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The determination of dioxin-like POPs in sediments and fish of the Vaal Triangle region, Gauteng, South Africa / Claudine Nieuwoudt

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dc.contributor.author Nieuwoudt, Claudine
dc.date.accessioned 2009-03-16T14:31:44Z
dc.date.available 2009-03-16T14:31:44Z
dc.date.issued 2006
dc.identifier.uri http://hdl.handle.net/10394/1619
dc.description Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.
dc.description.abstract Water resources in South Africa are scarce, and should therefore be protected against pollutants, also from persistent organic pollutants (POPs). This is emphasised by the Stockholm Convention on POPs, which aims at reducing and ultimately eliminating POPs. South Africa signed and ratified the treaty, and it became international law on 17 May 2004. POPS are highly stable, toxic, hydrophobic and lipophilic compounds, with the ability to accumulate in biological tissues. Previous research had shown that dioxin-like POPS are present in the aquatic environments of South Africa, with the highest concentrations of these substances measured in industrialised areas of South Africa. The present study aimed at investigating the extent of polychlorinated dibenzo-para-dioxin (PCDD), polychlorinated dibenzo-furan (PCDF) and polychlorinated biphenyl (PCB) pollution in the Vaal Triangle, by targeting aquatic sediments and biota. Sediment samples were collected from the Blesbok Spruit, Taaibos Spruit, Leeu Spruit and Suikerbosrand River, and fish tissue samples were collected from Blesbok Spruit and Suikerbosrand River, to determine bio-accumulation. The samples were extracted with organic solvents, cleaned-up and fractionated. Raw extracts and fractions were analysed with the H4IIE-luc reporter gene bio-assay. This bio-assay is a rapid, sensitive and relatively cost-effective method, which measures the effects of dioxin-like compounds on rat hepatoma cells, transfected with firefly luciferase gene. Selected samples were analysed with gas chromatographylmass spectrometry (GCIMS) to confirm results. Only one site had quantifiable amounts of dioxin-like substances in the sediment, measured to be 52.35 ng/kg [Effective Concentration 50 (EC 50)]. This value exceeds many of the European and USA quality guidelines, proposed for sediments. No dioxin-like substances were found in fish tissues. The absence of PCDD/Fs and PCBs in aquatic sediments and fish tissues from the Vaal Triangle area might be due to the climatic conditions of the area, dilution effects in streams, and degradation of these compounds by UV-radiation and microbial organisms.
dc.publisher North-West University
dc.subject Vaal Triangle region en
dc.subject Polychlorinated dibenzo-para-dioxins en
dc.subject Polychlorinated dibenzo-furans en
dc.subject Polychlorinated biphenyls en
dc.subject Sediment en
dc.subject Fish tissue en
dc.subject H4IIE-luc reporter gene bio-assay en
dc.title The determination of dioxin-like POPs in sediments and fish of the Vaal Triangle region, Gauteng, South Africa / Claudine Nieuwoudt en
dc.type Thesis en
dc.description.thesistype Masters


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    This collection contains the original digitized versions of research conducted at the North-West University (Potchefstroom Campus)

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