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Exploring barriers to the implementation of hazard analysis critical control point regulations in small foodservice establishments in South AfricaSmit, Michèl Maria. January 2012 (has links)
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.
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Assessment of oxidative stress in athletes during extreme endurance exercise using deuterium-labeled vitamin EMastaloudis, Angela 23 August 2000 (has links)
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
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Pesticides and produce : risk perceptions of extension clienteleLove, Margaret L. 30 August 1993 (has links)
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
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Relationships among preventive behavioral model concepts in individuals at risk for coronary artery diseaseHarwick, Michelle Anne January 1989 (has links)
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.
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Relationship between participation in physical activity and health risk behaviours among youth in high schools in Mtwara region, Tanzania.Nannyambe, Edgar Boniface. January 2007 (has links)
<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>
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Effects of parents’ attitudes, values, and beliefs on their risk decision-making on behalf of their children enrolled in minor hockeyKoo, Ean Tjenyee 03 January 2013 (has links)
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
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Development and applications of mutagenicity and carcinogenicity bioassays for human health risk assessmentAlhadrami, Hani Abdullah January 2011 (has links)
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.
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Health risk behaviours of high school learners and their perceptions of preventive services offered by general practitionersThomas, Caron 28 July 2011 (has links)
MFamMed, Faculty of Health Sciences, University of the Witwatersrand, 2007
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Environmental risk assessment of inorganic and organic pollutants in raw and cooked food in African countriesNuapia, Yannick Belo 19 September 2016 (has links)
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
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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 schemeGarbharran, Dinesh Hari Lall 08 March 2012 (has links)
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.
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