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Student Number : 0213468X - MPh dissertation - School of Public Health - Faculty of Health Sciences / Background: Noise Induced Hearing Loss (NIHL) is increasingly being regarded as one of the most important Occupational diseases, especially in the mining industry. As most mining houses have put systems in place to try and control this problem it remains to be seen if existing controls are effective in achieving the intended objective of preventing hearing loss. This study was conducted in one of the big South African Diamond mines, which has a well resourced Hearing Conservation Program. Objectives: This study was conducted with the purpose of establishing if there has been additional incidence of NIHL in noise exposed workers during the observation period of five years. The other objective of this study was to determine the effect of age. Study design and method: The population in this study was made up of permanent employees of the mine. They were divided into low risk and high risk groups according to the noise/acoustic zoning of their work areas by the mine’s Occupation Hygiene Section, with the low exposure group acting as the control group. A retrospective record review was done using the Occupational Health records in the mine’s Occupational Health Centre. The period of observation spanned 1 January 1999 – 31 December 2004 (inclusive). Trends of the collated data were used to compare the two exposure groups with regard to the various outcomes that are commonly associated with hazardous noise exposure. Results: The outcomes that were analyzed in this study were: Incidence Rates for NIHL, Notching and Down-sloping. All these were observed to have occurred more among the exposed group during the period of observation. The incidence rates, in particular, were found to 92.8 per thousand person years in the high exposure group and 52.3 per thousand person years in the low exposure group. The statistical test that was used was the z-test and the results were z=5.844 with a p<0.05. Having decided on a significance level of 5% for the statistical test, this result was found to be statistically significant. This can be regarded as some proof that the exposed group had a worse outcome than their non-exposed counterparts. Another observation that was made was that the incidence of NIHL was proportionately higher among the older study subjects. Conclusion: Since the exposed group of workers was found to show statistically significant incidence of NIHL compared to the low exposure group it shows that the current Hearing Conservation Program (HCP) that is employed by the mine is not effective in preventing NIHL. However there were some limitations in the study design that preclude generalization of these results. Therefore a recommendation was made for a prospective cohort study to address these limitations.

By 1980, the United States had lost over 50 percent of its original wetland resources. The U.S. National Wetland Inventory estimates that 95 percent of annual wetland losses since 1955 occurred to palustrine wetlands. The majority of these losses occurred to the three types of palustrine vegetated wetlands: emergent, forested, and shrub. The primary cause for wetland losses from the mid-1950s to the mid-1980s was agricultural conversion supported by federal agricultural policies, especially the Agricultural Conservation Program that provided significant direct and indirect support for wetland conversions. The rate of converting wetland to agriculture has declined since the mid-1950's with a significant decrease occurring between the mid-1970s and mid-1990s. Statistical analysis using correlation, regression and principal component analysis was performed to identify the major contributory factors in loss rates in the Midwest, Lower Mississippi River Valley and the Southeast United States. The variables considered are: Swampbuster provisions of the Food and Security Act of 1985, Conservation Reserve Program enrolled acreage and rental rates, Wetland Reserve Program and The Clean Water Act Section 404 permits; prices of corn, soybeans and wheat; and the percent of wetlands remaining. The results indicated agricultural policies and Clean Water Act Section 404 permits and wetland loss rates were negatively correlated and prices of corn, soybeans and wheat were positively correlated. The percentage of wetlands remaining, were also positively correlated with loss rates. Taken together, the selected agricultural policies, Section 404 permits, commodity prices and percent of wetland remaining, explain 96 percent of the variance in wetland loss rates and 94 percent of the agricultural losses nationally. These results are consistent, with minor variations, across geographic wetland strata and wetland types. Regional differences exist in the major type of wetland losses; emergent wetland losses were more prevalent in the agricultural Midwest, with forested wetland losses concentrated in the Lower Mississippi River Valley and the Southeast United States. The results of this research reflect the intricate relationships between federal legislation, regulatory programs, legal decisions, economic factors, and changes in society's view and understanding of the importance of wetlands and the need to merge conservation programs with agricultural policies. Economic factors exert a significant impact in decision-making of whether to convert or conserve wetland resources. The economic feasibility of installing drainage system to make wetlands farmable depends upon the relationship of capital investment cost and crop prices. Commodity prices impact decisions regarding enrollment into the Conservation Reserve Program and the Wetland Reserve Program; higher commodity prices can make conversion more profitable but low crop prices will make these programs more appealing economically. The Swampbuster provisions are effective in conserving wetlands if the economic penalties are significant to the individual farmer. The policy, legal and commodity variables were used to create models that explain the inter-relationship between agricultural economic factors, policy impacts and commodity prices. The models indicate how the variables could affect decision-making in determining whether to convert or conserve palustrine vegetated wetlands; increased commodity prices coupled with lower conservation program payments could jeopardize wetland conservation efforts and result in increased wetland loss rates due to increased wetland drainage and conversion.

Call number: LD2668 .T4 1986 H64 / Master of Science / Civil Engineering

The City of Dallas Environmental Education Initiative (EEI) is a hands-on, inquiry-based, K-12 water conservation education program that teaches students concepts about water and specific water conservation behaviors. Few descriptions and evaluations, especially quantitative in nature, of water conservation education programs have previously been conducted in the literature. This research measured the quantitative effects and impacts of the education program on water use in single-family homes in Dallas, Texas. A total of 2,122 students in 104 classrooms at three schools in the Dallas Independent School District received hands-on, inquiry-based water conservation education lessons and the average monthly water use (in gallons) in single-family homes was analyzed to measure whether or not there was a change in water use. The results showed that over a period of one calendar year the water use in the single-family homes within each school zone and throughout the entire research area in this study experienced a statistically significant decrease in water use of approximately 501 gallons per home per month (independent, t-test, p>0.001). Data from this research suggests that EEI is playing a role in decreasing the amount of water used for residential purposes. Additionally, this research demonstrates the use of a quantitative tool by which a water conservation education program’s effect on behavior change can be measured. This research shows great promise for reducing use and increasing the conservation of our world’s most precious resource.

This diploma thesis describes by a feasibility study the introduction of a new product, which has the name Green credits. This project responds to a flexible manner on a prospective and dynamically growing market for environmentally friendly and energy-saving solutions and its implementation may allow a particular financial institution to obtain the position of leader and new business in this market.

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