Many local authorities are major polluters and are ignoring each and every rule in the book. Raw sewerage is dumped in to rivers and the Vaal River is already a national health threat. Pollution of land, air and water is a common consequence by large corporations capable of causing harm to humans and other living organisms. Research on the pollution of these key natural resources is required to understand cumulative impacts, so as to take measures of precaution to minimize such pollution and reduce its consequences. Risk Assessments are therefore encouraged to identify and explore in quantitative terms, the types, intensities and likelihood of undesired consequences related to the risk of pollution. This study has identified a potential risk from creosote bleedings at Eskom pole yards and aims to explore the probability of such occurrences cumulatively so as to identify precautionary measures at the forefront of this problem to develop effective contingency plans. Soil samples were collected systematically and analysed for polycyclic aromatic hydrocarbons (PAH), a component of creosote that preserves wood. Studies have indicated that concentrations of this preservative beyond acceptable limits can impact negatively on natural resources especially water and soil. The laboratory analysed data indicates that the soil samples collected from the Howick Pole Yard were contaminated with PAH beyond the threshold values. The severity of the contamination, as determined by the application of the Risk Assessment tool, indicates that mitigation measures are essential. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2008.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 74-76)

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 214-228).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 418-425). Available also in a digital version from Dissertation Abstracts.

Major paper (M.U.R.P.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 64-69). Also available via the Internet.

Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 148-164).

In this study, the formation mechanisms, distribution characteristics, and potential environmental risks of hazardous air pollutants from industrial-scale waste incineration processes were investigated. First, to clarify the dominant formation mechanism of polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) in a hazardous waste (HW) incinerator, three tests were designed by adding different precursors in phenol-containing raw materials. With the addition of p-dichlorobenzene, PCDD/F levels at the quenching tower outlet were ten times higher than levels observed at the inlet. This indicates that the quenching tower failed to suppress the formation of PCDD/Fs and surface-mediated precursor reaction is the dominant formation mechanism in low-temperature stages. Besides, adsoprtive memory effect in air pollution control devices (APCDs) also led to high PCDD/F emissions. These findings suggest that to control PCDD/F emissions, strict regulation of chlorine contents in feed materials and frequent cleaning of APCDs are necessary. Meanwhile, single particles and solid residues were collected from the same HW incinerator. Morphologies and elemental compositions of particles in flue gas and indoor air were characterized by transmission electron microscopy-energy dispersive X-ray spectrometry (TEM-EDS). Eight types of single particles were classified, as organic, soot, K-rich, S-rich, Na-rich, Fe-rich, mineral and fly ash particles. The heavy metal partitioning behavior study suggested that Hg, Cd and Pb were mainly enriched in fly ash through evaporation, condensation, and adsorption; while Cr, Cu, Mn, and Ni were mostly remained in the bottom ash due to their low volatilities. In addition, the study also investigated environmental behaviors of certain characteristic pollutants. Thrity-two soil samples surrounding a cement plant co- processing HW were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 12 heavy metals. Ten samples were selected for PCDD/Fs analysis. The highest concentration of PCDD/Fs occurred 1200 meters downwind from the cement plant. Levels of ∑16 PAHs ranged from 130.6 to 1134.3 μg/kg in soil. Source identification analysis suggested that the cement plant was the most likely source of PAH contamination. The concentrations of Cd and Hg were on average two times and six times higher than background values, respectively. Both incremental lifetime cancer risk model (ILCR) for PAHs and potential ecological risk index (RI) for heavy metals indicate potential risks to the population and the environment surrounding the cement plant. Last, to identify whether waste incineration is a major source for airborne environmentally persistent free radicals (EPFRs), tree leaf samples were collected from 120 sites surrounding four waste incinerators and one urban area. EPFR concentrations on leaves ranged from 7.5 × 10 16 to 4.5 × 10 19 spins/g. For the 10 N.D. samples, they were all collected from areas inaccessible by vehicles. Although previous work has linked atmospheric EPFRs to waste incineration, the evidence in this study suggests that vehicle emissions, especially from heavy-duty vehicles, are the main sources. According to our estimation, over 90% of the EPFRs deposited on tree leaves might be attributed to automotive exhaust emissions, as a synergistic effect of primary exhausts and degradation of aromatic compounds in road dust

Considering the prominence of green supply chain management (GrSCM) research has developed expressively in this field. However, there is a dearth of studies from emerging economies comprised of modelling and empirical testing of hypotheses. Moreover, the literature is lacking the empirical evidence on the determinants of GrSCM practices by small and medium enterprises (SMEs) especially in the case of Pakistan. The literature has yet to determine what green practices are being adopted by SMEs in Pakistan, an elucidation why GrSCM practices are adhered, what construct is appropriate to evaluate adoption of GrSCM practices by SMEs in Pakistan, and whether mediation of internal factors exits between the relationship of GrSCM practices and external pressure. This dissertation uses Structural Equation Modelling (SEM) to investigate GrSCM practices adoption, the appropriate construct for evaluating green practices, and examining three potentially important determinants in Pakistani SMEs. With the data collected in two stages from the SMEs sector of Pakistan, exploratory factor analysis (EFA) revealed a three-dimension structure for measuring the GrSCM practices. Subsequently, the confirmatory factor analysis (CFA) was carried out on two measurement models (i.e. first and second order) of GrSCM adoption based on EFA. The empirically outcomes advocates that both models for GrSCM adoption are valid and reliable, however the second order model has better fit indices. The SEM testing shows significant results for mediation of internal factors in the hypothesized relationship among the GrSCM practices and external pressures. For academicians and supply chain mangers these results yield several exciting theoretical and practical implications.

In this study, the formation mechanisms, distribution characteristics, and potential environmental risks of hazardous air pollutants from industrial-scale waste incineration processes were investigated. First, to clarify the dominant formation mechanism of polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) in a hazardous waste (HW) incinerator, three tests were designed by adding different precursors in phenol-containing raw materials. With the addition of p-dichlorobenzene, PCDD/F levels at the quenching tower outlet were ten times higher than levels observed at the inlet. This indicates that the quenching tower failed to suppress the formation of PCDD/Fs and surface-mediated precursor reaction is the dominant formation mechanism in low-temperature stages. Besides, adsoprtive memory effect in air pollution control devices (APCDs) also led to high PCDD/F emissions. These findings suggest that to control PCDD/F emissions, strict regulation of chlorine contents in feed materials and frequent cleaning of APCDs are necessary. Meanwhile, single particles and solid residues were collected from the same HW incinerator. Morphologies and elemental compositions of particles in flue gas and indoor air were characterized by transmission electron microscopy-energy dispersive X-ray spectrometry (TEM-EDS). Eight types of single particles were classified, as organic, soot, K-rich, S-rich, Na-rich, Fe-rich, mineral and fly ash particles. The heavy metal partitioning behavior study suggested that Hg, Cd and Pb were mainly enriched in fly ash through evaporation, condensation, and adsorption; while Cr, Cu, Mn, and Ni were mostly remained in the bottom ash due to their low volatilities. In addition, the study also investigated environmental behaviors of certain characteristic pollutants. Thrity-two soil samples surrounding a cement plant co- processing HW were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 12 heavy metals. Ten samples were selected for PCDD/Fs analysis. The highest concentration of PCDD/Fs occurred 1200 meters downwind from the cement plant. Levels of ∑16 PAHs ranged from 130.6 to 1134.3 μg/kg in soil. Source identification analysis suggested that the cement plant was the most likely source of PAH contamination. The concentrations of Cd and Hg were on average two times and six times higher than background values, respectively. Both incremental lifetime cancer risk model (ILCR) for PAHs and potential ecological risk index (RI) for heavy metals indicate potential risks to the population and the environment surrounding the cement plant. Last, to identify whether waste incineration is a major source for airborne environmentally persistent free radicals (EPFRs), tree leaf samples were collected from 120 sites surrounding four waste incinerators and one urban area. EPFR concentrations on leaves ranged from 7.5 × 10 16 to 4.5 × 10 19 spins/g. For the 10 N.D. samples, they were all collected from areas inaccessible by vehicles. Although previous work has linked atmospheric EPFRs to waste incineration, the evidence in this study suggests that vehicle emissions, especially from heavy-duty vehicles, are the main sources. According to our estimation, over 90% of the EPFRs deposited on tree leaves might be attributed to automotive exhaust emissions, as a synergistic effect of primary exhausts and degradation of aromatic compounds in road dust

A dissertation submitted to the Faculty of Science, University of the Witwatersrand in fulfilment of the requirements for the degree of Master of Science. Johannesburg 2015 / Exposure to inorganic and organic pollutants residues causes negative effects to human health. They can cause damage to the living organism as well as to the environment. Humans take up these pollutants through skin absorption, respiration and ingestion of contaminated food and also the drinking water as a potential contaminants exposure route for inorganic and organic pollutants to humans. Studies have shown that inorganic and organic pollutants can be retained in food crops at higher than the permissible levels, thus posing some health risks to consumers. This study sought to assess the potential risk posed by inorganic and organic pollutants to human health as a result of consuming raw food and processed food cooked in traditional utensils. The food samples and the traditional utensils were collected in Kinshasa and Johannesburg markets. In total ninety- two food samples were assessed. The food crops included: cabbage, cassava, beans, beef meat and fish (tilapia). Ten trace elements, namely: Al, As, Cd, Cr, Cu, Hg, Mn, Pb, Se and Zn were analysed in raw food samples using ICP-OES, ICP-MS and mercury analyser. These metals were also analysed in food cooked with the traditional utensils. The health risk indices calculated were: Daily Intake of Metal (DIM) and Hazard Index (HI). The results obtained reveal that the raw food collected in Johannesburg markets contained a significant (p ˂ 0.05) higher concentration in all elements than the food samples collected in Kinshasa markets. Hg was detected only in fish samples. It was observed that cooking utensils can leach some significant quantities of trace elements into food during processing, hence resulting increase the concentration of these metals in processed foods. The DIM exceeded the oral reference dose (Rfd) and the HI were ˃ 1 in all the food cooked. The results of metal found in this current investigation were above the standard permissible limit set by FAO/WHO. On the other hand, the levels of 17 organochlorine pesticides were assessed in uncooked and cooked beans, cabbage, cassava, fish and beef meat collected in Kinshasa and Johannesburg markets. It was noticed from the results recorder that the mean concentration of organochlorine pesticides in uncooked food collected in Johannesburg market were significantly high (p ˂ 0.05) than the uncooked food from Kinshasa markets. DDE recorded its highest mean level (253.58±4.78 μg kg-1) in beef meat samples collected in Johannesburg markets. The results from the current study revealed that after cooking the amounts of organochlorines were significantly reduce than the uncooked food. Residue amounts of organochlorine pesticides found in this study are considerably lower than the recommended amount of organochlorines set by WHO/FAO (300 μg kg-1). / MT2016