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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Persistent Organic Pollutants (POPs) are chemical substances that are widely distributed throughout the environment, accumulate in the fatty tissue of living organisms, are found at higher concentrations in the food chain and are toxic to both humans and wildlife. In the present work, POPs were determined in honey samples from different geographic regions, evaluating both the quality and safety of honey as food, and the environmental contamination of the studied regions. Organochlorine pesticides were analysed in 186 samples from the South region of Brazil, with concentrations between <LOQ and 92 ng g-1. Pesticides Endosulfan alpha and Endosulfan sulfate were the most frequent, with mean of 1.84 and 1.68 ng g-1, respectively. Samples from Santa Catarina State had higher Aldrin concentrations when compared to those from Rio Grande do Sul and Paraná States, while there was a reduction in the Endrin concentration in the samples collected in 2011, when compared with those collected in 2010. With regard to food security, 18% of the samples exceeded the maximum residue limits allowed by law for compounds Aldrin, p,p'-DDT, Endosulfan alpha, Endrin, and Heptachlor, which may pose a risk to consumer health. Indicator PCBs were analysed in 137 samples from Rio Grande do Sul, Santa Catarina, Paraná, and São Paulo States. PCBs 28 and 52 were the most frequent, with means of 1.18 and 0.74 ng g-1, respectively. Samples from São Paulo State exhibited the highest levels (ΣPCBs 7.52 ng g-1), followed by samples from Paraná (ΣPCBs 5.4 ng g-1), Santa Catarina (ΣPCBs 2.59 ng g-1), and Rio Grande do Sul (ΣPCBs 1.24 ng g-1), with significant difference for PCBs 28 and 52. There was no difference between the concentrations of samples collected in the years 2009, 2010, and 2011. DL-PCBs, PCDDs and PCDFs were analysed in 16 samples from four Brazilian States (RS, SC, PR and SP). DL-PCB concentrations ranged between 24.3 and 260 pg g-1, while PCDD/Fs, between <LOD and 5.4 pg g-1. TEQ values were between 0.002 and 0.343 pg WHO-TEQ g-1. No significant difference was found among the concentration levels of the samples from the four States. Brominated flame retardants (PBDEs, BTBPE and DBDPE) were analysed in 35 honey samples from Brazil, Spain, Portugal, Morocco, and Slovenia, with concentrations ranged between <LOD and 24.7 pg g-1. Brazilian honeys exhibited the highest mean concentration (5.19 pg g-1), followed by Moroccan (4.4 pg g-1), Portuguese (2.24 pg g-1), Spanish (1.77 pg g-1), and Slovenian (0.93 pg g-1) samples. PBDE 47 was the most frequent, being detected in 91% of samples, and followed by PBDE 99, in 63%. These compounds were the main contributors in the BFR total concentration in samples from Europe, while the novel flame retardants, BTBPE and DBDPE, had greater contribution in samples from Brazil and Morocco. With regard to food security, there is no limit established by law for PCBs, PCDDs, PCDFs, and BFRs in honey. Although the levels detected were quite low when compared to other foods of animal origin, the honey samples analysed showed significant contamination, demonstrating that the studied regions contain sources of environmental contamination to be investigated. / Os Poluentes Orgânicos Persistentes (POPs) são compostos químicos sintéticos que estão amplamente distribuídos no meio ambiente, acumulam-se nos tecidos lipídicos dos seres vivos, são encontrados em altas concentrações na cadeia alimentar e apresentam efeitos tóxicos aos seres humanos e animais. No presente trabalho, os POPs foram determinados em mel de abelhas de diferentes regiões geográficas, buscando avaliar a qualidade e segurança do mel como alimento, bem como a contaminação ambiental das regiões estudadas. Os praguicidas organoclorados foram analisados em 186 amostras da região Sul do Brasil, com concentrações que variaram entre <LQ e 92 ng g-1. Os praguicidas Endosulfan alfa e Endosulfan sulfato foram os mais frequentes, com média de 1,84 e 1,68 ng g-1, respectivamente. As amostras provenientes de Santa Catarina apresentaram concentrações maiores de Aldrin quando comparadas às provenientes do Rio Grande do Sul e Paraná, enquanto que observou-se uma redução na concentração de Endrin nas amostras coletadas no ano de 2011, quando comparadas com as coletadas em 2010. Com relação à segurança alimentar, 18% das amostras superaram o limite máximo de resíduos permitido pela legislação para os compostos Aldrin, p,p -DDT, Endosulfan alfa, Endrin e Heptacloro, o que pode representar risco à saúde do consumidor. Os PCBs indicadores foram analisados em 137 amostras provenientes dos estados do Rio Grande do Sul, Santa Catarina, Paraná e São Paulo. Os congêneres 28 e 52 foram os mais frequentes, com média de 1,18 e 0,74 ng g-1, respectivamente. As amostras provenientes do estado de São Paulo apresentaram os níveis mais elevados (ΣPCBs 7,52 ng g-1), seguidas das amostras do Paraná (ΣPCBs 5,4 ng g-1), Santa Catarina (ΣPCBs 2,59 ng g-1) e Rio Grande do Sul (ΣPCBs 1,24 ng g-1), com diferença significativa para os PCBs 28 e 52. Não houve diferença entre as concentrações das amostras coletadas nos anos de 2009, 2010 e 2011. DL-PCBs, PCDDs e PCDFs foram analisados em 16 amostras provenientes de quatro estados brasileiros (RS, SC, PR e SP). As concentrações de DL-PCBs variaram entre 24,3 e 260 pg g-1, enquanto que as de PCDD/Fs, entre <LD e 5,4 pg g-1. Os valores de TEQ ficaram entre 0,002 e 0,343 pg WHO-TEQ g-1. Nenhuma diferença significativa foi encontrada entre as concentrações das amostras provenientes dos quatro estados. Retardantes de chama bromados (PBDEs, BTBPE e DBDPE) foram analisados em 35 amostras provenientes do Brasil, Espanha, Portugal, Marrocos e Eslovênia, com concentrações que variaram entre <LD e 24,7 pg g-1. As amostras provenientes do Brasil apresentaram a maior concentração média (5,19 pg g-1), seguidas das provenientes do Marrocos (4,4 pg g-1), Portugal (2,24 pg g-1), Espanha (1,77 pg g-1) e Eslovênia (0,93 pg g-1). O PBDE 47 foi o mais frequente, tendo sido detectado em 91% das amostras analisadas, seguido do PBDE 99, em 63%. Estes compostos foram os que mais contribuíram na concentração total de BFRs nas amostras provenientes da Europa, enquanto que os novos retardantes de chama, BTBPE e DBDPE, tiveram maior contribuição nas amostras do Brasil e Marrocos. Com relação à segurança alimentar, não há limite máximo estabelecido para PCBs, PCDDs, PCDFs e BFRs em mel de abelhas. Embora os níveis detectados destes compostos tenham sido baixos quando comparados a outros alimentos de origem animal, as amostras de mel de abelhas analisadas apresentaram contaminações importantes, demonstrando que as regiões estudadas contêm fontes de contaminação ambiental a serem investigadas.

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans(PCDFs) are two groups of lipophilic, persistent organic pollutants that are produced as by-products of various anthropogenic and industrial processes. Due to their relatively high toxic potencies and potential to bioaccumulate and biomagnify in organisms and through the food chain, the contemporary widespread distribution of these compounds is a concern to the health of the environment, wildlife and humans. This study determined the distribution, pathways and fate of PCDD/Fs in the coastal zone of Queensland, Australia, including the inshore marine environment of the World Heritage Great Barrier Reef Marine Park. This ecosystem supports unique fauna and flora such as the marine herbivorous mammal dugong (Dugong dugon) and its food source, seagrass. Elevated PCDD/Fs were present in soils and sediments along the entire Queensland coastline. Highest concentrations were found in soil from agricultural irrigation drains and in sediments near the mouths of major rivers. Elevated concentrations were associated with rural and urban types of land-use, and PCDD/Fs were present even in locations remote from anthropogenic activities. PCDD/F congener-specific analysis revealed an unusual profile in all samples, dominated by OCDD, with PCDFs present in low concentrations or below the limit of detection. Distinct HxCDD isomer patterns were observed, with the 1,2,3,7,8,9-HxCDD/1,2,3,4,6,7-HxCDD isomer pair dominating the 2,3,7,8-substituted HxCDDs. Similar congener and isomer characteristics were reported in sediments, soil and clay samples from other continents, but could not be attributed to any known source. Possible PCDD/F sources in Queensland were assessed using segmented estuarine sediment cores, for which radiochemical chronologies were established for each depth. Variations of PCDD/F concentrations in the sediment cores over several centuries of depositional history were relatively small. Elevated PCDD levels were still present in sediment slices from the early 17th century. PCDD/F homologue profiles in sediments deposited during the last 350 years were almost identical and correlated well to the characteristic profiles observed in surface sediments and soils from the entire Queensland coastline. These results suggested the presence of an unidentified PCDD source prior to the production of commercial organochlorine products. To investigate the formation of the unusual PCDD/F profiles, congener and isomer specific analyses were undertaken in soils, sediments and dated sediment cores. The results demonstrated that specific transformation processes in the environment have resulted in the observed PCDD profile characteristics. Dechlorination of OCDD was proposed to result in distinct 1,4-pattern characteristics (i.e. formation of isomers chlorinated in the 1,4,6,9-positions). Consequently, the environmental samples do not reflect the signatures of the original source. An alternative hypothesis to natural formation is discussed evaluating these processes and their implications for possible source contributions. This hypothesis explores the potential for the influence of anthropogenic PCDD precursors (e.g. pentachlorophenol) during the 1940s to 1990s. Transport of PCDD/Fs from the land-based source via impacted tributary river systems, and subsequent deposition processes are proposed to result in PCDD/F accumulation in the inshore marine ecosystem. The extent of the sediment PCDD/F contamination governs the concentrations in the extensive inshore marine seagrass meadows of Queensland. Partitioning processes in the sediment-seagrass system lead to increased toxic equivalency (TEQ) in the seagrass, compared to sediment.The relationship between contaminated inshore sediments, seagrass and dugongs were evaluated using six dugong habitat regions along the coastline. PCDD/F body burdens in dugongs are governed by sediment (and seagrass) PCDD/F concentrations in their habitat. High seagrass (and incidental sediment) ingestion rates, selective retention of toxicologically potent congeners and relatively low PCDD/F elimination capacities in dugongs are proposed to result in elevated PCDD/F concentrations and TEQ levels in adult animals. Transfer efficiencies of 4 and 27% of maternal TEQ levels to foetuses and calves (respectively) during gestation and lactation result in relatively high exposure potentials to offspring. Compared to no-observed-adverse-effect-levels in other mammals, and based on the results of this study, a tolerable daily intake (TDI) of 10-24 pg TEQ kg-1 day-1 was estimated for dugongs. The results of the present study found that dugongs from some regions along the coastline of Queensland exceed this TDI by up to 20 fold, suggesting that these populations may be at risk from PCDD/F contamination in their habitat. These results have important implications for the health of the environment, wildlife and humans and were used to develop a conceptual understanding of the sources, pathways and fate of dioxins in Queensland, Australia.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of struc-turally related chlorinated aromatic hydrocarbons, generally referred to as “dioxins” are of great concern due to their extreme toxicity and presence in all compartments of the environment. Since they occur at very low levels, their analysis is complex and challenging, and there is a need for cost-efficient, reliable and rapid analytical alternatives to the expensive methods in-volving use of gas chromatography high-resolution mass spectrometry (GC-HRMS). It is im-portant to routinely monitor food and feed items to detect contaminations at an early stage. For the regulation of dioxins and dioxin-like PCBs in food and feed according to current legis-lation, large numbers of samples have to be analysed. Furthermore, soils at many industrial sites are also contaminated with dioxins and need remediation. In order to optimize the cost-efficiency of reclamation activities it is important to acquire information about the levels and distribution of dioxins in the contaminated areas. The aim of the studies underlying this thesis was to investigate the potential of comprehen-sive two-dimensional gas chromatography with a micro-electron capture detector (GC × GC-µECD) as a cost-effective method for analysing dioxins and dioxin-like PCBs in food, feed, fly ash and contaminated soils. Quantification studies of dioxins and dioxin-like PCBs were con-ducted and results were compared with GC-HRMS reference data. Generally, there was good agreement between both the congener-specific results and data expressed as total toxic equiva-lents (TEQs). The developed GC × GC-µECD method meets the European Community (EC) requirements for screening methods for control of dioxins and dioxin-like PCBs in food and feed. The presented results also indicate that GC × GC-µECD has potential to be used as a routine method for the congener-specific analysis of 2,3,7,8-PCDD/Fs and dioxin-like PCBs in matrices such as food and feed, fly ash and soil. However, to fully exploit the potential of the GC × GC-µECD technique, it should be combined with a fast and cost-efficient sample preparation procedure. Therefore, a number of certified reference materials (CRMs) were extracted using a new shape-selective pressurized liquid extraction technique with integrated carbon fractionation (PLE-C), and the purified extracts were analysed for PCDD/Fs using GC × GC-µECD. The results compared well with the certified values of a fly ash and a sandy soil CRM, but they were much too high for a com-plex clay soil CRM. It was concluded that this combination of techniques was very promising for screening ash and highly permeable soils. Further assessments and method revisions are still required before GC × GC-µECD can be used on a routine basis, and available software packages need to be refined in order to accelerate the data-handling procedures, which currently restrict the sample throughput.