BACKGROUND For many years, the Durban south community has raised concerns about ambient air pollution including particulate matter. The Durban South Industrial Basin (DSIB) may be high risk for exposure to significant levels ofPMI0 due to its geographic relationship with two major petroleum refineries, together with a pulp and paper manufacturing facility. While potential sources of elevated levels of PMlOin the south are industrial, the north is likely to be exposed to controlled burning of vacant fields and use ofbiomass fuels, particularly in informal settlements. Adverse health effects from particulate matter (PM) were well documented by extensive epidemiological observations by animal and human studies, following laboratory exposures. Studies across a variety of environmental settings have demonstrated a strong association between ambient air particulate matter (PMlO) and cardiopulmonary morbidity and mortality. Studies have reported that particulate matter is associated with adverse health effects resulting from inflammatory responses in the lower respiratory tract. Exposure to particulate matter may increase the risk of lung cancer. Some studies suggested that small temporal increases in ambient particulate matter are sufficient to cause health impacts. Other studies attributed strong seasonality to temperature inversions associated with temperature changes. Studies also illustrated the impact of temporal variation on PMl 0 levels across regions. OBJECTIVES The main objectives of this study were to determine and compare the levels of ambient PMIO in industry exposed and non-industry exposed communities, to determine temporal variation and to make recommendations. METHODS This study focused on determining the 24-hour ambient PMI0 levels in the Durban south community. The PMIO levels in Durban south (industry exposed) were compared with the PM10 levels in an area north of Durban (non-industry exposed). Relevant data obtained from the monitoring program of the South Durban Health Study (SDHS) was reviewed for the purposes of this study. The different techniques used to measure PMI0 are gravimetric sampling and tapered elemental oscillating microbalance (TEaM). Both methods were used to collect PMI0 data. The data comprised of quantitative and categorical variables. The dependent variable was the PM10 values and the independent variable was the sampling sites. Non-parametric tests were used to analyse the data. RESULTS PMI0 was recorded in all sites in north and south areas. The levels varied across all sites. Both the north and south areas recorded high PMI0 values at regular intervals. No particular trend was observed when the 24 hour PM10 concentration was compared against the standard. All sites recorded medians that were generally in the region of 40-S0,ug/m3. The site with the highest median (SIA,ug/m3 ) was Assegai. Briardale recorded the lowest median (34.9,ug/m3 ). Exceedances of the South African National Standard code 1929 maximum 24-hour concentrations of7S,ug/m3 were observed across all sites. Overall there were 163 (16.7 % of all samples) exceedances, and these ranged widely between the various sites, with no particular regional trend. Overall .June experienced the highest PMl 0 values. No differences in seasonal trends were observed in north and south. CONCLUSION On average the levels ofPMI0 do not exceed national or international standards. The findings did not reveal any statistical difference in exposure levels between the industry exposed and non-industry exposed areas. / Thesis (MMed.)-University of KwaZulu-Natal, Durban, 2008.

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The feasibility of improving water quality by food web manipulation in an urban eutrophic tropical reservoir, Lago Paranoa (Brasilia, Brazil) was investigated. The potential of promising biomanipulation strategies was experimentally tested in limnocorrals: reduction of internal nutrient loading by controlling tilapia overpopulation, and suppression of nuisance cyanobacteria by stocking non reproducing filter-feeding silver carp. A four-month test in two large littoral isolated areas of the reservoir (1,000 m2 each) stocked with high vs. low tilapia biomass revealed that fish over-population promoted blooms of Microcystis and decreased water clarity by supplying phytoplankton with additional nutrients (mainly phosphorus, "P"). Since reduction of tilapia biomass from 150 to 40 g/m3 resulted in significant water quality improvements, the release of commercial fisheries using cast-nets was recommended. Field experiments III floating net-cages (10 m3) were conducted to evaluate silver carp adaptation to Lago Paranoa and to determine fish growth rates when maintained feeding exclusively on the abundant plankton in the reservoir. High growth rates (up to 6 g/day) and survivorship (> 90%) of young-of-the-year (72 g), juveniles (300 g) and adult silver carp (1100 g) during both dry and rainy season were observed. Efficient ingestion of nuisance algae was evidenced by the dominant presence of Microcystis aeruginosa and Botryococcus braunii colonies in the fore-intestine of experimental fishes. Results indicate the great potential for silver carp cage culture as a low-cost and environmentally beneficial economic activity. Following indications from literature and previous studies in Lago Paranoa, the optimum range of silver carp biomass which maximize phytoplankton control was determined in ten large replicated limnocorrals (50 m3 ). Although a significant decrease in Microcystis abundance was achieved by stocking silver carp at all biomass levels, net-phytoplankton biomass was only significantly suppressed at moderate fish stocking densities of 40 and 60 g/m3 . Two additional limnocorral experiments during dry and rainy seasons were performed to test the effectiveness of both biomanipulation strategies when adopted separately or simultaneously. Water quality improvements through control of tilapia abundance (from 100 to 40 g/m3) and stocking with silver carp (at moderate stocking rates of 40-50 g/m3) induced significant decreases in total phosphorus (21- 31 %), cyanobacteria density (40-44%) and phytoplankton biomass (22-38%). As those strategies were found to act independently, the combination of both enhanced water quality benefits by reducing total phosphorus by 38%, cyanobacteria density by 75% and phytoplankton biomass by 60%. To predict the internal P-loading reduction that could be achieved by implementing both biomanipulation strategies on a whole-reservoir scale, P excretion rates were quantified in indoor tanks for 16 and 40 g tilapia (0.527-1.576 ug SRP/g ww/h) and silver carp (0.391-0.737 ug SRP/g ww/h). It was estimated that the tilapia contribution to internal P-Ioading (5.4 mg TP/m2/day for 1,300 kg/ha) is equivalent to external P input to the Bananal Branch (6.0 mg TP/m2/day). A 60% reduction in tilapia biomass plus stocking of silver carp at densities of up to 60 g/m3 after three years would not change internal P-Ioading (5.6 mg TP/m2/day) but would (1) reduce by 60% the input of "new" phosphorus to the water column from tilapia bottom feeding, and (2) increase grazing on phytoplankton following silver carp introduction.

In near-shore marine environments, two of the most prevalent anthropogenic disturbances affecting ecosystem diversity and function are the invasion of exotic species, and the release of toxic chemicals. Estuarine and harbour environments worldwide are dually subjected to high levels of toxic disturbance and ever increasing rates of invasion, via activities such as boating and shipping. It is not clear, however, whether the success of invasive species is influenced by the presence of toxic contaminants in these impacted environments. In particular, nonindigenous marine species (NIS) may be advantaged in chemically disturbed environments if they are more tolerant of toxicants. This thesis examines whether nonindigenous and native sessile invertebrate species have differential tolerance to a common aquatic contaminant, copper (Cu), which has links to both the invasion process (via its use in antifouling paints and the vector of hull fouling) and the modification of recipient environments (via human-mediated pollution). A series of laboratory- and field-based experiments showed that the cosmopolitan invasive bryozoans Watersipora subtorquata, Bugula neritina and Schizoporella errata are highly tolerant of copper pollution. The larvae and adults of W. subtorquata and B. neritina in particular were able to survive and grow in copper-polluted environments far exceeding most observed real-world levels (< 100 /??g 1-1). These nonindigenous species also showed very strong postexposure recovery. In contrast, the co-occurring native bryozoans Celleporaria nodulosa and Fenestrulina mutabilis demonstrated comparatively low tolerance to copper, with markedly reduced survival and fitness under Cu contaminated conditions, and inferior recovery abilities post-exposure. These findings were further supported by a long-term manipulative field experiment, examining the effect that varying levels of Cu exposure have on the structure and diversity of developing sessile invertebrate assemblages. Cu exposure decreased native species diversity by up to 50%, yet had no effect on NIS numbers. Consequently, in the presence of copper contamination, NIS dominated sessile communities, often resulting in substantial changes to community structure. Important insights were also gained into the nature of metal tolerance in NIS. Toxicity studies on larvae of the introduced bryozoan Bugula neritina revealed intraspecific differences in tolerance to Cu, associated with the level of pollution experienced by the adult source populations. There was also evidence of fitness costs related with increased Cu tolerance. In summary, we have found evidence that the success of invasive species is influenced by chemical contamination. NIS may be advantaged in contaminated estuaries relative to native species and this may assist in their establishment and persistence in new habitats.

M.Tech. (Operations Management) / The field of study is of a multi-disciplinary nature relating to chemistry, microbiology, electrical engineering, soil technology and legislation dealing with different aspects of soil, water and environmental contamination in South Africa The relevant basic principles involved as applicable to the problem being researched are discussed in the dissertation. The reader is introduced to the statement ofthe problem in Chapter 1. A study was carried out of research projects which were conducted elsewhere in the world with regard to oil pollution and the remediation procedures followed. This research project has focused on a problem which revolved around the pollution of soil from insulating oil spillages. Insulating oil is used in electrical equipment, such as transformers, tap changers and other items in the distribution of electricity throughout South Africa. Insulating oils perform three functions namely, a cooling function, acts as an insulator and as an indicator ofthe condition ofa transformer. The aim ofthe research was to develop methods and techniques, under the South African climatic conditions, to clean insulating oil polluted soil cost effectively. Oil in its various forms and derivatives is part of our modem society. Scientists are continuously designing new applications for various types of lubricants without the knowledge of the impact the product might have on the environment. When a pollution problem becomes intolerable, then a solution is investigated. Then man, with its superior brain power, goes to the simplest life on earth to solve his pollution problem. Various products and applications were investigated theoretically and also in practice. Case studies were investigated to determine the success rate of different products and applications. Laboratory tests were carried out to determine the true results of some of the products. The laboratory results were tested in practice on two test sites to confirm the results. The consequence of the research project has indicated that excellent results have been achieved. The results have indicated that insulating oil polluted soil can be cleaned in a...

M.Tech. (Biotechnology) / Please refer to full text to view abstract

Thesis (M. Ed.)--University of South Africa, 2002.

In the first phase of the study, the effect of five Safol surfactants on the aqueous solubility of phenanthrene and acenaphthene was determined. The fixed variables were temperature and ionic strength, while surfactant concentration and pH were varied. Quantification of the polyaromatic hydrocarbons (PAHs) was conducted by UV-Visible spectrophotometry. The surfactants had little or no effect on analyte solubilisation below the critical micelle concentration (CMC) while a linear relationship between surfactant concentration and amount of solubilised phenanthrene was observed above CMC concentrations. Safol 45E5 had the highest phenanthrene molar solubilisation ratio (0.83) of the five surfactants tested. The solubilisation of phenanthrene increased marginally (4.1 % for Safol 45E12 and 15.2 % for Safol 45E7) by decreasing the pH from 8 to 5. The concentration of solubilised acenaphthene was 8.4 % higher than phenanthrene in a 1 mM solution of Safol 45E7. The aqueous solubility of phenanthrene was enhanced 11.0, 21.2, 19.6, 15.9 and 14.7 times in 1 mM solutions of Safol 45E3, 45E5, 45E7, 45E9 and 45E12 respectively. Seasand, Longlands sand, Longlands soil and a standard soil sample were spiked with the two PAHs and aged for two weeks. API sludge provided by Sasol and unspiked samples of the above mentioned sorbents were subjected to determinations of organic matter content, particle size distribution and moisture content. The spiked soils and sands and the sludge samples were then washed in various concentrations of Safol 45E7 (0.5, 1.0 and 2.0 mM) at the same temperature used in the solubility studies. A soil mass to solution volume of lg to 10 mL was used. Analyses of the soil and sand samples were conducted by High Pressure Liquid Chromatography (HPLC). Using a 2 mM Safol 45E7 surfactant solution, 100 % and 90 % of phenanthrene and acenaphthene were respectively extracted from Longlands sand and 88 % and 100 % of phenanthrene and acenaphthene were removed from seasand. 8.4 % phenanthrene and 8.17 % of acenaphthene was removed from Longlands soil, while 7.03 % phenanthrene and 6.64 % acenaphthene was removed from the standard soil sample. In the sand desorption studies, the amount of desorbed contaminants initially increased rapidly with increasing surfactant concentration, before levelling off at equilibrium. The amount of desorbed acenaphthene and phenanthrene increased exponentially with increasing surfactant concentration while contaminant concentrations decreased with increasing time in the Longlands soil and standard soil desorption experiments. Dry API sludge samples were also subjected to soil washing studies. The washed samples were Soxhlet extracted and analysed by gas chromatography. The 0.5 mM and 1 mM Safol 45E7 washed sludge samples showed respective phenanthrene peak area percent reductions representing a 44 % and 47 % extraction of phenanthrene from the API sludge. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Ihis work on the Sado outer estuary (western coast of Portugal) considers its bio-sedimentary characterization, and evaluates the prevailing hydrophysical and sedimentary environmental conditions. The quality status of the estuary is discussed. The thesis is based on the analysis of superficial sediments and benthic macrofauna collected from 133 sites, and on hydrodynamical data obtained from a mathematical model. The environmental variables considered were the superficial sediment temperature, granulometry and organic matter content, together with the water current velocities, flow and shear stress. The macrofaunal characterization and the analysis of the state of disturbance was based on a study of the composition, structure and spatial distribution of faunal assemblages and their relationship to the prevailing environmental conditions. The Sado was shown to be inhabited by an abundant and diversified fauna with high biomass. Two major faunal assemblages have been identified, a marine and an estuarine community, separated by a transition region. The estuarine community comprises the majority of the area and contains important subdivisions. The regions identified have been shown either to be controlled by anthropogenic inputs or to reflect mainly the effects of natural forces. The main structuring factors influencing the benthos are the hydrodynamic conditions, coupled with sediment type, and organic matter of natural and anthropogenic origin. Sedimentary organic enrichment effects have been noted in all the areas studied and in general the Sado outer estuary reveals signs of eutrophic conditions. In the more disturbed regions the macrofauna data also suggest chronic toxicity effects. Although disturbance effects due to anthropogenic inputs are suggested through the biosedimentary approach, the estuary as a whole can not be considered badly polluted. However, defaunated, impoverished and over-enriched areas, appear as a result of localised severe pollution indicating the need to improve effluent treatment systems. The methodological approach followed in this study has been shown to be effective in assessing the quality status of the Sado outer estuary. Multivariate and direct gradient analysis proved to be very useful methods and a detailed analysis of the macrofaunal species has been shown to be effective in the detection of organic enrichment effects in some of the areas. The extreme aspects of the gradients were identified by all the analytical techniques, but the univariate methods were shown to be poor at discriminating the more subtle effects.

Dissertation submitted in compliance with the requirements for the Masters Degree in Technology: Environmental Health, Durban Institute of Technology, 2005. / South Durban is in the province of Kwazulu-Natal in South Africa and is home to two international petro-chemical refineries, a paper mill, sewage works, an international airport, a chemical tank farm with approximately 970 tanks, a number of landfill sites, an airport, various processing and manufacturing industries which are all in close proximity to residential and recreational areas. This area is known as the South Durban Industrial Basin (SDIB). Serious concerns have arisen about the potential health impacts that could arise from ambient air pollution from these industries. Learners and staff at the Settlers Primary School situated in Merebank, a suburb in the SDIB, perceived themselves to be at risk for air pollutant related health effects owing to the schools’ geographic location. The aims of this study was a) to determine the prevalence of asthma among learners from Grades 3 and 6 and staff at Settlers Primary School and b) To investigate whether outdoor air pollutant concentrations of sulphur dioxide (SO2), oxides of nitrogen (NOx), ozone (O3), total reduced sulphur (TRS), carbon monoxide (CO) and respirable particulate matter less than 10 microns (PM10) were associated with increased signs and symptoms of asthma in the study population. / M