<p>Many modern products, especially electronic goods, are protected by brominated flame retardants (BFR). Some of the most common flame retardants are polybrominated diphenylethers (PBDE), tetrabromobisphenol-A (TBBP-A) and hexabromocyclododecane (HBCD). These compounds have been found in environmental samples and shown to have physiological effects on experimental animals. This thesis considers end-of-life aspects of brominated flame retardants. When spread in the environment, these compounds may be degraded into other forms. For example, if sludge contaminated with PBDE is used as an agricultural fertilizer, the PBDE could be degraded by sunlight to species of PBDE with lower degree of bromination and, to some extent, also form polybrominated dibenzofurans (PBDF). In addition, PBDF and polybrominated dibenzo-p-dioxins (PBDD) are formed during combustion of brominated flame retardants. When waste products with brominated flame retardants are co-combusted with household waste or other chlorinated fuel, polybrominated- chlorinated dibenzo-p-dioxins (PBCDD) and polybrominated- chlorinated dibenzofurans (PBCDF)will be formed. The bromin/chlorine composition of dioxins and furans is dependent on the bromine/chlorine ratio in the fuel, but the types of brominated flame retardants that are being combusted is less important. In the studies reported here, bromine levels higher than "normal" for household waste has been used. The results show that there is a pronounced increase in total dioxin levels in fluegas when when bromine is present, implying that waste containing brominated flame retardants should only be incinerated at combustion plants with effecient air pollution control devices.</p>

Snow and ice can significantly affect the environmental fate of contaminants. This thesis presents a laboratory technique for measuring mercury in metamorphosing snow, and a computer model for organic contaminants in a seasonally ice covered ocean. The laboratory method to study the fate of mercury in snow was developed using laboratory-made snow of controlled composition made in a cold room, aged and melted, with mercury quantified in air, snow, and dissolved and particulate fractions of the melt water. It was found that the method gave a mass balance for mercury, and can be used to look at mercury fate in snow representative of different environments. The fugacity based fate and transport model for organic contaminants in a seasonally ice-covered ocean was parameterized to Barrow Strait, and tested against environmentally derived net air to sea water fluxes. It was found that the model could reproduce these environmental data.

Snow and ice can significantly affect the environmental fate of contaminants. This thesis presents a laboratory technique for measuring mercury in metamorphosing snow, and a computer model for organic contaminants in a seasonally ice covered ocean. The laboratory method to study the fate of mercury in snow was developed using laboratory-made snow of controlled composition made in a cold room, aged and melted, with mercury quantified in air, snow, and dissolved and particulate fractions of the melt water. It was found that the method gave a mass balance for mercury, and can be used to look at mercury fate in snow representative of different environments. The fugacity based fate and transport model for organic contaminants in a seasonally ice-covered ocean was parameterized to Barrow Strait, and tested against environmentally derived net air to sea water fluxes. It was found that the model could reproduce these environmental data.

Thesis (M. Ed.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 76-82).

Thesis (M.Ed.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 76-82). Also available in print.

<p>The nitrogen cycle in freshwater bodies is complex and consists of many separate processes affected by a number of important factors for example oxygen concentration in the water, temperature and circulation. Knowledge of the different components of the nitrogen cycle exists; however, a complete and comprehensive picture is difficult conceptually as well as theoretically. The available literature illustrates that the research on nitrogen and the related freshwater processes is still associated with high uncertainty of how much of the supplied nitrogen from the catchment is transported with the water versus and how much is lost due to denitrification, sedimentation or uptake by plants. This report is an interdisciplinary survey of Nitrogen discharge permitting. The research focuses in particular on the decision-making process, the levels of scientific standard and the administrative framework.</p><p>Application for Nitrogen discharge permits are decided by the Environmental Court with council from their own experts as well as relevant government authorities and organisations. The court bases their decisions largely on a report that is produced by a third party with direct input from the permit applicant. With the goal aimed at cheapest production of report results in a situation where data is incomparable and discontinuous and hinders consistent rulings. Where there is a lack of knowledge, decisions are based on assumptions, estimations and intuition. To be able to make profitable decision for the society in environmental questions concerning Nitrogen there has to be an adequate basis. It has also pushed the Environmental Court to use the Precautionary Principle since threshold values become general and are not context specific. This has resulted in court rulings that, in hindsight, are uneconomical both for the applicant and broader society.</p><p>The permitting process must consider a range of directives and regulations. The basis for Swedish environmental law, and more specifically Nitrogen permitting, includes Miljöbalken, the Council Directive concerning urban waste-water treatment, the Council Directive concerning the protection of waters against pollution caused by nitrates from agricultural sources and the Water Policy Directive. Furthermore, the Broviken area investigated in this report is classified as a Natura 2000 in which some portions are slated to switch over to nature reserve status. In addition to all these directives and regulations, Nitrogen permitting must also take into consideration the 15 Environmental Goals declared by the Swedish Government.</p> / <p>Kvävets kretslopp i limniska miljöer är ett komplext förlopp bestående av flera processer vilka påverkas av en rad omgivande faktorer. Kännedom finns om de olika delprocesserna men exakt kunskap och en täckande helhetsbild är svår att få. Vid litteratursökning och samtal med verksamma inom området framkommer en bild av att forskning bedrivits med fokus på kväve och dess processer men har under 1990-talet stannat av och inriktats mer på andra områden och ämnen. Man vet för tillfället till exempel inte med säkerhet hur stor del av det kväve som tillförs vattnet som transporteras vidare och hur står del som denitrifieras, sedimenterar eller tas upp av växter. Detta skapar en osäkerhet i massbalansberäkningar och olika analyser och beräkningar av kvävets transport och påverkan på sin omgivning.</p><p>I miljödomstolens arbete att bedöma en ansökan om kväveutsläpp för en verksamhet ber de utöver sina egna experter olika myndigheter och organisationer om synpunkter. Dessa hämtar fakta för sina utlåtande från rapporter om miljöstatus i området. Ofta baseras olika myndigheter och organisationers uttalanden på samma rapport, en rapport som sökanden indirekt varit med att framställa genom ett vattenvårdsförbund. Då vattenvårdsförbundet genom påtryckning från sina medlemmar söker den billigaste lösningen av uppgiften miljöövervakning låter man de som tar minst betalt framställa en rapport och utföra arbetet. Detta har lett till byte mellan utförare av analys, miljöövervakning och rapportsammanställning vilket gett en diskontinuitet i data då provtagning inte skett på samma sätt. Underlagen blir osäkra och svåra att jämföra med tidigare analyser, långsiktiga trender blir svåra att se. Gränsvärden blir inte platsspecifika utan generella vilket kan leda till ekonomiskt olönsamma beslut både för den sökande och för samhället.</p><p>Kunskap är nyckeln till framgång. Det gäller inom många områden och så även när det kommer till kvävets processer i limniska miljöer. Vid bristande kunskap fattas beslut som baseras på antaganden, uppskattning eller känsla. För att kunna fatta samhällsekonomiskt lönsamma beslut om miljöfrågor krävs det att man har adekvata underlag.</p><p>Det finns många direktiv och förordningar att ta hänsyn till vid en tillståndsprocess. Till grund för miljölagstiftningen som berör kväveutsläpp ligger miljöbalken, avloppsdirektiv, nitratdirektiv och ramdirektivet för vatten. Broviken, som är en del av det geografiskt undersökta området i Mälarens avrinningsområde, är ett Natura 2000 område i vilket delar även kommer att bli naturreservat. Utöver dessa bestämmelser ska hänsyn till de av regeringen uppsatta 15 miljömålen tas vid tillståndsansökan. Hur dessa ska implementeras i lagstiftningen är dock osäkert.</p><p>Detta arbete är en tvärvetenskaplig kartläggning av de processer som leder till ett tillstånd för kväveutsläpp. Arbetet fokuserar på tillståndsprocessen, kunskapsnivån och vem som förvaltar kunskapen. Arbetet visar på svårigheter med många olika direktiv och mål utan klarhet i hur de ska följas och hur brist på vetenskapligt adekvata underlag leder till en stor osäkerhet i miljöstatus och en situation där utvecklingen av kvävehantering står still.</p>

<p>An extensive use of chemicals in countless consumer products has resulted in human exposure to several persistent organic pollutants (POPs). Sufficient knowledge about their chemical composition properties and environmental faith is required, to be able to proper risk assess and regulate the substances. Significant data gaps exist regarding knowledge of actual exposure to humans and toxicological effect data.</p><p>The objective of this thesis was to add human exposure data of a few POPs from four case studies. The analytes discussed in this thesis are polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD).</p><p>Three European populations were studied. Milk was analysed from a group of women, who were accidentally exposed to high levels of 2,3,7,8-TetraCDD (TCDD) in Seveso, 1976. Still today, twice as high TCDD levels were recorded in the milk, compared to background concentrations. Serum was analysed from mothers and their infants from The Netherlands. Cord serum contained equal amounts of POPs as in mother’s blood, indicating non-hindered placenta transfer. Serum analysed from Swedish men and women with a high fish intake had elevated PCB and PCB metabolite (OH-PCB) levels. Additionally, butter was collected worldwide and shown to be a suitable matrix for dairy product survey of POPs.</p><p>The exposure levels in the four papers were compared to recently reported exposure levels in Europe. It is indicated in the thesis that the PCDDs/PCDFs and PCBs toxic equivalency (TEQ) levels are of concern, i.e. the ratio between threshold levels for adverse health effects and TEQ exposure levels is lower than requested margin of safety. Average levels of PBDE/HBCDD in the European population are estimated to be of no concern today, but for individuals with intakes at the 95th percentile are the current margins of safety small.</p>

Orientador: Washington Luiz Pacheco Carvalho / Banca: Dario Xavier Pires / Banca: Maria Celina Piazza Recena / Banca: Lizete Maria Orquiza Carvalho / Banca: Adriana Bortoletto / Resumo: Este trabalho apresenta uma atividade de pesquisa realizada no âmbito da Universidade Federal da Grande Dourados por meio do componente curricular de estágio curricular supervisionado em ensino III (Estágio III), com a participação de 23 graduandos do sétimo semestre do curso de bacharelado e licenciatura em química, que foram organizados em grupos para participar da atividade de pesquisa. Foram selecionados, por meio de critérios estabelecidos, três grupos para análise. Os conceitos norteadores da tese se referem à teoria de Henry Giroux: de professor como intelectual transformador, questões sociocientíficas, avaliação do ciclo de vida de produtos e o conteúdo curricular de química. No que tange aos objetivos da pesquisa, o objetivo geral foi o de investigar as contribuições do processo formativo de futuros professores de química como intelectuais transformadores no desenvolvimento e execução de uma sequência didática nas aulas de química da escola pública, embasada na articulação de quatro campos teóricos previamente experenciados por eles. Destacamos três objetivos específicos, entre eles, o primeiro foi investigar quais as relações os licenciandos expressam entre os conceitos avaliação de ciclo de vida de produtos e questão sociocientífica permitida pelo conteúdo disciplinar. A tese defendida aponta que "a utilização da avaliação de ciclo de vida de produtos como uma temática sociocientífica, associada ao conteúdo disciplinar de química, potencializa o estágio como um amb... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This paper presents a research activity carried out within the scope of the Federal University of Grande Dourados, through the curricular component supervised in teaching III (Teaching Internship III), with the participation of 23 seventh semester undergraduate students of the baccalaureate degree and teaching degree in chemistry, who were organized into groups to participate in the research activity. We selected three groups to be analyzed using established criteria. The guiding concepts of the thesis refer to Henry Giroux's theory, which are: of the teacher as a transformative intellectual, socio-scientific questions, product life-cycle assessment and the curricular content of chemistry. Regarding the objectives of the research, the general objective was to investigate the formation process contributions of future chemistry teachers as transforming intellectuals in the development and execution of a didactic sequence in the public school's chemistry classes based on the articulation of four fields previously experienced by them. We highlight three specific objectives, among them, the first one was to investigate which relations the licensees express between the concept product life-cycle assessment and socio-scientific issues allowed by the disciplinary content. The thesis argued that "the product life-cycle assessment as a socio-scientific subject use, associated with chemistry's curriculum, enhances the internship as a teaching learning environment in which the licensee r... (Complete abstract click electronic access below) / Doutor

Microcystin-LR (MCLR) is hepatotoxic to animals and humans with disruption of liver structure causing cytoskeletal damage, necrosis and pooling of blood in the liver, leading to large increase in liver weight. It is also a strong liver tumor promoter and protein phosphatase inhibitor. Microcysin-LR binds protein phosphatases 1 and 2A, and influences regulation of cellular protein phosphorylation. In the present study, a colloidal gold based immunoassay test strip was developed for Microcystin-LR detection. The detection limit was found to be 1 ng/mL. 5 nm colloidal gold test strips exhibits more efficient for detection, compared with 20 nm colloidal gold test strips. The interaction between Microcystin-LR antibody (immunoglobulin G) and colloidal gold nanoparticles was investigated by various analytical methods, including Ultraviolet/Visible (UV/VIS), Fourier Transform Infrared (FTIR) and Fluorescence spectroscopy as well as transmission electron microscopy (TEM). / by Jiesi Xu. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Resumo: Os antibióticos, oxitetraciclina, tetraciclina, clorotetraciclina e doxiciclina, os estrógenos naturais, estrona, 17 β-estradiol, e o sintético 17 α-etiniletradiol tornaram-se objetos de estudo nos últimos anos devido aos impactos ambientais que podem causar, mesmo estando presentes em ambientes aquáticos em baixas concentrações provocando alterações biológicas através de diversos mecanismos de ação. Por este motivo, este trabalho teve como objetivo validar métodos para análise dessas substâncias em água superficial, água subterrânea e esgoto sanitário tratado. O método validado para análise de antibióticos baseou-se em cromatografia líquida com detector ultravioleta, foi utilizada extração em fase sólida com cartuchos Oásis-HLB, obtendo-se limites de quantificação de 6,5 ng L-1 para a oxitetraciclina e tetraciclina e 15 ng L-1 para clorotetraciclina e doxiciclina, em água superficial e água subterrânea, não foi possível a validação do método para esgoto sanitário tratado. A cromatografia líquida com detecção por fluorescência foi utilizada para a determinação dos estrógenos. A otimização do preparo das amostras foi obtida utilizando extração em fase sólida com cartuchos C18, o limite de quantificação para a estrona foi de 0,6 μg L-1 e de 6,25 ng L-1 para o 17 β-estradiol e 17 α-etinilestradiol, para as matrizes de água superficial, subterrânea e esgotos sanitário tratado. Os resultados referentes à validação do método mostraram níveis aceitáveis para a recuperação (entre 76 e 118%) e coeficiente de variação (entre 1 e 13%), o que atesta a exatidão e a precisão do mesmo para os níveis de concentração estudados, para todas as matrizes. No estudo em Campo Grande, as amostras de água superficial foram coletadas nos rios Lageado e Guariroba próximo aos pontos de captação do sistema de abastecimento público... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The antibiotics, oxytetracycline, tetracycline, chlortetracycline and doxycycline and the strogenes: naturals, estrone, 17β-estradiol, and the sinthetic 17 α-ethinylestradiol becaome object of study in the last years due to environmental impacts and serious health problems that they can cause, even when they are present in aquatic environment at low concentrations provoking biological changes though the several mechanisms of action. For this reason, this work had as goal certificate methods to analyze these chemicals in superficial water, subterranean water and treated sanitary drainage. The certificate method to antibiotic analyzes was based in liquid chromatography with ultraviolet detector, it was used extraction in solid phase with cartridge Oasis-HLB, obtaining with that limits to quantification of 6,5ng L-1 to the oxytetracycline and tetracycline and 15 ng L-1 and 6,25 ng L-1 to the 17 β-estradiol and 17 α-etinilestradiol, it was not possible the method validation for treated sanitary drainage. The liquid chromatographic with fluorescence detection was used to estrogens determination. The optimization os samples prepare was obtained using ecxtraction in solid phase with C18 cartridge, the limit of quantification to the estrone was 0,6 μg L-1 and 6,25 ng L-1 to the 17 β-estradiol and 17 α- ethinylestradiol, to the matrixes of subterranean water and treat sanitary drainage. In Campo Grande resource, the samples of capitation of superficial water were collected at the rivers Lageado and Guariroba next to the capitation places of public supplying system. Subterranean water samples and treated sanitary drainage were obtained at the campus of Universidade Federal de Mato Grosso do Sul. The results referring to the validation of the method shown acceptable levels to the recover (between 76 to 118%) and the variation coefficient (between 1 to 13%), these show... (Complete abstract click electronic access below) / Orientador: Mary Rosa Rodrigues de Marchi / Coorientador: Nilva Ré Poppi / Banca: Maria Lúcia Ribeiro / Banca: Maria Lucia Arruda de Moura Campos / Banca: Marcia Cristina Bisinoti / Banca: Anne Helene Fostier / Doutor