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.

Amphibians are regarded as sensitive indicators of environmental change and are therefore excellent subjects for use in ecotoxicology. The Phongolo River floodplain is South Africa’s most diverse natural floodplain system and hosts more than 40 frog species. It is also a malaria endemic region and is subjected to active spraying with Dichlorodiphenyltrichloroethane (DDT) through means of indoor residual spraying over the summer months. The upper Phongolo River runs through agricultural landscape and is subjected to runoff from forest plantations, orchards and sugar cane plantations. In this study residue levels of 22 different organochlorine pesticides (OCPs) were analysed in selected amphibian species from in and around the Ndumo Nature Reserve coupled with 12 different biomarker response assays to determine environmental exposure levels and possible sublethal effects in amphibians from the lower Phongolo River floodplain. Seasonal change, direct influence of anthropogenic activity and the influence of species’ aquatic preference in habitat selection were all factors considered during this assessment. Stable Isotope analyses were performed on 11 different food web components In order to determine the food web structure pertaining to Xenopus muelleri (Müller's platanna). Samples were collected during both high and low flow seasons from inside and outside Ndumo Nature Reserve. Organochlorine pesticide bioaccumulation was analysed in whole frog samples using a GC-μECD. Results indicated significant seasonal variation in OCP levels and exposure composition. Significant differences between inside and outside sites were also noted. Dichlorodiphenyltrichloroethane in its different isomer forms and their metabolites along with the hexachlorocyclohexane (HCH) isomers was the two main contributing OCP groups detected. Total OCP levels from all sample sets ranged between 8.71 ng/g lipid and 21,399.03 ng/g lipid. An increase in OCP accumulation was observed for X. muelleri over a period of one year. Organochlorine pesticides are known to have neurotoxic effects causing imbalances in Na+, K+, and Ca+ ion exchange. Hyperactivity has been reported in Rana temporaria (European Common frog) tadpoles exposed to p,p-DDT concentrations above 110,000 ng/g lipid. Despite OCP levels measured in frogs from this study being lower than reported toxic levels, the biomarker response assays indicated definite oxidative stress responses correlating to OCP bioaccumulation, with other minor responses shown. Cellular energy allocation showed a shift in the main energy source type from proteins to lipids correlating to increased OCP bioaccumulation. A slight inhibition response was noted in the hepato-somatic index correlating to γ-HCH bioaccumulation. Stable isotope analyses indicated food web structure differences between inside and outside the reserve, with outside showing less clear distinction between trophic groups and nitrogen enrichment of primary producers. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Amphibians are regarded as sensitive indicators of environmental change and are therefore excellent subjects for use in ecotoxicology. The Phongolo River floodplain is South Africa’s most diverse natural floodplain system and hosts more than 40 frog species. It is also a malaria endemic region and is subjected to active spraying with Dichlorodiphenyltrichloroethane (DDT) through means of indoor residual spraying over the summer months. The upper Phongolo River runs through agricultural landscape and is subjected to runoff from forest plantations, orchards and sugar cane plantations. In this study residue levels of 22 different organochlorine pesticides (OCPs) were analysed in selected amphibian species from in and around the Ndumo Nature Reserve coupled with 12 different biomarker response assays to determine environmental exposure levels and possible sublethal effects in amphibians from the lower Phongolo River floodplain. Seasonal change, direct influence of anthropogenic activity and the influence of species’ aquatic preference in habitat selection were all factors considered during this assessment. Stable Isotope analyses were performed on 11 different food web components In order to determine the food web structure pertaining to Xenopus muelleri (Müller's platanna). Samples were collected during both high and low flow seasons from inside and outside Ndumo Nature Reserve. Organochlorine pesticide bioaccumulation was analysed in whole frog samples using a GC-μECD. Results indicated significant seasonal variation in OCP levels and exposure composition. Significant differences between inside and outside sites were also noted. Dichlorodiphenyltrichloroethane in its different isomer forms and their metabolites along with the hexachlorocyclohexane (HCH) isomers was the two main contributing OCP groups detected. Total OCP levels from all sample sets ranged between 8.71 ng/g lipid and 21,399.03 ng/g lipid. An increase in OCP accumulation was observed for X. muelleri over a period of one year. Organochlorine pesticides are known to have neurotoxic effects causing imbalances in Na+, K+, and Ca+ ion exchange. Hyperactivity has been reported in Rana temporaria (European Common frog) tadpoles exposed to p,p-DDT concentrations above 110,000 ng/g lipid. Despite OCP levels measured in frogs from this study being lower than reported toxic levels, the biomarker response assays indicated definite oxidative stress responses correlating to OCP bioaccumulation, with other minor responses shown. Cellular energy allocation showed a shift in the main energy source type from proteins to lipids correlating to increased OCP bioaccumulation. A slight inhibition response was noted in the hepato-somatic index correlating to γ-HCH bioaccumulation. Stable isotope analyses indicated food web structure differences between inside and outside the reserve, with outside showing less clear distinction between trophic groups and nitrogen enrichment of primary producers. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

[pt] PCBs, PBDEs e OCPs foram determinados em amostras de pequenos cetáceos, lulas e peixes oriundos da Costa Centro-Norte do Estado do Rio de Janeiro. Esta faixa litorânea apresenta extrema importância para a economia do país e compreende duas regiões distintas, que são o Norte Fluminense e a Região dos Lagos. Os níveis de todos os POPs determinados foram superiores nos pequenos cetáceos, seguidos de peixes e lulas. Os níveis de PCBs variaram entre 12,54 e 5202,95 ng g-1 (ww), onde os principais congêneres encontrados foram PCB 138, 153 e 180. Os PCBs predominantes em cetáceos foram os hexaclorados e nas demais espécies os pentaclorados. PBDEs foram encontrados apenas em amostras de pequenos cetáceos, com exceção dos músculos de P. blainvillei. Foram determinadas concentrações de PBDEs entre 7,82 e 184,02 ng g-1. O perfil da contaminação por PCBs e PBDEs sugere a utilização das misturas Aroclor 1254, 1260 e Penta-BDE. O principal pesticida organoclorado encontrado em todas as amostras foi o p,p -DDE, o qual apresentou valores entre 4,47 e 373,97 ng g-1. Foram estabelecidas correlações significativas entre os níveis de POPs e as variáveis morfométricas dos indivíduos de todas as espécies. Por fim, a análise dos isótopos estáveis de carbono e nitrogênio foi realizada a fim de determinar relações tróficas, preferências alimentares e diferenças no habitat destas espécies. Estes resultados contribuem para aumentar os dados disponíveis acerca da contaminação orgânica em organismos costeiros do Brasil e Hemisfério Sul. / [en] PCBs, PBDEs and OCPs were determined in samples of small cetacean, squid and fish from the Central-northern coast of Rio de Janeiro. This region has great importance for the Brazilian economy and comprises two distinct regions, which are Norte Fluminense and Região dos Lagos. The levels of all POPs were higher in small cetaceans, followed by fish and squid. PCB levels ranged from 12.54 to 5202.95 ng g-1 (wet wt). The main congeners found were PCB 138, 153 and 180. Hexachlorinated PCBs were the predominant congeners in cetaceans and pentachlorinanted PCBs were predominant in fish and squid. PBDEs were found only in cetaceans, except in muscles of P. blainvillei. PBDE concentrations ranged from 7.82 to 184.02 ng g-1. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and Penta-BDE mixtures in Brazil. The main organochlorine pesticide found in this study was p,p-DDE, which presented levels in the range of 4.47 to 373.97 ng g-1. Significant correlations were found between the levels of POPs and morphometric variables of all the individuals. Finally, the analysis carbon and nitrogen stable isotopes was performed in order to assess trophic relationships, feeding preferences and differences on their habitat. These results contribute to extend the database on organic contamination in the Brazilian southeastern coast and in the Southern Hemisphere.

The mobility of low-income students who do not have access to stable housing creates numerous challenges both at home and in school. Among these challenges, academic performance certainly is one of the most important. The lack of a more permanent, familiar, and safe environment is presumed to impact home life as well as students' performance in the classroom. This research compares two groups of current and former students of Orange County Public Schools (OCPS) in Florida (1) children of families who are Habitat for Humanity (HFH) homeowners, and (2) a matched socioeconomic control group. The HFH program is designed to provide a stable, affordable housing for families who cannot acquire it through standard means. The research question is: Does stability in housing make an impact on academic performance in the particular area of FCAT scores and attendance? Data were gathered from OCPS and the HFH homeowners themselves. This data were used to evaluate the impact of HFH homeownership on students' academic environment. Results showed better attendance at school, but HFH students fared worse in FCAT performance when compared to control group especially in reading.

In this study, the Persistent Organic Pollutants (POPs) specifically / 17 Organochlorine Pesticides (OCPs) and 19 Polycyclic Aromatic Hydrocarbons (PAHs) were evaluated in the sediment samples of Balikesir (Ikizcetepeler) Dam Lake. Sixteen sampling points were chosen for determination of concentrations of OCPs and PAHs After ultrasonic bath extraction of the sediment samples GC-MS was used as analytical tool. Extraction efficiencies changes from 63.8 to 87.4% depending on the type of the POPs. Average OCP concentration was found in the range of 3.33-379 &micro / g/kg a, average PAH concentration was found in the range of 3.28-32.9 &micro / g/kg. Pollution maps regarding OCP and PAH distributions were drawn and the correlation between these two pollutant types was investigated. The quality control (QC) and quality assurance tests were applied by the analysis of standard reference materials (SRMs), surrogate standards and analysis replicates.

The recent developments and improvements of instrumental methods for the analyses of the environmental contaminants, especially the persistent organic pollutants (POPs), have made it possible to detect and quantify these at very low concentrations in environmental and biotic matrices. The main objective of this thesis is to demonstrate the capability of the atmospheric pressure chemical ionization technique (APCI), using gas chromatography coupled to tandem mass spectrometry for the determination of a wide range of environmental contaminants, including the POPs regulated by Stockholm Convention, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), but also the derivates of PBDEs and novel brominated flame retardants (NBFRs). The APCI was operated in charge transfer condition, preferably producing molecular ions. Multiple reaction monitoring (MRM) experiments were optimized by adjusting cone voltage, collision energy and dwell time. Optimization of source parameters, such as gas flows and temperatures was also performed. Low concentration standards were analyzed, achieving a visible chromatographic peak for 2 fg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) demonstrating the excellent sensitivity of the system. Adequate linearity and repeatability were observed for all the studied compounds. The performance of APCI methods was validated against the conventional methods using gas chromatography coupled to high resolution mass spectrometry for chlorinated compounds in a wide range of matrices including environmental, air, human and food matrices. The GC-APCI-MS/MS method was successfully applied to a set of 75 human serum samples to study the circulating levels of POPs in epidemiologic studies. Moreover the method was utilized to establish temporal trends of POPs in osprey eggs samples collected during the past five decades.

The master’s thesis was focused on the determination of persistent organic pollutants, namely polychlorinated biphenyls were detected (PCB 28, 52, 101, 118, 138, 153 and 180) and organochlorine pesticides. A total of 31 were evaluated contamination of organochlorine compounds. The level of contamination by organic pollutants were detected in 20 samples, 9 samples were sediments from the river Jevišovka, which is located in the South Moravia and 11 samples represented arable soil samples and were collected in the vicinity of this river. In the theoretical part are characterized both groups of substances, their fate in the environment and negative effects on living organisms. The experimental part focuses on the sampling procedures and processing for analysis by gas chromatography. There is described a complex analytical process involving the three extraction methods (accelerated solvent extraction, microwave extraction and ultrasonic extraction), extract purification and self-determination by gas chromatography with electron capture detector (GC / ECD). In the samples of sediment were detected these PCB congeners (138, 153 and 180) and organochlorine pesticides (b-HCH, HCB, p,p’-DDE, p,p’-DDD, p,p’-DDT and o,p’-DDT).. In soil samples were detected PCB congener 28 and organochlorine pesticides (HCB, b-HCH, heptachlor, aldrin, dieldrin, p,p’-DDE, p,p’-DDD, p,p’-DDT and o,p’-DDT).

Byla provedena studie bioakumulace POP v potravním řetězci a historických trendů hladin POP v sedimentech Brněnské přehrady. Současné úrovně kontaminantů byly stanoveny v jelci tloušti z řeky Svratky a rovněž byla posouzena hygienická kvalita ryb z rekreačního rybolovu. Současné úrovně POP v terestrickém ekosystému byly posouzeny pomocí analýz jehličí jako přirozeného indikátoru znečištění. Studium jedinců tří druhů dravých ptáků z ČR bylo zaměřeno na zhodnocení kontaminace těchto vrcholných predátorů POP. S pomocí analýz vybraných druhů ryb ze Záhlinických rybníků byl rovněž studován proces bioakumulace. Posouzení parametrů dvou moderních extrakčních technik a jejich využitelnosti pro izolaci POP z různých matric bylo námětem poslední části dizertace.

Water is a crucial natural resource, indispensable to food production, life, the environment, power generation, industry, sanitation and hygiene. The presence of Organochlorine Pesticides (OCPs) in the environment is not wanted due to their negative effects on human beings and animals. As a result, there is a need to continuously monitor their presence in the environment. In this study, surface water samples were collected once a month during the dry season and during wet season from the selected five points along the Olifants River and stored at a temperature of < 50C before analysis. The OCPs were extracted with dichloromethane (DCM) using the Liquid-Liquid Extraction (LLE) method. After undertaking the sample through the clean- up process, the crude extracts obtained were put into the column chromatography and eluted with hexane, about 1.5 μL of the purified extracts were analysed by the Gas Chromatographic- Mass Spectrophotometer (GC/MS). The percentage recoveries, varied from 32- 116 % for p, p’-DDT and 4,4'-DDD respectively in triply spiked water samples. The standard deviation for most of the compounds is less than±0.04, with the exclusion of Heptachlor (±0.14). The seasonal variability of OCPs in water samples along Olifants River results show that in dry season, the Olifants River is mostly polluted at the Oxford site with (BHC-beta, Aldrin, Heptachlor-epoxide, Endosulfan-alpha and Endrin), at the Ga- Selati site with (Heptachlor-epoxide and Endrin) and at the Wolvekrans site with (Endosulfan-alpha), with Aldrin up to 834.20 ng/ L indicating the highest hazard toward the aquatic environment while in summer the Olifants River is mostly polluted at the Ga- selati site with BHC-beta and at the Waterval site with (Heptachlor and BHC-gamma) with BHC- gamma up to 560 ng/ L indicating the highest hazard toward the aquatic environment. The levels reached from the Olifants River catchment were meaningfully above the drinking water quality guidelines for organic chemical recommended by WHO, 2006 i.e. (BHC-gamma,DDT-44, Aldrin, dieldrin and Endrin are (2.0,1.0,0.03,0.03 and 0.6) respectively for the protection of the domestic use, aquatic ecology and agricultural use (irrigation and livestock watering) for compounds with local guideline values; while, the international water quality guidelines to protect the aquatic ecosystems are 0.00083 ng/mℓ (4,4’DDD), 0.00059 ng/mL (4,4’DDE), (4,4’DDT), 0.00021 ng/mL (heptachlor), 0.0092 ng/mℓ (α-HCH), 0.0186 ng/mL (γ- HCH), and chronic values are 0.056 ng/mL (ENDO I and II) and 0.0023 ng/mL endrin) (USEPA, 2002). Levels detected were significantly higher than some research studies conducted up to now in South African aquatic environments. These results confirm the contamination of the Olifants River catchment by the OCPs. / Water and Sanitation / M. Sc. (Environmental Science)