Dissertations / Theses on the topic 'Health risk assessment Victoria'

The purpose of the study was to conduct a community risk assessment of the city of Huntington Park, California by utilizing the Communities That Care model to identify the most concerning risk factors for delinquency and school dropout. Forty-seven indicators measuring 18 risk factors were gathered from public sources. Data from Huntington Park was compared to data from Los Angeles County and California. The risk factors of main concern for the community appeared to be transition and mobility, low neighborhood attachment and community disorganization, extreme economic deprivation, family management problems, academic failure beginning in elementary school, early and persistent antisocial behavior, friends who engage in the problem behavior and early initiation of the problem behavior. Efforts to reduce involvement in delinquency and school dropout should target the community, school and peer and individual domains. Suggestions for evidence-based programs and approaches to reduce the most salient risk factors are provided.

Real-world problems especially the ones that involve natural systems are complex and they are composed of many non-deterministic components. Uncertainties associated with these non-deterministic components may originate from randomness or from imprecision due to lack of information. Until recently, uncertainty, regardless of its nature or source has been treated by probability concepts. However, uncertainties associated with real-world systems are not limited to randomness. Imprecise, vague or incomplete information may better be represented by other mathematical tools, such as fuzzy set theory, possibility theory, belief functions, etc. New approaches which allow utilization of probability theory in combination with these new mathematical tools found applications in various engineering fields. Uncertainty modeling in human health risk assessment and groundwater resources management areas are investigated in this thesis. In the first part of this thesis two new approaches which utilize both probability theory and fuzzy set theory concepts to treat parameter uncertainties in carcinogenic risk assessment are proposed. As a result of these approaches fuzzy health risks are generated. For the fuzzy risk to be useful for practical purposes its acceptability with respect to compliance guideline has to be evaluated. A new fuzzy measure, the risk tolerance measure, is proposed for this purpose. The risk tolerance measure is a weighed average of the possibility and the necessity measures which are currently used for decision making purposes. In the second part of this thesis two decision making frameworks are proposed to determine the best groundwater resources management strategy in the Savannah region, Georgia. Groundwater resources management problems, especially ones in the coastal areas are complex and require treatment of various uncertain inputs. The first decision making framework proposed in this study is composed of a coupled simulation-optimization model followed by a fuzzy multi-objective decision making approach while the second framework includes a groundwater flow model in which the parameters of the flow equation are characterized by fuzzy numbers and a decision making approach which utilizes the risk tolerance measure proposed in the first part of this thesis.

[Truncated abstract] The aim of the research was to explore the association between wrist guard use and wrist fracture risk in snowboarders in Australia. During the study, the opportunity was also taken to examine the relationship between wearing wrist guards and the severity of wrist and elbow injury. A case-control study was conducted at the Mount Buller Medical Centre, Victoria, Australia. A total of 494 participants was recruited during the 2004 and 2005 ski seasons. Cases were defined as any snowboarder seen at the Clinic with a fractured wrist (N = 119), and controls as any snowboarder seen at the clinic for any reasons other than a fractured wrist (N = 375). Severity of forearm injuries were defined and analysed separately. Study participants completed a questionnaire consisting of: basic demographics (age and sex only); wrist guard use on the day of presentation; normal use of protective equipment; the number of days spent snowboarding that season; the ability of the snowboarder; and ski run difficulty. Risk taking behaviour was assessed by a history of any previous fracture or joint injury and psychometric questions. Clinic medical staff recorded site and severity of fractures and soft tissue injuries. Logistic regression was used to obtain adjusted odds ratios for these risk factors against the main outcome measure. Presence of wrist fracture and injury in snowboarders with and without wrist guards. ... There was a significant association between wrist guard use and soft tissue elbow injuries (adjusted odds ratio = 17.6, p = 0.011, 95% CI: 1.93 – 160.2), but no significant association with elbow fractures (adjusted odds ratio = 1.84, p = 0.385, 95% CI: 0.46 – 7.30). There was thus no evidence in this study that wrist guards increase the occurrence of other severe injuries in the forearm by transferring the impact force away from the protected wrist up the arm. No evidence was found for compensatory risk taking behaviour in participants wearing protective equipment. A local injury prevention strategy was implemented in schools in the Mt Buller district during the course of this study. Education about the protective effects of wrist guards enabled a policy change in the local secondary college so that wrist guard use is now mandatory for all snowboarders in the school ski programme: That policy states:

This thesis analyses heat health risk spatially in Birmingham (UK) via a combination of remote sensing and GIS techniques, including urban influences which are not generally considered in heat risk assessments or climate change projections. The world’s urban population is growing rapidly, and the risk of extreme heat to human health has been highlighted by recent events such as the 2003 heatwave in Europe, where mortality rates significantly increased. This thesis presents a methodology using satellite data to quantify the surface urban heat island of Birmingham at 1 km resolution, with results showing extreme events are much warmer (\(\sim\)5°C) than average conditions (\(\sim\)2°C). This urban heat island data is combined with social data in a spatial risk assessment, illustrating that many vulnerable people live in areas of increased heat risk. A custom collection of ground based sensors is utilised to investigate the relationship between surface and air temperatures, finding air temperatures are warmer than LST measurements at night. Then UK Climate Projections 2009 are used to explore the influence of the urban heat island on climate projections in Birmingham, showing that changes could be large (90% increase in minimum temperature under 2080s extreme scenarios).

Mental-health risk assessment practice in the UK is mainly paper-based, with little standardisation in the tools that are used across the Services. The tools that are available tend to rely on minimal sets of items and unsophisticated scoring methods to identify at-risk individuals. This means the reasoning by which an outcome has been determined remains uncertain. Consequently, there is little provision for: including the patient as an active party in the assessment process, identifying underlying causes of risk, and eecting shared decision-making. This thesis develops a tool-chain for the formulation and deployment of a computerised clinical decision support system for mental-health risk assessment. The resultant tool, GRiST, will be based on consensual domain expert knowledge that will be validated as part of the research, and will incorporate a proven psychological model of classication for risk computation. GRiST will have an ambitious remit of being a platform that can be used over the Internet, by both the clinician and the layperson, in multiple settings, and in the assessment of patients with varying demographics. Flexibility will therefore be a guiding principle in the development of the platform, to the extent that GRiST will present an assessment environment that is tailored to the circumstances in which it nds itself. XML and XSLT will be the key technologies that help deliver this exibility.

The continued rise in accident and ill health statistics throughout the member states of the European Union indicate that the standards of occupational health, safety and environmental control require further improvement to minimise the current level of loss. Management systems are regarded as an effective means of reducing this loss by continuously improving standards. Whilst there is much discussion and debate about the possibilities of integrating management systems, at present, there are no national or international published integrated management standards, although some multi-national companies have introduced their own internal integrated standards. The research explored the development of an integrated health, safety and environmental (HSE) management system within a range of industrial organisations. This included the development of tools for successful implementation of integrated systems, specifically for significance review, risk assessment and auditing. Resources and accreditation constraints precluded exhaustive testing of all clauses within the proposed integrated management standard. However, analysis of key aspects of the standard revealed: 1. The introduction and use of separate health, safety and environmental (HSE) management systems improved the standards of risk control within organisations. 2. Organisations perceived that there were clear business advantages in some form of integration of existing standards. 3. The developed integrated HSE standard was technically possible in the area of policy development, process operations, working instructions and documentation. However, the integration of risk assessment and audit tools gave limited advantages compared to existing separate systems. 4. The proposed integrated HSE standard complied with both individual European member states national legislative requirements and European/World-wide management standard criteria. In summary this thesis represents an original contribution to the field of integrated management systems. The thesis also identifies areas of further work that will increase the knowledge base, scope of application of the work carried out.

Lyme disease (LD) is emerging as one of the major global health challenges of the 21st century. Although data on the diagnosis and treatment of LD is available, research focusing on people's perceptions of LD appears to be limited. Because individual perceptions can significantly affect compliance with preventative measures, such data are critical for the design and successful implementation of interventions to control the disease. The purpose of this qualitative phenomenological study was to explore risk perceptions and knowledge of LD among residents of a county in the U.S. state of New Jersey where the disease is prevalent. The health belief model and the social ecological model served as the theoretical foundation for the study. Research questions centered on the perceptions of the study participants regarding their risk of contracting LD and the factors that may influence or interfere with preventive behaviors against ticks. A convenience sample of 11 individuals, aged 18–55 years, participated in a focus group discussion. Data were analyzed using thematic analysis and participant responses revealed that information dissemination methods regarding LD were ineffective. Participants believed that lack of knowledge on LD was the main barrier to protective behaviors. Participants who perceived no risk from LD reported that they were not taking preventive measures against tick bites. Dissemination of study results through presentations to public health departments and LD organizations in New Jersey may benefit the public health sector by furthering understanding of the public's risk perceptions and knowledge about LD. Positive social change implications include increased awareness of LD and improved risk communications of the disease.

Background: The NHS Health Check, the largest systematic cardiovascular disease (CVD) primary prevention programme globally, aims to reduce CVD burden and health inequalities by assessing and managing CVD risk among 40 to 74 year old individuals without existing vascular diseases. I evaluated the impact of the programme at local and national levels. Methods: Using electronic medical record data from general practices in Hammersmith and Fulham, I assessed CVD risk factor recording before the programme, the programme uptake in the first two years and the impact of the programme on CVD risk. National coverage of the programme in one financial year was assessed using data from Primary Care Trusts (PCTs). Results: There was good recording of smoking status (86.1%) and blood pressure (82.5%), with lower BMI (59.5%) and cholesterol (47.5%) recording among Health Check eligible patients before the programme in Hammersmith and Fulham. Uptake of the Health Check was lower than the national target (75%) at 39.2% among patients with an estimated high CVD risk, but matched the national required rate at 20.0% among all remaining eligible patients. There was significant reduction in mean global CVD risk score (28.2% to 26.2%) after one year among patients with estimated high risk that had a complete Health Check. The programme uptake was higher in patients living in more deprived areas among those not at estimated high risk (adjusted odds ratio = 0.88 (0.73-106)). Mean national coverage of the programme was lower (8.1%) than anticipated (18%), with large PCT-level variation (0% to 29.8%). Coverage was significantly greater in PCTs in more deprived areas (coefficient = -0.51 (-1.88-0.00), p-value: 0.035). Conclusions: Population-wide impact of the NHS Health Check may be limited by poor uptake of the programme. This and other limitations to the programme suggest that a targeted screening approach along with population-wide strategies may be a better option for more cost-effective prevention of CVD.

The principal use of sodium monofluoroacetate (1080) in New Zealand is to control brushtail possums (Trichosurus vulpecula). Aerial application of baits containing 1080 is the most common method used for large-scale control of possums. The use of 1080 attracts a great deal of controversy, in particular the effects on the environmental, non-target species, and the potential chronic effects in humans associated with environmental exposures. Although the nature of the acute toxicity of 1080 has been known for more than fifty years, little is known of its effects on humans, in particular its chronic effects to environmental exposures. A benchmark dose (BMD) as an alternative to a no-observed-adverse-effect-level (NOAEL) approach was investigated as a means to improve current health risk assessment values of 1080. Both approaches were investigated for three critical toxicological end points, namely cardiomyopathy, testicular toxicity and teratogenic effects identified from the few available critical studies. The calculated BMDs and lower-bound confidence limits (BMDLs) for the three end points were estimated using the Weibull, probit and quanntal linear models. A benchmark response (BMR) of 10% (extra risk) was chosen and the Akaike�s information criterion (AIC) was used in selecting the appropriate model. The BMDL estimates derived were generally slightly higher but comparable to the corresponding NOAEL for those same endpoints. The computed BMD₁₀ and BMDL₁₀ for cardiomyopathy and testicular effects were 0.21 mg kg⁻�bw⁻� and 0.10 mg kg⁻�bw⁻�, respectively. Tolerable Daily Intakes (TDIs) were derived using the NOAEL approach and the BMD methodology and applying an uncertainty factor of 3000. The resulting TDI using the BMDL were generally consistently slightly higher than those derived using the NOAEL approach. Based on the best fit of modelled dose-response data, a TDI of 0.03 [mu]g kg⁻�bw⁻�day⁻� is proposed for human health risk assessment. Two sets of Provisional Maximum Acceptable Values (PMAV) were derived using the highest concentration of 4.0 [mu]g L⁻� 1080 found in water (N=1450), and using the maximum allowable concentration of 2.0 [mu]g L⁻� of 1080 in water for adults (0.58 [mu]g L⁻� and 0.94 [mu]g L⁻�, respectively) and children (0.23 [mu]g L⁻� and 0.4 [mu]g L⁻�, respectively). Parameters used in the derivation of PMAVs were average weight, average quantity of water consumed, and proportion of total intake allocated to drinking water. The derived adult PMAV of 0.60 [mu]g L⁻� is proposed in revising the PMAV for 1080 in the Drinking Water Standards New Zealand. This value is 6-fold lower than the current PMAV of 3.5 [mu]g L⁻�. Additional toxicology studies are recommended to meet the definition of a "complete database" and therefore estimating a more defensible TDI, and consequently a PMAV for 1080. Risk management approaches are consistent with the Ministry of Health�s current precautionary approach. A PMAV of 0.60 [mu]gL⁻� in drinking water is recommended to consider it suitable for human consumption and that continuous monitoring be carried if the level of 1080 exceeds 50% of the proposed PMAV as a requirement for Priority 2 determinands in the Drinking Water Standards. Precautionary approach appears to be warranted and this was supported by information provided by the Public Health Units (PHU) where 1080 was permitted to be dropped onto drinking water catchments. The PHUs exercised precautionary measures by imposing appropriate conditions to suit local circumstances. As 1080 may likely remain an essential tool to contain tuberculosis spread by possums and to reduce possum damage to forests and crops until better methods of control are developed, a number of recommendations were proposed to protect public health.

Human impact on groundwater resources has led to a rapid growth of social concerns worldwide owing to an increasing presence of toxic chemicals released in the subsurface. Risk assessment provides the scientific tool needed to quantify the actual thread that these potential hazards pose to human health. Specifically, risk analysis enables decision makers to answer: What can happen? How likely is it to happen? What can be the consequences? Risk assessment is in this context essential. However, modeling efforts involve in risk analysis are still facing several problems. Among them, in some cases, degradation products can constitute new noxious chemical compounds not necessarily less toxic than their parent product. Thus, the original pollutants and their daughter products are susceptible to co-exist in the aquifer forming a hazardous chemical mixture composed of products of different toxicity. This renders the quantification and interpretation of human health risk a non-trivial and challenging task. Also, the lack of information in the hydraulic and biochemical properties renders transport predictions to be highly uncertain. Stochastic human health risk assessment incorporates hydrogeological uncertainty in human health predictions. This way, probabilistic risk models can be used to determine the likelihood of risk exceeding a given regulatory threshold value or the expected threat to the exposed population and its uncertainty. Unfortunately, these approaches are very computationally demanding. Moreover, the diverse mineralogical composition of a real soil and the complex spatial variability of aquifer properties can produce a mixture of rates of mass transfer between regions of mobile and immobile contaminants. Finally, risk predictions are typically challenged by the complexity of the source zone condition. Existing reactive transport models based on Eulerian methods still undergo computational burden and numerical problems when modeling strong hydro-biochemical heterogeneities with complex reactions in multi-porosity systems. In this context, Particle Tracking Methods constitute a feasible alternative but these methods are limited in the range of applicability. The work presented in this thesis proposes an efficient particle tracking solution capable to simulate serial-parallel degradation reactions in multiple porosity systems with rate-limited mass transfer and strong heterogeneities. The method is then used to characterize the human health risk posed by chemical mixtures in highly heterogeneous porous media under complex source zone conditions. In particular, we investigate the interaction between aquifer heterogeneity, connectivity, contaminant injection mode and chemical toxicity in the probabilistic characterization of health risk. We illustrate how chemical-specific travel times control the regime of the expected risk and its corresponding uncertainties. Results indicate conditions where preferential flow paths can favor the reduction of the overall risk of the chemical mixture. The overall human risk response to aquifer connectivity is shown to be non-trivial for multi-species transport. This non-triviality is a result of the interaction between aquifer heterogeneity and chemical toxicity. To quantify the joint effect of connectivity and toxicity in health risk, we propose a toxicity-based Damköhler number. Results also show that the degradation capacity of immobile water regions and the mass depletion model can play a significant role on the spatiotemporal behavior of the contaminant mixture. Our work furthermore highlights the potential impact of the water flux passing through the source zone on the effective increased lifetime cancer risk due to a reactive chemical mixture. Counter-intuitively, the source zone efficiency is shown to have a beneficial effect on the risk. The total risk tends indeed to decrease for high source zone efficiency due to the consequential decrease in travel times near the source zone.
El impacto humano sobre los recursos hídricos que forman los acuíferos es actualmente una de las grandes preocupaciones sociales en crecimiento debido a la presencia antrópica cada vez mayor de productos químicos tóxicos liberados en el subsuelo. El análisis de riesgo proporciona la herramienta científica necesaria para cuantificar el peligro real que estos contaminantes suponen para la salud humana. En concreto, el análisis de riesgo permite tomar decisiones que respondan a las siguientes preguntas: Qué puede pasar?. Qué tan probable es que suceda? Cuál pueden ser las consecuencias?. El análisis de riesgo es una herramienta clave en este sentido. Sin embargo, los esfuerzos de modelación necesarios para llevar a cabo el análisis de riesgo se enfrentan con varios problemas. Entre ellos, algunos productos tóxicos de degradación pueden constituir nuevos compuestos químicos nocivos no necesariamente menos tóxico que su producto padre. Por lo tanto, los contaminantes originales y sus productos hijos son susceptibles de coexistir en los acuíferos formando una mezcla de compuestos químicos de diferente toxicidad. Esto hace que la cuantificación e interpretación del riesgo para la salud humana sea una tarea no trivial y desafiante. Por otra parte, la falta de informaci´on en las propiedades hidráulicas y bioquímicos hace que las predicciones sobre el comportamiento de dichos contaminantes en el subsuelo sean altamente inciertas. El análisis de riesgo estocástico incorpora de forma natural la incertidumbre hidrogeológica que existe en las predicciones de riesgo para la salud humana. De esta manera, estos modelos pueden ser utilizados para determinar la probabilidad de que el riesgo supere un valor umbral o el valor esperado del riesgo y su incertidumbre. Desafortunadamente, estos enfoques son muy exigentes en tiempo de cálculo. Además de estas dos problemáticas, también se tiene que tener en cuenta que la composición mineralógica de un suelo real es diversa y variable en el espacio. Muchas veces esto implica la transferencia de masa entre zonas de contaminantes móviles e inmóviles. Esto último exige modelos sofisticados de transporte que, por ejemplo, conceptualicen el medio poroso como un sistema multi-porosidad. Finalmente, la complejidad que existe en el comportamiento del foco de contaminación hace complicado un análisis de riesgo. Los líquidos tóxicos densos y no acuosos ilustran perfectamente esta complejidad. Una vez en el subsuelo, estos líquidos liberación lentamente los contaminantes dentro del acuífero de acuerdo con una tasa de agotamiento que depende fuertemente de la arquitectura errática del foco de contaminación. Los modelos de transporte reactivo eulerianos tienen problemas numéricos cuando se simulan fuertes heterogeneidades hidro-bioquímicos en el terreno al mismo tiempo que reacciones químicas complejas en sistemas multi-porosidad. En este contexto, los métodos de trayectorias de partículas constituyen una alternativa viable. Sin embargo, estos métodos pueden tener en cuenta un rango pequeño de reacciones químicas. El trabajo presentado en esta tesis propone una solución a estos problemas mediante un método de trayectoria de partículas. El método es eficiente y capaz de simular cadenas y redes de degradación en sistemas heterogéneos con porosidad múltiples. El método se basa en el desarrollo de probabilidades de transición que describen las probabilidades de que las partículas que pertenecen a un estado determinado (producto químico y región móvil / inmóvil) en un momento dado se transformará en otro estado en un momento posterior. El método se utiliza para caracterizar el riesgo para la salud humana que representan las mezclas de degradación en medios porosos altamente heterogéneos derivados de focos de contaminación complejos. En particular, se investiga la interacción entre la heterogeneidad, la conectividad, el modo de inyección de los contaminantes y su toxicidad química con respecto a la caracterización probabilística del riesgo para la salud humana. Los resultados indican las condiciones mediante las cuales las vías de flujo preferencial pueden favorecer la reducción del riesgo para la salud humana. La dependencia de la conectividad con el riego se demuestra que no es nada trivial cuando se trata de mezclas de compuestos químicos. Esta no trivialidad es el resultado de la interacción entre la heterogeneidad del acuífero y la toxicidad de los compuestos químicos. Para cuantificar el efecto conjunto de la conectividad y la toxicidad en el riesgo para la salud, se propone un número de Damköhler nuevo que tiene en cuenta la toxicidad. Además, el riesgo también se caracteriza en términos estadísticos mediante momentos de bajo orden y funciones de densidad de probabilidad. Los resultados también muestran que tanto la capacidad de degradación de zonas inmóviles como los modelos existentes de agotamiento del foco pueden desempeñar un papel muy significativo en el análisis espacio-temporal del riesgo. Este trabajo también muestra que la eficiencia del foco de contaminación para concentrar el flujo puede tener un efecto beneficioso sobre el riesgo. El riesgo total de hecho tiende a disminuir para eficiencias grandes debido a la disminución consecuente en tiempos de viaje cerca del foco de contaminación, limitando la producción de productos de degradación más tóxicos.

Multiple studies have indicated a higher burden of overweight/obesity and exposure to environmental toxins, such as alcohol and tobacco smoke, in association with higher prevalence of cardiovascular disease (CVD) in the African American population. Thus, the purpose of this research was to determine if there was a significant difference in the use of lifestyle adjustments such as moderating alcohol consumption, weight loss, and smoking cessation on the prevalence of CVD in the African American population. The theoretical foundation was social cognitive theory and the social ecological model that posits the interplay of individual, social, and environmental factors. This cross-sectional quantitative study was designed to assess the effects of lifestyle adjustments of weight loss, moderating alcohol consumption, and smoking cessation in the prevalence of CVD in African Americans between 40 and 60 years of age. Analysis of secondary data from the National Health and Nutrition Examination survey for the years 2013-2014 was conducted using binary logistic regression. The findings showed no significant difference in the use of weight loss, moderating alcohol consumption, and smoking cessation in the prevalence of CVD in African Americans between 40 and 60 years of age. However, the odds of moderate alcohol consumption and weight loss were greater than 1. Thus, this study may have a small potential impact on CVD in African Americans by encouraging lifestyle adjustments, and may contribute to positive social change by increasing life expectancy, improving quality of life, and reducing the burden of certain chronic diseases and reduction of healthcare cost.

Biosolids are valuable products which can be beneficially used in land application. However, the possibility of serious health effects on humans due to several pollutants in biosolids creates a big concern. To address this issue, risk-based methodologies are commonly used to evaluate health effects associated with the land application of biosolids. This study aims to investigate the health risks associated with ingestion of biosolids or soil mixed with biosolids by a child. This study is the first health risk assessment study in Turkey for land application of biosolids. Monthly sludge samples taken from Ankara Central Wastewater Treatment Plant (ACWWTP) in 2012 were analyzed for seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn), and two organic contaminants (PCB and NPE) concentrations. To calculate health risks, methodologies developed by U.S. Environmental Protection Agency (U.S. EPA) and French National Institute for Industrial Environment and Risks (INERIS) were used. With both methods, cancer and non-cancer risks for the ingestion by a child pathway were determined and found to be below the acceptable cancer and non-cancer risk levels suggested by U.S. EPA and INERIS. Additionally, same health risk calculations were conducted for sludge and soil limit values provided in Turkish Regulation for the Use of Sewage Sludge in Agriculture (2010) to determine what the maximum health risk would be for the worst case scenario in Turkey. According to the results, even if the concentrations are at the maximum possible regulatory levels, the health risks are still low.

The linkage between arsenic contaminated water and increased cancer risk is well recognized. The potential health risk posed by separate inorganic and organic arsenic species through combined exposure to arsenic contaminated water and staple foods is not well understood though. Therefore, this research aims to improve arsenic risk assessment by investigating the primary exposure sources, pathways, metabolism and response indicators in an integrated manner. The population based water and food consumption pattern characterised by this research was used to validate the cancer risk modelling which demonstrated that using water or food intake values from the developed world may not represent cancer risks to the specific population in question. Integrating this characterisation with arsenic species provided several key insights. Arsenate was identified as the main species in the ground water aquifers of five villages whilst the predominance of arsenite and its co-existence with arsenate in one village indicated variations in aquifer redox conditions. Wheat cultivated with arsenic-rich irrigation water proved to be an alternate exposure pathway of inorganic arsenic. The species specific probabilistic cancer and non-cancer risks were found to be higher for arsenite followed by arsenate, whilst no risk was found for dimethylarsinic acid of dietary origin. The comparative impact of various reference doses on chronic health risk substantiated that children are at higher vulnerability, whilst using population based exposure characteristics of this study population and relative risk estimates from southwest Taiwan, showed females to be at higher risk of life time bladder and lung cancer due to inorganic arsenic. No risk was associated with low doses of arsenic. Total ingested arsenic from water or food under the effect of certain potential modifiers was a significant predictor of arsenic species in human biomarkers and proved toenail to be a comparatively effective biomarker. At low arsenic levels in water, food associated total arsenic was a better predictor of urinary metabolites. The total arsenic intake from water and urinary metabolites under the effect of labour jobs strongly predicted the increased risk of arsenical skin lesions. Probabilistic risk modelling indicated that persons with skin lesions were at higher risk of transformation of skin lesions into skin cancer, also evidenced with their lower methylation capability. Overall, this thesis provides evidence that species based risk assessment requires a greater understanding of exposure matrix, toxicological thresholds and metabolic reactions from ingestion to potential endpoints. This study has provided a baseline of inorganic arsenic for risk management to set public health water supply goals and to minimize the daily consumption of cooked rice for compliance with the safe arsenic limit. The findings are suitable to support future regulatory processes for species based arsenic limits in water together with staple foods.

In assessing human health risk of potentially toxic elements (PTEs), it is not the concentration of PTEs in the environmental matrices that is of greatest concern but the fraction that is absorbed into the body via the exposure pathways. The determination of this fraction (i.e. the bioaccessible fraction) through the application of bioaccessibility protocols is the focus of this work. The study investigated human health risk of PTEs (As, Cd, Cr, Cu, Pb, Mn, Ni and Zn) from oral ingestion of soil / dust, inhalation of urban street dust and air-borne dust (PM10). To assess health risk via oral ingestion of soil and dust, total PTEs were determined in twenty nine soil samples collected from children’s playing fields and ninety urban street dusts collected from six cities. Analysis of total PTE content in these samples via ICP-MS revealed high Pb concentrations (> 450 mg/kg) in 3 playground soils and 32 urban street dusts. Detailed quantitative risk assessment (DQRA) carried out in the playgrounds showed that no significant possibility of significant harm exist in the playgrounds. The concentration of Pb from a particular dust sample based on 50 mg/day ingestion rate that a child might possibly ingest to reach the estimated tolerable daily intake was calculated and it exceeded the tolerable daily intake for oral ingestion in 4 cities. The bioaccessible PTEs were determined both in the soil and dust samples using the Unified BARGE method and the result showed that in all the samples, the PTEs solubilised more in the gastric phase than in the intestinal phase. A new method has been developed; simulated epithelial lung fluid (SELF) and was used to assess the respiratory bioaccessibility of Pb from inhalable urban dust (<10 µm). Low bioaccessibility (<10 %) was recorded in all the samples analysed.

Background: HIV is increasingly prevalent among youth in the US. Objective: To assess the impact of HIV/AIDS education on health-risk behaviors associated with HIV infection in the state of Georgia. Methods: Descriptive analyses of the 2005 Georgia Student Health Survey were conducted by cross-tabulating the presence of HIV/AIDS education and each of the health-risk behaviors of interest. In addition, a survey with a sample of metro Atlanta health educators that assessed ASK US was conducted and analyzed. Results: The percentage of Georgia high school students that had ever been taught about AIDS or HIV infection in school was 91.8% (n = 1,547).The only self-reported risk factor that appeared to have a relationship with HIV/AIDS education was binge drinking (p = 0.0060). Results of the health educator survey demonstrated that ASK US is a good HIV/AIDS education tool. Conclusions: Although HIV/AIDS education is widespread, the prevalence of various health-risk behaviors remain high and, therefore, different models of HIV/AIDS education may be called for.

碩士
臺北市立教育大學
環境教育與資源研究所環境資源組
95
The risk of chlorinated volatile organic compounds (VOCs) resulting pollution in the neighborhood of contaminated sites is high and the pollution is difficult to be remediation. Therefore, how to use limited resource for site remediation and achieve the balance between environmental protection and economical development are very important. Thus, the chlorinated VOCs pollution is an important issue that needs to be thoroughly discussed. It also reveals the importance of the application of health risk assessment in its pollution remediation. In this research, a chlorinated VOCs polluting site was assessed by using the “Health Risk Assessment Analogous System (HRAAS)” developed by Environmental Protection Administration (EPA) to evaluate the human health risk and calculate the life-time excess cancer rate（CR） and the hazard index（HI） in the neighborhood. Base on the monitoring data which were proceeded by the study site, the different assessment levels of simulation analysis inside and outside the site show that both carcinogenic risk and non-carcinogenic risk have similar trend. The carcinogenic risk value is between 10-1~10-2 and the non-carcinogenic risk value is between 10~104 in the selected site. The outside the polluted site, carcinogenic risk value is between 10-2~10-4 and the non-carcinogenic risk value is between 1~10. The results above show that the carcinogenic risk value is over 10-6 and the non-carcinogenic risk value is above 1 for both inside and outside of the study site. In the uncertainty analysis, the total health risk obtained from various exposure pathways should be over estimated. The inhalation exposure resulted from the usage of in-site polluted groundwater is the main one. Out of the pollution site, drinking is the main exposure factor. Thus, both pathways should be noticed in the following evaluation and analysis. Skin contact only accounts for 2% of the total risk value but still surpasses the first and second level of the carcinogenic risk. Further study should be done in the evaluation of its pathway or barrier. In the sensitivity analysis of parameters, the exposure period (ED), exposure frequency (EF) and taking shower times (EVshower) have positive correlation with risk calculation. But the average time (AT) of exposure and body weight (BW) have negative correlation with it. Therefore, these parameters would need further investigations.

M.Cur.
Occupational health nurses are qualified registered nurses with a post-graduate qualification in occupational health nursing as a specialised discipline, and provide the basic healthcare aspect of the occupational health programme. Their most important activity is to identify and assess the health hazard risks in the workplace. Health risk assessments are conducted by occupational health nurses to determine all the stresses, e.g. hazardous chemicals, vibration, insufficient lighting, noise exposure and thermal exposure, which may affect employees‟ health and working efficiency. The researcher conducted audits and, over a period of time, observed that 85% (n=23) of occupational health nurses in different settings conduct health risk assessments only to a certain extent. The following questions were raised: To what extent do occupational health nurses conduct health risk assessments? What are the possible reasons for them conducting the health risk assessments only to a certain extent, or not at all? What can be done to improve this? The purpose of this study was thus to explore and describe the extent to which occupational health nurses conduct health risk assessments; and the possible reasons for not conducting them or conducting them only to a certain extent. Guidelines were developed to assist occupational health nurses in conducting health risk assessments. A quantitative, descriptive design was used in this study. A sampling frame was developed from a list of all the members of the South African Society of Occupational Health Nursing Practitioners (SASOHN) in Gauteng. From the target population of occupational health nurses in Gauteng, a systematic cluster sampling method was used. A developed questionnaire was distributed by mail and e-mails, and reminders were sent by the researcher to the respondents (Burns & Grove, 2006). The researcher ensured validity and reliability throughout the study by means of theoretical review, content securing and statistical assistance (Burns & Grove, 2006). Ethical standards of the right to self-determination, right to privacy, right to confidentiality and autonomy, right to fair treatment and right to protection from discomfort and harm were adhered to. The findings revealed that the occupational health nurse is a mature, predominately female experienced practitioner who operates on behalf of a disproportionably large number of employees. Four factors influencing these nurses in conducting a health risk assessment to a certain extent were identified: competence, ignorance about the role of the occupational health nurse, workload and attitude. The researcher formulated guidelines to assist practising occupational health nurses to conduct health risk assessments.

碩士
國立高雄師範大學
環境教育研究所
101
Many gas stations were established since the government permited the private sector to own gas stations. For instance, there are about 265 stations in Kaohsiung. Each has four underground storage tanks. The total number of underground storage tanks is over 1100. With so many reservoirs, the ensuing problems, such as contamination and the nearby inhabitants’ health problems need to be further discussed. The objective of this study is to assess the health risk posed to adults and children who exposed to contaminated soil and groundwater, and to assess the carcinogenic and non-carcinogenic risk caused by the chemicals of concerns. As for carcinogenic risk, the results indicate that the simulated risk of both adults and children are higher than 10-6, the acceptable level for ordinary people. Inhalation poses the highest risk followed by oral exposure, and dermal exposure poses the lowest risk. The carcinogenic risk through inhalation for children is ten times higher than that for adults. Inhalation contributed 95.74% of the total carcinogenic risks to adults. To children, inhalation also poses 95.10% of the total carcinogenic risk. The total carcinogenic risk posed by benzene is much higher than ethylbenzene and methyl tert-butyl ether. The carcinogenic risk of children exposed to benzene is five times higher than adults. As for non-carcinogenic risk, the result of this study indicates that inhalation exposure poses higher risk than oral and dermal exposure to adults and children. The results of this study also suggest that benzene poses the highest non-carcinogenic risk through oral exposure, benzene is through inhalation, and toluene is through dermal exposure to adults. To children, benzene poses the highest non-carcinogenic risk through oral exposure and inhalation; toluene is through dermal exposure. The results of this study indicate that both adults and children exposing carcinogenic risk are caused by gasoline contaminated site. It concluded that the contamination concentration released from contaminated site results in the carcinogenic risk is higher than 10-6. The non-carcinogenic risk is higher than 1. Future evaluation related to regulation criteria will be necessary for the health risk aspect.

碩士
中山醫學大學
職業安全衛生學系碩士班
104
1.The Impact of Occupational Safety and Health Act Amendment to the Chemical Management and Supervision. To assess the impact and preparation of Occupational Safety and Health Act before the revision and implementation may have caused this study to collect and analyze the leading practices relevant in other countries of national chemicals management mechanism, and consider our country to be implemented laws and regulations to show our country integration into international in the implementation of chemicals management control mechanism. Order to understand Occupational Safety Act revised, on the impact of industry and prosecutorial institutions, structured questionnaire designed for government prosecutors and industrial investigations, the results obtained to quantify that at all levels of difficulty, showed that in response to the Occupational Safety and Law Enforcement, Industry and check in urgent need of mentoring programs as follows (1) industry agency inspectors are in urgent need to be related to chemicals management guidelines for risk classification management, manufacturing or enter a new chemicals assessment report cognitive training; (2) regulatory chemicals and priority management chemical operations management products and licensing inspection, supervision of the standard procedure. (3) Establishing the use of hazardous chemicals and training of login information, but also provide screening high-risk workplaces, supervision and inspection as priority of decision-making. In addition, the urgent need by the National Chemical Information Systems cloud, quick access to detailed information and institutions to use chemicals that can enhance the management capacity of the industry to implement management. Should be established professional counseling and supervision necessary checking mechanisms and uniform enforcement of the standards, recommendations, planning and implementation of industrial grade or group executive management; to share with the industry experience, it is recommended that future work planning inspectors and industrial implementation of education and training materials. 2.The Cause of Foot Pain of Long Standing Worker：Analysis and Improvement Recently year, industry still need a large amount of human resources, because of the characteristic of working space and factory building , workers have a tendency to suffer from myalgia, In addition, they may have difficulty perspiring and dissipating excess heat from body. Owing to workers spend most of time doing their job again and again and long standing, they may constantly feel exhausted or suffer from muscle fatigue. Although these problem won’t be life-threatening, it might lower their working performance and affect their quality of life. The purpose of this study is analysis why long-standing workers have foot-pain, in addition, we want to improve our analysis. At first we tried to analysis the workers’ pain resulted form long standing. In order to finish our test, we provided them with industry protective insoles and gave them Borges Perceived Exertion and Pain Scales. At first they are required to finish this once a week and until the fourth week they are followed by once a month. All of these took about five months .We hope to compare the result before they wear industry protective insoles with the result after them using the industry protective insoles. After during 20 weeks’ observation, the results show that the test’s participant have improved a lot. The degree of pain resulting from long-standing increased with days.The data about pain of workers whether they wear industry protective insoles or not have a significant differences (p< 0.001). According to pressure plate data, low food had obviously difficulty in adoption no matter what kind of leg type after wearing insole, however, less pressure relieving of high arch foot after wearing insole were noted. These results can help long-standing workers maintain their posture more easily.What’s more, it can let us know the differences of the results before and after workers wear industry protective insoles. All of the records we get from this study can be used to analysis the effect of industry protective insoles on alleviating fatigue and pain, in addition, we can improve our material of industry protective insoles by using these data.

碩士
國立中央大學
環境工程研究所碩士在職專班
93
ABSTRACT The objectives of this study were aimed to assess the human health risk of worker and residents near the petroleum hydrocarbons released site in central Taiwan in accordance with ASTM E1739-95, Standard Guide for Risk-Based Corrective Action (RBCA) Applied at Petroleum Release Site. Also, the major exposure pathways, analysis of sensitivity parameters and the risk of exposure regardless of correction were investigated in this study. Furthermore, values of the health risk were compared to the results from the Procedures for the Evaluation of Environmental Impact and Treatment Grading on the Definition of the Extent of Contaminants for Remediation Sites, announced by the Taiwan E.P.A. in 2003. According to the study, for residents living outside the site, consuming vegetable, fruits and groundwater, and taking bath with groundwater, the risk of getting cancer is up to 1.0E-4. Even after the benzene concentration in the soil and groundwater has been significantly reduced, consuming of vegetable, fruit and groundwater brought the residents a risk of getting cancer up to 1.0E-7. Therefore, it is not recommendable to consume vegetable, fruits and groundwater from the site or its neighbor land. Basement at organic contaminated site is one of the main pathways of exposure to the risk. The main risk for workers in the site is from inhalation of indoor air contaminated by pollutants volatilized from the soil and groundwater. The result of a sensitivity analysis indicated that the sensitivity parameter is gas exchange rate in closed space. Therefore, sufficient ventilation should be provided at basement to lower the risk. Residents and pupils living outside the site are exposed to a considerable risk provided they drink groundwater or use it for bath. Thought a sensitivity analysis, it was concluded that the positive sensitivity parameter is hydraulic gradient, and the main negative sensitivity parameter is organic carbon content in the soil at the pathway of exposure. Therefore, restricting contaminated groundwater in the site from flowing to the neighbor land can effectively lower the risk outside the site, hydraulic control or construction of underground continuous walls are ways to stop the flow of groundwater to the neighbor land. The result of an evaluation made with the Procedures for the Evaluation of Environmental Impact and Treatment Grading on the Definition of the Extent of Contaminants for Remediation Sites, announced by the Taiwan E.P.A. in 2003 showed that groundwater is the main contamination pathway, and the result of evaluation under ASTM 1739-95 also concluded that groundwater is a main contamination pathway. The results of these two evaluations are consistent. This is because the benzene concentration in the groundwater is much higher than that in the soil, and the main exposure pathways at the site are all related to the groundwater. Moreover, the physical and chemical properties of benzene, the hydrological and soil parameters of the site also contributed to the high score of groundwater in the evaluation. Thus, the groundwater is more important than the soil in the pathways of contamination. Keywords：health risk assessment, RBCA, cancer risk, sensitivity analysis , petroleum hydrocarbon

碩士
逢甲大學
風險管理與保險學系
107
Due to the precedent of participating (par) health insurance in foreign markets nowadays, in order to integrate with international advanced countries and accelerate the development of innovative products in Taiwan, and to meet the needs of the current market, this paper mainly focuses on the feasibility of participating health insurance, and explore the potential of market development. Additionally, this study proposes risk assessment model for the feasibility evaluation. Under this model, some important factors or variables which may cause impact on the financial sustainability are considered: such as uncertainty in medical costs and longevity risks faced by insurance companies in designing participating health insurance. Finally, different policy design schemes and dividend mechanism are also proposed to reduce the previously mentioned risks. The feasibility of participating health insurance includes the following three parts: Firstly, reviewing the current insurance regulations which are related to participating health insurance. As stated in Article 140 of “Insurance Law in Taiwan”, there is no apparent limitation on the issue of health insurance with participating features. Most of the laws and regulations are principle-based and are not specific to participating in health insurance. Therefore, it is not necessary to propose new laws for participating health insurance but with minor extent of “life insurance” to “life and health insurance”. However, according to the Disclosure Principle, insurance companies are required to the disclose bonus declaration, with more complex formula or expression including morbidity factors for Participating Health Insurance. Secondly, Risk-Based Capital of Participating health insurance has no needs to be modified, since the current liability reserve for the risk capital system has already reflected the risk of future losses and exposure to risks, along with the future bonus declaration. Thirdly, empirical evidence in this study shows that, insurance companies have achieved well underwriting effects and are profitable in some health insurance contracts with reimbursement on outpatient or hospitalization and surgeries. Therefore, it is feasible for insurance companies to issue such participating health insurance for promotion and marketing consideration. As for the dividend mechanism, this study compares two main participating features: non-cash bonus and cash-bonus. Furthermore, the utility of the bonus reserve is also discussed in this study. All the researches as above could provide a reference for the risk of the insurance companys product design for par health insurance.

碩士
國立中山大學
環境工程研究所
102
Petroleum hydrocarbons-contaminated soil and groundwater is a world-wide environmental problem, which results in environmental hazard and human health risk problems. Because petroleum is a complex composition mixture rather than a single compound, health risk assessment for petroleum-hydrocarbon contaminated site is a complicated process. In this study, the human health risks were assessed and calculated following the risk-based corrective action (RBCA) protocol for a total petroleum hydrocarbon (TPH)-contaminated site. This study was conducted on one of the TPH contaminated sites in the south of Taiwan where the health risk calculation, evaluation of the pollution concentrations and health risks on the pollution sites was carried out. Results show that the main on site human health risk was from the soil vapor inhalation, which resulted in 88.8% of the total carcinogenic risk, and the calculated hazard index was 7.11×10-2. The soil ingestion was also a major risk cause, which resulted in 10.1% of the total carcinogenic risk, and the calculated hazard index was 8.1×10-2. The total non-carcinogenic risk (hazard index) was 8.01×10-1, which was less than the acceptable level of 1. This indicates that the total risk caused by the TPH was within the acceptable range. The calculated total risk after 30 years of exposure was 4.40×10-1, which was also less than the acceptable level of 1, and thus, health risk due to the TPH spill can be ignored. Furthermore, the major causes of increased hazard index value include aliphatic components (C8-C10 and C10-C12) and aromatic components (C10-C12). Because TPH is not an acute toxic compound, the calculated health risk via the oil spill is not significant.

碩士
國立中山大學
環境工程研究所
101
non-sensory. A survey and severity of the pollution on a contaminated site cannot often be easily identified without carrying out investigations. In the SG pollution investigation, pollutions can often be found in farmlands, factories, gas stations and storage tanks. Gas stations and storage tanks, in particular, are commonly seen contaminated by oil products. The key components found in oils products inclusive of total petroleum hydrocarbon (TPH), petrol additives- methyl tertiary-butyl ether (MTBE), BTEX (benzene, toluene, ethylbenzene, xylenes) and TMB (1,2,4-trimethylbnezene and 1,3,5-trimethylbenzene) pose health risks to human body. There is a certain degree of difficulty to assess the health risks that are exposed to the sites which are contaminated by TPH. The health risk assessment is based on the hypothesis of one single chemical element; therefore, when it is applied to TPH pollutions with multiple carbon compounds, it becomes more complicated. Besides, the analytic and technical threshold has to be overcome to separate the compound, TPH effectively. This study was conducted on one of the TPH contaminated sites in the south of Taiwan where the health risk calculation, evaluation of the pollution concentrations and health risks on the pollution sites was carried out. The result of evaluation revealed that on-site, non-cancerigenic risk value in adult and child receptors was the same, 1.44×10-4; whereas off-site, non-cancerigenic risk value in adult and child receptors fell in the acceptable range. The result disclosed that, under the circumstances of low pollution concentrations (if abiding by laws and regulations), there was no significant difference between adult and child risk value, both of which met the requirement of regulations in risk limiting values. However, the risk value represented profound variations in areas just 50 meters away, from which we learned that when vapors of the contaminated groundwater evaporated into atmosphere, the pollution concentration reduced by means of atmospheric transmission. It then further lowered risks that receptors were exposed to. In addition, pollution concentration of the site in this study met the standards of soil and groundwater pollution control and the result of health risk calculation also conformed to the standards of risk limiting values. This indicated that the toxicity in the TPH-contained pollutants should be in the category of non-acute toxic compounds because the risk value did not exceed the legal limit in the existence of small volume (e.g. in the condition of extremely low pollution concentration).

This study demonstrates that hybrid methods can be used for measuring the risk severity of technology-induced errors (TIE) that result from use of health information technology (HIT). The objectives of this research study include: 1. Developing an integrated conceptual risk assessment model to measure the risk severity of technology-induced errors. 2. Analyzing the criticality and risk thresholds associated with TIE’s contributing factors. 3. Developing a computer-based simulation model that could be used to undertake various simulations of TIE’s problems and validate the results. Using data from published papers describing three sample problems related to usability and technology-induced errors, hybrid methods were developed for assessing the risk severity and thresholds under various simulated conditions. A risk assessment model (RAM) and its corresponding steps were developed. A computer-based simulation of risk assessment using the model was also developed, and several runs of the simulation were carried out. The model was tested and found to be valid. Based on assumptions and published statistics obtained by publically available databases, we measured the risk severity and analyzed its criticality to classify risks of contributing factors into four different classes. The simulation results validated the efficiency and efficacy of the proposed methods with the sample problems.
Graduate
0723
0680
0769
tschio2011@gmail.com

博士
國立臺灣大學
環境工程學研究所
95
The decision as to whether a contaminated site poses a threat to human health and should be cleaned up relies increasingly upon the use of risk assessment models. However, the more sophisticated risk assessment models become, through inclusion of such concepts as stochasticity, multimedia transfer, and site-specificity, the greater the concern with the uncertainty in, and thus the credibility of, risk assessment. It has been demonstrated in the literature that model uncertainty may significantly affect the assessment result, but no research has provided the practical methods on how to analyze and decrease them. Therefore, how to eliminate unsuitable model or select right model in order to reduce model uncertainty is an important issue in the research. Based on the relationship between exposure pathways and estimated risk results, this study develops a screening procedure to compare the relative suitability between potential multimedia models, which would facilitate the reduction of uncertainty due to model selection. MEPAS, MMSOILS, and CalTOX models, combined with Monte Carlo simulation, are applied to a realistic groundwater-contaminated site to demonstrate the process. The results reveal that this procedure can decrease model uncertainty by eliminating unsuitable model. In particular, when there are several equally plausible models, decision makers are confused by model uncertainty and perplexed as to which model should be chosen for making decisions objectively. When the correctness of different models is not easily judged after objective analysis has been conducted, the cost incurred during the processes of risk assessment has to be considered in order to make an efficient decision. In order to support an efficient and objective remediation decision, this study develops a methodology to cost the least required reduction of uncertainty and to use the cost measure in the selection of candidate models. The focus is on identifying the efforts involved in reducing the input uncertainty to the point at which the uncertainty would not hinder the decision in each equally plausible model. First, this methodology combines a nested Monte Carlo simulation, rank correlation coefficients, and explicit decision criteria to identify key uncertain inputs that would influence the decision in order to reduce input uncertainty. This methodology then calculates the cost of required reduction of input uncertainty in each model by convergence ratio, which measures the needed convergence level of each key input’s spread. Finally, the most appropriate model can be selected based on the convergence ratio and cost. A case of a contaminated site is used to demonstrate the methodology. The outcome shows that this methodology can efficiently and objectively select the best model to support decision with considering the influence from uncertainty. Although the previous two model comparison methods have both proved that an objective model selection method could effectively reduce model uncertainty, different model selection method based on different consideration and criteria would cause different results that can be seen as the source of scenario uncertainty. Therefore, this study finally develops a framework of total uncertainty to not only quantify scenario uncertainty due to different model selection methods but also explicitly reveal the reduction of total uncertainty resulting from model selection.

碩士
國立成功大學
環境醫學研究所
94
Organic foods are generally defined as pesticide-free agricultural products with no artificial treatment, and being taken in their fresh forms without cooking. People who claim to engage in macrobiotic diet tend to consume multi-grains, vegetables, fruits and nuts in their fresh, uncooked forms. Without application of pesticides, herbicides, antibiotics, or hormones, organic produce is likely to be contaminated by environmental micorbes during the storage and transportation. Situating in a typical subtropical climate, Taiwan offers an optimal condition to facilitate active mold growth in many media. Mycotoxins, common bio-product of microbial contamination in organic foods, therefore become a major health concern for population adopting dietary pattern of mainly organic products in Taiwan. 　　Previous studies have observed a significant presence of environmental microbes in Taiwan, and this investigation aimed to analyze, by HPLC-Flu, levels of Afatoxins (B1, B2, G1, G2) and Ochratoxin A in a total 90 food samples, including multi-grains, starchs , nuts, fruits, vegetables, mushrooms, beans and sprouts collected from northern, central, eastern and southern Taiwan. Questionnaires were distributed to people who regularly purchase the organic foods from the registered stores for the preliminary estimate of health risk associated with such a dietary habit. 　　A total of 229 valid questionnaires of dietary habit were obtained from 4 city/counties across different parts of Taiwan. Results indicate that the major items in their purchase/consumption list were grain rice and fruits, especially brown rice and apple. Only 7% of all samples analyzed could be detected with presence of Aflatoxin B1, and a small 2% of samples were detected with mycotoxin level greater than the proposed standard. Afatoxins level as high as 5.7ppb has been found in sample from millets of southern Taiwan, a level greater than the proposed Euro standard of 4ppb, while another 13.14 ppb sample was found in black bean sample from eastern Taiwan, exceeding the China standard of 5ppb. Ochratoxin A has not been identified in any food items analyzed in this study. Risk assessment calculated for the Hepatitis B carriers and >20 year-old groups of organic-foods consumers that eat organic foods over 30 years have increased risk of cancer, and healthy population and <20 year-old group does not present any immediate risk based on the dietary patterns interviewed. 　　Our study showed that Aflatoxins were mainly found in organic nuts and grains then organic vegetables. Preliminary findings from this investigation of limited samples emphasized that foods with claim of non-artificial process and additives are not necessarily free of other health concerns such as contamination by richly-available environmental microbes and their metabolic toxins like Afatoxins. Future certification on food items in the market may consider the examination of mycotoxins levels, in addition to the pesticides residues, to ensure the safety of “diet” for people in general.

碩士
國立臺灣大學
職業醫學與工業衛生研究所
89
Objective: Assessing site-specific carcinogenic risks of incinerator-emitted dioxins and risk transfers among the areas covered by 9 municipal incinerators in Taiwan. Methods: We used actual emission data and the industrial source complex model (ISC3) to determine the dioxins impact areas within the 8x8 km simulation region grids surrounding the incinerators. We used geographic information system (GIS) to plot the simulated results. We then used modified TRI-multimedia model to estimate cancer risks in individual impact areas. We based on the surveyed agricultural production information to calculate risks for exposure scenarios of sufficient and insufficient foods production for consumption in each impact area. We also used information of food flows between impact areas to calculate risk transfers among 9 incinerators. Results: The carcinogenic risks of dioxins under the exposure scenarios of sufficient food production ranged from 1.43×10-8(Jia-yi incinerator) to 7.08×10-5(Nei-hu incinerator). The carcinogenic risks of dioxins under the exposure scenarios of insufficient food production ranged from 8.69×10-8 (Kaohsiung incinerator) to 1.07×10-6 (Tai-chun incinerator). The food ingestion was the main exposure pathway, which accounted for 64~88% of total dioxins intake among 9 impact areas. For the 9 major food items consumed by residents in the impact areas, eggs (14%~35%) and chicken (11%~26%) were two main routes of dioxins exposure in the sufficient food production scenario, while chicken (8%~78%) and vegetables (0.2%~81%) were two main routes of dioxins exposure in the insufficient food production scenario. Significant risks of dioxins were transferred among incinerators, which accounted for 0.2%~99% among the incinerators. Tai-chun incinerator was the major export source of risk to 6 other incinerators except the Nei-hu and Mu-cha incinerators. For these 6 incinerators, the Tai-chun incinerator accounted for their 51-88% imported risks. Conclusions: We should consider risk transfers among incinerators through routes of food consumption in assessing health risks associated with incinerator-emitted dioxins in Taiwan. We should also emphasize on analyzing dioxins contents in eggs, chicken, and vegetables in order to improve dioxins-related health risk assessments in the future.

碩士
國立高雄師範大學
生物科技系
101
The dwindling fossil fuel sources and the creasing dependency on imported crude oil have led to a major interest in expanding the use of bioenergy in many countries. Furthermore, the addition advantage of biofuels is reduction in air pollutant and emission of greenhouse gas. Therefore, Taiwan is promoted the use of E3（gasoline with addition of 3％ ethanol）and B2（diesel fuel with addition of 2％ ethanol）in 2007 and 2010, respectively. Biofuel will alter the distribution of petroleum contaminants in soil and groundwater. Groundwater contamination by gasoline and other petroleum-derived hydrocarbons released from underground or above ground storage tanks is a serious and widespread environmental problem. The problem of petroleum contaminants will become complicated after biofuels widely utilized. The objective of this study is to assess health and ecological risk when biofuel spill occurs. The results of this study can be used as a reference for risk management. Conventional octane number 95 gasoline, ethanol-blended gasoline (i.e., E3, E10, E25 and E85) and biodiesel (i.e., B2, B5 and B20) were studied. The framework of human health risk assessment used in this study is adopted from “Risk Assessment Guidance for Superfund Human Health Evaluation Manual” from United States Environmental Protection Agency（USEPA）in 1989. The assessment endpoint is the adverse health effects of human. In the ground water media, concentration of petroleum contaminants was estimated by the LevelⅢ Fugacity Model. US EPA human exposure assessment models have been used to evaluate the exposure dose via inhalation, ingestion and dermal contact pathway, when human use groundwater. The risk characterization of human non-carcenogenic risk is estimated by hazard quotient（HQ）value. Carcinogenic risk was assessed by multiplying total exposure by the carcinogenic slope factor for each pathway. The framework of ecological risk assessment used in this study is adopted from “Guideline of Ecological Risk Assessment” from USEPA in 1998. The assessment endpoint is the mortality of aquatic and terrestrial organisms. In the aquatic and terrestrial ecosystem, exposure dose and concentration of biota was estimated by the RAIDAR Model and LevelⅢ Fugacity Model. The risk characterization of biota is estimated by risk quotient（RQ）value. The result of human carcinogenic risk assessment was assessed, which was higher than the threshold value（10-6） that general people can withstand. This indicates potential cancer risks for the exposed population. The results show that human use contaminated water as drinking water will ingest benzene. It exposes the highest carcinogenic risk for E3 gasoline. The result of human non-carcinogenic risk assessment was assessed, which was lower than the accepted threshold value（1）that ordinary people can withstand. This indicates no potential health hazards for the exposed population. The result show that human use contaminated water as drinking water or dermal clean water will ingest MTBE or absorb aliphatics C8-C10 from derma, respectively. The highest non-carcinogenic risk was exposed by conventional research octane 95 gasoline. Human use contaminated groundwater as clean water will inhale naphthalene vapor or absorb aliphatics C16-C21 from derma, respectively. It is the highest non-carcinogenic risk for B20 diesel. The hazard of the E85 gasoline and B5 diesel is the lowest for human health. Since the biofuel will alter the distribution of petroleum contaminants in groundwater, more contaminates will be anticipated in the exposure pathway. Ecological risk assessment results indicate that the aquatic and terrestrial total ecological risk index is lower than the threshold value（1）, this indicates no potential hazard for the exposed biota. By evaluating the results, it is clearly that m,p-xylene in gasoline pose the highest risk for terrestrial avian scavenger in contaminated food chain. In addition to, pyrene in biodiesel blended diesel pose the highest risk for terrestrial avian omnivore in the terrestrial ecosystem. The hazard of the E85 gasoline and B20 diesel is the lowest. Because E85 gasoline and B20 diesel contains less petroleum contaminants. Comprehensive ecological risk assessment results demonstrate that biofuels are the most serious impact for terrestrial organisms. The results conclude that differences in chemical properties and environment range lead to profound differences in the concentration of exposure and risk from emission to target biota. The implications of these results and draw attention to the insights gained about ecological risks and effective chemicals management associated with biofuels.

碩士
國立陽明大學
環境與職業衛生研究所
98
In recent years, the capability of patient’s care by families has decreased because of the factors such as the aging of population and the economic development. Nursing assistants became the important supplemental manpower of the medical service system. The hospital Nursing assistants work in the hospital, but not be the hospital staff. It does ignore that Nursing assistants’ healthy and occupational safety. This study aims is assess mental health and risk factors among nursing assistants in Taiwan and also provide data for the authorities to assess occupational hygiene of nursing assistants. Female nursing assistants are participants and 271 workers are analyzed in 14 hospitals. The questionnaires include socio-demographic characteristic, work stress, subjective fatigue symptoms, mental health and sleep quality. Physiological measurements include heart rate, blood pressure, triceps skin fold and back muscle strength. Urinary 17-hydroxycorticosteroids (17-OHCS) concentration is also measured. The research was divided the nursing assistants’ age into three groups of the below 39 years old, 40~54years old and above 55years old, the number of the subjects were 38, 172 and 61 respecyively. Drinking coffee rate was23.6% and smoking rate was 2.6%. Muscle skeleton disease was 14%which is the highest prevalence of all disease. Next for the eye disease is 11.8%. Half of nursing assitants felt uncomfortable in the working environment. 19% nursing assistants endured patient's language violence. The results for physical fitness indicated that, for triceps skin fold, the young group, middle-age and old group were 18.96±9.48mm、20.28±9.58mm and 18.08±8.51mm, respectively. About grip strength test, the three groups respectively were17.11±6.70kg、17.48±5.04 kg and14.67±5.63kg in the left hand, and in the right hand were 18.82±7.24kg、17.79±5.38kg and 14.90±5.48kg. For back muscle strength, the young group, middle-age and old group respectively were38.98±25.83kg、39.18±19.79kg and 33.32±16.42kg. The grip strength of nursing assistants presented with the age increment and gradual descend of trend significantly. 93% nursing assistants care the patient who doesn’t walk independently. The average work year was 6.67±4.84 years, the average work day was 5.16±1.04 days/week, the average daily working hour was 12.35±6.88 hours, and the average holiday was 1.81±1.05 days/week. Regarding work-related stress, results showed that older nursing assistants are higher in the score of work control and society support aspect (better condition); young workers’ are higher in the score of mental state burden (worse condition). It’s likely that the elder people who have more experience and skill for the control power on work, get the boss and colleague supports more easily. Relatively, the young age is too young to have good performances, contribute to mental burden than others. The mental health analysis showed that the nursing assistants who had the sleep barrier or 4 hours/8hours shifts get higher CHQ-12 score which showed they didn’t have good health. About fatigue symptoms, the tiredness of eyes was the most, secondary was backache. Biochemistry fatigue measurements showed that, the urinary 17-OHCS/creatinine was 9.42±3.55 mg/g cr., significantly higher than other workers. The nursing assistants lacked training of the occupational hygiene. We suggested that government should arrange related training courses about occupational hygiene to protect their health, take care and benefit to this minority group seriously.