher than that proposed by Brazilian legislation (0.0010 mg/L) in respect to safe human consumption. Mercury concentrations were significantly correlated with nickel ones (r>0.5), suggesting possible common anthropogenic sources of pollution, since those elements are not geologically well correlated. Although mercury has a strong affinity with Cl-, no significant correlations were detected between such elements (r<0.5). Preliminary human health risk assessment indicated the absence of significant risks on adults, since administrated doses were lower than the considered oral reference dose for mercury. However, significant risks were detected in respect to the consumption of water by children.

RG11-P4 — 11:00-12:00 and 17:30-18:30
APPLICATION AND VALIDATION OF THE NATIONAL DESCRIPTIVE MODEL OF MERCURY IN FISH
Authors: BRIGHAM, Mark1, FIENEN, Michael N1, DONATO, David I1, WENTE, Stephen P2, LORENZ, David L1, TROMBLEY, Molly M1, SANOCKI, Chris A1
(1) U.S. Geological Survey, mbrigham@usgs.gov; (2) U.S. Environmental Protection Agency;

The National Descriptive Model of Mercury in Fish (NDMMF; Wente, S. P., 2004, U.S. Geological Survey Scientific Investigation Report 2004-5199, http://pubs.usgs.gov/sir/2004/5199/) is a powerful tool for analyzing fish-mercury data sets with many observations. The NDMMF accounts for variations in fish-mercury concentrations due to species, sampled cut (for example, skin-off fillet, whole body, etc.), fish length, and event (defined as all fish samples collected at a site during a given year). The NDMMF facilitates analysis of the distribution of mercury in freshwater fish by allowing standardized comparisons among sampling events (that is, among sites and over time). We applied the NDMMF to a data set of 101,927 observations of fish-mercury concentrations compiled from numerous state, federal, and tribal monitoring programs. The data set spans the years 1967-2005, and includes data from more than 10,000 sites across 49 states in the United States. The median standard error of prediction was 10.3 percent (expressed as a percentage of concentration). The median ratio of model-predicted to measured fish-mercury concentration was 0.94, indicating low bias; the 10th and 90th percentiles of this ratio were 0.48 and 2.0, respectively, meaning that the central 80 percent of predicted values ranged from about half to twice the measured value. In addition to general measures of model performance, this presentation will summarize a leave-one-out cross-validation study that is currently underway. The goal of the validation study is to gain a better understanding of model performance across a broad range of characteristics that could affect model predictions, including fish species, geographic region, and number of observations in a sampling event. Model performance will also be assessed in relation to various site attributes (water body type, watershed area, etc.), which were determined with aid of a Geographic Information System (GIS), after verifying and correcting (where necessary) agency-supplied site location data.

RG11-P5 — 11:00-12:00 and 17:30-18:30
ASSESSMENT OF MERCURY POLLUTION OF SOME RIVERS DRAINING THE BIBIANI-ANWIASO – BEKWAI MINING COMMUNITY OF SOUTH WESTERN GHANA
Author: NARTEY, V.K.1
(1) UNIVERSITY OF GHANA, vknartey@ug.edu.gh

Surface-water and sediment samples were collected from seven streams in Bibiani-Anwiaso-Bekwai district, a gold mining community in the Western Region of Ghana and analyzed for total mercury, organic mercury and elemental mercury. Mercury concentrations of non-filtered water was determined using the ICP-OES after reduction with Stannous Chloride (SnCl2). While sediment samples were also pretreated and mercury content determined using the same instrumental technique. Physico-chemical parameters were also determined for the water samples. Total mercury content of the water ranged between 0.125 to 1.341µg/l while sediment values ranged between 0.169 to 1.739mg/kg. In all cases except for one site, mercury levels in the sediment have been found to be significantly higher than the corresponding water column. Except for site SW7(1.341µg/l), total mercury in water has also been found to be lower than 1.0µg/l, the WHO guideline value for drinking water. On the contrary, except for site ASUS(169mg/kg), all sampled sediments recorded values that are above 0.2mg/kg, the US-EPA guideline value for soils. Since sediments serve as sink for mercury and release the metal into water column with time, it can be concluded that these streams are polluted with mercury.

RG11-P6 — 11:00-12:00 and 17:30-18:30
DETERMINATION OF MERCURY CONCENTRATION IN NATURAL WATERS FROM SEVERAL LAKES IN LATVIA USING CV AAS ON RA-915+ MERCURY ANALYZER
Authors: GAVARE, Zanda1, BOGANS, Egils1, SVAGERE, Anda1, TILUGA, Liga1, POIKANE, Rita2
(1) Institute of Atomic Physics and Spectroscopy, University of Latvia, zanda.gavare@gmail.com; (2) Latvian Institute of Aquatic Ecology.

The toxicity of mercury and its organic and non-organic compounds is well known for a long time. However, mercury pollution in different parts of ecosystem and wildlife still is a very important problem. Mercury is not usually found free in nature and, though it is released by some natural processes too, additional releases from anthropogenic sources have led to a significant increase in environmental exposure and deposition.

This study was performed to determine background level of mercury concentration in natural waters of lakes in Latvia, along with evaluation of different sample pre-treatment methods.

Mercury was analyzed in water samples collected from several lakes in Latvia. The mercury concentration was determined using mercury analyzer RA-915+ together with RP 91 attachment. The principle of operation of RP 91 attachment is based on reduction of Hg (II) to the atomic state by reducing solution and then transporting mercury atoms to the analytical cell by air flow (Cold Vapor Atomic Absorption Spectroscopy – CV-AAS). High sensitivity of RA-915+ analyzer allows determination of mercury without mercury accumulation on a sorbent, and in combination with RP 91 attachment such system allows Hg determination in water down to concentrations as low as 0,5 ng/l. The measurement time for a single sample is ~1 minute.

Prior to the measurements, the samples were digested using two different methods: (1) with a dilute potassium permanganate-potassium persulfate solution, or (2) with a potassium bromate-potassium bromide solution. After oxidation, the samples were sequentially pre-reduced with NH2OH·HCl. The Hg(II) in the digested water sample was reduced with stannous chloride to elemental mercury which was purged from the sample and detected by atomic absorption spectrometer. Mercury concentration was determined in non-digested samples, too. The comparison of the results will be shown.

The overall results show that mercury concentration in lakes of Latvia does not exceed 5 ng/l.

Acknowledgments:
The work was supported by ESF project “Spectrometric techniques for detection of heavy metal contaminants” (Nr. 2009/0210/1DP/1.1.1.2.0/09/APIA/VIAA/100).

RG11-P7 — 11:00-12:00 and 17:30-18:30
IN-SITE MEASUREMENT FOR TRANSPORT OF TRACE MERCURY BY HIGHLY- FREQUENT WATER SAMPLING IN MINAMATA BAY
Author: YANO, Shinichiro1
(1)Kyushu University, yano@civil.kyushu-u.ac.jp

We conducted highly-frequent water sampling for mercury speciation in sea water and suspended solid (SS) in Minamata Bay, in which bottom sediment is contaminated by trace mercury (<10ppm, dry weight [Tomiyasu et al.(2006)]), with continuous current and suspended solid (SS) measurements. Current and SS measurement was carried out by the Acoustic Doppler Current Profilers (ADCP) mounted on sea bottom at measurement site (32o11.072’N, 130o22.084’E, mean depth: 13.5m) in Minamata Bay from 29th July, 2009 to 25th October, 2009. ADCP measured vertical profile of current velocity and SS concentration which was estimated from echo intensity every 15 minutes. In the measurement period, water sampling for speciation of particulate total Hg, dissolved total Hg, and dissolved methyl-mercury was also carried out every 1 week. We sampled sea water from 7 layers (0m(sea surface), 2m, 4m, 6m, 8m, 10m, bottom layer (1m above the sea bottom)) at the same point as the ADCP measurement point. Finally, temporal change of vertical profile of mercury flux was estimated from these measurement results of velocity, SS concentration and particulate total mercury, and net particulate total mercury transport from the Minamata Bay to the outer sea area was also evaluated.

As a result, the followings were clarified: i) particulate total mercury in bottom layer was higher than that in surface and middle layer; ii) dissolved total mercury and methyl-mercury were almost uniform vertically. Negative correlation between total mercury and methyl-mercury was shown; iii) annual particulate total mercury transport from Minamata Bay to the outer sea area (Yatsushiro Sea) was estimated as 5-13kg. In the past research, Rajar et al. (2004) evaluated the annual mercury transport as about 150kg (including dissolved mercury) from the numerical modeling, and Yano et al. (2003, 2004) reported that it is around 10-30kg from the field measurement. But, these previous research included uncertainty due to unknown factors for numerical modeling and small number of mercury measurement (only once). Thus, these results suggest that highly-frequent mercury measurement plays an important role in an accurate estimation of mercury mass balance.

RG11-P9 — 11:00-12:00 and 17:30-18:30
MERCURY IN NORTHERN MISSISSIPPI, USA: ATMOSPHERIC SPECIATION, HISTORICAL DEPOSITION, AND CONCENTRATIONS OF METHYLMERCURY IN NATURAL WATERS
Authors: CIZDZIEL, James1, JIANG, Yi1, BROWN, Garry1, CHAKRAVARTY, Pragya1
(1)University of Mississippi, cizdziel@olemiss.edu

Mercury has emerged as a serious public health concern in north Mississippi, USA. Fish consumption advisories were issued for the Enid Reservoir and the Yocona River in 1996. The origin of Hg in these water bodies is unclear but may include atmospheric deposition, geological formations that leach Hg into the watershed, and historic land use practices. As a result we have recently begun a research program investigating the biogeochemical cycling of mercury in northern Mississippi. To that end, we are monitoring airborne mercury species, determining the concentrations of total-mercury and methylmercury in wetlands, rivers, and lakes, and assessing historical deposition of mercury to the region. Airborne measurements include gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (P-Hg) using Tekran’s 1130/1135/2537 system. Water is being analyzed for total-mercury by oxidation, purge and trap, and cold vapor atomic fluorescence spectrometry (CVAFS), and for methylmercury by aqueous ethylation, purge and trap, gas chromagraphy, pyrolysis and CVAFS. Sediments cores, collected from oxbow lakes and adjacent wetlands, are being analyzed by for total mercury using a direct mercury analyzer based on combustion, amalgamation, and atomic absorption spectrometry. Preliminary results indicate that: (1) concentrations of GEM, GOM and P-Hg are at or near expected background levels 1-2 ng/m3, 1-10 pg/m3 and 1-10 pg/m3, respectively; (2) methylmercury concentrations in the Yocona River varied with flow levels, with higher concentrations during a “low” flow period (0.051 ± 0.005 ng/L) compared to a “high” flow event (0.018 ± 0.006 ng/L); (3) mercury in a Beasley Lake open water sediment core (dating back nearly a hundred years) was significantly lower in concentration (3.7 ± 0.9 ng/g) than the adjacent wetland core (34 ± 11 ng/g). The increased variability in the wetland core is due to a trend of decreasing concentration with depth (from about 50 ng/g to 15 ng/g); the open water core showed no such trend. This poster will provide an update on the data we collect during the winter, spring and early summer of 2011. It will include more detailed information on: (1) the extent of mercury contamination in the area, (2) temporal and spatial patterns, (3) mercury speciation in the air and water, (4) and mercury loadings to the reservoirs.

RG11-P11 — 11:00-12:00 and 17:30-18:30
THE EMECO PROJECT: AN INTERNATIONAL PROJECT TO ASSESS THE ENVIRONMENTAL IMPACT OF MERCURY IN ECOSYSTEMS OF HIGH ECOLOGICAL VALUE IN SPAIN AND BRAZIL
Authors: DÍEZ, Sergi1, BARATA, Carlos1, BAYONA, Josep M.1, DA SILVA, Carolina J.2, FERNÁNDEZ-GÓMEZ, Cristal1, GUIMARAES, Jean R.D.3, IGNÁCIO, Aurea R.A.2, JOVER, Lluís4, LÁZARO, Wilkinson L.2, LLORENTE, Gustavo4, MALM, Olaf3, PIÑA, Benjamí1, RALDÚA, Demetrio1, SANPERA, Carola4
(1) Institute of Environmental Assessment and Water Research, IDAEA-CSIC, sdsqam@cid.csic.es; (2) Biodiversity and Ethnobiology Research Center, CELBE-UNEMAT; (3) Rio de Janeiro Federal University (UFRJ); (4) University of Barcelona, UB;

During a three-year FBBVA project, Spanish and Brazilian researchers investigated the environmental impact of mercury in some high ecological value scenarios. The two areas studied are the Ebro river basin in Spain, and the Pantanal of Mato Grosso, in Brazil. In both areas, the source of anthropogenic pollution is different; while in the Pantanal is due to the Hg used in gold amalgamation at mining sites, in Spain is because of mercury-cell chlor-alkali plants.

During the progress of the project, innovative techniques for the determination of species of Hg (ethyl-Hg and methyl-Hg) have been established, as well as the development and implementation of passive samplers employing the diffusive thin-film technique (DGT) to monitor and measure bioavailable Hg species. Validated biochemical and gene expression biomarkers to monitor the oxidative stress of invertebrates and fish, including CYP1A, GST and MT were also developed. Furthermore, we investigated the natural pigments (colouring bird’s beak) as novel indicators of exposure to Hg at trace levels and its correlation with oxidative stress in birds. The study of Hg levels in claw and blood of freshwater turtles in Spain, provides a nonlethal monitoring tool for estimating the environmental impact of mercury in aquatic ecosystems.

The highest total and methyl-Hg concentrations ever reported for zebra mussels were found in a reservoir in front of a chlor-alkali plant located at the Ebro river basin. Interestingly, maximal levels of mercury in carp tissues as well as the highest biological impact did not occur at the discharge sites, but several kilometres downstream, evidencing the capacity of Hg contamination transport over long distances from the emission sites.

In Brazil, the Hg levels in fish are relatively low compared with those observed in Spain, although Hg concentration in several caimans in the Pantanal may indicate some evidence of risk. However, analysis of human hair mercury content in relation to fish and alligator diet of several riverine communities at the Cuiabá, Bento Gomes and Paraguay rivers, does not suggest any risk to these populations. On the other hand, it should be highlighted that results obtained in methylation studies in the Pantanal suggest that an accurate characterization of periphyton could be a good indicator of the production of methyl-Hg in aquatic systems.

RG11-P12 — 11:00-12:00 and 17:30-18:30
A YOUNG-OF-THE-YEAR (YOY) PREDATORY FISH STUDY TO ASSESS TRENDS IN ATMOSPHERIC HG DEPOSITION IN MARYLAND
Authors: HEYES, Andrew1, GILMOUR, Cynthia C.2, PROCHASKA, Tony3, SHERWELL, John3, JENNY, Elizabeth1, RULE, Tim4
(1)University of Maryland Center for Environmental Science, heyes@umces.edu; (2) Smithsonian Environmental Research Center; (3) Maryland Department of Natural Resources ; (4) Maryland Department of the Environment.

Regulations to control mercury (Hg) emissions from power utilities have been implemented in the State of Maryland. These regulations arose in response to elevated levels of methylmercury (MeHg) in fish and other animals, and the associated risks to people and wildlife. Maryland’s major coal-fired power plants have implemented a mix of flue gas desulfurization and activated-carbon Hg capture technologies, which came online at the onset of 2010. To assess the impact of expected Hg emission reductions, we developed a standardized young-of-the-year (YOY) predatory fish monitoring program to provide a rapid assessment of changes in Hg bioaccumulation. The program is designed to measure year-to-year and long-term trends in MeHg bioaccumulation in both Maryland freshwater reservoirs and Chesapeake Bay. Two widespread species were chosen as monitoring sentinels: Micropterus salmoides (largemouth bass) for freshwaters, and Morone americana (white perch) for the tidal Chesapeake. This project utilizes the existing Maryland Department of Natural Resources YOY fish collection and monitoring programs.

Each year since 2008, 25 YOY fish have been collected from each of nine freshwater reservoirs and four sites in the Chesapeake Bay and its tributaries. Samples were collected in at the same time of year (late summer) to coincide with existing state YOY monitoring programs and capture fish of the same age and size.

Mercury concentrations in largemouth bass vary greatly among sites, with mean site concentrations ranging from 14 to 160 ug g-1 wet weight. This is consistent with wide variations observed among water bodies in prior measurements of adult bass and other species across Maryland. Mercury concentrations in white perch were smaller and ranged from 4 and 12 ug g-1 wet weight. Site differences in the average concentration of Hg in YOY white perch collected in 2008, 2009 and 2010 were small, falling within the standard deviation of the mean of the 25 fish collected from each site. In 2010, concentrations in largemouth bass collected at three of nine the freshwater sites were significantly lower than the previous two years. We will compare Hg deposition data from mercury deposition network [MDN] sites in Maryland and the region with the temporal and spatial trends observed in YOY fish. Other factors that may influence Hg concentrations in YOY fish will be also discussed such as water level manipulations in the reservoirs and interannual changes in fish size.

RG11-P13 — 11:00-12:00 and 17:30-18:30
USE OF HUMAN BIOMONITORING RESULTS TO VALIDATE IN VITRO BIOACCESSIBILITY DATA FOR INORGANIC MERCURY IN SOIL FROM A NORTHERN CANADIAN SMELTER COMMUNITY
Authors: SAFRUK, Adam1, SIGAL, Elliot1
(1) Intrinsik Environmental Sciences Inc., asafruk@intrinsikscience.com

Emissions from a base metal smelting complex in Flon Flon, Manitoba, Canada have resulted in elevated concentrations of metals in the surrounding environment. As part of the Flin Flon Soils Study, a human health risk assessment (HHRA) was conducted to assess exposure and risks associated with a number of metals including mercury. An in vitro bioaccessibility study was completed for residential soils and indicated an average bioaccessibility of 1.2% for total mercury (gastric phase analysis). In vitro studies have been designed to simulate conditions of the human gastrointestinal tract (e.g., pH, temperature, and chemical composition of solutions in both the stomach and small intestine) in order to mimic the mobilization of compounds from soil during digestion and to help reduce uncertainty associated with predicting exposure from soil ingestion pathways. Most regulators in Canada only consider in vitro results for lead and arsenic to have been sufficiently validated with in vivo studies to allow for its use in the HHRA process. Therefore, in vitro bioaccessibility results for inorganic mercury were not utilized in the HHRA. Assuming 100% bioaccessibility for inorganic mercury in soil, results from the HHRA indicated the need for further assessment of exposure and risk. An Exposure Study (biomonitoring) was undertaken for children (under 15 years of age) in the Flin Flon area to examine urinary inorganic mercury levels. The Exposure Study was conducted to help validate the HHRA’s exposure estimates and to examine how levels of exposure compare to levels in children living in other parts of Canada and the U.S. Approximately 50% of urine samples (n=188) had levels of urinary inorganic mercury below the limit of detection (0.1 µg/L), with an average level of 0.11 µg/L. Despite high variability in mercury soil concentrations within sub-communities, soil concentrations did not appear to influence urinary mercury levels. These results provide evidence that mercury bioaccessibility in residential soil in the Flin Flon area was likely well below 100% and HHRA estimates would have been better approximated through inclusion of the in vitro study results.

RG11-P14 — 11:00-12:00 and 17:30-18:30
MERCURY EXPOSURE PROFILE FOR SALTMARSH SPARROWS (AMMODRAMUS CAUDACUTUS) ACROSS NEW YORK AND NEW ENGLAND, USA
Author: LANE, Oksana1
(1)BioDiversity Research Institute, oksana.lane@briloon.org

We non-lethally sampled blood and collected feathers from Saltmarsh Sparrows (Ammodramus caudacutus) nesting in 18 salt marshes throughout New England (Maine, New Hampshire, Massachusetts, Connecticut and Rhode Island) and Long Island (New York) USA to assess methylmercury (MeHg) availability. Mean whole blood Hg levels in adult sparrows by site ranged from 0.24 +/- 0.06 µg/g wet weight in Clinton, Connecticut, to 1.7 +/- 0.36 µg/g on Long Island, New York. Several of the sites were sampled annually from 2004 to 2010 and the results indicate different blood mercury trends among sites. Mean mercury concentrations of feathers grown on the breeding sites ranged from 5.7 µg/g to 22.9 µg/g. A high proportion of adult sparrows sampled on Plum Island in Massachusetts (109 of 239), and from two sites on Long Island, New York exceeded the current LOAEL. Mercury exposure significantly differed among marshes within and among states. Plausible explanations for elevated levels include Hg inputs, habitat sensitivity to increased Hg methylation rates from land sources, and dietary influences. This study uses Saltmarsh Sparrow as an indicator species of mercury exposure in salt marsh habitats of the Northeast. Our results reveal that this obligate salt marsh passerine which is listed as a “Bird of Conservation Concern” by USFWS Northeast Region, and is globally red-listed, is exposed to potentially harmful levels of mercury on its breeding grounds.

RG11-P15 — 11:00-12:00 and 17:30-18:30
DEVELOPING A MERCURY RISK MANAGEMENT PLAN FOR THE WESTERN CAPE PROVINCE, SOUTH AFRICA
Authors: BAIJNATH-PILLAY, Nitasha1, LEANER, Joy J2, MAKOALA, Millicent2, BILL, Catherine2, CHETTY, Kamaseelan 2, WINGROVE, Heinrich2, BARRANTES, Vera3, MASON, Robert4
(1) Dept Environmental Affairs and Development Planning, npillay@pgwc.gov.za; (2) D:EADP; (3) UNITAR; (4) University of Connecticut, USA

Anthropogenic activities such as coal combustion, mining of ferrous and non-ferrous metals, especially gold extraction and refining, as well as the disposal and incineration of consumer products, release significant amounts of mercury (Hg) to the regional and global environment (UNEP 2002). Despite the presence of several known sources of Hg emissions in southern Africa, there are few policies that focus on Hg in terms of its risk to human health and the environment. Given the potential severity and risks associated with Hg pollution, the Department of Environmental Affairs and Development Planning (D:EADP) and UNITAR, with funding obtained from the USEPA, set out to develop a Mercury Risk Management Plan for the Western Cape Province. Preliminary work included identifying potential Hg sources in the Province, and using the information to develop the Mercury Risk Management Plan. The key issues of the Risk Management Plan will be outlined. Recommendations for research in terms of reducing the Hg risk to the environment and human health in the Province will also be made.

RG11-P16 — 11:00-12:00 and 17:30-18:30
CAPACITY BUILDING AND KEY LEARNING POINTS DURING THE DEVELOPMENT OF THE MERCURY RISK MANAGEMENT PLAN FOR THE WESTERN CAPE PROVINCE, SOUTH AFRICA
Authors: LEANER, Joy1, BILL, Catherine2, BAIJNATH-PILLAY, Nitasha2, MAKOALA, Millicent2, CHETTY, Kamaseelan2, WINGROVE, Heinrich2, BARRANTES, Vera3, MASON, Robert4
(1) Dept Environmental Affairs and Development Planning, jleaner@pgwc.gov.za; (2) D:EADP; (3) UNITAR; (4) University of Connecticut, USA.

The Provincial Risk Management Plan for the Western Cape project was initiated through funding obtained from the USEPA, and managed by the UNITAR. The information obtained included a Situational Analysis of Mercury in the Western Cape, a Mercury Risk Management Plan, a Hg inventory which links to the Pollutant Release and Transfer Register, as well as an assessment for setting up a Mercury Monitoring System for the Western Cape Province. The process followed and the information obtained in the project was used to strengthen capacity and understanding of mercury sources, fate and transport in the Western Cape. The knowledge gained in the assessment was used to develop capacity on Hg sources, fate and transport in other Provinces, through a multi-stakeholder workshop, thereby supporting national level activities in South Africa. The procedures followed, and the key findings of the assessment will be outlined, as well as the key learning points established during the project.

RG11-P17 — 11:00-12:00 and 17:30-18:30
MERCURY CONCENTRATION IN MACROBRACHIUM BRASILIENSE AND MACROBRACHIUM JELSKII (SHRIMP) IN THE MADEIRA RIVER BASIN – OCCIDENTAL AMAZON
Authors: GALVÃO, Roberta Carolina Ferreira R C F1, HOLANDA, Igor Bruno Barbosa I B B1, MUSSY, Marília Higino M H1, DE CARVALHO, Dario Pires D P1, MIRANDA, Márcio Rodrigues M R2, BASTOS, Wanderley Rodrigues W R1
(1) UNIR, roberta_biologa@yahoo.com.br; (2) UFRJ;

Studies by several authors in the Madeira river basin indicate high levels of mercury (Hg) in fish, however it is not observed in the abiotic compartments. The Hg source to the study area in the aquatic environment is antropic, like gold mining activities that used mercury during the amalgamation process of gold, and natural sources, like the Amazonian soils. Mercury in shrimp has been studied by several authors for being bioturbed agents and being part of the food chain transferring methyl-Hg along of the chain, but the species of freshwater Macrobrachium jelskii and Macrobrachium brasiliense have no commercial value. 502 shrimps belonging of Macrobrachium brasiliense to were collected in August 2010 in Madeira river and 47 individuals of Macrobrachium jelskii were sampled in the Jaci Paraná river, Madeira River’s tributary, in the same period. Data collection was performed using a bottom sweeping net (7 mm between adjacent nodes). At the laboratory, the shrimps were identified and weighed on analytical balance and digested in microwave equipment specific for digestion of samples using H2O2, HNO3 and KMnO4. After digestion, the samples Hg concentration was performed by AAS cold vapor generation system with flow injection. The mercury concentration average in Macrobrachium brasiliense ranged from 0.020 to 0.070 mg.kg-1, while in Macrobrachium jelskii ranged from 0.008 to 0.040 mg.kg-1. The Hg concentration average in these species may be related to total length (extremity of rostrum to posterior portion of telson) of individuals, because the smaller specimens are those with the highest Hg concentration average. It assigns preliminarily that this may be related to the Hg losses by exoeskeleton’s elimination or biological age dilution.

RG11-P18 — 11:00-12:00 and 17:30-18:30
MERCURY IN BRAIN AND MUSCLE TISSUES OF MIGRATORY FISH OF THE MADEIRA RIVER - AMAZON, BRAZIL
Authors: MUSSY, Marília Higino M H1, HOLANDA, Igor Bruno Barbosa I B B1, NERES, Lauana Almeida L A1, GALVAO, Roberta Carolina Ferreira R C F1, MELO, Larissa L C R1, AYALA, D M1, CARVALHO, Dario Pires D P1, DORIA, Carolina Rodrigues da Costa C R C1, BASTOS, Wanderley Rodrigues W R1
(1) UNIR, mariliahigino@yahoo.com.br

The aim of this study was to relate the mercury concentration between muscle and brain tissue of large migratory fish of the Madeira River Basin (Rondônia). It was selected five species of large catfish for a total of 100 specimens: Brachyplatystoma platynemum (babão, n=47), Pseudoplatystoma punctifer (dourada, n=20), Brachyplatystoma filamentosum (filhote, n=12), Pseudoplatystoma punctifer (surubim, n=03) and Brachyplatystoma vaillantii (piramutaba, n=18). All these species have diets based mainly on the consumption of other fish, and held the position of the main species consumed in the region not only by the riverside population but also by regional population. For example of species Brachyplatystoma rousseauxii and Pseudoplatystoma punctifer of high commercial value. Fish were collected by local fishermen. These heads were cut bilaterally, the brain removed and a portion of muscle tissue.. The total Hg determination was performed by atomic absorption spectrophotometry by cold vapor generation with flow injection system. The mercury concentrations average in brain and muscle tissues of fish species are: Brachyplatystoma platynemum 0.37±0.25mg.kg-1 (brain) and 2.22±1.14mg.kg-1 (muscle); Brachyplatystoma rousseauxii 0.13±0.11mg.kg-1 (brain) and 0.85±0.59 mg.kg-1 (muscle); Brachyplatystoma filamentosum 0.40±0.32mg.kg-1 (brain) and 1.92±0.99mg.kg-1 (muscle); Pseudoplatystoma punctifer 0.17±0.20mg.kg-1 (brain) and 1.05±0.67mg.kg-1 (muscle); Brachyplatystoma vaillantii 0.16±0.10mg.kg-1 (brain) and 0.64±0.26mg.kg-1 (muscle). The relationship between mercury concentration in muscle and brain tissue was 17% for Brachyplatystoma platynemum and Pseudoplatystoma punctifer, 16% for Pseudoplatystoma punctifer, 21% for Brachyplatystoma filamentosum and 25% for Brachyplatystoma vaillantii. Although still preliminary, there’s an efficient mercury accumulation in the brains of fish species. According to Brazilian legislation three species exceeded the value for human consumption (1.00mg.kg-1 for predatory species). The average values for all species studied exceeded the level set by World Health Organization for human consumption down 0.50mg.kg-1. Experiments with a larger number of individuals are in progress, taking into account the lifetime of these individuals through otoliths analysis and the possible increase in the Hg concentration in the brain.

RG11-P19 — 11:00-12:00 and 17:30-18:30
EVALUATION OF ACCUMULATION IN FISH OF MERCURY FROM SEAWATER BY THE FISH PRESERVE EXPERIMENT IN MINAMATA BAY
Authors: AKITO, matsuyama1, JIRO, Koyama2, SAICHIRO, Yokoyama2
(1) National Institute for Minamata Disease, matsuyam@nimd.go.jp; (2) Kagoshima University Faculty of Fisheries;

In Minamata Bay, the dredging project involving sediment with a mercury concentration of more than 25 ppm was implemented from 1977 until 1990. Currently, although the characteristics are different for each fish species, in Roch fish, the average mercury concentration and methylmercury concentration in fish muscle for 3 years in Minamata Bay were 0.36 ppm and 0.28 ppm, respectively. Since the average value of total mercury in muscle of the same fish in Japan is 0.12 ppm, it is just 3 times higher. Although seawater quality in Minamta Bay is on the way to recovery, it is comparatively high level yet because the average values of dissolved total mercury concentration and dissolved methylmercury concentration are 0.42±0.06 ng/l and 0.09±0.02 ng/l respectively. The FDA (2001, 2004) and Health Canada (2008) suggested that a part of mercury accumulated in fish is derived from seawater. Therefore, to evaluate absorption and accumulation of mercury in fish, the fish preserve experiment using young fish (sea bream) and a fish bait that do not include mercury because was made using only several chemical reagents was implemented for 2 years continuously in Minamata Bay. ?his bait does not contain mercury because it is made using only some chemical reagents such as casein and α-starch. Also, the amount of bait per day kept at 1.5% of body weight. As a result, total mercury concentration in fish decreased chronologically. On the other hand, the fish body weight increased chronologically. Thus, in 2010, although the total mercury concentration of young fish at the starting point (March, 2010) was 0.06 ppm±0.006 (average body weight 115 g, n=5), the total mercury concentration at the ending point (December, 2010) was 0.01 ppm±0.002 (average body weight 480 g, n=5). However, there is no variation, since the total mercury contents in fish muscle of the starting point and the ending point were 7.3 µg±1,5 (n=5) and 6.8 µg±0.8 (n=5) respectively, Therefore, the total mercury concentration in fish seems to be diluted with the body growth of fish. Based on these facts, absorption and accumulation of mercury in seawater via fish gills etc currently do not seem important for mercury accumulation in the fish of Minamata Bay.

Thursday, 28 July, 2011