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This thesis examines the air-soil and air-water gas exchange of persistent organic pollutants (POPs) with emphasis on organochlorine pesticides (OCPs). The current status of net exchange, factors which influence the exchange process, and different approaches used to estimate the surface exchange were explored. The net exchange of chemicals was evaluated using the fugacity approach, with the aid of chemical tracers (congener profiles of complex mixtures and enantiomer proportions of chiral chemicals) to infer current use vs. legacy sources to the atmosphere. DDT in southern Mexico was undergoing net deposition from air to soil. Occurrence of fresher DDT residues in the south was indicated by a higher proportion of p,p’-DDT relative to p,p’-DDE and racemic o,p’-DDT in air and soils. Congener profiles of toxaphene suggested soil emissions as the source to air. The influence of chemical aging on soil-air exchange and bioaccessibility was studied in a high organic soil. The use of nonexhaustive extraction with hydroxypropyl-beta-cyclodextrin (HPCD) to predict bioaccessibility was optimized for OCPs and polychlorinated biphenyls (PCBs). Reduced volatility of spiked chemicals correlated with reduced HPCD extractability for soil that had been aged under indoor and outdoor conditions for 730 d and infers volatility could be used as a surrogate for bioaccessibility. Measured soil-air partition coefficients (Ksa) were lower than those predicted from the Karickhoff relationship, which considers octanol as a surrogate for soil organic matter. The role of soil moisture, organic carbon, temperature, depth of soil surface horizon and dissolved organic carbon in the fate of organic contaminants in soil were assessed using chemical partitioning space maps. These maps allow instant visual prediction of the phase distribution and transport process of a chemical among the three major phases in soil; i.e., air, water and solid. Net volatilization of alpha-hexachlorocyclohexane from water to air was found in the southern Beaufort Sea using fugacity calculations and flux measurements. The influence of ice cover on volatilization was indicated by a winter-summer shift from racemic to nonracemic alpha-HCH in boundary layer air.

Eighteen-month-old adult female Peking Ducks (Anas platyrhynchos) were placed in the Ottawa, and St. Lawrence rivers for periods varying between 14 and 72 days during the summers of 1987, 1988 and 1989. Two stations located on Lake St. Francis were selected for establishing a time-curve for the accumulation of organochlorine pesticides (OC) and PCB in the liver. The ducks rapidly lost weight during their first 20 days in the natural environment but stabilised after about 40 days. This weight loss was caused by the stress of habitat, change, the energetic costs in searching for food and moulting. / There was a rapid increase in the number and concentration of contaminants detected in the livers of ducks exposed to pollutants in the natural environment. The concentrations found were low (99.9% of OC-PCB are under 1 mg/kg wet weight basis). These individuals were generally from 10 to 1000 times more contaminated than the control ducks for 40 days of exposure. / The use of domestic ducks as bioindicators has several advantages. They can be obtained readily and cheaply, and the sex and age of the individuals can be controlled. Since they are not very mobile and therefore are easy to locate, they provide information on the contamination (metals or OC-PCB) of specific sites. The use of Peking ducks has some limitations. There is a need for appropriate habitats to ensure their survival, and there is considerable stress caused by transferring the ducks from the breeding farm to the natural environment, thereby obliging them to search for food and exposing them to predators and poachers. (Abstract shortened by UMI.)

Chlorinated aromatic compounds are an important group of compounds. Many of them have been produced in large quantities and they are indispensable to technological and societal benefits. But regulatory agencies have tightened regulations on the use and release of chlorinated aromatic compounds because of the scientific understanding of their toxicity, persistence, behavior in the environment and their potential to cause adverse effects on the ecosystem and human health. / Pentachlorophenol (PCP), octachloronaphthalene and decachlorobiphenyl are all highly chlorinated aromatic compounds, of which, PCP has been used mainly as a biocide. Octachloronaphthalene and decachlorobiphenyl don't have practical use, but their congeners have been used widely as chemicals in industry. These compounds are toxic, recalcitrant and bio-accumulated within organisms. As the conventional treatment, incineration of these compounds can cause more serious problems, so that suitable alternatives need to be developed for their detoxification. / When compared with biodegradation or the thermal treatment of these compounds, chemical degradations have several merits. (Abstract shortened by UMI.)

This thesis examines the air-soil and air-water gas exchange of persistent organic pollutants (POPs) with emphasis on organochlorine pesticides (OCPs). The current status of net exchange, factors which influence the exchange process, and different approaches used to estimate the surface exchange were explored. The net exchange of chemicals was evaluated using the fugacity approach, with the aid of chemical tracers (congener profiles of complex mixtures and enantiomer proportions of chiral chemicals) to infer current use vs. legacy sources to the atmosphere. DDT in southern Mexico was undergoing net deposition from air to soil. Occurrence of fresher DDT residues in the south was indicated by a higher proportion of p,p’-DDT relative to p,p’-DDE and racemic o,p’-DDT in air and soils. Congener profiles of toxaphene suggested soil emissions as the source to air. The influence of chemical aging on soil-air exchange and bioaccessibility was studied in a high organic soil. The use of nonexhaustive extraction with hydroxypropyl-beta-cyclodextrin (HPCD) to predict bioaccessibility was optimized for OCPs and polychlorinated biphenyls (PCBs). Reduced volatility of spiked chemicals correlated with reduced HPCD extractability for soil that had been aged under indoor and outdoor conditions for 730 d and infers volatility could be used as a surrogate for bioaccessibility. Measured soil-air partition coefficients (Ksa) were lower than those predicted from the Karickhoff relationship, which considers octanol as a surrogate for soil organic matter. The role of soil moisture, organic carbon, temperature, depth of soil surface horizon and dissolved organic carbon in the fate of organic contaminants in soil were assessed using chemical partitioning space maps. These maps allow instant visual prediction of the phase distribution and transport process of a chemical among the three major phases in soil; i.e., air, water and solid. Net volatilization of alpha-hexachlorocyclohexane from water to air was found in the southern Beaufort Sea using fugacity calculations and flux measurements. The influence of ice cover on volatilization was indicated by a winter-summer shift from racemic to nonracemic alpha-HCH in boundary layer air.

Thesis (Ph. D.)--Carleton University, 2001. / Includes bibliographical references. Also available in electronic format on the Internet.

Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references. Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 173-180).

Existem muitos estudos sobre a ocorrência de poluentes orgânicos persistentes (POPs) no ambiente marinho utilizando bioindicadores como os tubarões. Entretanto, no Brasil, ainda há carência de dados de POPs nesses organismos. O objetivo desta pesquisa foi investigar a ocorrência e o comportamento dos PCBs, pesticidas organoclorados e PBDEs no ambiente marinho, a partir da utilização dos tubarões como indicadores. Musculatura e fígado de vinte tubarões-azul (Prionace glauca) foram coletados em agostosetembro de 2008. Os PCBs foram os poluentes predominantes, presentes em 80% das amostras, com concentrações variando de <n.d. a 427,28 ng.g-1 de peso úmido. Os diclorodifeniletanos apresentaram concentrações variando de 0,43 a 202,42 ng.g-1 de peso úmido, no qual o 4,4´-DDE foi o composto mais significativo, com 77,6% de contribuição para os DDTs totais. As concentrações no fígado foram 1-2 ordens de grandeza mais elevadas, em relação às de musculatura. Houve um padrão de distribuição dos poluentes com níveis equivalentes entre indivíduos imaturos. Os machos maduros apresentaram concentrações de POPs sensivelmente maiores que as fêmeas maduras, indicando a transferência dos POPs para os filhotes. Os resultados demonstraram a ampla distribuição desses poluentes no ambiente marinho. / There are many studies about the occurrence of persistent organic pollutants (POPs) in the marine environment using sharks as bioindicators. However, there is still a lack of data of POPs in those organisms in Brazil. The goal of this research was to investigate the occurrence and behavior of PCBs, organochlorine pesticides and PBDEs in the marine environment, using sharks as indicators. Muscle and liver of twenty blue-sharks (Prionace glauca) were collected in august-september 2008. The PCBs were the predominant pollutants and being present in 80% of samples, with concentrations ranging from <n.d. to 427.28 ng.g-1 wet weight. The dichlorodiphenylethanes present concentrations ranging from 0.43 to 202.42 ng.g-1 wet weight, where the 4,4´-DDE was the most significative compound, with contributions of 77,6% of the total DDTs. The concentrations in the liver were 1-2 orders of magnitude higher than in the muscle. There was a distribution pattern of the pollutants, with equivalent levels among the immature specimens. The concentration of POP was significantly higher in the mature males and relatively lower in the mature female, showing the maternal transference of POPs to the pups. The results have demonstrated a wide distribution of these pollutants in the marine environment.

Bifenilos policlorados (PCBs) e pesticidas organoclorados são compostos que não ocorrem naturalmente no ambiente e não são facilmente degradados química ou microbiologicamente. Seu estudo no ambiente é importante devido à sua persistência, toxicidade, lipossolubilidade e conseqüente biomagnificação. Por isso, representam a maioria dos poluentes orgânicos persistentes (POPs) considerados prioritários pela UNEP (United Nations Environmental Programme) e banidos ou restritos pela Convenção de Estocolmo, de maio de 2001. Tais poluentes podem ser facilmente emitidos para a atmosfera, atingindo áreas remotas como a Antártida, integrando um processo cíclico de contaminação conhecido como destilação global. No presente trabalho otimizou-se uma metodologia analítica capaz de detectá-los em ovos gorados de pingüins e indivíduos de krill coletados na Baía do Almirantado, Ilha Rei Jorge, Antártida. Tal metodologia foi avaliada e enquadrou-se em critérios internacionais de controle de qualidade. Os compostos mais presentes foram, de um modo geral, os PCBs, DDTs e o HCB e a ocorrência pareceu ser espécie-específica dentro do gênero Pygoscelis. Em todos os casos, o teor dos compostos não foi superior ao de aves árticas em nível trófico semelhante. A análise do krill permitiu estimar a biomagnificação dos compostos encontrados nos ovos, cuja única fonte de contaminação é a transferência fêmea-filhote. / Polychlorinated biphenyls (PCBs) and organochlorine pesticides are compounds that do not occur naturally in the environment and are not easily degraded by chemical or microbiological action. Their study in the environment is important due to persistence, toxicity, liposolubility and consequent biomagnification. For these reasons, they represent the majority of the persistent organic pollutants (POPs), considered to have priority by the UNEP (United Nations Environmental Programme) and banished and/or restricted by the Stockholm Convention of May, 2001. Such pollutants can be easily ejected into the atmosphere and reach areas as remote as Antarctica, integrating a cyclical contamination process known as ?global distillation?. In the present work an analytical methodology capable of detecting such compounds in unhatched penguin eggs and whole krill was optimized. The samples were collected in Admiralty Bay, King George Island, Antarctica. This methodology was evaluated and fitted international quality control criteria. The compounds found in higher levels were, in most of the samples, the PCBs, DDTs and HCB and the occurrence seemed to be species-specific for the Pygoscelis genus. In all of the cases, the levels found were not higher than the ones in arctic birds in a similar trophic level.The krill samples analysis made it possible to estimate the biomagnification of the compounds found in eggs, whose only source of contamination is the female-offspring transfer.