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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Cardiovascular risk factors of Anglos and Mexican-American Hispanics in Pima County, Arizona

Dodson, Mary Ann Jokerst, 1939- January 1988 (has links)
A comparison study of cardiovascular risk factors between Anglos and Mexican-American Hispanics, by gender and age, was conducted with 1343 subjects in Pima County, Arizona. Data was collected through public health screenings at a variety of sites (39) throughout the community. A self-administered questionnaire and measurements of height, weight, blood pressure, total blood cholesterol and blood glucose provided the data. Risk factors (total blood cholesterol, hypertension, smoking, genetic tendency, diabetes, obesity and lack of exercise) were analyzed individually and in combination by age, gender and ethnicity. Some of the significant findings (p ≤ 0.05) were females, greater than 50 years of age, had higher cholesterol levels and more multiple risk factors than comparable males, that more Anglos (p ≤ .005) both males and females, had elevated blood cholesterol levels than did Mexican-Americans but that Mexican-Americans were more obese and exercised less than Anglos.
152

Knowledge, awarness and practices regarding tuberculosis among gold miners in Tanzania

Mtaita, Ghuhen Reuben 02 1900 (has links)
The overall aim of this study was to investigate the knowledge, awareness and practices regarding TB at a selected gold mine in Tanzania in order to enhance the paucity of knowledge in this area of public health. The mining population is considered to be at high risk of tuberculosis infection and illness. However, there is little data available on the knowledge, awareness and practices in the mining population in Tanzania. A quantitative, descriptive study, using the Health Belief Model as the conceptual framework, was conducted among 100 workers in order to give a detailed description of the knowledge and awareness of tuberculosis. The study confirms the role of the media, particularly radio broadcasting, health workers, teachers, and the community in promoting information and education on TB. Fever as a symptom was a problem. The study area is a malaria endemic area where fever is the commonest presentation hence every fever is regarded as malaria. This complicated picking up and identifying other causes of fever. Despite feeling compassion for and wanting to help TB sufferers, most avoided them, which emphasised people’s general fear of TB. This indicated the general isolation and stigmatisation of TB sufferers. The findings highlighted the need for on-going education about TB and its treatment, especially early diagnosis and adherence to treatment. / Health Studies / M.A. (Public Health)
153

Teores de elementos potencialmente tóxicos em solos de uma bacia hidrográfica e avaliação de risco à saúde humana / Watershed soils contents of potentially toxics elements in soils from an watershed and human health risk assessment

Silva, Evandro Barbosa da 23 April 2013 (has links)
A contaminação dos solos por elementos potencialmente tóxicos (EPTs) provoca alterações na estrutura e no funcionamento dos ecossistemas, além de oferecer riscos à saúde pública. Os EPTs estão presentes naturalmente no ambiente, sendo constituintes de rochas e sedimentos. Entretanto, atividades antropogênicas como emissões industriais, uso de efluentes urbanos, dejetos de animais, biossólidos, fertilizantes e defensivos agrícolas podem contribuir para aumento da concentração dos EPTs. O solo é um dos principais meios de exposição dos EPTs aos seres humanos. Logo, é importante quantificar os teores dos EPTs nos solos e sua distribuição na microbacia para poder avaliar o risco a saúde humana. Os efeitos dos elementos tóxicos que chegam ao solo sobre a diversidade e funcionalidade da biota podem ser avaliados por meio de testes ecotoxicológicos. Alguns organismos são bons indicadores ambientais por participarem de processos biológicos importantes do solo. Os principais organismos utilizados são os colêmbolos, artrópodes terrestres com alta diversidade e abundância, sendo encontrado em todos os biomas. Nesse estudo, quantificaram-se os teores de Arsênio (As), Cádmio (Cd), Cobalto (Co), Cobre (Cu), Cromo (Cr), Chumbo (Pb), Níquel (Ni) e Zinco (Zn) em amostras de 15 solos da microbacia do Rio Guamium, localizada em Piracicaba, São Paulo. Foi realizado experimento em casa de vegetação com alface (Lactuca sativa L.), pepino (Cucumis sativus L.), beterraba (Beta vulgaris L.) e rúcula (Eruca sativus Mill.) para avaliar o risco a saúde humana. Foi avaliado também o efeito da aplicação de doses de As na reprodução dos colêmbolos. Para tanto, foram coletadas amostras de solos nas profundidades 0 - 0,1; 0,1 - 0,2; 0,2 - 0,3; 0,3 - 0,4; 0,4 - 0,6; 0,6 - 0,9 e 0,9 - 1,2 m. Foi realizada a extração dos EPTs pelo método EPA 3051a (0,5 g de solo + 9 ml HNO3 + 3 ml HCl com digestão assistida por forno microondas). Os EPTs que apresentaram as maiores concentrações foram o As (3 pontos) e Cu (1 ponto), sendo as concentrações superiores ou iguais ao valor de prevenção estabelecido pelo órgão ambiental paulista (Cetesb). O As apresentou elevado risco carcinogênico, enquanto o Cu apresentou risco à saúde humana apenas quando 100 % dos vegetais consumidos eram provenientes da área com elevado teor de Cu, sendo este o cenário mais restritivo. Houve diferença na disponibilidade de As entre o solo natural e o solo artificial tropical (SAT), composto por areia, caulinita e pó de fibra de coco. O SAT apresentou alta disponibilidade de As o que reduziu a taxa de reprodução dos colêmbolos. No SAT a LOEC (Lowest Observed Effect Concentration) foi 0,25 mg kg-1 e a NOEC (No Observed Effect Concentration) < 0,25 mg kg-1. No solo natural não foi possível determinar a NOEC, enquanto a LOEC foi 8,41 mg kg-1. / Soil contamination by potential toxics elements (PTEs) can change the ecosystem structure, its function and can cause risk to human health. PTEs occur naturally in the environment; however human activities such as industrial emissions, urban sewage, animal waste, biosolids, fertilizers and pesticides can increase their concentration. Soil is one of the main pathways to human exposure, so it is important to evaluate the contents of PTEs in soils and their distribution in the watershed in order to assess the human health risk. The effects of PTEs that reach the soil on the diversity and functionality of microorganisms can be evaluated by ecotoxicological tests. Organisms that take part of the biological process can be used as environment quality indicators. One of them is the springtails (Collembola) that are wide spread and have high diversity, being found in all ecosystems. In this study, we evaluated the Arsenic (As), Cadmium (Cd), Cobalt (Co), Copper (Cu), Chromium (Cr), Lead (Pb), Nickel (Ni) and Zinc (Zn) contents in 15 soil from Guamium watershed, located in Piracicaba, state of Sao Paulo, Brazil. To assess the human health risk lettuce (Lactuca sativa L.), cucumber (Cucumis sativus L.), sugar beet (Beta vulgaris L.) and rocket (Eruca sativus Mill.) were cultivated under greenhouse conditions. The effect of As rates on collembola reproduction was also evaluated. Soil samples were collected in the following depths: 0 - 0.1; 0.1 - 0.2; 0.2 - 0.3; 0.3 - 0.4; 0.4 - 0.6; 0.6 - 0.9 e 0.9 - 1.2 m. Contents of PTEs were obtained after microwave extraction by EPA 3051a method (0.5 g soil + 9 mL HNO3 + 3 mL HCl). As and Cu had the highest contents, and their concentration were close or higher than prevention value established by Sao Paulo state environmental agency (Cetesb). As showed high carcinogenic risk, otherwise Cu only represented risk to human health in the most restrictive scenario, when 100% of the vegetables consumed were taken from the contaminated area. There was difference in the As availability between natural soil and artificial soil (ArtS) which was composed by sand, Kaolinite and powdered coconut fiber. As availability was high in the ArtS and it decreased the collembola reproduction. The Lowest Observed Effect Concentration (LOEC) on SAT were 0.25 mg kg-1, while and the No Observed Effect Concentration (LOEC) were less than 0.25 mg kg-1. Otherwise, the LOEC were 8.41 mg kg-1 in the natural soil, but it was not possible to define the NOEC.
154

Predictive modeling for wellness

Unknown Date (has links)
Wellness and healthy life are the most common concerns for an individual to lead a happy life. A web-based approach known as Wellness Scoring is being developed taking into people’s concerns for their health issues. In this approach, four different classifiers are being investigated to predict the wellness. In this thesis, we investigated four different classifiers (a probabilistic graphical model, simple probabilistic classifier, probabilistic statistical classification and an artificial neural network) to predict the wellness outcome. An approach to calculate wellness score is also addressed. All these classifiers are trained on real data, hence giving more accurate results. With this solution, there is a better way of keeping track of an individuals’ health. In this thesis, we present the design and development of such a system and evaluate the performance of the classifiers and design considerations to maximize the end user experience with the application. A user experience model capable of predicting the wellness score for a given set of risk factors is developed. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
155

Risk of injection using reclaimed water for aquifer recharge using rotavirus as surrogate contaminant

Unknown Date (has links)
Groundwater aquifers are precious resources that has been serving human consumption for many centuries. This resource is pristine in comparison with surface waters such as lakes and canals, however, as population grows exponentially so does the demand for groundwater and the need to study the potential of groundwater replenishment programs. The injection of treated water or wastewater into an aquifer is a method to protect this resource for current and future generations. Health concerns would be expected since migration of water of “impaired quality” can affect the drinking water by contamination. Regulatory barriers resulting from the perceived risks of adverse health effects from pathogens such as viruses have limited the concept of this impaired water resources from being used for groundwater replenishment programs. The objective of this study is to examine the risk assessment using computational modeling with MODFLOW and MT3D groundwater transport simulation. The results from the simulation showed that after two years, the risk of contamination based on concentration contours from the injection well to the production wellfields for the City of Hollywood stabilized below 10- 6. The risk assessment provided important aspect to demonstrate the concept of using injection of treated water as an option for groundwater replenishment. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
156

Teores de elementos potencialmente tóxicos em solos de uma bacia hidrográfica e avaliação de risco à saúde humana / Watershed soils contents of potentially toxics elements in soils from an watershed and human health risk assessment

Evandro Barbosa da Silva 23 April 2013 (has links)
A contaminação dos solos por elementos potencialmente tóxicos (EPTs) provoca alterações na estrutura e no funcionamento dos ecossistemas, além de oferecer riscos à saúde pública. Os EPTs estão presentes naturalmente no ambiente, sendo constituintes de rochas e sedimentos. Entretanto, atividades antropogênicas como emissões industriais, uso de efluentes urbanos, dejetos de animais, biossólidos, fertilizantes e defensivos agrícolas podem contribuir para aumento da concentração dos EPTs. O solo é um dos principais meios de exposição dos EPTs aos seres humanos. Logo, é importante quantificar os teores dos EPTs nos solos e sua distribuição na microbacia para poder avaliar o risco a saúde humana. Os efeitos dos elementos tóxicos que chegam ao solo sobre a diversidade e funcionalidade da biota podem ser avaliados por meio de testes ecotoxicológicos. Alguns organismos são bons indicadores ambientais por participarem de processos biológicos importantes do solo. Os principais organismos utilizados são os colêmbolos, artrópodes terrestres com alta diversidade e abundância, sendo encontrado em todos os biomas. Nesse estudo, quantificaram-se os teores de Arsênio (As), Cádmio (Cd), Cobalto (Co), Cobre (Cu), Cromo (Cr), Chumbo (Pb), Níquel (Ni) e Zinco (Zn) em amostras de 15 solos da microbacia do Rio Guamium, localizada em Piracicaba, São Paulo. Foi realizado experimento em casa de vegetação com alface (Lactuca sativa L.), pepino (Cucumis sativus L.), beterraba (Beta vulgaris L.) e rúcula (Eruca sativus Mill.) para avaliar o risco a saúde humana. Foi avaliado também o efeito da aplicação de doses de As na reprodução dos colêmbolos. Para tanto, foram coletadas amostras de solos nas profundidades 0 - 0,1; 0,1 - 0,2; 0,2 - 0,3; 0,3 - 0,4; 0,4 - 0,6; 0,6 - 0,9 e 0,9 - 1,2 m. Foi realizada a extração dos EPTs pelo método EPA 3051a (0,5 g de solo + 9 ml HNO3 + 3 ml HCl com digestão assistida por forno microondas). Os EPTs que apresentaram as maiores concentrações foram o As (3 pontos) e Cu (1 ponto), sendo as concentrações superiores ou iguais ao valor de prevenção estabelecido pelo órgão ambiental paulista (Cetesb). O As apresentou elevado risco carcinogênico, enquanto o Cu apresentou risco à saúde humana apenas quando 100 % dos vegetais consumidos eram provenientes da área com elevado teor de Cu, sendo este o cenário mais restritivo. Houve diferença na disponibilidade de As entre o solo natural e o solo artificial tropical (SAT), composto por areia, caulinita e pó de fibra de coco. O SAT apresentou alta disponibilidade de As o que reduziu a taxa de reprodução dos colêmbolos. No SAT a LOEC (Lowest Observed Effect Concentration) foi 0,25 mg kg-1 e a NOEC (No Observed Effect Concentration) < 0,25 mg kg-1. No solo natural não foi possível determinar a NOEC, enquanto a LOEC foi 8,41 mg kg-1. / Soil contamination by potential toxics elements (PTEs) can change the ecosystem structure, its function and can cause risk to human health. PTEs occur naturally in the environment; however human activities such as industrial emissions, urban sewage, animal waste, biosolids, fertilizers and pesticides can increase their concentration. Soil is one of the main pathways to human exposure, so it is important to evaluate the contents of PTEs in soils and their distribution in the watershed in order to assess the human health risk. The effects of PTEs that reach the soil on the diversity and functionality of microorganisms can be evaluated by ecotoxicological tests. Organisms that take part of the biological process can be used as environment quality indicators. One of them is the springtails (Collembola) that are wide spread and have high diversity, being found in all ecosystems. In this study, we evaluated the Arsenic (As), Cadmium (Cd), Cobalt (Co), Copper (Cu), Chromium (Cr), Lead (Pb), Nickel (Ni) and Zinc (Zn) contents in 15 soil from Guamium watershed, located in Piracicaba, state of Sao Paulo, Brazil. To assess the human health risk lettuce (Lactuca sativa L.), cucumber (Cucumis sativus L.), sugar beet (Beta vulgaris L.) and rocket (Eruca sativus Mill.) were cultivated under greenhouse conditions. The effect of As rates on collembola reproduction was also evaluated. Soil samples were collected in the following depths: 0 - 0.1; 0.1 - 0.2; 0.2 - 0.3; 0.3 - 0.4; 0.4 - 0.6; 0.6 - 0.9 e 0.9 - 1.2 m. Contents of PTEs were obtained after microwave extraction by EPA 3051a method (0.5 g soil + 9 mL HNO3 + 3 mL HCl). As and Cu had the highest contents, and their concentration were close or higher than prevention value established by Sao Paulo state environmental agency (Cetesb). As showed high carcinogenic risk, otherwise Cu only represented risk to human health in the most restrictive scenario, when 100% of the vegetables consumed were taken from the contaminated area. There was difference in the As availability between natural soil and artificial soil (ArtS) which was composed by sand, Kaolinite and powdered coconut fiber. As availability was high in the ArtS and it decreased the collembola reproduction. The Lowest Observed Effect Concentration (LOEC) on SAT were 0.25 mg kg-1, while and the No Observed Effect Concentration (LOEC) were less than 0.25 mg kg-1. Otherwise, the LOEC were 8.41 mg kg-1 in the natural soil, but it was not possible to define the NOEC.
157

Evaluation de l'exposition humaine liée aux activités pétrolières en Equateur : de la surveillance de la qualité de l'air à l'étude du transfert des contaminants métalliques dans le continuum sol-plante / Human exposure assessment related to oil activities in Ecuador : from the air quality monitoring to the study of metallic contaminants transfer in the soil-plant continuum

Barraza Castelo, Fiorella 13 October 2017 (has links)
L'Équateur est le 5ème pays producteur de pétrole en Amérique du Sud. Les étapes d'extraction et de raffinage génèrent des déchets contentant des métaux co-émis avec les hydrocarbures aromatiques polycycliques (HAPs), connus pour leurs effets cancérogènes et toxiques chez l'homme. Dans ce contexte et dans le cadre du programme ANR MONOIL, le premier objectif de cette thèse était de déterminer la distribution des métaux dans l'environnement sur les provinces d'Orellana et Sucumbíos (zones d'extraction du pétrole en Amazonie, " NAR ") et dans la ville d'Esmeraldas (raffinerie, sur la côte Pacifique," NPC "). Le 2ème objectif était d'étudier le transfert des métaux depuis le sol ou l'air vers les cacaoyers, largement cultivés en Equateur, et d'en déterminer les impacts sur la santé après ingestion. Enfin, le 3ème objectif était de surveiller la qualité de l'air (PM10) afin d'évaluer l'impact des activités anthropiques et le potentiel oxydatif des particules. Des sols et des cultures ont été collectés dans 31 fermes entre 2014 et 2016. Des échantillons d'air ont été prélevés mensuellement sur 3 sites, à proximité des plateformes pétrolières et de la raffinerie. La composition chimique (teneurs en métaux, carbone organique et élémentaire, ions, sucres, polyols, HAPs) a été déterminée dans les PM10. L'évaluation des risques sanitaires a été réalisée via 3 voies d'exposition. Les effets non cancérogènes et cancérogènes ont été quantifiés à l'aide de l'Indice de Risque (HI) et du Risque Total de Cancer (TCR). La bioaccessibilité du Cd par ingestion a été déterminée avec le test BARGE dans les pâtes et fèves de cacao. La formation d'espèces réactives de l'oxygène (ROS) a été quantifiée par spectrophotométrie en utilisant 3 essais acellulaires: DTT, AA et DCFH. Les résultats montrent que dans 72% des sites, les concentrations en Ba, Co, Cu, Cr, Ni, V et Zn dans les sols dépassent les limites de la législation équatorienne. Pour la plupart des cultures, les concentrations en métaux sont inférieures aux limites de détection, sauf pour le Cd dans le cacao et le Pb dans le manioc, qui dérogent aux normes de qualité alimentaire. Les cacaoyers accumulent le Cd dans les feuilles, les cabosses et les fèves. Comme la teneur en Cd du pétrole est inférieure à la limite de détection, les produits agrochimiques et les intrants organiques peuvent être incriminés. Près de 100% de la teneur totale en Cd dans les pâtes et fèves de cacao est bioaccessible par ingestion. Le risque pour la santé après consommation de chocolat oscille entre faible et élevé, selon la quantité ingérée. Dans les PM10, le Ba et le Mo, traceurs spécifiques des activités pétrolières, ont montré des valeurs beaucoup plus élevées que celles enregistrées dans les sites industriels. Les ratios OC/EC étaient plus élevés en Amazonie, suggérant des émissions biogéniques plus importantes. La teneur en HAPs est plus élevée sur la côte, cependant les niveaux de BaP étaient inférieurs aux limites de l'UE. Les résultats du potentiel oxydatif ont montré que les composés émis par l'industrie pétrolière (HAPs, Ba, Ni, Zn), par la combustion de la biomasse (sucres) dans le NAR ainsi que les traceurs industriels dans le NPC (As, Ba, Ni, NH4+) corrèlent avec la génération de ROS. Les principales voies d'exposition aux métaux sont l'ingestion et l'inhalation et, dans une moindre mesure, le contact dermique avec le sol. Les enfants tout comme les adultes sont vulnérables aux effets toxiques de ces composés. Enfin, d'autres facteurs comme la déforestation, l'agriculture et les émissions naturelles (volcans) dans le NAR mais aussi les industries dans le NPC contribuent également aux dégâts environnementaux constatés et aux effets néfastes sur la santé. / Ecuador is the 5th crude oil producer country in South America. Oil extraction and refining generate toxic waste containing metals co-emitted with polycyclic aromatic hydrocarbons (PAHs), naturally present in crude oil or added during production, and known for their carcinogenic and toxic effects in humans. In this context and as a part of the ANR MONOIL program, the first aim of this PhD research was to determine the distribution of metal(loid)s in the environment in the provinces of Orellana and Sucumbíos (oil extraction, North Amazon " NAR ") and the city of Esmeraldas (oil refining, North Pacific Coast, " NPC "). The second aim was to determine if there was a transfer of toxic metals, such as Cd, from soil or air to cacao crops, widely cultivated in Ecuador, and if the consumption of cacao-based products could imply risks for human health. Finally, the third aim was to monitor air quality over 2 years in both areas to assess the impact of anthropogenic activities and the oxidative burden of particulate matter (PM10). Soils and local crops were collected in 31 small-scale farms, between 2014 and 2016. Monthly PM10 samples were collected in 3 sites, in the vicinity of oil platforms close to the refinery. PM10 chemical composition (contents in metals, organic and elementary carbon (OC, EC), ions, sugars, polyols, PAHs) was determined. Human health risk assessment was performed taking into account ingestion, inhalation and dermal contact. Non carcinogenic and carcinogenic effects were quantified using the Hazard Index (HI) and the Total Cancer Risk (TCR). Bioaccessibility of Cd after ingestion was determined by the BARGE in vitro test in cacao beans and liquors. In aerosols, reactive oxygen species (ROS) formation was quantified using 3 acellular assays: DTT (dithiothreitol), AA (ascorbic acid) and DCFH (2',7'-dichlorodihydrofluorescein). Ba, Co, Cu, Cr, Ni, V and Zn concentrations in 72% of the study soils exceeded the limits of the Ecuadorian legislation. For most of the crops, elements were below the limits of detection but, Cd in cacao and Pb in manioc were above the international standards for food quality. Cacao trees accumulate Cd in leaves, pod husks and beans. Because Cd contents in crude oil were below the detection limits, agrochemical products and natural inputs may also be important sources. Almost 100% of the total Cd content in cacao beans and liquor was bioaccessible by ingestion. The health risk after chocolate consumption was low to high, depending on the ingestion rate and the cacao liquor percentage. In PM10, As, Cd, Ni and Pb were below the EU thresholds. However, Ba and Mo, specific tracers of oil activities, used as weighting agents or catalyzers during drilling and refining, showed values much higher than those recorded in other urban-industrialized sites. PM10 composition depended on oil activity. OC/EC ratios were higher in the NAR (oil extraction) than in the NPC (oil refining), suggesting that biogenic emissions were more important in the Amazon area. PAHs contents were higher in the NPC, but levels of benzo-a-pyrene were below the EU limits. Oxidative potential results showed that compounds emitted by oil industry (PAHs, Ba, Ni, Zn) and by biomass burning (sugars) in the NAR as well as industrial tracers in the NPC (As, Ba, Ni, NH4+) were correlated with ROS generation. Regarding residential exposure, the main routes of exposure to metal(loid)s were first ingestion, inhalation and in a small extent soil dermal contact, being both children and adults vulnerable. Finally, the oil Ecuadorian environment is not only contaminated by oil activities. Other factors like deforestation, agriculture and natural emissions (volcanos) in the NAR and industries in the NPC also contribute to environmental damages and may lead to adverse health effects.
158

Disinfection by-products and public health concerns

McAuley, Kimberley January 2009 (has links)
Disinfection by-products (DBPs) are a major group of water contaminants and their role in causing adverse health outcomes, including adverse pregnancy outcomes, endocrine disruption, respiratory related adverse health outcomes and cancer has been subject to extensive epidemiological and toxicological research and review. Determination of safe exposure to DBPs, particularly within drinking water supplies, has been a topic of extensive debate, with a wide range of acceptable levels set across the industrialized world. The focus of the research in this thesis was on two of the main health outcomes associated with DBP exposure, namely adverse pregnancy outcomes and asthma related symptoms. To assess adverse pregnancy outcomes in Perth, an extensive classification quantification of the major DBPs in Perth drinking water was conducted. A registrybased prevalence study was carried out to assess birth defects in relation to high, medium and low DBP areas (defined by the water sampling and analysis). It was found that women living in high THM areas are 22% (odds ratio (OR) 1.22, 95% confidence interval (95% CI) 1.01-1.48) more likely of having a baby with any birth defect. High exposure was also strongly associated with an increased risk of having a baby with a cardiovascular defect (62% increased risk). Low birth weight and prematurity were also assessed; however these outcomes were not associated with an increased risk through an increase in exposure. Following on from this analysis, a population risk assessment model was developed for DBPs in high exposure environments. This involved a three step process: (i) Firstly a questionnaire-based validation and reliability study was used to assess water consumption patterns of a population of pregnant women in Perth. (ii) Secondly a prediction model for teratogenic burden of DBPs in Perth was developed, related to the exposure patterns of the population of pregnant women involved in the validation and reliability study. (iii) Finally, combining the information collected in (i) and (ii), along with the regression slope estimates for birth weight from the prevalence study (defined in Section 2.2.1), a dose-response model for THMs and birth weight was developed. Predictive simulations for birth weights at given THM levels were then conducted. It was estimated that pregnant women in Perth are exposed to between 0.3 – 4.10 µg/day ingested TTHM, and of this, the more toxic brominated forms accounted for between 0.27 – 3.69 µg/day. Based on a dose-response model used, birthweights calculated for the ‘hypothetical’ exposures ranged from 3403.2g for the highest exposure to 3503.5g in the lowest exposure, which is a difference of over 100g. Although the resulting reduction in birth weight is not extreme, there is still a significant reduction in birth weight present as exposure to TTHMs increases. This is the first doseresponse model to be developed to assess an adverse pregnancy outcome based on pregnant women exposure data, and will be a useful tool for assessing varying exposures throughout not only Australia but also throughout the industrialised world, where DBP exposure is highly prevalent.
159

Toward the development of screening tests for heart attacks and back injuries in firefighters : a study to investigate back-specific fitness, perceived fitness and aerobic capacity in a firefighter population

Moore, Karlie J. 05 December 2012 (has links)
Firefighting is a very hazardous profession. Firefighters experience an injury rate that is three times higher than other physically demanding professions and the death rate in the fire service is also much higher compared to typical. Throughout the literature, data suggest the physical nature of firefighting contributes to the high incidence of injury and death among firefighters. As such, special interest groups and firefighting organizations advocate for firefighters to exercise and stay fit in order to safeguard their physical health. Yet, despite these efforts, firefighters still experience a very high incidence of back injuries and heart attacks which can lead to early retirement from disability or death. In the first aim of this dissertation, we examined the relationships between specific back fitness tests and history of back injuries in 113 firefighters in an effort to understand which fitness tests may aid in screening firefighters for risk of back injury. We found that a test of lumbar extension flexibility was associated with a higher incidence of back injuries among our sample (p<0.01). In the second aim of the study, we investigated whether perceived fitness was related to history of back injuries since firefighters’ perceptions of their fitness level may direct how they choose to perform job tasks that pose high risk for injury. Within the same sample of firefighters, we found that perceived fitness was not related to history of back injuries nor was the relationship between actual fitness and history of back injuries mediated by perceived fitness. However, perceived fitness correlated with scores on our back strength (r=0.28; p=0.003) and hamstring strength (r=0.21; p=0.03) tests. In the third aim of the dissertation, we sought to develop a treadmill walking protocol to screen firefighters for low aerobic capacity which is a major risk factor for heart attack. Thirty-eight male firefighters wore a vest weighing 20% of their body weight and performed a walking VO2max test in which the treadmill grade increased by 1% each minute. The predicted VO2max from this walking test was very accurate; within a standard error of the estimate of 3.2 ml/kg/min. This new (Moore) protocol requires only a standard treadmill and is more job specific than a running test. In conclusion, more research needs to be conducted to understand how firefighters’ perceived fitness directs their behaviors when performing job tasks and how high levels of fitness can protect against back injuries and heart attacks in firefighters. This dissertation has contributed to the development of screening protocols to aid in preventing these adverse events. / Graduation date: 2013
160

Study of coliform bacteria in Canadian pulp and paper mill water systems : their ecology and utility as health hazard indicators

Gauthier, Francis. January 2000 (has links)
Coliform bacteria have long been used to indicate fecal contamination of food, water, and solid surfaces, and thus the presence of a health hazard. In this study, the in-mill water and external effluent treatment systems of seven typical Canadian pulp and paper mills were shown to support the growth of numerous coliforms, especially Klebsiella spp, Escherichia coli, Enterobacter spp., and Citrobacter spp . Mill coliforms were shown to be not just simple transients from feedwater or furnish (wood), but to be continuously growing, especially in the primary clarifiers. Therefore, coliforms and fecal coliforms cannot be used as fecal contamination indicators in pulp and paper mill water and effluent treatment systems. / N2-fixing coliform populations were detected in mill water systems and were analyzed using N2-fixation assays and nitrogenase gene (nifH) probing. Both active in situ populations and cultured microbial isolates were tested. Active N2-fixation was demonstrated in six primary clarifiers. Measurement of the numbers and composition of the total culturable bacterial community in a primary clarifier revealed that approximately 50% of all aerobic cells contained nifH , of which >90% were Klebsiella. Coliforms growing on MacConkey agar plates from the primary clarifier were all identified as Klebsiella and 100% of these Klebsiella contained the nifH gene. Preliminary estimates indicate that the amount of N2 fixed per day is substantial in some clarifiers.

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