3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Environmental risk assessment of inorganic and organic pollutants in raw and cooked food in African countries(2016-09-19) Nuapia, Yannick BeloExposure 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).Item The relationship between modifiable health risk factors and health care costs for individuals who have completed a health risk assessment questionnaire for a South African health insurance scheme(2012-03-08) Garbharran, Dinesh Hari LallHealth care funders are seeking managed health care interventions to contain medical inflation. The purpose of this study is to assess the relationship between three health risk factors (smoking status, physical activity and body mass index (BMI)) and inpatient costs among health risk assessment (HRA) respondents at a South African health insurer. The results could inform the design of wellness programmes by ensuring that appropriate health risk factors are being targeted to reduce inpatient costs. This study utilises a two-part regression model to explore the relationships between the health risk factors and inpatient costs. The combined results of the two-part regression model indicate that increasing levels of physical activity and decreasing levels of BMI are associated with lower likelihoods of hospitalisation and lower magnitudes of inpatient costs for those that had a non-zero claim. The results of this study indicate no association between smoking cessation and lower inpatient costs.