Call number: LD2668 .T4 1950 L3 / Master of Science

The current work determined whether there is a constant tissue residue associated with narcotic compounds. In this investigation, the cladoceran, Daphnia magna was exposed to lethal levels (48h LC50) of ten, $ sp{14}$C-labelled, narcotic organic chemicals in a closed system. Exposure times, ambient concentrations, and body sizes were varied to evaluate their effects. The $ sp{14}$C-method developed in current work can detect chemicals in single D. magna in concentrations ranging from 0.02 to 6310 mmol/kg. Moreover, the technique detected phobic and lipophilic chemicals equally well. The technique's sensitivity (nmol/kg) allowed for detection of differences in the internal concentrations of pollutants among the unaffected, immobilized, and dead D. magna. Immobilized D. magna contained between 0.14 mmol/kg and 200 mmol/kg of narcotics. On the average, however, the internal residues were 3.1 mmol/kg (95%CL = 3.1 $ pm$ 2.0). This agreed with literature values. The effects of time of exposure, ambient concentration, and body size on the tissue residues of narcotics varied with the chemical compound.

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Municipal treated wastewater entering rivers contain biologically active pharmaceuticals capable of inducing effects in aquatic life. Phytoremediation of three of these pharmaceuticals and an herbicide was investigated using Sandbar willow (Salix exigua) and Arabidopsis thaliana. Both plants were effective at removing compounds from solution, with removal of 86% of the synthetic estrogen, 17α-ethynylestradiol, 65% of the anti-hypertensive, diltiazem, 60% of the anti-convulsant, diazepam (Valium®), and 51% of the herbicide atrazine, in 24 hours. Distribution of compounds within roots and shoots, in soluble and bound forms, differed among compounds. Uptake and distribution of pharmaceuticals within the study plants confirmed pharmaceutical behaviour can be predicted based on a physiochemical property, their octanol-water partitioning coefficients. An effective method for detection of 17α-ethynylestradiol within surface water using solid phase extraction and gas chromatography-mass spectrometry was developed. Previously unreported breakdown of 17α-ethynylestradiol into another common estrogen, estrone, during preparative steps and gas chromatography was resolved. / xv, 216 leaves ; 29 cm.

Ph.D. / The toxicant dichlorodiphenyl-trichloroethane, commonly known as DDT, is a broad spectrum insecticide and is currently banned in most countries due to its toxic effects. However, in some countries restricted use of DDT has been authorized as an effective vector control within malarial control programmes. South Africa is one such country, where spraying of DDT occurs in three provinces including the Limpopo Province, KwaZulu Natal and Mpumalanga. Specifically in the Limpopo Province, spraying of DDT has been ongoing for almost 56 years within the eastern malaria belt of the province. Despite this long term spraying there is still a scarcity of data regarding DDT and its effects on indigenous aquatic organisms in South Africa. Any research regarding DDT will therefore be of the utmost value. It was in this context that the present study was initiated, which primarily aimed to assess the extent of contamination within DDT sprayed areas in South Africa and the associated effects on indigenous species, whilst identifying techniques that could be used in future monitoring of these areas. This assessment was done in the Luvuvhu River catchment at three reference sites and four exposure sites situated within the areas where indoor residual spraying of DDT is done annually. At these sites the extent of DDT contamination within the water, sediment and biota (using the bioindicator pecies C. gariepinus from only the lentic sites) in the Luvuvhu river was evaluated. The results showed that DDT concentrations were well above recommended levels in all three of the measured phases, with the highest concentrations predominantly observed at the Xikundu weir. This site was particularly impacted by DDT due to a combination of its close proximity to the DDT sprayed areas, concentration accumulation from upstream sources and environmental conditions that accentuated contamination. These elevated levels of DDT did, however, not induce significant quantifiable effects in the bioindicator C. gariepinus or in the fish and macro-invertebrate community structures. Specifically, the effects in the catfish, C. gariepinus, were assessed using a range of biomarkers specific to the endocrine disrupting effects of DDT, including indirect measures of vitellogenin (calcium, zinc, magnesium and alkali-labile phosphate (ALP) that are all present on the VTG molecule in high abundances), gonad-somatic index (GSI), condition factor (CF), analysis of covariance (ANCOVA) manipulated gonads, protein carbonyls (PC) and intersex. Although none of these biomarkers could be significantly correlated with the DDT contaminations, DDT was shown to induce a slight sub-organismal effect by slightly inducing the synthesis of ALP and Ca as well as reducing the gonad mass (shown by GSI and adjusted gonad mass biomarkers) and body condition. In contrast, the fish and macroinvertebrate communities showed no conclusive relationship with DDT contamination, using a variety of methodologies, including informal assessments, univariate diversity indices, multivariate statistics, abundance models, fish response assessment index (FRAI) as well as average score per taxon (ASPT) and Ephemeroptera, Plecoptera and Trichoptera (EPT) richness. In conclusion, it was shown that DDT concentrations within the Luvuvhu River only induced effects at the lower levels of complexity, which highlights the importance of the utilisation of biomarkers to measure more subtle long-term effects as compared to the usage of community level effects.

Powdered laundry detergents are consumed in high volumes worldwide. Post use, they are directed toward water resources via wastewater treatment works or, as is the situation in many rural areas of South Africa, they enter the environment directly as a result of laundry washing activity undertaken alongside surface waters. Within wastewater treatment works, the main ingredient in powdered laundry detergents, the narcotic toxin linear alkylbenzene sulfonate (LAS), is mostly removed, rendering the waste stream a negligible risk to the aquatic biota of receiving waters. In contrast, the biological and ecological impacts of direct LAS input to the aquatic environment, as a consequence of near-stream laundry washing, are yet to be fully realised. Consequently, this thesis posed two research questions: 1) 'What are the LAS concentrations in a small rural South African river'? and 2) 'Is the in-stream biological community negatively affected at these concentrations?' The chosen study area, the community of Balfour in the Eastern Cape Province, is like many rural areas of South Africa where inadequate provision of piped water to homesteads necessitates laundry washing alongside the nearby Balfour River. The first research question was addressed in two ways: by predicting LAS concentrations in Balfour River water by assessing detergent consumption and laundry washing behaviour of residents living alongside the river; and measuring actual in- stream LAS concentrations on different days of the week and during different seasons. Results indicated that LAS concentrations were highly variable temporally and spatially. High peak concentrations of LAS occurred infrequently and were limited to the immediate vicinity of near-stream laundry washing activity with the highest measured concentration being 342 μg.L ⁻¹ and the average 21 μg.L ⁻¹ over the sampling period. The second research question was addressed by integrating the chemical evidence, determined from the first research question, with the biological evidence of stress responses measured in macroinvertebrates collected downstream of near-stream laundry washing activity on the Balfour River. Predicted and measured LAS exposure concentrations from the Balfour River were compared to a water quality guideline for LAS (304 μg.L ⁻¹), specifically derived in this thesis. Biological stress responses were measured at different levels of organisation: two sub-cellular responses (lipid peroxidation and cholinesterase activity); three measures of macroinvertebrate tolerance to water quality impairment; five measures of community composition; three measures of community richness; and a surrogate measure of ecosystem function (functional feeding groups). Weight-of-evidence methodology was utilised to assess, integrate and interpret the chemical and biological evidence, and at its conclusion, determined no effect on the in-stream biological community of the Balfour River downstream of laundry washing activity.