M.Tech. Business Administration. Business School. / The purpose of this study is to investigate the internal behavioural barriers to the implementation of hazard analysis and critical control point (HACCP). This investigation aims to assist the hospitality industry in implementing best practice in food hygiene to maximise public food safety and profitability. It also aims to investigate and possibly generate creative initiatives to control and monitor the long-term implementation of hazard analysis and critical control point principles in the sector so as to render it competitive on an international level.

To determine whether extreme endurance exercise induces lipid peroxidation, we studied 14 athletes (5 females: 9 males) during a 50 km ultramarathon (trial 1) and during a sedentary protocol (trial 2) one month later. At dinner the evening before the race (or sedentary trial), subjects consumed vitamin E labeled with stable isotopes (75 mg each d₃-RRR and d₆-all rac-α-tocopheryl acetates). Blood samples were taken at baseline, 30 minutes pre-race, mid-race, post-race, 1 h post-race, 24 h post-race, and at corresponding times for each individual during trial 2. During the sedentary day of trial 2, subjects consumed the same amounts of race day foods, including ergogenic aids, that they had consumed in trial 1; vitamin E intakes were 77 ± 40 mg, and vitamin C 406 ± 169 mg. All 14 subjects completed the race; average time to completion was 390 ± 67 minutes. Plasma F₂-isoprostanes (F₂-I), labeled and unlabeled α-tocopherol, and ascorbic acid (AA) were measured. F₂-I increased from 76 ± 24 pg/ml pg/ml at pre-race to 117.4 ± 38.0 pg/ml (p<0.0008) at mid-race to 130 ± 54 pg/ml (p<0.0001) at post-race, then returned to baseline at 24 hours post-race; F₂-I were unchanged during trial 2. Deuterated d₃ α-tocopheryl (d₃ α-Toc) disappearance rates were faster (2.8x10⁻⁴ ± 0.5x10⁻⁴) during the race compared to the sedentary trial (2.3x10⁻⁴ ± 0.6x10⁻⁴; p < 0.03). Plasma AA increased from 75.2 ± 11.2 μM at pre-race to 157.7 ± 36.2 μM at race end (p<0.0001) and decreased to below baseline concentrations at 24 h post-race (40.4 ± 5.2 μM p<0.0001). AA levels also increased during trial 2. Despite increased plasma AA, F2-I increased during exercise, but not during the sedentary period. Additionally, vitamin E disappeared faster during the run compared to the sedentary protocol. Thus, extreme endurance exercise results in the generation of lipid peroxidation and increased vitamin E utilization. / Graduation date: 2001

While there is growing public concern over the safety of the food supply, few studies have contrasted varying perceptions of pesticide risk. This study assessed and contrasted perceptions of three groups of Oregon State University Extension Service clientele (home food preservers, Master Gardener volunteers, commercial growers) and factors influencing these perceptions. The impact of the pesticide risk perceptions on purchasing decisions and pesticide application practices was assessed. Two questionnaires were developed: one for home food preservers/Master Gardener volunteers and one for commercial growers. One hundred twenty-seven questionnaires were completed by a convenience sample of home food preservers (85% adjusted return rate) and 155 questionnaires were completed by randomly selected Oregon State University Master Gardener volunteers (81% adjusted return rate). A shortened version of the questionnaire was completed by 124 participants at the annual meeting of Willamette Valley Processed Vegetable Growers. Home preservers were 84% female (mean age=49 ± 14 years), volunteers were 50% female/50% male (mean age=56 ±14 years), and commercial growers were 95% male (mean age=42 ± 11 years). Three different measures of pesticide risk perceptions were used to test six hypotheses: Respondents rated 1) "eating foods produced using pesticides" as high, low, or no risk, and agreed/disagreed (on Likert scales) whether 2) "chemical residues remaining on produce are a major health concern," and 3) "children are at a greater risk for illness from pesticides than adults." Produce selection decisions, pesticide application practices, life stages, gender, media awareness, and knowledge of agricultural production techniques and practices were also assessed to determine their relationship with risk perceptions. Perceptions of risk varied among the three groups. Fifty-five percent of preservers rated "eating foods produced using pesticides" as a "high" risk compared to 34% of volunteers and 2% of growers. Thirty-four percent of preservers strongly agreed that "chemical residues remaining on produce are a major health concern" compared to 25% of volunteers and 7% of growers. Forty-six percent of preservers strongly agreed that "children are at a greater risk of illness from pesticides than adults" compared to 42% of volunteers. Fifty-two percent of growers strongly/ somewhat agreed that children are at no greater risk. Gender was significantly associated with respondents' perceptions. Eighty-nine percent of preservers rating the risk of "eating food produced using pesticides" as "high" were female as were 65% of volunteers. Female volunteers moderately agreed that "chemical residues remaining on produce are a major health concern" compared to males who tended to neither agree nor disagree. The presence of children living in the home was significantly related to the volunteers' perceptions that chemicals are a major health concern and that children are at greater risk. Preservers and growers' results indicated there were no significant differences. Awareness of pesticide reports in the media was measured by recall of four media events. Media awareness was significantly associated with preservers' perceptions that eating foods produced with pesticides was "high" risk and that children are at a greater risk for illness because of pesticide residues. There was no media association for either volunteers or growers. Influence of risk perceptions on produce purchase decisions was measured with a series of questions about past, present, and future purchases. Results indicated that volunteers' pesticide risk perceptions were significantly related to more produce selection decisions than were home food preservers. The risk perception measure that "chemical residues remaining on produce are a major health concern" was most significantly associated with purchase decisions for both preservers and volunteers. For preservers and volunteers there were significant relationships between all three measures of pesticide risk perceptions and three of the twelve purchase decisions tested. Those who perceived a higher risk were 1) more willing to pay a higher price for certified residue free produce, 2) more concerned about pesticide residues when buying imported produce, and 3) intended to purchase produce grown without synthetic pesticides even if it costs more. Knowledge of agricultural practices was measured by a set of five questions. Mean scores ranged from 0.9 ± 0.9 for preservers to 1.6 ± 1.0 for volunteers out of a possible 5.0. Volunteers' with higher scores were significantly more likely to agree that chemicals are a major health concern and that children are at a greater risk of illness from pesticide residues. No significant associations were seen for preservers. Pesticide application practices were significantly related to pesticide risk perceptions. Preservers and volunteers who generally perceived the risks as "high" reported not using pesticides. Preservers reporting changes in application practices moderately agreed chemical residues are a major health concern while volunteers' reporting changes in application practices strongly agreed that children are at higher risk than adults. Growers tended to disagree that pesticides are a major health concern and they were less concerned that children are at a greater risk from pesticides. The study concluded that the home food preservers and Master Gardener volunteers perceived the risks associated with pesticides and produce as much higher than commercial vegetable growers. This difference in perceptions is reflected in some of their produce selection decisions and pesticide application practices. Children living at home, gender, media awareness, and knowledge of agricultural practices were associated with the pesticide risk perceptions of these Extension clientele. Results suggest that educational programming to increase knowledge about pesticide usage in agricultural production is warranted. There is also a need to foster better communications among groups with differing points of views about pesticide residue risks. / Graduation date: 1994

The Purpose of this research was to describe relationships between Murdaugh and Verran's (1987) Preventive Behavior Model Concepts in military-affiliated individuals at risk for coronary artery disease. One hundred forty-three subjects were recruited by their primary care physician and were requested to voluntarily complete questionnaires measuring health beliefs, health locus of control, value orientations, and health care activities. Laboratory values and blood pressure were also evaluated. There were significant positive correlations between health beliefs, health locus of control, and value orientations. However, these PBM concepts explained only 13% of the variance in dietary habits, 9% of smoking behaviors, 16% of habitual physical activity, 4% of cholesterol levels, 2% of diastolic blood pressure, 7% of body mass index, and 21 percent of glucose levels. PBM concepts explained a relatively small amount of the variance in the dependent variables within this sample and the results were not clinically significant.

<p>Physical inactivity is one of the leading risk factors for major non-communicable diseases, which contribute substantially to the global burden of chronic diseases, disability and death. The burden of disability, morbidity and mortality, attributable to non-communicable diseases, is currently enormous in the developed countries and is increasingly growing in the developing countries. The purpose of this study was to investigate the relationship between participation in physical activity and health risk behaviours among high school students in the Mtwara region, Tanzania. The objectives of this study were to identify the physical activity levels among high school students in Mtwara region, Tanzania, to identify health risk behaviours among the above mentioned high school students, to identify the factors that influenced them to engage in health risk behaviours and to establish the relationship between physical activity and health risk behaviours.</p>

Although there have been many studies examining the factors involved in children’s risk of injury, there has been a dearth of research that examines specific individual parental factors in children’s risk of injury. This thesis examined how the attitudes, values, and beliefs of 119 Canadian minor hockey parents of children (aged 9 to 12 years) with respect to their decision-making regarding their children’s safe participation in hockey. Two studies are reported. The first study describes: (a) the development of a questionnaire that quantifies the constructs of perceived control, probabilities, values, risk propensity, competitiveness, and assertiveness expectancies; and (b) a sample of hockey parents in terms of their demographic characteristics and their attitudes, values, and beliefs regarding their children’s participation in minor hockey. The second study examined the relationships between these attitudes, values, and beliefs and a measure of their risk decision-making. Overall, results showed that (a) this sample of hockey parents tended to be well educated, and did not see themselves as being generally over-competitive or aggressive; (b) hockey parents’ attitudes, values, and beliefs regarding their children’s risk of concussion had very little predictive value or reliable connection with respect to their risk decision-making on behalf of their children; and (c) the most significant factors in parents’ risk decision-making were the opinions of their children, and the opinions of the doctors. The implications of these findings for future research and practice are discussed. / Thesis (Master, Education) -- Queen's University, 2012-12-21 16:12:00.221

Young children are particularly sensitive to environmental pollutants. They can directly ingest soil by putting dirty hands and objects in their mouths. The reliance on animal derived models for human health risk and exposure assessment has several limitations. In this investigation, a tool-kit was developed and optimised to facilitate more accurate, reliable and representative predictions of soil contaminants that might pose a significant hazard to young children. The tool-kit was developed and optimised using an in vitro human digestion bioassay. This procedure was followed by the optimisation of several mutagenicity bioassays to link to the bioaccessible fraction which quantified by the in vitro bioassay. The application of novel and sensitive environmental-based biosensors requires them to work in parallel with effective and proven extraction techniques. In this study, chemical analysis was used to quantify the bioaccessible (human assimilated portion) of pollutants in soils. Acute toxicity was measured using constitutively marked bioluminescent bacterial biosensors and these were indicative of the total contaminant burden. A range of mutagenic assays were applied and optimised. In the Ames assay, any compound exhibiting a greater than two-fold increase in the number of revertants colonies over the number of spontaneous revertants was considered as a mutagen. Mutagenic-responsive SOS-lux based microbial biosensors were compared to the Ames assay. Mutagenicity assessment of a broad range of environmental pollutants (i.e. B[a]P, DiB(a,h)A, B[a]A, Ni and Cu), was performed using four SOS-lux microbial biosensors; E. coli DPD1718, E. coli K12C600, S. aureus pAmiUmuC and S. aureus pAmiRecA. The results substantiated that the four biosensors were unable to be induced by these pollutants. Nevertheless, E. coli DPD1718 and E. coli K12C600 were successfully induced by Mitomycin C (MMC) in a dose response manner. The Ames assay was performed for the above pollutants in the absence and the presence of the metabolic activation S9 mix. The standard plate incorporation assay and a modification protocol for the Ames assay were applied. Results reported from the Ames assay confirmed mutagenicity responses of the tested pollutants except Cu and Ni. MMC was selected and introduced into soil samples as a case study to assess the performance of the developed tool-kit. Soils amended with MMC were extracted by the in vitro human digestion bioassay, and the mutagenicity of the bioaccessible fraction was measured using the Ames assay and the biosensors. A comparison was made between the permissible concentrations of MMC obtained from the developed tool-kit and RISC4 derived concentrations. The four microbial biosensors applied in this study were incapable to detect the mutagenicity of the tested pollutants. On the other hand, the Ames assay was more robust and sensitive to a broad range of environmental pollutants. The in vitro human digestion bioassay enabled the quantification of the human bioaccessible fraction of the tested pollutants. This fraction posed a concern due to its estimation of the doses that would reach the blood circulation and cause harm to human. While the permissible concentration of MMC measured by the developed tool-kit was less than 10 μg MMC/g, the RISC4 model calculated that it should be 40 μg MMC/g. This revealed that, in this situation, risk assessment model was less conservative than empirical study for human health risk assessment. This study enabled the assessment of the permissible concentrations of environmental pollutants that could remain in a soil and pose permissible harm to humans. This approach also enabled a comparison of modelled and empirical data to allow a measure of sensitivity to be judged. There is a need to develop bioassay techniques more able to assess the potency of hydrophobic compounds both in isolation and combination.

MFamMed, Faculty of Health Sciences, University of the Witwatersrand, 2007

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

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Health 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.