The indoor environment is a potentially dominant source of exposure for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). This thesis describes a study on levels, sources, emissions, and fate of PBDEs and PCBs indoors. PBDEs and PCBs air levels in 20 indoor environments in Toronto were sampled and measured. The geometric means of PBDE (Σ10BDE) and PCB (Σ35PCB) concentrations were 0.072 and 7.2 ng m-3 respectively. Statistical analysis on chemical profiles distinguished the chemical sources in the 20 environments. A multimedia indoor environmental model was applied on two test rooms. Estimated PBDE and PCB emission rates were 5.4-550 ng h-1 and 280-5870 ng h-1 respectively. Particle movement dominates within-room transport processes, and dust removal and air advection are the main chemical loss processes. Temperature, particle concentration and deposition velocity, and air exchange rate are the most influential parameters, which can alter source or sink behaviors of household products for the chemicals.

No description available.

Polychlorinated biphenyls (PCBs) are synthetic persistent organic compounds that are known to be carcinogenic to humans. Changes in telomerase activity and telomere length are hallmarks of aging and carcinogenesis. Retention of telomerase activity and long telomeres are key characteristics of stem cells and progenitor cells. I hypothesize that PCBs modulate telomerase activity and telomeres of hematopoietic stem cells and progenitor cells via interference of gene regulation and potentially disrupt cell differentiation. To investigate this possibility, I used progenitor-like cells, human promyelocytic leukemia cells (HL-60), and stem cells from rat bone marrow. I show that PCB126 and PCB153 display toxic effects on telomerase activity, telomere length and their related gene expression in progenitor-like HL-60 cells, but they did not exert much effect on differentiation. Further, an in vivo/in vitro study using rat bone marrow cells shows that PCB126-induced hematotoxicity, evidenced by reduction in telomerase activity and TERT gene expression, an increase of the differentiation and a change in the differentiation direction towards granulocytes, which indicate an effect on stem cell function. I also show that the most potent dioxin-like congener, PCB126, regulates hTERT gene expression by activation of the AhR pathway. Both AhR and ARNT work together as a repressor of hTERT transcription. This research improves our understanding of mechanisms of PCB126 and PCB153 toxicity on hematopoietic stem cells and progenitor cells, which will ultimately have significant implications for human health.

Juvenile rainbow trout (Oncorhynchus mykiss) were fed either 5 or 20 μg 2,2′,4,4′,5,5′‐hexachlorobiphenyl (245‐HxCB)/g diet (wet wt.) for 4, 8, or 12 weeks. Hepatic xenobiotic‐metabolizing enzyme activities and dietary 245‐HxCB accumulation in liver, muscle, and remaining carcass were determined. Liver‐to‐body weight ratios were not altered by either of the two 245‐HxCB concentrations. Relative growth rate increased with time but was not altered by 245‐HxCB concentration. Bioaccumulation of 245‐HxCB was dose and time dependent in all tissues without reaching apparent steady state. Hepatic arylhydrocarbon hydroxylase (AHH) activities increased with 245‐HxCB dose and with time. Ethoxyresorufin‐O‐deethylase (EROD) activities also increased in fish fed 20 μg 245‐HxCB/g diet. No 245‐HxCB‐induced changes in uridine diphosphoglucuronosyl transferase (UDP‐GT) or NADPH‐cytochrome‐c reductase (NCCR) activities were determined. High‐resolution GC‐MS analysis of the 245‐HxCB standard revealed trace (0.4‐0.5%) contamination by two mono‐ortho pentachlorobiphenyls (PnCBs): 2,3,3′,4,4′‐PnCB and 2,3,4,4′,5‐PnCB. Total liver accumulation of these contaminants was inversely related with corresponding EROD and AHH activities and estimated to contribute minimally to their induction. Results from this study suggested that long‐term dietary 245‐HxCB exposures induced cytochrome P4501A activities in rainbow trout liver.

The potential for biodegradation of contaminants in soil was assessed using an array of molecular methods, including terminal restriction fragment length polymorphism (TRFLP), quantitative polymerase chain reaction (qPCR), and traditional culturing techniques combined with sequencing of the 16S or ITS regions of the cultured bacteria and fungi. Soil was collected from the Santa Susana Field Laboratory (SSFL), which was the site of numerous liquid-propulsion rocket engine tests as well as nuclear energy research and development, which led to contamination of the soil with a wide variety of constituents. The contaminants of interest (COIs) at this site include polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic hydrocarbons (PAHs) and non-PAH petroleum hydrocarbons (PHCs). Various metals, most notably mercury and silver, are also present on the site. The purpose of this study was to determine if biodegradation is contributing to natural attenuation of contaminants in the soil, what organisms are likely causing biodegradation, and what rate(s) can be expected in the future. A literature review was conducted to investigate the chemical properties of theses COIs, their toxicity, and abiotic and biotic degradation. This research concluded that these COIs can be biodegraded if the right bacteria and/or fungi are present and active in the soil in sufficient numbers under the right conditions. Many known biodegraders of the COIs were identified in the literature review along with the most common pathways of biodegradation and degradation rates observed in field and laboratory studies. Soil was collected from 30 sample locations, with 3 sets of 10 samples containing high concentrations of one COI but low concentration of the others. PHCs and PAHs were found to be largely co-located, so 10 samples were selected for both of them. The remaining 20 samples were split evenly between PCBs and dioxins. DNA was extracted directly from all 30 soil samples and amplified using PCR for TRFLP analyses. Two soil samples were sent to Microbial Insights® for qPCR analysis. This analysis included 18 gene targets for the degradation of PHCs and PAHs, as well as the target gene for Dehalococcoides (an anaerobic dechlorinating bacteria). For each culturing a model chemical was selected to represent each COI and added to Bushnell-Haas agar plates containing no added carbon source other than the model compounds. The model chemicals were No. 2 diesel fuel for PHCs, naphthalene for PAHs, PCB #1 (monochloro) for PCBs, and dibenzofuran for dioxin. These plates were used to screen for biodegrading bacteria and fungi for each COI. Once cultured, 16S and ITS sequencing were used to identify these potential COI degraders and determine what TRFLP peak they would produce. The identity of isolated organisms was compared to information from the literature to assess the likelihood of COI biodegradation at SSFL. From the culturing experiments, 45 organisms were isolated, sequenced, and identified. The 45 included 14 unique bacteria and seven unique fungi. Of these, 10 different bacterial species and 5 different fungal species have been reported as COI biodegraders or belong to genera that contain reported COI biodegraders. TRFLP analysis revealed that the soil type has more effect on the microbial population than the presence of any of the COIs. There were no specific peaks that were significantly correlated to any specific COI. The peak distributions were fairly even, indicating a large amount of biodiversity in the microbial populations of the soil samples. The qPCR analysis revealed that SSFL soils contain significant populations of microbes that can degrade PHCs aerobically. Anaerobic PHC, anaerobic PAH, and aerobic PAH targets were not detected. A small amount of Dehalococcoides was detected in one of the samples. Collectively this study suggests that microbes present in SSFL soils are capable of biodegrading PHCs, and the genes for such biodegradation are actively being expressed. With the exception of a small population of Dehalococcoides, bacteria associated with the biodegradation of PAHs, PCBs, and/or dioxins were not detected. However, several strains of fungi were identified which have been reported to mediate cometabolic biodegradation of these compounds. Since these fungi do not require anaerobic conditions, they are more likely to contribute to natural attenuation than bacterial reductive dechlorination. Laboratory microcosm experiments are suggested for estimating rates of biodegradation at SSFL under natural attenuation conditions. Bioaugmentation and/or biostimulation methods should also be investigated in addition of natural attenuation. These microcosm experiments are currently underway in a companion study at Cal Poly by graduate student Mackenzie Billings.

The present studies determine the accumulation of persistent organic pollutants (POPs) in three pinniped species, evaluate the relationship with relevant biomarkers of exposure, and calculate toxic effect thresholds. Stranded harp and hooded seals were found to be accumulating PBDEs at levels which could pose a based on threshold levels determined in this study. Northern fur seals are accumulating all three classes of POPs (PCBs, PBDEs, and OCPs) with significant relationships being seen with blubber percent lipid. Correlations between contaminant concentrations and expression levels of relevant biomarkers were seen potentially indicating an effect on multiple pathways. Overall risk can be hard to determine due to factors such as sex and age. Broad threshold response values and hazard quotients were calculated for toxic effect endpoints in pinnipeds. Overall these results suggest that certain populations of pinnipeds are at high risk of experiencing toxic effects due to POP exposure, but it is important to understand effects even at lower concentrations. The relationship between exposure, toxic effects, and other stressors, both environmental and physiological, can impact the overall fitness and survival of pinnipeds.

Field and laboratory investigations have demonstrated that halogenated aromatic hydrocarbons (HAHs), which include PCBs and dioxin, are associated with developmental and population-level problems in fish-eating birds of the Great Lakes. Other studies have shown that perinatal exposure to HAHs causes thymic atrophy and suppresses T lymphocyte function in laboratory animals. Higher exposure suppresses antibody production and alters white blood cell (WBC) counts. This study investigated whether persistent contaminants alter immunocompetence in Great Lakes herring gulls (Larus argentatus) and Caspian terns (Sterna caspia). It also evaluated the use of various immunological tests as biomarkers for contaminant-associated health effects in wild birds. Masses of immune organs and WBC counts were assessed in herring gull chicks at 11 colonies and adults at 13 colonies, including two colonies outside the Great Lakes. T-cell- and antibody-mediated immune functions were assessed in chicks at five sites for each species. This ecoepidemiological study revealed a strong association between persistent contaminants and suppression of T-cell-mediated immunity. In herring gull chicks, thymus mass decreased as the activity of liver ethoxyresorufm-O-deethylase (EROD), an index of HAH-exposure and Ah-receptor activation, increased. In Caspian tern and herring gull chicks, the phytohemagglutinin skin test for T cell function showed a strong negative exposure-response relationship with organochlorines. There was no discernible association between contaminants and suppression of antibody-mediated immunity as measured by the sheep red blood cell antibody test and bursal mass. However, contaminant effects on bursal mass were confounded by fluke infections. Several WBC variables in both species were associated with contaminants, but the evidence was weaker than for effects on T-cell-mediated immunity. The identity of the particular organochlorine( s) responsible for alterations of T cell function and WBC counts could not be determined because concentrations of organochlorines were highly co-correlated in bird tissues. However, PCBs were the most likely cause because of their high concentrations and immunotoxic potential. Tests of immune function, WBC counts, and immune organ masses are useful biomarkers for assessing health effects, including those associated with contaminants, in wild birds. / Ph. D.

This feasibility study was performed at Virginia Polytechnic Institute and State University (Blacksburg, VA) in collaboration with BioSystems Technology, Inc. (Blacksburg, VA). In this study, degradability of PCBs (Aroclor 1242) from an aged surface soil was evaluated using serum bottle microcosms containing aceticlastic methanogenic consortium, enriched from a municipal anaerobic digester. Two different experiments, "intermediate feed" and "starve and feed" were conducted by manipulating the methanogenic consortium with different amounts of acetate feeding, during 30 days of incubation. Disappearance of Aroclor 1242 in the microcosms was quantified using gas chromatography (GC). Significant differences in Aroclor 1242 removal between inoculated and uninoculated (control) microcosms were observed suggesting that the methanogenic consortium was responsible for Aroclor 1242 disappearance. However, GC-mass spectrometry (GC-MS) results could not confirm that disappearance of Aroclor 1242 was due to anaerobic dehalogenation. From another experiment, it was confirmed that removal of Aroclor 1242 was not due to evaporation losses during sample extraction. Toxicity of an aged Aroclor 1242 contaminated surface soil was evaluated on an aceticlastic methanogenic consortium, enriched from a municipal anaerobic digester. Microcosms were set up using different amounts of soil and inoculum. Total gas production in the microcosms was monitored during 30 days of incubation, using a glass syringe. Total methane production in the microcosms was quantitated using GC. Toxicity of the soil on the methanogenic inoculum was determined based on the decreased rate of methane production in the microcosms relative to non- soil containing controls. Compared to the control, there was reduction in total methane production in soil containing microcosms. Between 3-27% reduction in total methane production was noticed in microcosms containing different amounts of soil and consortium. Reduction in methane production seemed to increase with increasing amount of soil. Whether this decrease in methane production was due to toxicity of Aroclor 1242 on the methanogenic consortium or due possibly to the toxicity of trapped oxygen in the soil could not be determined. The rate of gas production in the soil microcosm was linear. / Master of Science

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.

[pt] Este trabalho consistiu na implementação, e consequente validação, de metodologia para determinação de bifenilas policloradas (PCBs) em amostras de água e material particulado por cromatografia gasosa acoplada à espectrometria de massas em tandem (GC-MS/MS). O método de análise de água superficial foi desenvolvido para a determinação simultânea de 41 PCBs; utilizando a Extração Acelerada por Solvente (ASE) para o material particulado em suspensão e a Extração em Fase Sólida (SPE) para a fração dissolvida. A quantificação foi realizada no modo de Monitoramento Seletivo de Reação (SRM), com monitoramento de dois padrões de fragmentação m/z precursor-produto. A linearidade das curvas analíticas foi confirmada pelo valor do coeficiente de determinação (R2), além do comportamento aleatório do gráfico de resíduos e pelo teste F na análise da variância (ANOVA) da regressão. A homocedasticidade dos dados foi confirmada pelo teste de Cochran. O Limite de Detecção (LD) para cada um dos dois métodos de extração utilizados variou de 0,06 a 0,50 ng L(-1) para o SPE e 0,01 a 0,12 ng L(-1) para o ASE. A repetibilidade, expressa através dos coeficientes de variação (CV), apresentou valores inferiores a 20 por cento. A recuperação média dos analitos variou de 60 por cento a 118 por cento quando da extração em fase sólida (SPE) e de 65 a 106 por cento para o material particulado suspenso. A seletividade do método foi avaliada pelo Teste F (Snedecor) de homogeneidade de variâncias e pelo Teste t (Student) de comparação de médias. Possíveis perdas durante o processo foram monitoradas pelo uso do padrão surrogate e encontraram-se em limites aceitáveis. O método validado foi aplicado para a análise da água do Canal do Mangue, região central do Rio de Janeiro, e o intervalo encontrado para o somatório de PCBs totais variou de 2,17 ng L(-1) a 5,29 ng L(-1). / [en] The aim of this work consists of the implementation and validation of a methodology for determination of polychlorinated biphenyls (PCBs) in water samples and particulate matter by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The surface water analysis method was developed for the simultaneous determination of 41 PCBs; using the Solvent Accelerated Extraction (ASE) for the suspended particulate matter and the Solid Phase Extraction (SPE) for the dissolved fraction. Quantification was performed in Selective Reaction Monitoring (SRM) mode, with monitoring of two m/z precursor-product fragmentation patterns. The linearity of the analytical curves was confirmed by the coefficient of determination (R2), the random behavior of the residual plots and by the F test in the analysis of variance (ANOVA) for the regression. The homoscedasticity of the data was confirmed by the Cochran test. The limit of detection (LD) for each one of the two extraction methods used vary in a range of 0.06 to 0.50 ng L(-1) for the SPE and 0.01 to 0.12 ng L(-1) for the ASE. Regarding the repeatability studies, the coefficients of variation (CV) found were less than 20 per cent. The average recovery of the analytes ranged from 60 per cent to 118 per cent on Solid Phase Extraction (SPE) and from 65 to 106 per cent for the suspended particulate matter. The Method selectivity was evaluated by the F (Snedecor) test of homogeneity of variances and by the t-Test (Student) of means comparison. Possible losses during the process were monitored by using surrogate standards that were within acceptable limits. The validated method was further applied to analyze the surface water of Mangue Canal, central region of Rio de Janeiro, and the sum of total PCBs ranged from 2.17 ng L(-1) to 5.29 ng L(-1).