The aims of this study include (1) Examine the total mercury and organic mercury concentrations in the muscle and liver tissues of dolphinfish, Coryphaena hippurus that collected in Tungkang and Taitung, Taiwan, in order to understand their safety consumption by human beings due to their high trophic level in a marine ecosystem; (2) Investigate the species difference in comparison to other marine high trophic organisms, e.g. shark, tuna; (3) Look for the pattern of Hg bioaccumulation to see whether it matches the three models defined by Holsbeek et al. A total of 209 samples of Coryphaena hippurus were collected from Tungkang and Taitung. In the 34 samples from Tungkang, males and females were 11 and 23, respectively, whereas 197 samples from Taitung included 92 males and 83 females. Samples from Tungkang were investigated individually, but those from Taitung were pooled by size into 58 samples, 27 males and 24 females. The Hg levels in the samples were wet digested and determined by cold vapor atomic absorption spectrophotometer. The results showed that there was no gender and site difference in the relationship between fork length and body weight in both Tungkang and Taitung samples. The relationship was BW = 0.00005 FL2.7443. The mean and range of total and organic Hg concentrations in muscles and livers of dolphinfish were 0.138 (0.045~0.506) and 0.103 (0.009~0.388), and 0.103 (0.037~0.260) and 0.077 (0.003~0.249), respectively. These concentrations were lower than the WHO food safety level for human consumption and Hg concentrations of shark and tuna. The total Hg concentrations in the muscles were significantly higher than those in livers in both sites. However, only samples of Taitung revealed the organic Hg concentrations of muscles were higher than those of livers. Concerning the site difference, the muscle concentrations of organic Hg, and the liver concentrations of total and organic Hg in Taitung were higher than those of Tungkang. There was positive linear relationship between total and organic Hg as well as in muscle and liver. However, no significant relationship was found between the Hg concentrations and fork length/body weight. The Hg bioaccumulative model of dolphinfish was similiar with Holsbeek et al.¡¦s models. In muscle, the largest sizes of the fish contained the highest organic Hg levels. In companying with no variation of total and inorganic Hg, it looks like Type I model of Holsbeek et al.¡¦s results.

Mercury contamination is a global issue due to its neurotoxicity, and China is not an exception due to its increasing industrialization. Fish is of the most concern, in respect to human exposure to mercury, because fish accumulates methylmercury through food chain in aquatic systems. The province of Zhejiang is renowned for its cuisine that incorporates freshwater fish. Qiandao Lake, in Zheijang, was the site of a case study examining the link between the total mercury (THg) concentration in hair samples and fish consumption. A questionnaire survey and hair sampling were carried out on women of childbearing age (17-46 years) from a fishing town by Qiandao Lake. The average hair THg concentration was 0.76±0.51μg/g dw. The most-frequently consumed species included four species of carp (golden, bighead, silver and predatory) and the Mongolian redfin. Hair THg concentrations accumulated rapidly during younger years, reaching a plateau around age 25, implying that the hair mercury concentrations in adult females >25 years can be interpreted by environmental exposure. Hair THg concentrations were positively correlated both with the frequency and the average weekly amount of fish consumption. This indicates that fish consumption is an important contributor to hair mercury concentrations in the absence of occupational or environmental mercury sources. A positive correlation between selenium and mercury in hair samples was also observed, suggesting a possible antagonistic relationship. This is the first study to look at mercury exposure in an eastern China community dependent on freshwater fish. This study also compared element trends (Mg, Ca, Cr, Mn, Cu, Zn, As, Se, Pb) in hair samples from three groups: 50 residents by Qiandao Lake (QD), 17 people from Fudan University, China (FU), and 20 people from Queen’s University, Canada (KI). Trends of mean Mg, Cu, Ca, As concentrations among groups are the same (KI>FU>QD). Mn, Cr, and Hg share the same trends of QD>FU>KI. Se concentrations follow the trend of QD>KI>FU. Strong correlations between Ca and Mg were observed within each group. Relationships between Se and Hg are clear in QD but not in FU and KI, probably due to the different dietary proportion of fish. / Thesis (Master, Environmental Studies) -- Queen's University, 2009-12-14 11:52:06.906

Burning of fossil fuels by coal-fired power plants (CFPPs) is one of the largest sources of environmental mercury in the United States and there have been conflicting reports of local impacts due to CFPPs in the US. Illinois has 23 coal-fired electrical generating plants that may be contributing to elevated environmental mercury concentrations that have contributed to mercury advisories for 13 bodies of water located throughout the state. The objective of the current study is to determine if there is a pattern of total mercury concentrations in sediment and tadpoles collected from ponds located upwind and downwind of 4 coal-fired electrical generating plants in Illinois. Baldwin, Joppa, Newton, and Southern Illinois Power Cooperative (SIPC) coal-fired power plants were chosen for study. Three sediment samples were collected from ponds located 3-5, 8-10, and 13-15 km downwind and from ponds located 3-5 km upwind of each power plant and analyzed for total mercury concentration. Temperature of overlying water (C), pH, oxidation-reduction potential (mV), and texture were determined for each sediment sample. Bullfrog (Lithobates catesbeiana) or Green frog (Lithobates clamitans) tadpoles were collected opportunistically from 29 of the 44 ponds chosen for study. Each tadpole was identified to species and Gosner stage, and then weighed and measured for total length prior to total mercury analysis. For Baldwin, Joppa, and SIPC power plants, no significant pattern of total mercury could be determined from either sediment or tadpole data. For Newton power plant, total mercury concentrations were significantly greater 3-5 km downwind for sediment, and 8-15 km downwind for tadpoles compared to concentrations at upwind locations. Sediment total mercury concentrations were not significantly correlated with any of the characteristic variables (e.g. pH). Tadpole total mercury was significantly negatively correlated with length and weight, but not significantly correlated with any of the sediment variables. Sediment and tadpole concentrations were not significantly correlated.

Contamination of methylmercury (MeHg) in aquatic products has been a wide spread health concern. The objective of this study is to determine total mercury (THg) and MeHg concentrations in different species of aquatic products from major offshore farms in China, and to assess health impacts from consumption. Results showed that the concentrations of THg and MeHg ranged 5.6–328.4 ng/g (wet weight) and 4.3–303.6 ng/g (wet weight) in aquatic products, respectively, and were very variable among species and origin sources. Target hazard quotient (THQ) suggested that MeHg exposure via consumption posed high health risks to children aged 2–7 and higher income families. Residents above the age of 13 and with low income have relatively lower health risk of MeHg exposure. Health impacts on heart attacks and newborns’ IQ from MeHg exposure were evaluated using dose-response relationships. Results showed that mother’s consumption of aquatic products (at 6 ounce per day) may cause a loss of 0.38 IQ points for newborns. For non-pregnant, consumption of aquatic products may cause an increase rate of mortality and morbidity of heart attacks at 10.59 and 78.45 per 100,000 persons, respectively. The negative health impact of consuming seawater fish was higher than freshwater fish.

White muscle samples of bigeye tuna, Thunnus obesus, collected in the Atlantic Ocean and the Indian Ocean were analyzed for total (THg) and organic mercury (OHg) concentrations. A total of 231 white muscle samples showed that THg and OHg concentrations ranged from 0.217 to 0.386 (0.786 ¡Ó 0.386) and 0.143 to 2.222 (0.595 ¡Ó 0.238) mg/kg wet weight, which did not differ with other previous studies. THg and OHg were linearly correlated with fork length (cm) and body weight (kg). The THg and OHg concentrations of 121 bigeye tuna samples collected in the Atlantic Ocean were linearly correlated with fork length, body weight and age. The OHg of 110 bigeye tuna in the Indian Ocean were linearly correlated with fork length, body weight and age, but only the the THg concentrations were linearly correlated with fork length. The average THg and OHg concentrations of bigeye tuna from the Atlantic Ocean showed significantly higher value than those from the Indian Ocean (p< 0.05). Furthermore, the slope of the regression lines between mercury concentrations (THg and OHg) and fork length in the bigeye tuna from the Atlantic Ocean was significantly higher than those from the Indian Ocean (p< 0.05). It¡¦s suggested that different Hg accumulation patterns exist in the two oceans. In the Atlantic and Indian Ocean, 1.7% and 0% of the bigeye tuna, respectively, had OHg concentrations of the muscles above the authorized limit (< 2 mg/kg wet weight) set by the Department of Health, Taiwan, and 13% and 2.7%, respectively, of the levels exceeded the safety food standard (< 1 mg/kg wet weight) set by WHO and FDA. Accordingly, for adult men and women with 65 kg and 55 kg of body weight, the maximum allowable weekly intake of bigeye tuna are suggested to be 170 and 145 g, respectively.

The objects of this study were to investigate the differences of total mercury(THg), organic mercury(OHg) concentrations in the muscles of albacore and bigeye tuna from the Pacific Ocean, and the THg and OHg concentration in the livers , and the trace elements (Cu, Fe, Mn and Zn) in the muscles and livers of albacore, in order to evaluate the bioaccumulative status of the oceanic migratory fishes. Meanwhile, The relationships between mercury concentration and size (length and weight) and age were established, and the differences of mercury concentrations in the tuna between species and geography were examined. And that the safety consumption level was also discussed. One hundred eighty-five albacore and 134 bigeye tuna were sampled from the period October 2001 to April 2006 and from September 2005 to November 2006, respectively, in the Western and Central Pacific Ocean. The results showed that the average THg (mg/kg flesh wt.) and OHg (mg/kg flesh wt.) of muscles were 0.435¡Ó0.145 and 0.279¡Ó0.087, respectively, for albacore, and 0.935¡Ó0.655 and 0.544¡Ó0.396, respectively, for bigeye tuna. The THg and OHg of livers of albacore were 0.426¡Ó0.363 and 0.193¡Ó0.121, respectively. The average OHg percentages of the THg in albacore and bigeye tuna were 67¡Ó19 % and 62¡Ó20 %, respectively. Except there was no significant correlation between OHg and age in the liver of albacore, the THg and OHg in the muscles, and THg in the livers of albacore, and THg in the muscles of bigeye tuna showed a positive correlation with size and age. The THg and OHg levels in the muscles of albacore were lower than those of bigeye tuna, and the accumulative rates of THg and OHg in albacore were lower than those in bigeye tuna. No significant different of muscles-THg and -OHg concentrations of albacore from the four samplind areas. However, the THg and OHg levels in muscle of bigeye tuna showed that north group higher than those in equator. The concentrations of THg were similar in muscle and liver of albacore, but those OHg, Cu, Fe, Mn and Zn concentrations in liver were significantly higher than those in muscle. A detoxificated mechanism may be commenced when the concentration of THg in liver of albacore exceed 0.8 mg/kg, to maintain the muscle concentration of THg at a level about 0.7 mg/kg. The OHg concentrations of all albacore and 88% of bigeye tuna were below WHO food safety standard for migratory fishes(1.0 mg/kg). The consumption amount of albacore and bigeye tuna were no more than 300 and 150g, respectively, will not exceesed the PTWI(provisional tolerable weekly intake) set by WHO, that will not cause any health threat for consumer.

[pt] Neste estudo foram determinadas as concentrações de mercúrio total (Hgtotal) na fauna agregada aos recifes arenosos formados por poliquetas, Phragmatopoma lapidosa, com o intuito de se verificar a transferência trófica deste elemento. Além da biota presente como, mexilhão (Perna perna), alga verde (Ulva spp.), caranguejo-porcelana (Pachycheles sp), molusca gastrópoda (Thais haemastoma) e sua postura, o Hgtotal também foi determinado no material particulado em suspensão e no sedimento superficial da região localizada no Farol de São Tomé (22 04 52 S e 041 06 59 W), no norte do Estado do Rio de Janeiro. Esta área oceânica pertence a uma região de transição faunística, que apresenta uma grande biodiversidade. O Hgtotal nas amostras bióticas e abióticas secas foi determinado em um espectrômetro de absorção atômica com vapor frio, acoplado a um sistema de injeção em fluxo Perkin Elmer, modelo FIAS 400. Para se caracterizar a área, os parâmetros físicos e químicos pH, Eh, salinidade e temperatura foram determinados. A concentração de clorofila a também foi determinada (0,004 ug.L menos 1) classificando o ambiente como oligotrófico no momento da coleta. O total de sólidos em suspensão apresentou uma concentração baixa de Hgtotal (156,78 mais ou menos 0,61 ug.kg menos 1). Dentre a biota analisada a molusca gastrópoda apresentou a maior concentração nos seus tecidos moles (82,75 mais ou menos 5,78 ug.kg menos 1). Entretanto a sua principal fonte de alimento, o mexilhão apresentou uma concentração de Hgtotal quatro vezes menor (19,13 mais ou menos 0,58 ug.kg menos1) e a sua postura aproximadamente onze vezes menor (7,36 mais ou menos 0,71 ug.kgmenos1). A partir destes dados conclui-se que houve a transferência trófica do Hgtotal entre os organismos estudados. / [en] In order to verify the trophic transfer of mercury, the concentrations of total mercury (Hgtotal) were determined in the aggregated fauna from a sand reef region formed by polychaetes, Phragmatopoma lapidosa. In addition to the aggregated fauna, mussel (Perna perna), green algae (Ulva spp.), porcelain crab (Pachycheles sp) and gastropod (Thais haemastoma) and its posture, Hgtotal were also determined in the suspended particulate matter and in the superficial sediments from the region of the Lighthouse of St. Tomé Reef, Northern Rio de Janeiro State (22 04 52 S, 041 06 59 W). This oceanic area belongs to a transitional faunistic region, which presents a great biodiversity. Hgtotal in the biotic and abiotic samples were determined by a cold vapor atomic absorption spectrometry, coupled to a flow injection system, Perkin Elmer FIAS 400. In order to characterize the superficial water layer of the region, some physical and chemical water parameters (pH, Eh, salinity and temperature) were determined. At the moment of the water sampling, the concentrations of chlorophyll a (0.004 ug.L less 1) in the water column indicated that the trophic state was oligotrophic. The total suspended particulate matter showed a low mean of Hgtotal (156.78 more or less 0.61 ug.kg less 1). The gastropod soft tissues presented the highest Hgtotal (82.75 more or less 5.78 ug.kg less1) and were approximately fourfold higher than those found in its main food items, the mussel (19.13 more or less 0.58 ug.kg less 1). However, mercury concentrations in gastropod posture (7.36 more or less 0.71ug.kg less 1) were eleven times lower than those found in gastropod soft tissues. From these data, it suggests that there is trophic transfer of mercury between organisms studied.

Final publication is available at http://www.tandfonline.com/doi/full/10.1080/19393210.2014.968808 / 京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第19637号 / 社医博第70号 / 新制||社医||9(附属図書館) / 32673 / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 木原 正博, 教授 小杉 眞司, 教授 YOUSSEFIAN Shohab / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

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O Reservatório Rio Grande, localizado na Região Metropolitana de São Paulo (RMSP), é um importante manancial de abastecimento de água dessa região. Foram analisadas amostras de água de fundo e de sedimentos coletadas nesse reservatório em 4 pontos, em 4 campanhas, de setembro de 2008 a janeiro de 2010, sendo estas quantificadas em relação à concentração de Hg total pela técnica de CV AAS. Em seguida, adaptou-se uma metodologia da literatura para quantificação de Hg orgânico em sedimentos, que consistiu na extração dos compostos organomercuriais com diclorometano em meio ácido e, posterior destruição dos compostos orgânicos com cloreto de bromo. A validação dessa metodologia, em termos de precisão e exatidão, foi realizada por meio da análise dos materiais de referência BCR CRM 580 e IAEA 405. Para avaliação dos mecanismos de metilação e desmetilação de Hg nesse ambiente, foram determinados os seguintes parâmetros físicos e químicos, in situ: pH, temperatura da água, potencial redox (EH), transparência e profundidade. Nos sedimentos foram determinados também a granulometria, carbono orgânico total, bactérias redutoras de sulfato, N total e P total, além de Co, Cu, Fe e Mn. A seleção destes parâmetros esteve relacionada diretamente a fatores que influenciam o comportamento do MeHg em sedimentos e sua zona de transição. Foram encontradas concentrações para Hg total variando entre 1,0 e 71,0 mg kg- 1 e de Hg orgânico entre <10,0 a 47,2 &mu;g kg-1 e taxas de metilação entre 0,06 e 1,4% em sedimentos, ao longo do reservatório. Discutiram-se também as diferentes condições de metilação e suas influências, ao longo do reservatório. Como estudo suplementar, avaliou-se a concentração de outros metais e elementos traço presentes nos sedimentos, por meio da técnica de ativação neutrônica. Foram quantificados os elementos As, Ba, Br, Co, Cr, Cs, Hf, Fe, Na, Rb, Sb, Sc, Zn e os elementos terras raras Ce, Eu, La, Lu, Nd, Sm, Tb e Yb. Os fatores de enriquecimento calculados em relação aos valores da crosta terrestre utilizando-se Sc como elemento normalizador apresentaram valores acima de 2,0 para os elementos As, Br, Sb, U e Zn. Verificou-se uma forte influência antrópica para alguns dos elementos analisados, principalmente nos pontos localizados na entrada do reservatório, que recebem descarga de efluentes domésticos e industriais dos rios que alimentam o reservatório. / The Rio Grande reservoir is located in the metropolitan area of São Paulo and it is a very important water supply for this region. In the present study bottom waters and sediment samples collected in this reservoir, in four sampling points, in four campaigns, from September 2008 to January 2010, were analyzed. Firstly total Hg was determined in sediment and bottom waters by cold vapor atomic absorption technique (CV AAS). Following, the analytical methodology for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. The validation of this methodology, in terms of precision and accuracy, was performed by means of IAEA 405 and BCR-CRM 580 reference materials analyses. For methylation and demethylation processes evaluation in this environment, the following physical and chemical parameters were assessed, in situ: pH, water temperature, redox potential (EH), transparency and depth. For the sediment samples, granulometry, total organic carbon, sulphate-reducing bacteria, total N and P, besides the metals Co, Cu, Fe and Mn were evaluated. The selection of these parameters was related to the factors that influence the behavior of MeHg in the sediments and its transition zone. Total Hg ranging from 1.0 to 71.0 mg kg-1 and organic mercury from <10.0 to 47.2 &mu;g kg-1 in sediments and methylation rates from 0.06 to 1.4% were found, along the reservoir. Different methylation conditions along the reservoir and its influences were also discussed. As supplementary study the concentration of some metals and trace elements in the sediments by neutron activation analysis technique was determined. As, Ba, Br, Co, Cr, Cs, Hf, Fe, Na, Rb, Sb, Sc and Zn and rare earth elements Ce, Eu, La, Lu, Nd, Sm and Yb were determined. The enrichment factor in relation to earth crust values using Sc as normalizer element reached values higher than 2.0 for the elements As, Br, Sb, Th, U and Zn, indicating a strong enrichment. A strong anthropogenic influence was verified for some of the elements analyzed, mainly in the points located in the entrance of the reservoir that receives domestic and industrial effluents from the rivers that reach the reservoir.