Spelling suggestions: "subject:"foxicity potential"" "subject:"3toxicity potential""
1 |
Environmental LCA of water use in South Africa : the Rosslyn industrial area as a case studyLandu, Landu 24 April 2006 (has links)
International LCA literature indicates that little data is available pertaining to potable water production and supply, in particular with respect to the environmental burdens generated within the system. This study aims to investigate and assess the environmental burdens associated with the potable water supply to an industrial area (Rosslyn, north of Pretoria, in the Tshwane Metropolitan Municipality). The procedure, as well as the assessment of the environmental impacts of a life cycle, is dependent on a comprehensive life cycle inventory (LCI) of the evaluated system. Water use is included in LCIs, which are incorporated into the LCIA procedure, as it reflects a direct extraction from available resources. The water supply system diagram has been developed and data was collected, treated and analysed in the inventory analysis phase. The study closely followed the four phases as stipulated in the International Organization for Standardization (ISO 14040 series of standards) for conducting LCAs, including: -- goal and scope definition; -- LCI analysis; -- LCIA; and -- interpretation, conclusions and recommendations. The methodology used in the impact assessment phase was the introduced LCIA framework for South Africa in order to determine the extent of different environmental impacts. The inventory analysis, conforming to the scope of the study, provided an overall inventory of energy and other resource requirements, emissions to water and air, dust fallouts and solid or liquid wastes for the system under study. By using this methodology and by tracing all unit processes involved in the potable water supply system, the main contribution to the environmental burdens imposed on the potable water supply system was found to be the extraction of the required water from nature to supply potable water to Rosslyn. The toxicity potential impacts on water resources, mainly due to the electricity required for the water supply system, are of minor importance. This conclusion is valid for the system investigated, and as a result, the recommendations for environmental improvements should focus on water losses that must be addressed foremost. What is required at this stage is strategic planning regarding the extraction, use and conservation of water resources. Furthermore, to optimise all processes of water extraction, and to make them more efficient, electricity and other energy inputs are also of importance, albeit to a lesser extent. / Dissertation (M (Applied Sciences : Environmental Technology))--University of Pretoria, 2007. / Chemical Engineering / unrestricted
|
2 |
Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic ProductsMcCanna, David January 2009 (has links)
The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes.
The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.
|
3 |
Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic ProductsMcCanna, David January 2009 (has links)
The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes.
The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.
|
Page generated in 0.0802 seconds