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Dove, Jonathan Thomas Barnett Mark O. "Mercury immobilization by subsurface reactive barriers." Auburn, Ala, 2009. http://hdl.handle.net/10415/1901.
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Howard, Bruce Mark. "Mercury accumulation in fishes of the Rio Tapajos, Brazilian Amazonia." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271141.
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Wei, Jian. "Microcolumn field sampling and flow injection techniques for mercury speciation." Thesis, Sheffield Hallam University, 1993. http://shura.shu.ac.uk/20513/.
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Mercury is one of the most toxic heavy metals, and many serious incidents have resulted from mercury poisoning. The methylation of mercury and its amplification by marine life have aggravated this pollution problem. Studies over the last three decades have shown that the toxicity of mercury is related to chemical form. A basic aim of the research has been to devise new methodology for the measurement and speciation of mercury. Key points of the investigation reported were the literature review of methodologies and techniques for mercury speciation and the development of a novel manifold which incorporates microcolumns of sulphydryl cotton which have a relatively high affinity and selectivity for inorganic and / or organomercury, and to utilise a continuous flow procedure for mercury speciation based on flow injection-atomic fluorescence spectrometry. This new and novel system has been used for the determination and speciation of mercury in a variety of water samples. The other column packing materials, eg. xanthate cotton, activated alumina and 8-hydroxy-quiniline were also investigated. A further aspect of element speciation concerns the development of a field sampling technique using sulphydryl cotton columns. Sample collection and preconcentration using microcolumns at the site of sampling was successfully performed. Preliminary experiments indicated that the field sampling technique in combination with FIA-AFS was a robust and potentially useful speciation tool. Field surveys on mercury distribution and speciation in the Manchester Ship Canal and the River Rother have been intensively carried out in collaboration with the National Rivers Authority (North West Region). The analytical data on different mercury species in waters of the Manchester Ship Canal are reported for the first time. A high correlation between organomercury and organolead in the Manchester Ship Canal is found and the related data have been assessed in order to clarify the possible origins for organomercury. Related work concerning participation in interlaboratory studies is reported in the Appendices.
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Costa, Monica Ferreira da. "Mercury photochemistry in natural waters." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338305.
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Evmorfopoulos, Evangelos. "Chemical and biological aspects of mercury in seafoods." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/27859.
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Two open wet oxidation methods are described for the digestion of selected seafoods prior to total mercury determination using a cold vapour atomic absorption spectrophotometric technique. The first employs two acids (i.e. HNO3 and H2SO4) and two oxidants (i.e. KMnO4 and K2S2O8), and is suitable for use with a Perkin-Elmer Mercury Analysis System (MAS) and a Perkin-Elmer Mercury Analyzer 50A (MA). Excellent recoveries were obtained for mussel samples spiked with various quantities of inorganic mercury [Hg(N03)2]. For the optimum part of the calibration curve of the MAS (0.1–0.7 μg/ml Hg), the percentage recovery (%R) fluctuated between 98.26 and 101.98. The limit of detection (LOD) was calculated to be 18.7 ng of mercury per sample analysed and sensitivity of 0.011 μg of mercury was obtained. Results for fish samples determined with both units showed excellent agreement and precision (RSD = 3.23 -4.25). However, the MA was found inadequate for the determination of the low mercury levels encountered with the mussel samples. It was shown that a desiccant assembly must be installed whenever samples with low mercury content are analysed, i.e. less than 0.5 μg per sample digested.
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Miserendino, Rebecca Adler. "Tracing mercury pollution in aquatic ecosystems| Implications for public health." Thesis, The Johns Hopkins University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3571745.
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This dissertation addressed questions pertaining to mercury (Hg) fate and transport in aquatic ecosystems by applying stable Hg isotopes as a tracer. Mercury poses a public health burden worldwide. In parts of the developing world, Hg-use during artisanal and small-scale gold mining (ASGM) is pointed at as the source of elevated Hg in the environment. However, Hg from other sources including soil erosion associated with land cover and land-use change (LCLUC) may also contribute to local Hg pollution.
Stable Hg isotope profiles of sediment cores, surface sediments, and soils from two aquatic ecosystems in Amapá, Brazil, one downstream artisanal gold mining (AGM) and one isolated from AGM were assessed. Although previous studies attributed elevated environmental Hg levels in this area to AGM, stable Hg isotopic evidence suggests elevated Hg downstream of AGM sites is dominantly from erosion of soils due to LCLUC.
In contrast, the impact of Hg-use during small-scale gold mining (SGM) in the Southern Andean Region of Portovelo-Zaruma, Ecuador on Hg in the trans-boundary Puyango-Tumbes River was also investigated. By comparing preliminary isotopic Hg signatures from river sediment along the Puyango-Tumbes to soil and sediment from upstream locations along the Puyango tributaries, we suggest Hg-use during SGM in this region is likely responsible for elevated Hg downstream and into Peru. Technical and policy challenges in measuring and responding to gold mining-related cumulative impacts were also reviewed in the context of Portovelo-Ecuador.
Together, the findings not only answer questions of critical importance to preventing Hg pollution in two of the world's most vulnerable ecosystems but also provide information that can be used to better target interventions to reduce environmental Hg levels and subsequent human exposures. Furthermore, the validation and application of the stable Hg isotope method to trace Hg pollution from ASGM in different aquatic ecosystems represents a critical step to the application of stable Hg isotopes to trace pollution in other complex natural environments and to address public health-related questions.
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Kuiken, Todd. "Mercury air/surface exchange over terrestrial background surfaces of the eastern USA and its policy implications : a dissertation presented to the faculty of the Graduate School, Tennessee Technological University /." Click to access online version, 2007. http://proquest.umi.com/pqdweb?index=76&did=1394664171&SrchMode=1&sid=1&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1255093439&clientId=28564.
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Gauchard, Pierre-Alexis. "Étude d'un processus singulier d'oxydation du mercure atmosphérique en zone polaire : les « Atmospheric Mercury Depletion Events »." Phd thesis, Grenoble 1, 2005. http://tel.archives-ouvertes.fr/tel-00009980.
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Le mercure est un composé toxique. En zone polaire, au printemps, une chimie extrêmement particulière est à l'origine, après oxydation, de son dépôt en surface du manteau neigeux. Ces phénomènes appelés « Atmospheric Mercury Depletion Events » (AMDEs) ou « pluies de mercure » sont à la base d'une contamination encore mal renseignée des écosystèmes polaires. Lors de campagnes de terrain en Arctique, nous avons observé sept AMDEs, et avons étudié les paramètres physico-chimiques susceptibles de gouverner l'apparition de ces événements. Le rôle des basses températures et l'implication des nuages glacés parmi les surfaces gelées actives sont évoqués. L'impact de ces AMDEs en terme de teneurs en mercure dans la neige de surface a également été examiné. Les dépôts résultant de ces phénomènes n'aboutissent pas forcément à une contamination marquée de la neige de surface, et nos connaissances sont aujourd'hui trop limitées pour pouvoir quantifier l'apport toxique des AMDEs sur l'Arctique.
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Al-Majed, Nahida Bader. "An evaluation of mercury pollution of the marine and atmospheric environment in Kuwait." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367999.
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Clifford, Martin John. "Environment, health and mercury pollution in the small-scale gold mining industry." Thesis, University of Reading, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590120.
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The extensive use of mercury, a persistent contaminant, in the artisanal and small-scale mining (ASM) sector is a growing environmental issue. Mounting concern over findings which point to the widespread use of mercury to amalgamate gold in ASM having significant environmental and health-related impacts has fuelled the launch of numerous donor-funded and government backed projects aimed at minimising its use. Most have taken the form of educational and technical assistance, implemented specifically to stem emissions from the industry and introduce miners to safer practices. These interventions, however, have had minimal impact. In an attempt to understand why the 'mercury pollution agenda' has yielded so little in the way of improvement, two divergent viewpoints have emerged. The first of these explanations, a view prevalent in donor and regulatory circles, is that miners ignore messages about the dangers of mercury and are reluctant to adopt more environmentally-friendly practices. The second body of opinion contests that approaches taken to educate and provide training on mercury management to communities are flawed, failing to take stock of the successful aspects of previous work and sufficiently eng~e target communities. There is insufficient empirical evidence to support either view, however. A broadened understanding of operators' perceptions toward the environmental impacts of amaJgamation is a necessary first step towards improving the policy context for mercury management in the ASM sector. This thesis helps to bridge this gap, focllsing on the case of Ghana, the location of one of the largest ASM industries in sub-Saharan Africa. It determines levels of awareness and prevaJent attitudes towards mercury use amongst small-scale gold miners, capturing a level of detail not yet undertaken. It also identifies barriers that prevent miners from adopting improved mercury management practices. To address these issues, a mixture of qualitative and quantitative analyses were undertaken: interviews with key institutional stakeholders; individual interviews, group discussions and feedback sessions with miners; and an environmental assessment. This research provided a comprehensive understanding of the dynamics of mercury use in Ghana's ASM industry.
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Trudel, Marc. "Bioenergetics and mercury dynamics in fish." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36723.
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This research focuses on the development, evaluation, and application of a mercury (Hg) mass balance model for predicting the accumulation of Hg in fish. This model requires accurate estimates of Hg elimination rate by fish and feeding rates to adequately predict Hg concentration in fish. An empirical model was developed to estimate Hg elimination by fish using data obtained from published experiments. This analysis showed that Hg elimination rate was overestimated in short-term experiments, positively correlated to water temperature, negatively correlated to body size, and that the elimination rate of inorganic Hg was faster than that of methylmercury. This empirical model was then incorporated in a Hg mass balance model to predict the concentration of Hg in fish. The Hg mass balance model accurately predicted Hg concentration in fish when it was combined with food consumption rates that were determined using a radioisotopic method. This analysis suggested that the parameters of the Hg mass balance model were adequate for predicting Hg concentration in fish. I also showed that Hg concentration tended to be underestimated by the Hg mass balance model when it was combined with feeding rates determined with a laboratory-derived bioenergetic model, probably because activity costs derived in the laboratory do not reflect activity costs of fish in the field. Beside predicting Hg concentration in fish, I showed that this mass balance model could also be used to estimate feeding rates of fish in the field by measuring the concentration of Hg in fish. This approach was validated using data obtained from a published experiment. It was also successfully tested using independent estimates of feeding rates obtained with a radioisotopic method. I applied this Hg mass balance model to compare the energy budget of sympatric populations of dwarf and normal whitefish (Coregonus clupeaformis). This analysis showed that dwarf whitefish consumed 40--50% more food than normal whitefi
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Ullrich, Susanne Maria. "Industrial mercury pollution with particular emphasis on its impact in the aquatic environment." Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438710.
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Starr, Lindsay D. "Mercury pollution in an urban and suburban lacustrine system in Summit County, Ohio." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron149434254589456.
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Papadimitriou, E. "Studies of the post-depositional cycle of mercury in a marine and a lacustrine environment : response during early diagenesis." Thesis, Bangor University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484162.
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Blanchet, Peggy D. C. "Mercury in hair : method development and application to population studies." Thesis, Sheffield Hallam University, 1996. http://shura.shu.ac.uk/19358/.
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As part of the Avon Longitudinal Study of Pregnancy And Childhood, the toxic metal, mercury, is studied in order to assess whether it presents a danger to the development of children in the UK.The development and optimisation of a digestion procedure for the determination of total mercury in hair is described. The procedure chosen consists of the microwave digestion of 0.2-0.5g hair with 2 ml HNO3 and 1 ml H2O2 . The effect of washing and drying of the samples is investigated, and found not to influence analytical results when hair samples are collected after shampooing. However, freeze-drying of the samples results in the loss of 30% of mercury. The distribution of mercury along the length of a strand of hair is studied. It is shown to vary in adults (up to a factor of 7) but not in children (less than 20%). In the applications of this analytical method to population studies, the frequency of fish meals, and the age of the subject are positively correlated to the mercury levels in adults' hair (r = 0.539 and 0.513, respectively). Breast-feeding and mercury levels in children's hair are also correlated (r = 0.433). The relationship between number of fillings and mercury levels in adults' hair is not significant. No correlation was found between mercury levels in children's hair and Developmental Quotient (Griffith's scales) (r = -0.24 to 0.18).The optimisation of a coupled High Performance Liquid Chromatography - CV-AFS system for the study of mercury speciation is described. The use of KOH and microwave digestion for the extraction of mercury species was unsuccessful, and thus recommendations for future work are made.
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Markström, Jimmy. "Is mercury mobilized from acid sulfate soils? : Interpreting the mercury record from lake- and marine sediments in Persöfjärden and adjacent sea bay." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171611.
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Acid sulfate (AS) soils are characterized by a large pool of sulfates which may provide significant amounts of acidity and heavy metals – commonly nickel (Ni), Cobolt (Co), Zinc (Zn) and Arsenic (As) - to surrounding surface waters. The occurrence of AS soils is widespread, covering 17 million ha globally, and they are known for threatening freshwaters in Australia, North America as well as in many tropical regions. Mobilization of mercury (Hg) from AS soils is however poorly studied and could potentially be an environmental problem of concern due to its toxicity and capacity of bioaccumulating in food webs. In this study I investigated whether Hg is mobilized from AS soils by conducting chemical analyses on sediment samples from a 1,6 m deep lake core and a transect of surficial sediment samples in an adjacent sea bay. Here, I used zircon (Zr) and zinc (Zn) as proxies for silicate sources and sulfide soil sources, respectively. I found that Zn and Hg concentrations normalized to the organic matter content (LOI) showed a significant correlation in the lake core; hence, Hg in the sediment co-varied with my sulfide proxy and showed no correlation to my silicate proxy, and I then conclude that a considerable fraction of mercury in the studied sediment has a likely origin from AS soils.
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Snyder, Craig David. "Physiological, population, and genetic responses of an aquatic insect (Isonychia bicolor) to chronic mercury pollution." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-165554/.
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Sauer, Robert Eugene Jr. "Development and use of saltmarsh mesocosms in studies of sedimentary mercury transformation." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/19608.
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Silberberger, Jamie. "Reducing dental mercury discharge in Missoula, Montana collaborative opportunities /." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-05182007-144430/.
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"Professional paper presented in partial fulfillment of the requirements for the degree of Master of Science, Environmental Studies, the University of Montana, Missoula, MT, spring 2007."Title from PDF title page (viewed on Aug. 12, 2007). Includes bibliographic references (p. 67-69).
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Hsiao, Hui-Wen. "Verification of methodologies for estimating human exposure to high levels of mercury pollution in the environment." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/72988/.
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A considerable amount of work has been conducted developing exposure estimate models for quantitative evaluation of Hg intake and human health risks, but few have assessed the applicability and the validity for evaluating the risks posed by Hg in the environment and have achieved very mixed results. The present study focused on verifying the daily Hg intake estimates using exposure estimate models. Deterministic methods and the probabilistic methods (the Monte Carlo) were applied to simulate the daily Hg intake doses which were verified by comparing the estimates to those established from measured Hg concentrations in the hair of 289 participants. The results showed that the single-value deterministic method for simulating Hg exposure levels overestimated the level of risk by a factor of 1.5 when compared with the highest concentration of the Hg observed in the hair of the study population. The average daily Hg intake doses simulated using the probabilistic simulation were similar in distribution to the biomarker data, with the variability of 23%. The difference between the probabilistic simulation and the data derived from hair Hg levels was considered to be most likely due to the uncertainties in unconfirmed questionnaire-based survey data, small sampling sizes and the surrogates used in the exposure models. When the reference dose (RfD) of 0.1 μg/kg body weight/day was adopted as the acceptable dose for daily intake rate, there were approximately 19% estimated to have potential Hg exposure risks based on the Monte Carlo simulation. This percentage was favourably similar to the 17% determined from Hg concentrations in the hair samples. The findings implied that the existing exposure models together with the probabilistic approach were appropriate for the research of human exposure to Hg. On the other hand, low Hg levels in the participants’ hair indicated that Hg accumulated in the study population was not very serious, probably due to the good Hg absorptivity of the on-site fly ash. However, it should be advised that consumption of river fish elevates the health risks to the local population.
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Williams, Chavon R. "A National survey of Mercury levels in South Africa's water management areas." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8674_1298356510.
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This study forms part of a broader project co-funded by the Water Research Commission (WRC), and CSIR Parliamentary Grant (PG) and Strategic Research Panel (SRP) research grants, aimed at surveying selected water resources within the 19 Water Management Areas in South Africa. Furthermore, it aims at determining the concentrations of Hg and MeHg in various environmental compartments collected from priority water resources, to identify the potential Hg hotspots, and to assess the degree of compliance with national and international guidelines. Mercury concentrations in the environment have increased globally and this has caused much anxiety in terms of the adverse effects it has on aquatic ecosystems, their organisms, and the communities they sustain. Human health risks associated with the consumption of fish elevated containing Hg concentrations have received minimal attention particularly in South Africa. It is imperative that any potential adverse impacts of Hg on aquatic ecosystems, and the subsequent impacts on human health, be investigated.
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Basu, Niladri. "Neurochemical biomarkers to evaluate mercury toxicity in mink." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85882.
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Mercury (Hg) is a toxicant of global concern, but few strategies exist to evaluate its biological effects on the ecosystem. Piscivorous wildlife, such as mink (Mustela vison), are particularly at risk because they can bioaccumulate Hg to concentrations known to impair neurological systems. Given that biochemical changes in the brain precede functional and structural impairments, I evaluated the use of neurochemicals as early-warning biomarkers of Hg toxicity in mink. Initial studies demonstrated that neurochemical biomarkers could be measured from mink carcasses collected from the field, as long as factors such as storage temperature and freeze thaw cycles were accounted for. To determine if Hg could directly impair neurochemicals in mink, an in vitro study demonstrated that Hg (HgCl2 and MeHg) could inhibit radioligand binding to the muscarinic cholinergic (mACh) receptor in the cerebellum and cerebral cortex regions of the brain. By analyzing whole brains collected from wild mink, it was demonstrated that a significant positive correlation existed between concentrations of brain Hg and levels of mACh receptors. These field observations were confirmed by results from a controlled methyl Hg (MeHg) feeding trial in captive mink, whereby sub-chronic exposure of mink to 0.5 - 2 ppm MeHg (ecologically relevant levels) resulted in significant increases in acetylcholinesterase activity and mACh receptor levels in specific brain regions. Collectively, these results demonstrated that exposure of mink to environmentally realistic concentrations of Hg can be related to alterations in neurochemicals at multiple tiers of biological organization. Given the importance of a functional nervous system in wildlife health, the physiological and ecological significance of these findings need further exploration. The results demonstrate that neurochemical approaches may be novel biomarkers to assess the ecotoxicology of Hg, and by extension, other pollutants o
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Farren, Alex. "Mercury and selenium speciation and toxicity in common loons." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81331.
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Approximately 10,000 tones of Hg are deposited annually as a result of anthropogenic activities. This increased Hg burden is known to have adverse neurological and reproductive effects on Common loons. A positive correlation between mercury (Hg) and selenium (Se) has been reported to exist in marine mammals and various species of marine and aquatic piscivorous birds. It has been hypothesized that the Hg/Se interactions may involve in the multiple mechanisms of Hg detoxification. This study focused on the suggested Hg/Se complex that forms in association with specific proteins. Specifically, this project focuses on the nature of these interactions in different tissues from wild Common loons (Gavia immer) that have been collected by the Canadian Wildlife Service. The Hg and Se concentrations in the various tissues were quantified using AAS. MALDI-TOF-MS and protein sequencing characterized the nature of the Hg/Se complex binding protein. Among the tissues, the liver had the highest concentrations of Hg and Se followed by kidney; muscle and brain. A strong association between Hg and Se was found in liver, kidney and eggs whereas there was no association in muscle and brain. In contrast brain and muscle had highest percentage of organic Hg suggesting that only inorganic Hg is associated with Se. Two Hg-Se binding protein complexes were found in liver both in the 15,200-15,300 Da range while one such complex in the same weight range was found in kidneys, when sequenced it was found that these proteins were the alpha A chain of Hemoglobin. The protein complex found in eggs was unique and although it was impossible to fully sequence it, it represents an unknown protein. The role of Se in Hg toxicity in eggs warrants further study.
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Merritt, Karen A. "Mercury Dynamics in Sulfide-Rich Sediments: Geochemical Influence on Contaminant Mobilization and Methylation within the Penobscot River Estuary, Maine, USA." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/MerrittKA2007.pdf.
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Siegel, Shefa. "The needs of miners: political ethics, mercury abatement, and intervention in artisanal gold mining communities." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/435.
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This dissertation examines the role of donor-funded international projects to reduce mercury pollution from artisanal and small-scale gold mining (ASM). ASM is the second largest source of anthropogenic global mercury pollution, accounting for roughly 1000tonnes of atmospheric emissions and releases to the environment per annum. The artisanal mining economy involves 10-15 million people across the developing world, and supports 80-100 million people directly and indirectly. In 2003 the Governing Council of the United Nations Environment Program reached consensus that there is sufficient scientific evidence to trigger an international response to global mercury pollution, including the pollution generated by ASM. Yet thus far most international interventions have concentrated on environmental monitoring and assessment, while virtually no efforts have focused on implementing solutions. The aim of this dissertation is to move global mercury policy for ASM past its emphasis on assessments. It does this by developing a philosophical and strategic policy framework to guide future interventions by international institutions. A brief history of global mercury policy is provided, illustrating how ASM has been neglected and examining divisions between ecocentric and technocentric theories of environmental intervention. The relationship between ASM and poverty is examined, reaching the conclusion that because artisanal gold mining is a form of upward mobility for the world's extreme poor, the idea of reducing mercury pollution by redirecting miners into alternative livelihoods is unrealistic; indeed gold itself is the alternative livelihood. Using case studies collected in the field, the issue of conflict over property rights between artisanal miners and large-scale mining companies is explored, and a risk mitigation framework presented to assist companies to coexist with artisanal miners. Finally, a new approach to international intervention is proposed based on three interdependent principles of formalization, capitalization, and education. A plan is developed for directing more expertise and financial resources to the field, and more effectively meeting the needs of miners. Specific recommendations include a rapid assessment methodology to select project sites, and improving operational linkages among public and private institutions.
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Jayaram, Varalakshmi. "Capture of Elemental Mercury in a Wet Membrane Plasma Enhanced Electrostatic Precipitator using Hydrochloric Acid as the Reagent Gas." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1133356270.
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Brown, Megan Elizabeth. "Geochemical and Taphonomic Signatures of Freshwater Mussel Shells as Evidence of Mercury-Related Extirpations in the North Fork Holston River, Virginia." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33028.
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This study utilized freshwater mussel shells to assess the role of mercury contamination in the North Fork Holston River, an aquatic habitat affected by extensive extirpations of mussel populations starting in the early 1970â s. Mussel shells (n=366) collected from 5 sites, upstream and downstream of Saltville (where mercury was used from 1950-1972) were analyzed to test if: (1) geochemical signatures of shells record variation in mercury levels relative to the contamination source; and (2) shell taphonomy could be used to differentiated affected and unaffected sites.
Analysis of 40 shells for geochemical signatures using atomic absorption spectroscopy indicated a strong longitudinal pattern. Mercury content was as follows: upstream sites had low Hg concentrations (<5 to 31ppb), shells directly below Saltville had high concentrations (23-4,637ppb), shells 18km downstream of Saltville displayed intermediate values (7-115ppb), and those 38.4km downstream were comparable to upstream sites (<10ppb). Two pre-industrial shells collected from Saltville in 1917 also yielded Hg estimates (5-6ppb) comparable with upstream estimates. The Hg content was not correlated with shell length (r=-0.3; p=0.2) or degree of taphonomic alteration (r=0.18; p=0.28). Analysis of 366 shells for taphonomic signatures indicated that shells are most heavily altered and fragmented directly downstream of Saltville. In contrast, upstream sites, inhabited by reproducing mussel populations, contain many fresh-dead shells. Taphonomic signatures can thus be used to differentiate sites with different extirpation histories. Relic mussel shells can provide useful spatial and temporal data on Hg concentrations in polluted ecosystems and offer a tool for delineating areas with unknown extirpation histories.Master of Science
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MALAGRINO, WALDIR. "Bioacumulacao e eliminacao de mercurio (sup(203)Hg) no mexilhao (Perna perna, Linne, 1758) .Modelo cinetico para avaliar o risco de ingestao no homem." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11095.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Johansson, Camilla. "Geokemin inom osorterade cirklar : Analys av tungmetallers distribution inom jordprofiler tagna från Abiskoområdet, nordvästra Sverige." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55452.
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The Arctic region appears as a pristine remote environment, yet there is increasing evidence that it is greatly impacted by pollution such as lead (Pb) and mercury (Hg). In this environment deposition of Hg has increased threefold since the last industrial revolution. In this study five cryosolic soil profiles within non-sorted circles (NSC) in the Abisko region, northwest of Sweden, has been analyzed to improve our understanding regarding how pollutants are distributed within such type of soil. The soil samples have been analyzed with the use of X-ray fluorescence analysis (XRF), for the measurements of the total concentrations of e.g. lead (Pb) and zirconium (Zr). The soil samples were also analyzed for Hg and LOI. In each sample Zr was used to determine whether metal concentrations were naturally derived from soil silicate minerals or from non-silicate (anthropogenic) sources. From the inner domains of the circles towards the outer domains where the latter contained the highest amounts of organic matter that bind these metals the Pb and Hg concentrations increased. The highest concentrations of Pb (47 mg/kg) and Hg (359 µg/kg) are found in the surface layer (about7 cmdeep) at the edges of the circles. In a buried layer (O-horizon) found in the inner domain, the concentration of Hg was 60µg/kg. Within the studied NSC the concentrations anthropogenic derived Pb and Hg in the surface layer of the circles outer domain was estimated to constitute 95 - 100 % of the total metal burden. In the buried organic layer 95 % of Hg was estimated to be anthropogenic. Clearly, the soil was strongly affected by anthropogenic Pb and Hg concentration.
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Sørensen, Rasmus. "Influence of topography and forestry on catchments : soil properties, runoff regime, and mercury outputs /." Uppsala : Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200985.pdf.
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Holloway, Jennifer C. "Investigation of white blood cell phagocytosis as a potential bio-marker of mercury immunotoxicity in birds." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33002.
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White blood cell phagocytosis was investigated and used with avian blood, and assessed as a potential biomarker for mercury immunotoxicity in free ranging birds (common loons). Phagocytosis is an essential immunological function and can be measured using flow cytometry. The assay was assessed with in vitro exposure using whole blood and isolated white blood cells (WBC) from domestic chickens, and with in vivo exposure using whole blood from captive doves and wild loons. McHg at 0.1ppm significantly depressed phagocytic capacity of isolated WBCs without affecting their viability, but did not affect phagocytic activity when added to whole blood up to 50ppm. Also, no significant relationship between blood-Hg level and phagocytic capacity of WBCs was observed in ringed turtle doves fed McHg in their diets, nor in wild common loons having a range of blood-Hg concentrations. The phagocytosis assay is a convenient assay for use in field studies of free-living birds, but is not responsive to McHg exposure in birds, and so is not recommended as a biomarker of immunotoxicity in Hg-exposed loons.
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HORTELLANI, MARCOS A. "Avaliacao da contaminacao por mercurio dos sedimentos do estuario Santos - Sao Vicente, no periodo de 1996 - 2000." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11077.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Carvalho, Paloma Calábria. "Concentração de metais no sangue e em penas de petréis do gênero Porcellanaria." reponame:Repositório Institucional da FURG, 2012. http://repositorio.furg.br/handle/1/4054.
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Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2012.Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-10-16T12:22:26Z No. of bitstreams: 1 Paloma.pdf: 489250 bytes, checksum: 19c1a510804e4f596b4c389dc55d9d48 (MD5)
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No presente estudo, indivíduos de duas espécies irmãs de petréis do gênero (P.conspicillata e P.aequinoctialis) foram avaliados para verificar possíveis diferenças nas concentrações de metais essenciais (Cu e Zn) e não: essenciais (Cd, Pb e Hg) em espécies filogeneticamente próximas, porém com nichos ecológicos distintos. Na invernagem, estas espécies são simpátricas em algumas áreas, com valores semelhantes de isótopos estáveis de nitrogênio (δ15N) e carbono (δ13C) no sangue, indicando que estas se encontram em um mesmo nível trófico e que possuem alimentação semelhante durante este período. No entanto, P.aequinoctialis apresentou maior variação individual, com valores isotópicos menores em indivíduos oriundos da região Antártica. Não houve correlações entre os valores de isótopos estáveis e a concentração de metais no sangue das duas espécies analisadas, porém, foi detectada diferença na concentração de Hg no sangue e nas penas, bem como de Cu e Zn nas penas, entre as duas espécies. Para ambas as espécies, todos os metais apresentaram menores concentrações no sangue que nas penas, exceto o Hg em P.aequinoctialis. Nas penas, a concentração de Hg foi dez vezes maior em P.conspicillata do que em P.aequinoctialis. E, além de distinguir as duas espécies, a concentração de Hg também foi diferente entre indivíduos juvenis e adultos de P.aequinoctialis. Todos esses resultados indicam que o alimento utilizado no Oceano Atlântico Sul Ocidental, onde P.conspisillata se distribui durante todo o ano e P.aequinoctialis forrageia durante o inverno, apresenta elevadas concentrações de Hg.
In the present study, specimens of two sister species from the genus (spectacled petrel P.conspicillata and white:chinned petrel P.aequinoctialis ) were evaluated to verify potential differences in the concentrations of essential (Cu and Zn) and non:essential (Cd, Pb and Hg) metals in phylogenetically closely: related species, but with distinct ecological niches. In wintering period, these species are sympatric in some areas, showing similar blood values of nitrogen (δ15N) and carbon (δ13C stable isotopes. This finding indicates that they are in the same trophic level and are feeding on similar food resources during this period. However, white: chinned petrel showed higher individual variation, with lower isotopic values in individuals from the Antarctic region. For both species, there were no correlations between blood values of stable isotopes and metal concentrations. However, there was a significant difference between species in Hg concentration in blood and feathers, as well as in Cu and Zn concentrations in feathers. For both species, all metals analyzed showed lower concentrations in blood than in feathers, except for Hg in white:chinned petrel.In feathers, Hg concentration was 10: fold higher in spectacled petrel than in white: chinned petrel. Besides to distinguish the two species, Hg was also different between juveniles and adults white: chinned petrels Taken altogether, these findings indicate that food consumed in the South Atlantic Ocean, where spectacled petrels occurs throughout the year and where white: chinned petrel forages in wintering period, has elevated concentrations of Hg.
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Mamani, Matamet Fanny Roxana. "Biodisponibilidade de mercurio e outros metais-traço em sedimentos do Rio Cubatão, Sistema Estuarino de Santos-Cubatão (SP)." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287689.
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Orientador: Wanilson Luiz SilvaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: Os ecossistemas costeiros da Baixada Santista no Estado de São Paulo encontram-se degradados, em conseqüência da concentração populacional e da instalação de um pólo petroquímico e siderúrgico. Essa degradação iniciou-se na década de 1950, com a construção do mais importante complexo de fábricas da América Latina, o Pólo Industrial de Cubatão. Apesar do controle por órgãos de governo das emissões de efluentes industriais, elevados níveis de mercúrio e outros metais têm sido encontrados nos sedimentos do rio Cubatão, um dos mais impactados do sistema estuarino de Santos-Cubatão. O mercúrio constitui um dos poluentes de maior risco para o equilíbrio ecológico e para a saúde humana, justificado pela elevada toxicidade e potencial de bioacumulação e biomagnificação na cadeia trófica. Este estudo objetivou analisar o risco de biodisponibilidade de mercúrio e outros metais-traço em sedimentos do rio Cubatão e a variabilidade de suas concentrações totais e lábeis no inverno e no verão. Para isso, vários aspectos específicos foram investigados em sedimentos de testemunhos curtos, tais como, os níveis totais de mercúrio e outros metais de interesse; as concentrações de sulfetos volatilizáveis por acidificação (AVS) e metais simultaneamente extraídos (SEM = Ni, Zn, Cd, Cu, Pb e Hg), cuja razão molar SEM/AVS < 1 é um indicativo de não biodisponibilidade dos elementos-traço de interesse; o papel do pH e Eh da água intersticial, da matéria orgânica e granulometria como possíveis reguladores dos níveis de metais no ambiente sedimentar. Os resultados mostraram concentração média de Hg total nos sedimentos amostrados no verão (0,70 mg/kg) superior àquela do inverno (0,05 mg/kg). Em adição, maiores concentrações de metais totais (Fe, Ni, Zn, Cd, Cu e Pb) também foram notificadas na estação chuvosa. As análises de AVS e SEM dos sedimentos mostraram excesso de metais em relação aos sulfetos (SEM/AVS > 1) especialmente no verão, sugerindo que o papel do AVS no controle da biodisponibilidade de metais é limitado na estação quente. Condições de pH levemente ácidas a neutras, Eh redutor e incremento nos níveis de matéria orgânica mostraram-se favoráveis à formação de sulfetos, aspectos importantes na fixação dos metais nos sedimentos. Em adição, a textura fina dos sedimentos mostrou-se particularmente importante no controle de metais totais, AVS e SEM
Abstract: Coastal-estuarine ecosystems from the south of São Paulo State are presently degraded specially in Cubatão municipality, in consequence of population concentration and, industrial and petrochemical complexes. These environmental impacts have begun in the 1950¿s after the construction of the largest Latin America petrochemical complex in the Cubatão city. Despite the control by government agencies, effluent emissions from these industries have raised mercury (Hg) concentrations to critical levels within the Cubatão river sediments. Mercury (Hg) constitutes one of the greatest risk pollutants for ecological balance and human health risus. This metal has high toxicity and bioaccumulation potential, as well as biomagnification potential through food chains. The objective of this study is to analyze seasonal bioavailability of mercury and trace-metals concentrations in Cubatão river sediments. Several aspects were investigated in sediment cores as mercury and other metals concentrations in whole sample, acid volatile sulfides (AVS) and simultaneously extracted metals (SEM = Ni, Zn, Cd, Cu, Pb and Hg). The molar ratio SEM/AVS < 1 is an indication of non bioavailability of trace-metals. The roles of pH and Eh from pore water, organic matter and grain-size were also studied as potential regulators of metal concentrations in the sedimentary environment. As results, mean mercury concentrations in sediments during summer (0.7 mg/kg) are higher than in winter (0.05 mg/kg) and other trace-metal concentrations (Ni, Zn, Cd, Cu and Pb) have the same behavior. AVS and SEM molar ratios were less than one, indicating an excess of trace-metal in relation to sulfides, especially in summer. This means that AVS control bioavailability is limited in this season. Conditions as slightly acid to neutral pH, reduced Eh and greater organic matter content favor sulfide formation, which are important for metal sorption by sediments. In addition, the fine texture of sediments was important to control total metal concentrations, AVS and SEM
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
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PALETTI, GERSON. "Determinacao de mercurio e metilmercurio em cabelos de populacoes residentes no Parque Indigena do Xingu." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10812.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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CAMPOS, MONICA S. de. "Estudo da correlacao mercurio-selenio em amostras de cabelos de indios Wari." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10946.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Durand, Alexis. "Diversité et caractérisation fonctionnelle des communautés microbiennes inféodées au peuplier et issues d'une friche industrielle enrichie en mercure." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD037/document.
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Le sol possède un capital naturel qui lui confère la capacité à produire des services écosystémiques aussi bien culturel que de régulation ou d’approvisionnement, il est indispensable à la Vie telle que nous la connaissons et au développement des activités humaines. Cependant les activités anthropiques et les pollutions, notamment par les éléments traces métalliques (ETMs) tel que le mercure (Hg), perturbent les sols et modifient en profondeur l’organisation des écosystèmes. Face à ces enjeux, des projets de remédiation et de gestion des sites et sols pollués se sont multipliés durant les dernières décennies en vue de futures ré-exploitations de ces sols. Cette thèse s’inscrit dans le cadre des projets ANR-BIOFILTREE et EC2CO FREIDI-Hg gérés par le laboratoire Chrono-Environnement. Mes travaux ont permis l’exploration de la diversité des communautés de microorganismes associées à une plantation de peuplier sur un site contaminé par le Hg et géré par phytomanagement, via les approches combinées de séquençage à très haut débit et par l’approche culture dépendante. Ces méthodes combinées ont permis de révéler i) la diversité des communautés bactériennes et fongiques de la peupleraie ; ii) les groupes de microorganismes particulièrement résistant au Hg (Trichoderma et Pseudomonas) ; et iii) des bactéries promotrices de croissance des plantes (PGPB). Par ailleurs, la compréhension des mécanismes cellulaires liés à l’accumulation de Hg par les microorganismes a été un de mes sujets d’étude en partenariat avec le LIEC (Université de Lorraine). Les modèles eucaryotes Saccharomyces cerevisiae et Podospora anserina ont été utilisés pour tester le rôle potentiel de certains transporteurs d’ions dans l’entrée du Hg dans les cellules fongiques. Les résultats ont montré que le transporteur de magnésium Alr1 situé sur la membrane plasmique pourrait participer au transport du Hg. En outre, une approche de transcriptomique chez Saccharomyces cerevisiae après une courte exposition au Hg des souches mutantes et sauvages a été mise en œuvre. Pour conclure, ce travail de thèse ambitionne d’être un travail de référence pour les futurs projets de phytomanagement en milieux contaminé par le Hg, qui met en avant les communautés de microorganismes et leurs rôles fondamentauxSoil has a natural capital that gives it the capacity to produce ecosystem services, cultural as well as regulation or supply, it is essential to the Life as we know it and the development of human activities. However, anthropogenic activities and pollution, in particular by trace elements (ETs) such as mercury (Hg), disrupt the soil and modify in depth the organization of ecosystems. Facing these challenges, remediation and management projects for polluted sites and soils have emerged during the last decades with a view to future re-exploitation of these soils. This thesis is part of the ANR-BIOFILTREE and EC2CO FREIDI-Hg projects managed by the Chrono-Environnement laboratory. My Ph-D work explored the diversity of microorganism communities associated with a poplar plantation at a Hg-contaminated site managed by phytomanagement, combining approaches such as very high-throughput sequencing and conventional culture-based techniques. These combined methods revealed i) the diversity of the bacterial and fungal communities of the poplar plantation; ii) the groups of microorganisms particularly resistant to Hg (Trichoderma and Pseudomonas); and iii) plant growth promoting bacteria (PGPB). In addition, understanding the cellular mechanisms related to the accumulation of Hg by microorganisms was one of my objectives carried out in collaboration with the LIEC (University of Lorraine). The eukaryotic models Saccharomyces cerevisiae and Podospora anserina were used to test the potential role of some ion transporters in the entry of Hg into fungal cells. The results showed that the magnesium transporter Alr1 located on the plasma membrane could participate in the transport of Hg. In addition, a transcriptomic approach in Saccharomyces cerevisiae after a short exposure to Hg of mutant and wild strains has been implemented. To conclude, this work aims to be a reference work for future phytomanagement projects in Hg-contaminated environments, which highlights micro-organism communities and their fundamental roles
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Castro, Neemias de [UNESP]. "Cádmio, chumbo, cromo, mercúrio e níquel nos rios do estado de São Paulo e em peixes do Rio Sorocaba (São Paulo, Brasil)." Universidade Estadual Paulista (UNESP), 2002. http://hdl.handle.net/11449/122191.
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000185379.pdf: 993355 bytes, checksum: 10c9ef2e5920d4d73ea7a3e5ec954ae8 (MD5)Com o objetivo de verificar os níveis de concentração de alguns metais pesados em peixes do Rio Sorocaba e avaliar se estão contaminados e se constituindo em risco para a saúde de quem os pesca e consome, foram estudados 63 exemplares de peixes capturados em quatro pontos ao longo desse recurso hídrico e pesqueiro, quanto à presença de cádmio, chumbo, cromo, níquel e mercúrio, com ênfase neste último, por ser reconhecidamente o mais tóxico e com maiores possibilidades de contaminar peixes. Constatou-se, analisando amostras de músculo por espectrometria de absorção atômica - vapor frio, que os peixes do rio Sorocaba não apresentam concentrações proibitivas de nenhum dos cinco metais pesados estudados, estando seguros para o consumo humano. Para subsidiar o objetivo principal deste trabalho, foi feito estudo crítico dos dados levantados pela CETESB nos Relatórios da Qualidade das Águas Interiores do Estado de São Paulo nos anos de 1997 a 2000 quanto ao cádmio, chumbo, cromo, níquel e mercúrio. O estudo aponta que nas 20 Unidades de Gerenciamento de Recursos Hídricos do Estado de São Paulo monitoradas pela CETESB ocorreram casos de desconformidades, frente aos padrões legais para a classe dos rios, para um ou mais dos cinco metais pesados avaliados, sendo recomendável uma melhoria das ações de controle para esses metais em todas as regiões.
To verify the levels of concentration of some heavy metals in fishes from Sorocaba river (São Paulo, Brazil) and evaluate if this contamination offers health risks to the fishermen, 63 samples of fishes collected from four points along the river were studied for cadmium, lead, chromium, nickel and mercury, with emphasis in this last, since it is the most toxic and most probable as a fish contaminant. Analyzing muscle samples by cold vapor atomic absorption spectrometry it was shown that the fishes are not contaminated. None of the five metals studied were present in prohibitive level and the fishes could be judged secure for human consume. It was also analyzed data from four years of cadmium, lead, chromium, nickel and mercury monitoring made by CETESB, from 1997 to 2000, in water from the main rivers of the State of São Paulo. The study pointed out that the majority of the monitored rivers still present contamination by those metals in a level that requires an improvement of the pollution control actions.
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Thomason, Krista A. "Trends Analysis and a Yearly Comparison of Point Sources of Atmospheric Mercury Using HYSPLIT Back Trajectories Focused in Athens, Ohio." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1557161272706908.
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Bank, Michael S. "Mercury Bioaccumulation and Habitat Relations of Lotic and Lentic Amphibians from Acadia National Park, Maine, USA." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/BankMS2005.pdf.
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Robson, Thomas. "Weathering of sulfide ores in model soils, potentially toxic element release and bioavailability." Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/2859.
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The exploitation of metallic sulfide ores produces vast quantities of fine-grained wastes hosting potentially toxic elements (PTEs). There are concerns that, if improperly disposed of and managed, waste mineral particles can behave as vectors that disperse PTEs via aeolian and fluvial transport, subsequently contaminating soils and crops used to support human populations. The importance of these particles, as sources and influencers of PTE biogeochemistry in productive soils, has received limited research. Long-term (365 d) batch incubation experiments, field weathering experiments and phytoavailability trials, were performed to establish the rate, patterns and factors limiting PTE (Cd, As, Hg) release from grains of sphalerite (Zn(Fe,Cd)S), arsenopyrite (FeAsS) and cinnabar (HgS) into soil matrices (0.1 % mineral:soil m/m), and the bioavailability of the liberated PTEs to important food crops (Tricitum aestivum, wheat and Oryza sativa, rice). All three of the ores underwent chemical weathering in oxic agricultural soils of both temperate and sub-tropical provenance, during which nonessential PTEs (cadmium, mercury, arsenic) were released in bioavailable forms, at rates relevant to agricultural production. Sphalerite weathered at a rate of 0.6 to 1.2 % a-1 (Cd basis) in the experimental soils, releasing 0.5 to 1 μmol Cd g-1 ZnS a-1 into the soil matrix. Cinnabar weathering reached a maximum of 12.0 – 13.5 % (Hg basis) after 90 days exposure in oxic soils, whereas arsenopyrite weathering was rapid and extensive, reaching 56 to 66 % (S basis) after 180 days. The PTE concentrations accumulated in edible grains of wheat and rice grown in the sulfide-contaminated soils were higher than international food safety limits by factors of 8 (Cd in rice), 10 – 30 (Hg in wheat and rice) and 8 – 12 (As in wheat and rice). The primary geochemical factors controlling PTE release and bioavailability were solid-phase associations (i.e. PTEs complexed by clays, metal oxyhydroxides and organic matter) and the precipitation of secondary mineral phases. Weathering arsenopyrite grains were passivated from further oxidation by secondary iron-arsenate phases, which also co-precipitated arsenic liberated from the ore. Secondary phase formation was identified as the cause of decreasing extractable Hg (liberated from cinnabar) after mercury release from cinnabar peaked (≤ 90 days exposure). For sphalerite, the evidence indicates that secondary sulfide phases formed under flooded (sulfate-reducing) soil conditions (paddy rice), limited the bioavailability of cadmium previously liberated under oxic conditions. These key findings demonstrate a potential human health hazard relating to the dispersal of PTE-hosting sulfide ore particles produced by mining activities into soils supporting human populations via crop contamination. This work also highlights differences in ore geochemistry, showing the need for additional research on different ore minerals and their alteration products.
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Carretero, Maria Eugenia. "Estudo de Tilápias do Nilo (Oreochromis niloticus) como bioindicadores da poluição por mercúrio nos lagos do Parque Ibirapuera e do Parque Ecológico do Tietê na Grande São Paulo." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-26062013-114248/.
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A Grande São Paulo, composta por 39 municípios, apresenta crescimento urbano e industrial expoente que contribuem para o constante acúmulo de poluentes no ambiente. Ainda assim, exibe áreas verdes remanescentes que contribuem para a sustentabilidade ambiental da cidade, como por exemplo, o Parque Ibirapuera e o Parque Ecológico do Tietê. Nesse contexto, o presente estudo visa verificar a viabilidade em utilizar as O. niloticus como bioindicadoras da poluição por mercúrio no ecossistema aquático dos dois parques da Grande São Paulo. Obteram-se para as tilápias do Nilo do Parque Ibirapuera pertencentes aos pontos de coleta A, B e C durante o inverno as respectivas concentrações de mercúrio total no sangue 2,72±4,20µg/L, 2,45±1,90µg/L e 1,19±0,05µg/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,07±0,02 µg/g, 0,06 ±0,005 µg/g e 0,16 ±0,07 µg/g. No verão as tilápias do Parque Ibirapuera apresentaram nos mesmos pontos de coleta as respectivas concentrações de mercúrio total no sangue 2,50±0,84µg/L, 2,67±1,03µg/L e 2,430±0,790µg/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,08 ±0,03 µg/L, 0,16 ±0,10 µg/L e 0,09 ±0,03 µg/L. Os peixes do Parque Ecológico do Tietê pertencentes ao ponto de coleta B durante o inverno e verão apresentaram no hepatopâncreas as concentrações de mercúrio total de 0,08±0,01µg/g e 0,10±0,0µg/g e, no sangue as concentrações e mercúrio de 3,59 µg/L e 2,00±1,00 µg/L. A análise estatística de regressão linear foi negativa, alta e com significância estatística apenas entre a idade estimada e a concentração do mercúrio no sangue sugerindo que as tilápias jovens são mais susceptíveis ao acúmulo de mercúrio. Viabilizou-se através deste estudo o uso das tilápias do Nilo como bioindicadores para a poluição por mercúrio nos lagos dos parques da Grande São Paulo.The Greater São Paulo, formed by 39 cities, presents high urban and industrial growth that contribute to environmental pollution accumulation. In contrast, the same area has residual green areas that contributes to the city\'s environmental sustainability, such as Parque Ibirapuera and Parque Ecológico do Tietê. This study intends to verify the feasebility of using O. niloticus as bioindicators of mercury pollution on the aquatic ecosystem of two Greater São Paulo parks. At winter, on Parque Ibirapuera, the collected Nile Tilapia presented 2,72±4,20µg/L, 2,45±1,90µg/L e 1,19±0,05µg/L mercury concentration on blood and 0,07±0,02 µg/g, 0,06 ±0,005µg/g e 0,16 ±0,07 µg/g mercury concentration on liver for collect points A, B and C respectively. At summer, Nile Tilapias collected on the same three points, presented 2,50±0,84µg/L, 2,67±1,03µg/L e 2,430±0,790µg/L mercury concentration on blood and 0,08 ±0,03 µg/L, 0,16 ±0,10 µg/L e 0,09 ±0,03 µg/L on liver. The Parque Ecológico do Tietê\'s fish, from point B, presented 0,08±0,01µg/g mercury concentration on liver and 3,59 µg/L mercury concentration on blood. At summer, the mercury concentrations were 0,10±0,0µg/g on liver and 2,00±1,00 µg/L on blood. The linear regression statistical analisys was negative, high and with statistical significance only between estimated age and blood mercury concentration, indicating that young tilapia are more likely to accumulate mercury. The use of Nile Tilapia as bioindicators for mercury pollution on Greater São Paulo\'s park lakes was made viable through this study.
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SILVA, SHARLLENY A. "Avaliação da concentração de micro e macroconstituintes do sedimento do reservatório Itupararanga/Sorocaba-SP." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10139.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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SEMMLER, MARILIA G. M. C. "Biomonitoração de Hg, Cd, Pb e outros elementos em áreas costeiras do estado de São Paulo por meio de mexilhão transplantado Perna Perna (LINNAEUS, 1758)." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11569.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares-IPEN-CNEN/SP
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Bridges, Kristin N. "Maternal Transfer of Dietary Methylmercury and Implications for Embryotoxicity in Fathead Minnows (Pimephales promelas)." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc955098/.
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Mercury (Hg) is a ubiquitous environmental contaminant, which is capable of global atmospheric transport. As a result, even the most pristine aquatic ecosystems are affected by atmospheric Hg deposition, following which microbial transformation yield organic Hg forms, the most concerning of which is methylmercury (MeHg). Methylmercury is capable of bioaccumulation and biomagnification in food webs, resulting in potentially toxic body burdens due to regular dietary exposure in long-lived organisms at higher trophic levels. It is also a molecular mimic of some endogenous amino acids, providing a route of transfer from mother to offspring via large amino acid transporters. Exposure during neurodevelopment can lead to serious, irreversible neurological dysfunction, associated with a variety of cognitive and motor abnormalities across species. The present studies evaluate the effects of maternally-transferred dietary MeHg, at environmentally relevant concentrations on early life stage fathead minnows (Pimephales promelas). Embryos were collected from adult fatheads exposed to one of three diets with varying concentrations of MeHg for 30 days. Adult reproductive metrics were also monitored over the course of the study, with results indicating no effects on spawning frequency, clutch size, or total egg output. In embryos, Hg concentration was a function of female diet and the duration (number of days) of female exposure. Offspring spawned in tanks administered the low Hg diet displayed altered embryonic movement patterns (hyperactivity), decreased time to hatch, decreased mean larval size, and alterations to several metabolite abundances when compared with controls. Significantly altered metabolites include those associated with cellular energetics, fatty acid metabolism, and polyamine synthesis, indicating current environmental exposure scenarios are sufficient to disrupt important cellular pathways. Dysregulation of the dopaminergic system of embryos is also characterized, and may be a possible mechanism by which hyperactive behaviors are observed in these embryos. Offspring from tanks administered the high Hg diet exhibited delayed hatching, increased mortality, and physiological abnormalities. Brain tissue of exposed adults from the low diet were dissected into regions, and also evaluated for alterations in dopamine cycling. Collectively, these results indicate current exposure scenarios in North American lakes and rivers are sufficient to cause reductions in fitness and survival of early life stage fish. The potential for community structure impacts exists, as sensitive individuals and species become disproportionately affected by chronic, low-level MeHg exposure.
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Orrling, Diana. "Towards Abatement of Selected Emissions from Metals Manufacturing." Doctoral thesis, KTH, Materialens processvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-26107.
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Although the metallurgical industry has made great strides in the reduction of unwanted emissions to the atmosphere as a result of production processes, significant challenges still exist. From a global perspective, even large reductions in emissions per produced ton become immaterial when considering that the total world production of metals continues to increase. Two such particularly hazardous emissions are sulfur dioxide, primarily from copper ore roasting, and mercury, which has had increasing emissions from the steel industry in recent years. Both pollutants have severe consequences for the environment and also for human health. The primary motivations of this work have hence been: (1). to study sulfate formation on soot from sulfur dioxide emissions reacting with ozone and H2O in the vapor phase and (2). to study factors involving the behavior of mercury adsorption on metal surfaces involved in steelmaking, in order to further the understanding of select emissions from scrap-based steelmaking. Gas phase experiments were conducted to examine the heterogeneous oxidation of sulfur dioxide on soot in the presence of ozone and water vapor. The sulfur dioxide oxidation into sulfate was quantified using a particle-into-liquid sampler coupled with ion chromatography to measure the sulfate formation at atmospheric pressure. Water vapor, ozone and sulfur dioxide concentrations were controlled. Due to the ozone oxidation, multilayer adsorption of sulfur dioxide on soot, as well as sulfate formation and physisorption on secondary surface layer sites were observed. The exposure also caused the soot to become hydrophilic, due to the sulfur dioxide adsorption and also likely the formation of carboxyl groups on the surface. No significant increase in sulfate formation was observed at ozone concentrations above 1000 ppm. The effects of common surface contaminants such as oxygen and chlorine were examined on the metal surfaces, as well as the impact of changes in temperature, with controlled conditions using thermal desorption auger electron spectroscopy. It was established that low temperatures (82 K through 111 K) were conducive to mercury adsorption, wherein physisorption and subsequent lateral mercury interactions in mercury adlayers occurred. Chlorine appeared to favor mercury uptake, as determined by the increased mercury coverage at low temperatures on polycrystalline iron, copper and zinc. Oxygen, however, was found to be an inhibitor of mercury, most notably at room temperature. It was surprising to establish that no mercury adsorbed on zinc surfaces at room temperature and only on polycrystalline samples at low temperature. The mercury signal intensity increased up to the limit of the melting temperature for iron systems, on the oxidized copper surface and the polycrystalline zinc surfaces, prior to desorption from the surfaces. It is suggested that this is due to a rearrangement of mercury atoms on the surface at increasing temperatures, whereas at 85 K, mercury adhered to its initial adsorption position. In other words, mercury wet these surfaces on annealing, transitioning from an islanded surface at low temperature to a smooth layer before desorption. Based on these results, it was concluded that the mercury bond to the oxidized surface was weakened compared to clean copper. Furthermore, it is proposed that a surface phase transition occurred on polycrystalline zinc prior to desorption. No such transition was observed on iron. Activation energies of desorption were calculated for the relevant metal surfaces. It was established that clean iron had the highest activation energy of desorption. The large bond strength between mercury and iron may account for the highest desorption temperature of the iron systems. Zinc and copper had similar activation energies and desorption temperatures, which were respectively lower than that of iron. X-Ray Photoelectron and Auger Electron Spectroscopy were used to ascertain common surface contamination, i.e. chlorine, oxygen and sulfur, which affected mercury adsorption. Laser Ablation Inductively Coupled Plasma Time of Flight Mass Spectrometry was used to determine the depth of mercury adsorption on the samples. The technique also showed that the samples contained mercury in the surface layers. Accompanied by the rising demand for metals is the increase in emissions from metals manufacturing. Moreover, it is critical to minimize sulfur dioxide emissions as particulates from soot continue to be released in the atmosphere. For scrap-based steelmaking, monolayer mercury adsorption on clean iron and copper at room temperature are significant results. With the rising use of electronic devices in vehicles, the sorting of scrap becomes increasingly important. Mercury not adsorbing on zinc at room temperature is also of relevance as it disproves the theory of increased mercury adsorption with the increased use of galvanized scrap in summer conditions. However, the low temperature studies showed multilayer adsorption of mercury on iron, zinc and copper, which has relevance for the reported temporal variations of mercury deposition in arctic regions. Keywords: mercury, iron, zinc, sulfur dioxide, adsorption, pollution, thermal desorption, polycrystalline, surfaces, spectroscopyQC 20120326
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Castro, Neemias de. "Cádmio, chumbo, cromo, mercúrio e níquel nos rios do estado de São Paulo e em peixes do Rio Sorocaba (São Paulo, Brasil) /." Rio Claro : [s.n.], 2002. http://hdl.handle.net/11449/122191.
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Orientador: Walter BarrellaBanca: Roberto Naves Domingos
Banca: João Donato Scorvo Filho
Resumo: Com o objetivo de verificar os níveis de concentração de alguns metais pesados em peixes do Rio Sorocaba e avaliar se estão contaminados e se constituindo em risco para a saúde de quem os pesca e consome, foram estudados 63 exemplares de peixes capturados em quatro pontos ao longo desse recurso hídrico e pesqueiro, quanto à presença de cádmio, chumbo, cromo, níquel e mercúrio, com ênfase neste último, por ser reconhecidamente o mais tóxico e com maiores possibilidades de contaminar peixes. Constatou-se, analisando amostras de músculo por espectrometria de absorção atômica - vapor frio, que os peixes do rio Sorocaba não apresentam concentrações proibitivas de nenhum dos cinco metais pesados estudados, estando seguros para o consumo humano. Para subsidiar o objetivo principal deste trabalho, foi feito estudo crítico dos dados levantados pela CETESB nos Relatórios da Qualidade das Águas Interiores do Estado de São Paulo nos anos de 1997 a 2000 quanto ao cádmio, chumbo, cromo, níquel e mercúrio. O estudo aponta que nas 20 Unidades de Gerenciamento de Recursos Hídricos do Estado de São Paulo monitoradas pela CETESB ocorreram casos de desconformidades, frente aos padrões legais para a classe dos rios, para um ou mais dos cinco metais pesados avaliados, sendo recomendável uma melhoria das ações de controle para esses metais em todas as regiões.
Abstract: To verify the levels of concentration of some heavy metals in fishes from Sorocaba river (São Paulo, Brazil) and evaluate if this contamination offers health risks to the fishermen, 63 samples of fishes collected from four points along the river were studied for cadmium, lead, chromium, nickel and mercury, with emphasis in this last, since it is the most toxic and most probable as a fish contaminant. Analyzing muscle samples by cold vapor atomic absorption spectrometry it was shown that the fishes are not contaminated. None of the five metals studied were present in prohibitive level and the fishes could be judged secure for human consume. It was also analyzed data from four years of cadmium, lead, chromium, nickel and mercury monitoring made by CETESB, from 1997 to 2000, in water from the main rivers of the State of São Paulo. The study pointed out that the majority of the monitored rivers still present contamination by those metals in a level that requires an improvement of the pollution control actions.
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Marcandella, Élise. "Caractérisation biophysicochimique du transfert d'un soluté réactif en milieu poreux saturé : application à la migration du phényl acétate de mercure à travers les sédiments du Rhin." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL026N.
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Prédire le risque de pollution d'une nappe lié à une décharge, accidentelle ou non, d'un pesticide dans l'environnement est nécessaire pour minimiser ses impacts sur l'écosystème souterrain. L’objectif de ce travail est de modéliser le transfert monodimensionnel d'un micropolluant organomercuriel (le phényl acétate de mercure ou PMA) à travers un milieu poreux saturé considéré comme homogène et isotrope (représenté par une colonne en verre remplie de sédiments du Rhin). Ce transfert fait intervenir des processus physicochimiques qui peuvent être couplés avec des effets biologiques. Après une synthèse des résultats relatifs à la réactivité physicochimique du PMA en présence de sédiments (essais statiques et dynamiques), les aspects biologiques ont été envisagés. Ainsi, des tests en laboratoire (essais statiques) ont été réalisés avec une souche de Pseudomonas fluorescens (souche PL IV) résistante au PMA qui a été isolée du milieu naturel après une pollution par des organomercuriels. Ces expériences ont permis de dresser un panorama des facteurs environnementaux influençant la croissance et les capacités de dégradation de la souche bactérienne sélectionnée. Parallèlement, un modèle mathématique et un code de calcul (SIMCOL) ont été utilisés pour simuler le comportement du polluant lors de sa migration à travers un milieu poreux saturé. Leur utilisation a permis d'écarter certaines hypothèses de transfert
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Åkerblom, Staffan. "Anthropogenic heavy metals in organic forest soils : distribution, microbial risk assessment and Hg mobility /." Uppsala : Department of Environmental Assessment, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200667.pdf.
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Gervais, Emelyne. "Design et optimisation d'une interface fonctionnalisée par des nanoparticules métalliques et des couches organiques électroformées pour la détection de métaux lourds à l'état de traces dans les eaux." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30258/document.
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Le mercure est un élément reconnu pour sa toxicité pour les êtres humains, pouvant être notamment la cause de maladies neurologiques ou rénales une fois absorbé dans l'organisme. Il est rejeté dans l'environnement, et en particulier dans les eaux de surface, par des phénomènes naturels comme le volcanisme, mais également par le biais des activités humaines liées à l'industrie. Une fois rejeté, il est ingéré par la faune et la flore marine et bioaccumule tout le long de la chaîne alimentaire. Il est alors présent dans les espèces marines prédatrices dans des proportions importantes, mettant en danger la santé de ces espèces animales et exposant les êtres humains à des quantités importantes de mercure dans l'alimentation. La législation Européenne est très stricte en ce qui concerne les taux de mercure autorisés dans les eaux et se base sur des valeurs relevant de la trace voir de l'ultra trace. Les techniques actuelles permettant de détecter de si faibles doses sont efficaces mais possèdent de nombreux inconvénients tel que leur coût ou l'impossibilité de faire des mesures in situ. Les capteurs électrochimiques sont actuellement l'une des alternatives les plus prometteuses pour la détection de ce métal lourd en solution. L'objectif de ces travaux a donc été de mettre au point un capteur électrochimique basé sur la fonctionnalisation d'une électrode en carbone vitreux par des couches organiques et des nanoparticules d'or pour la détection du mercure. Deux types de couches organiques ont été utilisées et les interfaces ainsi développées caractérisées par voltammétrie cyclique et Microscopie Électronique à Balayage. Deux protocoles d'activation des nanoparticules ont été testés. Les performances des interfaces ont été évaluées au regard de la détection de traces de mercure, ainsi que leur stabilité au stockageMercury is known for its toxicity on human beings, causing neurological and kidney diseases when absorbed in the body. It is rejected in the environment, and especially in surface waters, through natural processes like volcanism and human industrial activities. When present in water, it is ingested by marine plants and wildlife and bioaccumulates all along the food chain. It is then present in high proportions in marine predators, jeopardizing their health and exposing human beings to important mercury quantities in the food supply. The European legislation is very strict regarding to allowed mercury levels in waters, and is based on very low values, from traces to ultra traces. Current techniques able to detect such small doses are efficient but suffer from numerous drawbacks like their cost or the impossibility to use them for in situ measurements. Electrochemical sensors appear to be one of the most interesting alternatives for detection of this heavy metal in aqueous solution. The aim of this work was then to develop an electrochemical sensor based on the functionalization of a glassy carbon electrode with organic layers and gold nanoparticles for mercury detection. Two types of organic layers were used and the interfaces were characterised by using cyclic voltammetry and Scanning Electron Microscopy. Two different gold nanoparticles activation processes were tested. The interfaces performances were evaluated for detection of traces of mercury, as well as their storage stability