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Peters, Jaime Louise. "Generalised synthesis methods in human health risk assessment." Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/30474.
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Bruce, Erica Dawn. "Modeling toxic endpoints for improving human health risk assessment." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1277.
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Singh, Davinderjit. "Human Health Risk Characterization of Petroleum Coke Calcining Facility Emissions." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6391.
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Calcined coke is a high quality carbon material produced by calcining green petroleum coke. Calcining is the process of heating green petroleum coke in a kiln to remove excess moisture, extract all remaining hydrocarbons, and modify the crystalline structure of the coke into a denser, electrically conductive product. The final product, calcined coke, is primarily used to make carbon anodes for the aluminum industry and recarburizing agent for industries such as the steel industry. If not appropriately controlled, the calcining process could lead to excess production of particulate emissions from either handling or storing of raw coke, or from the stack emissions during the production of calcined coke. Though calcined coke has shown low hazard potential in human populations due to low volatile content, there remains some public health concern regarding the emissions from these facilities. This study is designed to evaluate the emissions of petroleum coke calcining facility and assess the public health concern from the processes engaged in the handling and storage of green coke as well as from the calcining process. The ambient air levels were measured from a calcining facility and compared with the standards promulgated by USEPA. The results showed that pollutant contribution from the facility, measured by monitoring carbon fraction of the emissions, was de-minimis. The current research also studied whether the exposure levels and health risks specified in various epidemiological studies correlate with the standards promulgated by USEPA to protect public health from petrochemical emissions.
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Marasinghe, Jeevani Prasadika. "Human Health Risk Assessment of Organophosphate Pesticides in Sri Lanka." Thesis, Griffith University, 2011. http://hdl.handle.net/10072/367958.
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Organophosphate (OP) pesticides cause a high morbidity and mortality in Sri Lanka due to intentional poisoning as well as accidental and occupational exposure. However exposure in the farming community and general population to OP at low levels goes unreported. Therefore the objectives of this study were to assess the health risks in farmers and the general population from low level exposure to OP pesticide in Sri Lanka and populations elsewhere using reported data and Guideline Values developed by regulatory agencies such as World Health Organization and U.S. Environmental Protection Agency. Clorpyrifos was identified as the principal pesticide of concern. The exposure was calculated in common units ng/kg body weight/day and presented as plots of cumulative probability and evaluated at the median (0.50 probability) and high (0.95 probability) exposure levels. The Guideline values of the regulatory agencies were used to characterise the health risk as Hazard Quotient.
The reported TCP levels (specific metabolite of chlorpyrifos) and residue data were collected from Sri Lanka and the other countries and the exposure dose (Equivalent Chlorpyrifos Ingested Dose, ECID in ng/kg/day) and the dose in the diet (Total Dietary Chlorpyrifos Intake, TDCI in ng/kg/day) were calculated. Similarly the ECID were calculated for the international populations.Thesis (Masters)
Master of Philosophy (MPhil)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Ades, Steven. "Human leukocyte antigen polymorphisms and risk of cervical neoplasia." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97882.
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The Biomarkers of Cervical Cancer Risk (BCCR) case-control study was designed to address the role of human leukocyte antigen (HLA) alleles as cofactors in the development of high-grade cervical intraepithelial neoplasia (HG-CIN). Cases were women with histologically-confirmed HG-CIN attending colposcopy clinics and controls were women from outpatient clinics with normal cytological screening smears. Cervical specimens were submitted for both human papilloma virus (HPV) testing and HLA genotyping. Risk ratios were generated using logistic regression modelling. This analysis includes 381 case and 884 control subjects, mainly of French-Canadian descent. The B7-DRB1*1501-DQB1*0602 haplotype was associated with a 41 % reduction in risk of HG-CIN [relative risk = 0.59; 95 % confidence interval = 0.36-0.96], and an 83 % reduction in risk for HPV 16 or HPV 18-positive subjects. Possession of the B7-DRB1*1501-DQB1*0602 haplotype was moderately protective, and may be associated with slowing of disease progression to HG-CIN in women who are carriers of common oncogenic HPV types.
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Tristan-Montero, Emma Esther. "Human health risk assessment for contaminated land in historical mining areas." Thesis, Imperial College London, 2000. http://hdl.handle.net/10044/1/7343.
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Broadway, Andrew. "Development of methodologies for soil metal bioaccessibility and human health risk." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/16948.
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Between 1830 and 1968 Glasgow was home to one of the world’s largest producers of Cr-based chemicals. Chromite ore processing residue (COPR) arising from the factory was used as infill material across large areas of SE Glasgow, resulting in widespread land contamination with Cr(VI), a known human carcinogen of significant mobility. This thesis presents the results of a research project into the bioaccessibility of Cr in Glasgow soils, using a physiologically based extraction test (PBET). 27 Samples were analysed, four of which had a Cr concentration above the residential SGV (200 mg/kg). Two samples where identified with a sizeable Cr(VI) concentration, 1485 ± 24 and 171 ± 5 mg/kg, respectively. Bioaccessible Cr was significantly less than the total concentration, being an average 5% of the total concentration. One sample had a notably high Cr bioaccessibility, at 1156 ± 32 mg/kg. This sample, from Rutherglen, was the only one to exceed assessment criteria, and as such pose a potential risk to human health. The solid phase distribution was also assessed, making it possible to identify the likely mineral sources of bioaccessible Cr within a sample. In the majority of samples Cr was associated with Fe oxide phases, resulting in a low bioaccessibility. Two samples had a sizeable amount of Cr associated with clay and carbonate phases, which have less acid stability, resulting in a higher bioaccessibility (1156 ± 32 and 116 ± 2 mg/kg). A carbonate phase, unique to samples from sites with known history of COPR disposal, was also identified. This had a large amount of associated Cr, suggesting it was derived from the COPR.
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Shaw, Brenda Jo. "Evaluation of risks to human health in Hong Kong from consumption of chemically contaminated seafood : a risk assessment approach /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14723657.
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Henri, Christopher. "Risk managment of complex aquifers contaminated by chemical mixtures : numerical tools and human health risk assessment." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/316393.
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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.
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Rousseau, Marie-Claude 1969. "Risk factors for incident cervical human papillomavirus infection in women in a high-risk area for cervical cancer." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20282.
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Human papillomavirus (HPV) is the sexually-transmitted etiologic agent of cervical cancer. Despite screening programs, cervical cancer remains too common, particularly in developing countries. Various correlates of prevalent infections have been identified. However, the determinants of incident infections have never been studied.Data were collected during a prospective cohort study conducted in Brazil. Incidence density rates of infection were calculated and determinants of incident infection were identified using Cox regression models. Analyses were done for HPV types classified into low-risk and high-risk depending on their association with cervical neoplasia.
The incidence density rates were 9.3 and 7.6 per 1000 women-months respectively for low-risk and high-risk HPV infection. Independent positive associations were found between the time of first occurrence of low-risk infection and age, number of sexual partners in the past 5 years, education level and use of non-commercial hygienic absorbents. The first occurrence of high-risk infection was independently predicted by age, age at first sexual intercourse, condom use (negative associations) and by the number of sexual partners in the past year (positive association). Elucidation of the dynamics of infection is a first step towards implementation of public health programs for reducing the risk of cervical cancer.
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Shittu, Whanda Ja'afaru. "Mapping oil spill human health risk in rivers state, Niger Delta, Nigeria." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14115/.
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Oil pipelines play a significant role in crude oil transportation and bring danger close to communities along their paths. Pipeline accidents happen every now and then due to factors ranging from operational cause to third party damage. In the Niger Delta pipeline system, interdiction is common; therefore, every length and breadth of land covered by a pipeline is vulnerable to oil pollution, which can pose a threat to land use. Weak enforcement of rights of way led to encroachment by farmers and human dwellings, thereby bringing people in close proximity to pipelines. Considering the impact exposure can have on human health, a method was developed for identifying vulnerable communities within a designated potential pipeline impact radius, and generic assessment criteria developed for assessing land use exposure. The GIS based model combines four weighted criteria layers, i.e. land cover, population, river and pipeline buffers in a multi-criteria decision making with analytical hierarchy process to develop an automated mapping tool designed to perform three distinct operations: firstly, to delineate pipeline hazard areas; secondly, establish potential pipeline impact radius; and thirdly, identify vulnerable communities in high consequence areas. The model was tested for sensitivity and found to be sensitive to river criterion; transferability on the other hand is limited to similar criteria variables. To understand spatial distribution of oil spills, 443 oil spill incidents were examined and found to tend towards cluster distribution. Meanwhile, the main causes of spills include production error (34.8%) and interdiction (31.6%); interdiction alone discharged about 61.4% of crude oil. This brings to light the significance of oil pipeline spills and the tendency to increase the risk of exposure. The generic assessment criteria were developed for three land uses using CLEA v 1.06 for aromatic (EC5-EC44) and aliphatic (EC5-EC44) fractions. The use of the model and screening criteria are embedded in a framework designed to stimulate public participation in pipeline management and pipeline hazard mitigation, which policy makers and regulators in the oil industry can find useful in pipeline hazard management and exposure mitigation.
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Gordon, Keith. "MACT Implementation at an Organic Chemical Manufacturing Facility: Human Health Risk Reduction." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1222.
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Human health risk assessments are used by environmental regulatory agencies to determine risk from Hazardous Air Pollutants (HAPs). In this study, the Human Exposure Model (HEM-3) was used to compare the cancer and non-cancer inhalation health effects of a single organic chemical manufacturing facility in Geismar, Louisiana prior to and after Maximum Achievable Control Technologies (MACT) were implemented. The results indicate significant reductions in both cancer risk and non-cancer hazards. The analysis also indicated that the equivalent cancer risk reduction could have been achieved by addressing MACT in only one production process and one single pollutant (ethylene dichloride) within that process. This demonstrates the value that these risk assessments have at evaluating emissions at the facility level, and how they could be used in the control strategy decision making process.
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Elom, Nwabueze. "Human health risk assessment of potentially toxic elements (PTEs) from environmental matrices." Thesis, Northumbria University, 2012. http://nrl.northumbria.ac.uk/15594/.
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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.
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Walczak, Katarzyna I. "Prototype decision support framework using geospatial technologies for analysing human health risk." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/103630/1/Katarzyna%20Izabella_Walczak_Thesis.pdf.
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This thesis concentrates on the development of a prototype Decision Support Framework based on the landscape epidemiology concept and using GIS to determine human health risk in Semarang (Indonesia). This site was selected as representative of a rapidly urbanizing area in a developing country. The decision support framework examines climatic, landscape and socio-economic factors identified as having significant impacts on water quality and subsequent causation of waterborne and water-related diseases. The research outcomes potentially may be applied worldwide to identify and isolate areas most vulnerable to the effects of the mentioned diseases thus improving quality of life in developing countries.
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Singh, Kavita. "Human Health Risks of Persistent Organic Pollutant Exposures in the Canadian Arctic." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37799.
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The persistent organic pollutants (POPs) refer to many different chemicals that, upon release into the environment, remain intact for several decades. These contaminants travel long distances through repeated cycles of deposition and evaporation, and eventually deposit in the Arctic regions. The purpose of this work was to examine the potential human health implications of POP exposures among the Canadian Inuit, using modelling and epidemiological approaches. Blood guideline values were developed for the organochlorine pesticides, chlordane and toxaphene, and the polychlorinated biphenyls (PCBs) using the concept of biomonitoring equivalents (BEs), which are based on toxicity endpoints and toxicokinetic modelling to convert an oral reference dose to an equivalent blood concentration. The biomonitoring data from the Adult Inuit Health Survey (2007-2008) and the Canadian Health Measures Survey (CHMS, Cycle 1 2007-2009) were compared with the derived guideline values to assess population-level risks of exposures for the Inuit and the general Canadian population, respectively. Epidemiological analyses were also conducted to explore if POPs were associated with diabetes and high cholesterol, using data from the Inuit Health Survey. A set of BE values were derived for chlordane isomers and metabolite, three abundant toxaphene isomers, and the PCBs. The derived values are in a similar range of the BEs of other POPs in the literature. Among the Inuit, a large percentage exceeded the trans-nonachlor guideline value, particularly among the elderly. Fewer exceedances were observed for cis-nonachlor and oxychlordane, none for toxaphene, and minimally for the PCBs. In comparison, no exceedances for any of the POPs were observed in the general Canadian population. Highest vs. lowest quartile exposures to PCBs and p,p’-DDE were associated with increased risk of diabetes and an increase in fasting glucose among the Inuit. In addition, PCBs were associated with increased risk of high cholesterol, and higher levels of serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol (LDL-C), but not high-density lipoprotein cholesterol (HDL-C). The results of this work suggest that exposures to POPs remain a potential health concern among the Canadian Inuit. Future research efforts should be devoted to collecting updated contaminant concentrations for the Inuit, measuring contaminants in prepared food samples, conducting cohort studies on contaminant exposures and health outcomes, and assessing the effects of chemical mixtures using statistical approaches and toxicokinetic modelling.
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Alhadrami, Hani Abdullah. "Development and applications of mutagenicity and carcinogenicity bioassays for human health risk assessment." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=166645.
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Young children are particularly sensitive to environmental pollutants. They can directly ingest soil by putting dirty hands and objects in their mouths. The reliance on animal derived models for human health risk and exposure assessment has several limitations. In this investigation, a tool-kit was developed and optimised to facilitate more accurate, reliable and representative predictions of soil contaminants that might pose a significant hazard to young children. The tool-kit was developed and optimised using an in vitro human digestion bioassay. This procedure was followed by the optimisation of several mutagenicity bioassays to link to the bioaccessible fraction which quantified by the in vitro bioassay. The application of novel and sensitive environmental-based biosensors requires them to work in parallel with effective and proven extraction techniques. In this study, chemical analysis was used to quantify the bioaccessible (human assimilated portion) of pollutants in soils. Acute toxicity was measured using constitutively marked bioluminescent bacterial biosensors and these were indicative of the total contaminant burden. A range of mutagenic assays were applied and optimised. In the Ames assay, any compound exhibiting a greater than two-fold increase in the number of revertants colonies over the number of spontaneous revertants was considered as a mutagen. Mutagenic-responsive SOS-lux based microbial biosensors were compared to the Ames assay. Mutagenicity assessment of a broad range of environmental pollutants (i.e. B[a]P, DiB(a,h)A, B[a]A, Ni and Cu), was performed using four SOS-lux microbial biosensors; E. coli DPD1718, E. coli K12C600, S. aureus pAmiUmuC and S. aureus pAmiRecA. The results substantiated that the four biosensors were unable to be induced by these pollutants. Nevertheless, E. coli DPD1718 and E. coli K12C600 were successfully induced by Mitomycin C (MMC) in a dose response manner. The Ames assay was performed for the above pollutants in the absence and the presence of the metabolic activation S9 mix. The standard plate incorporation assay and a modification protocol for the Ames assay were applied. Results reported from the Ames assay confirmed mutagenicity responses of the tested pollutants except Cu and Ni. MMC was selected and introduced into soil samples as a case study to assess the performance of the developed tool-kit. Soils amended with MMC were extracted by the in vitro human digestion bioassay, and the mutagenicity of the bioaccessible fraction was measured using the Ames assay and the biosensors. A comparison was made between the permissible concentrations of MMC obtained from the developed tool-kit and RISC4 derived concentrations. The four microbial biosensors applied in this study were incapable to detect the mutagenicity of the tested pollutants. On the other hand, the Ames assay was more robust and sensitive to a broad range of environmental pollutants. The in vitro human digestion bioassay enabled the quantification of the human bioaccessible fraction of the tested pollutants. This fraction posed a concern due to its estimation of the doses that would reach the blood circulation and cause harm to human. While the permissible concentration of MMC measured by the developed tool-kit was less than 10 μg MMC/g, the RISC4 model calculated that it should be 40 μg MMC/g. This revealed that, in this situation, risk assessment model was less conservative than empirical study for human health risk assessment. This study enabled the assessment of the permissible concentrations of environmental pollutants that could remain in a soil and pose permissible harm to humans. This approach also enabled a comparison of modelled and empirical data to allow a measure of sensitivity to be judged. There is a need to develop bioassay techniques more able to assess the potency of hydrophobic compounds both in isolation and combination.
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Polasek, Ozren. "Investigating the role of human genome-wide heterozygosity as a health risk factor." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4799.
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Aim The aim of this study was to investigate the most commonly used approaches to measure individual genome-wide heterozygosity (IGWH) and to investigate whether IGWH can be considered as a health risk factor or a protective factor in humans. Methods This study was based on two samples from isolated communities of Croatian Adriatic islands, with a total of 1,930 adult examinees from Islands of Vis (N=986) and Korcula (N=944). Examinees were genotyped with a total of 302,662 single nucleotide polymorphisms. Heterozygosity was estimated using five commonly calculated methods. Results Correlation coefficients between different heterozygosity methods were generally in the range of 0.7-0.8. A worsening in some phenotypic traits, including cholesterol and triglycerides as well as increased odds for osteoporosis and metabolic syndrome was recorded in cases of IGWH reduction. Nevertheless, in these cases heterozygosity explained a relatively low amount of variance, generally in range of 0.4-0.6% of total trait variance. Conclusion However, these results were significant in Vis Island sample, while in the replication sample, Korcula Island, most of the associations were not significant, possibly due to the overall lower amount of inbreeding and higher heterozygosity in Korcula Island sample. The results warrant further research in order to provide more information on the extent and importance of individual genome-wide heterozygosity, which might have an important role in communities which experience consanguinity on a greater scale. Two main shortcomings of the study include possible lack of power to detect inbreeding depression and the need to replicate the results in other populations.
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Li, Zijian. "Analysis of Worldwide Pesticide Regulatory Models and Standards for Controlling Human Health Risk." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1470137430.
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Nguyen, To Ngoc. "Essays on econometric modeling of subjective perceptions of risks in environment and human health." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2626.
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Mohammed, Fatima Sule. "Indoor and outdoor dust in Damaturu Nigeria : composition, exposure and risk to human health." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8376.
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Harmattan and Dust (sand) storms together with anthropogenic activities including the use of firewood and kerosene as fuel for cooking, and diesel/petrol generators for electricity generation are potential sources of particulate and gaseous pollutants in homes in Damaturu town, Nigeria. Other activities like the burning of locally produced incense and mosquito coils as well as the use of aerosol sprays are further possible sources of indoor pollution, which may result in exposure of people to a range of pollutants through inhalation, by ingestion of settled dusts as well as dermal contact. Local people associate occurrence of dust events with adverse health effects and hence there is a need for an understanding of the composition of the settled and airborne dusts in order to assess the possible associated health risks. The first phase of the study involved selection and development of methods of dust sampling and analysis. For validation of the methods employed and to establish a broad understanding of the characteristics of the settled dusts, an initial survey study was conducted involving the application of thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) analysis for organic compound analysis, scanning electron microscopy (SEM), inductively coupled plasma-mass spectrometry (ICP-MS) for analysis of metals, and microbiological analysis. Airborne samples were also collected using sorbent tubes to determine organic compounds in air during activities such as cooking with kerosene, gas, and firewood as well as during electricity generation with fossil fuels. Carbon monoxide (CO) and ultrafine particles (UFPs) monitored simultaneously during some of the household activities. The study involved a novel method of extracting organic chemical emissions from dust by heating of the dusts directly in a micro chamber (μ-CTETM) and collection of emissions on sampling tubes. The method provided a relatively quick way of collecting chemical emissions from dusts that are readily available for release. The sampled tubes were analysed by TD/GC/MS. The conventional solvent extraction of the dusts was also carried out and the extracts were analysed by liquid injection-GC/MS and results of the two methods compared. The study determined a number of constituents (metals, SVOCs, phthalates and physical properties) of dusts collected from households in Damaturu during different weather events and from different indoor/outdoor locations; and compared with some UK samples. The samples investigated include dusts deposited; during two notable dusty-weather events (Harmattan and Storm) as well as when there was no notable dust event; during human activities; and dusts from different types of buildings (modern and traditional homes) as well as inside and outside homes. A standard reference material for organic chemicals (SRM 2585) was also analysed. The physical characterization of the settled house dust samples analysed revealed the various shapes and sizes, and elemental composition of the constituents, which included respirable particles. The microbial analysis also indicated the presence of the spores of a host of fungi and bacterial species; and the possible contributions of household activities to the increased production of pollutants (UFP and CO) ascertained. The μ-CTE extraction of the house dusts by heating with TD/GC/MS analysis of the emissions as well as the solvent extraction-GC/MS revealed the presence of many organic chemical compounds with different analytical retention times and varying concentrations in the dust samples. Chemicals of interest quantified: benzene, hexanal, nonanal, diethyl phthalate (DEP), diisobutylphthalate (DIBP), dibutylphthalate (DBP), and diethylhexylphthalate (DEHP). A host of other chemicals commonly present in the analysed samples identified using the NIST library associated with the MS system software. These chemicals included naphthalene and C10-C16 aliphatic and aromatic hydrocarbons, which would need confirmation by running the pure compound samples. There was an observed higher concentration of the chemicals in the solvent extracts than the μ-CTE extracted dust. The higher concentration of the chemicals in the solvent extracts expected due to the aggressive removal of the chemicals by the organic solvent whereas in the case of thermal extraction only the readily available chemicals (loosely bound to the matrix) released by increases in temperature were removed. Generally, the concentrations of the chemicals found were higher in the indoor than in the outdoor dust samples. In the analysis of the dusts collected during weather events; higher chemical concentrations observed in the samples collected during Harmattan period than the other periods. The Harmattan dust period may pose increased exposures to dust and possible health risks. More exposure is expected to occur in the traditional homes compared with the modern homes due to the higher concentrations of the chemicals in both the indoors and the outdoors and this may be especially important to women and children who spend most of their times at home. Metal analysis involved microwave-assisted digestion of the dust samples followed by ICP-MS analysis. The total quant method of metal analysis for a general profiling indicated the presence of more than 50 elemental contaminants in house dust. The results of the quantitative analysis for six target metals: Cd, Cr, Cu, Ni, Pb, and Zn showed their presence in all indoor and the outdoor dust samples. The mean concentrations showed that the metals were in higher concentrations in the indoor dusts than in the outdoor dusts. The quantitative analysis carried out indicated higher metal contents in the storm dusts than the dusts during the other periods. Results of the dusts collected from modern and traditional homes indicated the presence of the metals in higher concentrations in the dusts from traditional homes than the dusts from the modern homes. The estimated mean concentrations of the metals and phthalates inadvertently ingested as a constituent of dust indicated that some of the pollutants could exceed the tolerable daily intake (TDI) due to high exposures to dust expected to be the case in Damaturu. The results of the investigation of the dust composition, combined with information on exposure to dust and pollutants, show that dusts are a risk to the health of people in the Damataru community. Recommendations are made for more studies to provide a better understanding of dust ingestion and exposure to some phthalates and heavy metals in particular and the possible health risks. To the best of my knowledge, this is the first ever research study of airborne and settled dusts undertaken in North-Eastern Nigeria.
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Millis, Peter R. "Uncertainty in the estimation of bioavailability and its implications for human health risk assessment." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517002.
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Atabila, Albert. "Human Health Risk Assessment and Management of Chlorpyrifos Exposure among Rice Farmers in Ghana." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/378754.
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Pesticides are commonly applied in the agricultural sector of Ghana by farmers. Owing to weaknesses in regulations and unsafe practices, applicators of pesticides in the country are vulnerable to excessive exposure and consequent health risks. However, there is no information on the levels of pesticide exposure and associated health risks among applicators in Ghana. In addition, the rice sector of Ghanaian agriculture has been growing in recent years, with significant use of pesticides among commercial growers. Therefore, the objectives of this study were to evaluate the patterns, determinants, magnitude and health risks of pesticide exposure among rice farmers in Ghana. In order to achieve the objectives, a representative cross-section of small-scale farmers who grow rice with irrigation in the catchment area of Kpone Irrigation Scheme (KIS) were recruited for the study. The research was based on the four-step health risk assessment framework of the United States’ National Research Council, which is generally accepted by regulatory agencies and researchers. Thus, the research involved hazard identification, exposure assessment, dose-response assessment and risk characterization. The hazard identification study with the farmers (n = 214), which was carried out by questionnaire survey, showed that chlorpyrifos was the most widely used pesticide with usage prevalence of 83%. The study also showed that pesticides were applied under unsafe conditions and all applicators had experienced symptoms compatible with pesticide poisoning, as described by the WHO. Evaluation of exposure to chlorpyrifos among the applicators during a typical spray event was carried out, based on two approaches. These were (1) whole-body dosimetry assessment of dermal exposure, using Tyvek coverall, hand gloves and socks to sample chlorpyrifos residues of applicators (n = 24); and (2) urinary trichloro-2-pyridinol (TCP) assessment of overall exposure from six urine samples (one sample collected prior to application and five samples collected over five days after application) from each applicator (n = 21). The dermal exposure study showed that the percentage Unit Exposure (UE) value calculated from Total Dermal Exposure (TDE) was 0.03% and 0.06% among the median-exposed and the 5% highly-exposed groups, respectively. The study also indicated that the hands (39% of TDE) and the lower anatomical (82% of TDE) regions of the applicators were the most contaminated and potential sources of dermal exposure. The urinary TCP assessment indicated that the mean elimination half-life (t1/2) of chlorpyrifos in the body of the applicators was 50 hours, which is higher than those (27 to 43 hours) previously reported. The median absorbed dose of chlorpyrifos estimated from urinary TCP due to chronic background exposure (LADDB), chronic application exposure (LADDA) and acute application exposure (ADDA) were 0.2 μg/kg/day (mean ± S.D of 0.3 ± 0.4 μg/kg/day), 0.1 μg/kg/day (mean ± S.D of 0.3± 0.3 μg/kg/day) and 6 μg/kg/day (mean ± S.D of 19 ± 24 μg/kg/day). The absorbed daily dose of chlorpyrifos estimated from urinary TCP and whole-body dermal dosimetry methods produced similar exposure estimates, based on the means ± S.D (15±22 and 16±7 μg/kg/day, respectively), with applicators who participated in both evaluations. The levels of chlorpyrifos exposure from occupational application were positively influenced by the quantity of chlorpyrifos formulation applied, spraying duration, the number of spray tanks applied and the height of the crops sprayed (p < 0.05). To evaluate the dose-response of chlorpyrifos, exposure data from human epidemiological studies from the scientific literature were collated. The exposure data associated with adverse effects were expressed as Cumulative Probability Distributions (CPDs) to obtain the Toxicant Sensitivity Distributions (TSDs) of chlorpyrifos for chronic and acute adverse effects. A guideline value determined at the 5th percentile of the TSD for chronic and acute adverse effects was 0.5 and 2 μg/kg/day, respectively. These guideline values derived with the TSD method are directly applicable to humans without the need for safety factors. On the other hand, conventional guideline values established by regulatory institutions require the application of safety factors when the No Observable Adverse Effect Level (NOAEL) or Lowest Observable Adverse Effect Level (LOAEL) methods are used. Except for the guideline values set by the WHO which gave HQ < 1, those of the USEPA, APVMA and the TSD threshold dose at the 5th percentile gave HQ > 1, suggesting adverse health effects would be observed among the applicators. The percentages of the applicators who were likely to suffer adverse effects due to chlorpyrifos exposure were quantified with the Overall Risk Probability (ORP) and the Monte Carlo Simulation (MCS) techniques. The ORP and the MCS techniques showed that between 1 to 3%, 2 to 4% and 5 to 8% of the applicators were likely to suffer chronic adverse effects due to chlorpyrifos exposure from background, occupational application and combined exposure from background and occupational application, respectively. Such chronic health effects may include altered thyroid functions and reductions in estradiol levels, based on the TSD. Also, the ORP and MCS techniques showed that between 31 to 33% and 32 to 34% of the applicators were likely to suffer acute health effects due to exposure from occupational application and combined exposure from background as well as occupational application, respectively. Comparison of these values with the TSD suggests that the acute health effects likely to be suffered by the applicators can include depression of cholinesterase activity, sub-clinical neuropathy and memory problems, particularly with occupational exposure. Recommendations proposed for adoption by government institutions to help reduce pesticide exposure and associated health effects among the applicators, include provision of training and technical services to enhance adoption of Integrated Pest Management (IPM), promoting use of less toxic pesticides, regular training of farmers and Agricultural Extension Officers (AEOs) on pesticide safety and regular monitoring of exposure among applicators. It is also recommended that farmers should avoid excessive pesticide use, reduce spray duration, reduce number of spray tanks, practice good hygiene and use adequate PPE, particularly for the hands and the lower anatomical regions of the body.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Hamidin, Nasrul. "Human Health Risk Assessment of Trace Chemicals in the Residential Environment Using Probabilistic Techniques." Thesis, Griffith University, 2011. http://hdl.handle.net/10072/367102.
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Humans are exposed to a wide range of chemicals in the environment which may be hazardous to health. In this thesis two groups of chemicals from different mediums were investigated namely disinfection by-products (DBPs) in chlorinated drinking water and volatile aromatic hydrocarbons (VAHs) in residential indoor air.
The level of risk to human health was evaluated by health risk assessment using probabilistic techniques. In this thesis three factors were evaluated, (1) the exposure dose (EXPD) based on human exposure data (2) threshold Human Equivalent Dose (HED) based on test results on surrogate animals and (3) the dose-response using epidemiological data on adverse health responses as related to the threshold Lifetime Average Daily Dose (LADDH). The values obtained were plotted as cumulative probability (CP) relationships. The risk was characterized by three approach, (1) by comparison between EXPD with threshold HED and threshold LADDH, (2) by calculating the hazard quotient at 95/5 (HQ95/5) which was derived as the high exposure population from 95% from the cumulative probability of exposure doses (CP-EXPD) with the sensitive populations 5% from the human dose-response in terms of threshold cumulative probability Lifetime Average Daily Dose (CP-LADDH) and (3) by using hazard quotient by Monte Carlo techniques (HQMC) using Monte Carlo simulation via Crystal Ball software. Literature data on exposure concentrations from more than 10 countries and the adverse effects on animal laboratory experiments in terms of HED as well as human exposure and epidemiological studies in terms of LADDH were used in these evaluations.
With DBPs in chlorinated drinking water, EXPD was calculated from literature data from more than 10 countries and compared with threshold HED values from surrogate animals representing the threshold dose-response values for adverse effects. The highest human EXPD was lower than the threshold HED for TCM, BDCM, DBCM, TBM, DCAA and TCAA. All the threshold HED values were approximately 102 to 104 higher than EXPD at the 95% level. However, with the human epidemiology data, there was an overlap between the highest EXPD and the threshold LADDH representing the threshold dose-response values for adverse effects for TTHM, TCM, BDCM, DCAA and TCAA. This suggests that there are possible adverse health risks such as cancers and developmental effects on humans. The HQ95/5 values for TTHM, TCM and BDCM are 4.7, 5.7 and 9.2, respectively. This suggests that 5% of the human population has a high risk of adverse health effects. A similar result was also obtained for HQMC where the HQMC for TTHM (0.30>1), TCM (0.13>1) and DBCM (0.41>1) are higher than the unity value.
In the evaluation of VAHs from literature data, the comparison between the highest EXPD with the lowest threshold HED for adverse effects using surrogate animal data for ethylbenzene, mp-xylene, o-xylene and styrene shows no overlap. The lowest thresholds HED of these compounds are approximately 10 times higher than the EXPD at the 95% level. However, the maximum EXPD exceeded the threshold HED of benzene, toluene and naphthalene at the 60%, 94% and 30% respectively. Comparison was made using human exposure and human epidemiological data. The maximum EXPD exceeded the threshold LADDH derived from human health data for benzene and toluene only. This suggests that there are possible adverse health risks such as leukemia, developmental effect, aplastic anemia and chromosome aberration in blood. The HQ95/5 for benzene, toluene and styrene was 22.2, 1.2 and 0.3, respectively suggesting possible adverse effects in the 5% of the population.
In addition, the measurement of VAHs in the residential indoor air was also conducted for 32 houses in Brisbane. The total VAHs (TVAH) levels ranged between 2 to 137 g/m3 and were lower than the literature data on houses in Melbourne and Perth. The VAHs concentrations from indoor air of houses in Brisbane are higher than the outdoor ambient air. With an internal garage, the VAHs concentration is higher than the indoor air of the living room by 25 to 50% and may be a source of indoor VAHs due to the presence of motor vehicle in the garage. The age of the house was found to be positively related to VAHs concentrations in the house. The half-life of TVAH was found to be approximately 13 years.
The health risk assessment of VAHs in the indoor air of Brisbane houses was conducted using similar techniques to those used with the literature data for DBPs and VAHs. There was no overlap between maximum EXPD and thresholds HED dose-response data for all compounds except benzene and naphthalene. The lowest threshold HED for toluene, ethylbenzene, mp-xylene and o-xylene and styrene were found to be higher than the EXPD at 95% level by approximately 10 to 102. With benzene and naphthalene the maximum EXPD exceeded the threshold HED at the 95% and 85% respectively. An overlap was observed between maximum EXPD and threshold LADDH derived from human data for benzene only. The HQ95/5 for benzene, toluene and styrene are 2.7, 0.1 and 0.01 respectively. The HQ95/5 for benzene suggests 5% high exposure group in the human population has a high probability of risks of leukemia, developmental effect and aplastic anemia.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering.
Science, Environment, Engineering and Technology
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Ma, Yukun. "Human health risk of toxic chemical pollutants generated from traffic and land use activities." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/92724/1/Yukun_Ma_Thesis.pdf.
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The research project developed a quantitative approach to assess the risk to human health from heavy metals and polycyclic aromatic hydrocarbons in urban stormwater based on traffic and land use factors. The research outcomes are expected to strengthen the scientifically robust management and reuse of urban stormwater. The innovative methodology developed can be applied to evaluate human health risk in relation to toxic chemical pollutants in urban stormwater runoff and for the development of effective risk mitigation strategies.
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Till, Anne. "Dietary risk assessment of Discovery Health Medical Aid’s vitality members in South Afric." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86308.
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Thesis ( Mnutr)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Background: The rising prevalence of non-communicable diseases (NCD) is cause for concern. Improving dietary quality is a key health promotion strategy aimed at reducing NCD morbidity and mortality. Assessments that quantify “risky” dietary behaviours are worthwhile, and may help to identify high risk individuals, that would benefit from targeted interventions. Purpose: Discovery Vitality is a wellness incentive business associated with Discovery Health medical aid in South Africa. This study developed a Dietary Behaviour Score (DBSPHR) that measured degrees of compliance of Discovery Vitality members with the “spirit of dietary guidance”. It further categorized scores and identified members who may be at risk for developing NCDs due to poor dietary compliance. Methods: The DBSPHR included proportionally weighted components related to the consumption of fruit, vegetables, low fat dairy, whole-grain foods, lean meat, chicken and discretionary fat. The study population included adult South African members of Discovery Vitality, who had completed the programme’s on-line health risk assessment (PHR) between the 1st February 2010 and 31st January 2011. Stratified random sampling was used (n=1600). Half the sample included members who participated in Vitality’s HealthyFoodTM benefit (HFB) programme. The different Vitality Status groups were equally represented, and reflect degrees of engagement with the programme. Genders were equally represented. DBSPHR data were categorized as: Poor (Score 0-18), Inadequate (18.5-22.5), Fair (23-26), Good (26.5-29), Excellent (29.5-36). DBSPHR data was analyzed for variables: Vitality status, HFB participation, smoking, physical activity, alcohol consumption, body mass index (BMI), age and gender. The relationships between continuous response variables and nominal input variables were analysed using analysis of variance (ANOVA). When ordinal response variables were compared versus a nominal input variable, non-parametric ANOVA methods were used. Further, the Mann-Whitney test or the Kruskal-Wallis test was used. A p-value of p < 0.05 was considered to represent statistical significance, and 95% confidence intervals were used to describe the estimation of unknown parameters. Results: Of the sample, 67.13% of members had DBSPHRs that were considered “poor” or “inadequate”. The mean DBSPHR of the sample was 20.47 points. Women achieved better DBSPHRs than men (p<0.01). Greater engagement with the Vitality programme was associated with better DBSPHRs (p<0.01). There was no significant difference between the mean DBSPHR of members participating in the HFB and Non-HFB members, however the HFB was not assessed as an intervention. Members with “risky” lifestyle behaviours such as; inactivity, smoking and consuming alcohol excessively, demonstrated lower DBSPHR than members without these risks. Obese members achieved significantly lower DBSPHRs than normal weight and overweight members (p<0.01). Conclusions: It is concerning that Discovery Vitality members did not perform better than the general global standard of inadequate compliance with the “spirit of dietary guidance”. Engagement with the Vitality programme seems to positively impact on dietary compliance. Members at an increased risk for NCD morbidity and mortality due to; aging, obesity, smoking, inactivity or non-compliance with alcohol consumption guidelines, demonstrated lower DBSPHRs compared to members without these risks. Targeted interventions aimed at addressing “risky” dietary and lifestyle behaviours may benefit these members.
AFRIKAANSE OPSOMMING: Agtergrond: Die styging in voorkoms van nie-oordraagbare siektes (NOS) is rede tot kommer. Verbetering van dieetkwaliteit is ‘n sleutel gesondheidsbevordering strategie gemik daarop om NOS morbiditeit en mortaliteit te verminder. Assesserings wat “riskante” dieetgedrag kwantifiseer is waardevol en mag help om hoë risiko individue te identifiseer wat sal baatvind by geteikende intervensies. Doel: Discovery Vitality is ‘n welwees motiveringsbesigheid wat geassosieer is met Discovery Health mediese fonds in Suid-Afrika. Hierdie studie het ‘n dieet-gedragstelling (“Dietary Behaviour Score - DBSPHR”) ontwikkel wat die graad van nakoming van Discovery Vitality lede gemeet het aan die “gees van leiding oor dieet”. Dit het verder tellings gekategoriseer en lede geïdentifiseer wat ‘n verhoogde risiko vir die ontwikkeling van NOS mag hê as gevolg van swak nakoming van dieet. Metodes: Die DBSPHR het proporsioneel geweegde komponente bevat, verwant aan die inname van vrugte en groente, laevet suiwelprodukte, volgraan voedsels, maer vleis, hoender en diskresionêre vet. Die studiepopulasie het volwasse Suid-Afrikaners ingesluit wat lede van die Discovery Vitality program was en wat die program se aanlyn gesondheidsrisiko assessering tussen 1 Februarie 2010 en 31 Januarie 2011 voltooi het. Gestratifiseerde, ewekansige steekproeftrekking was gebruik (n=1600). Helfte van die steekproef het lede ingesluit wat aan Vitality se HealthyFoodTM voordeel program deelgeneem het. Die verskillende Vitality Status groepe was gelyk verteenwoordig en reflekteer verskillende grade van interaksie met die program. Geslagte was gelyk verteenwoordig. DBSPHRs data was gekategoriseer as: Swak (Telling 0-18), Onvoldoende (18.5-22.5), Matig (23-26), Goed (26.5-29), Uitstekend (29.5-36). DBSPHR data was vir die volgende veranderlikes geanaliseer: Vitality status, deelname aan die HealthyFoodTM voordeel, rook, fisiese aktiwiteit, alkohol inname, liggaamsmassa indeks (LMI), ouderdom en geslag. Die verhouding tussen aaneenlopende reaksie veranderlikes en nominale inset veranderlikes was geanaliseer deur die gebruik van analise van variansies (ANOVA). Wanneer ordinale reaksie veranderlikes vergelyk was teenoor ‘n nominale inset variansie, was nie-parametriese ANOVA metodes gebruik. Verder was die Mann-Whitney toets of die Kruskal-Wallis toets gebruik. ‘n P-waarde van p < 0.05 was gesien as verteenwoordigend van statistiese beduidendheid en 95% sekerheidsintervalle was gebruik om die skatting van onbekende parameters te beskryf.Resultate: Van die studie monster het 67.13% van die lede DBSPHRs getoon wat gereken was as “swak” of “onvoldoende”. Die gemiddelde DBSPHR van die steekfproef was 20.47 punte. Vroue het beter DBSPHR as mans behaal (p<0.01). Meer interaksie met die Vitality program was geassosieer met beter DBSPHRs (p<0.01). Daar was geen beduidende verskille tussen die gemiddelde DBSPHR van lede wat aan die HealthyFoodTM voordeel program deelneem en die lede wat nie aan die program deelneem nie, alhoewel die HealthyFoodTM voordeel nie geëvalueer was as ‘n intervensie nie. Lede met “riskante” lewenstyl gedrag soos onaktiwiteit, rook en hewige alkoholinname het laer DBSPHR getoon as lede sonder hierdie risiko’s. Vetsugtige lede het laer DBSPHR behaal as normale gewig en oorgewig lede (p<0.01). Gevolgtrekking: Dit is ‘n bron van kommer dat Discovery Vitality lede nie beter vertoon het as wat blyk ‘n algemene globale standaard van gebrekkige nakoming van die “gees van leiding oor dieet” te wees nie. Interaksie met die Vitality program blyk ‘n positiewe impak te hê op dieet nakoming. Lede wat ‘n verhoogde risiko gehad het vir NOS morbiditeit en mortaliteit as gevolg van veroudering, vetsugtigheid, rook, onaktiwiteit of verontagsaming van alkohol inname riglyne het ook laer DBSPHRs getoon in vergelyking met lede sonder hierdie risiko’s. Geteikende intervensies gemik op die aanspreek van riskante dieet en lewenstyl gedrag mag tot voordeel van hierdie lede wees.
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Schumann, Jennifer N. "An analysis of ergonomic risk factors relating to strains at Company XYZ." Menomonie, WI : University of Wisconsin--Stout, 2007. http://www.uwstout.edu/lib/thesis/2007/2007schumannj.pdf.
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Farsi, Nada. "Risk factors of head and neck cancer: highlighting the importance of human papilloma viruses." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97185.
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Objective: To investigate Head and Neck cancer (H&NC) risk factors, and whether they varied by anatomical site or HPV-status. Methods: Data from 150 H&NC cases and 161 controls were drawn from an ongoing hospital-based case-control study: "HeNCe". Socio-demographic, behavioural and environmental characteristics were collected through questionnaires. HPV was detected from oral cells. Results: Logistic regression models identified smoking [(OR=1.01, 95%CI:1.00-1.02) per pack-year], low education [(OR=2.58,95%CI:1.28-5.20) high school or less vs. university], HPV-infection [(OR=4.84,95%CI:2.56-9.14) any vs. no-HPV] and higher number of missing teeth [(OR=2.25,95%CI:1.22-4.17) >9 vs. 0-9] as the strongest H&NC risk factors. Forty-three percent of the cases were HPV-positive, with predominance for HPV-16. The main risk factors for pharyngeal, laryngeal and oral cancers tended to differ. The main risk factors for HPV-negative H&NC were smoking and number of missing teeth, while for HPV-positive H&NC they were sexual behaviour and low education. Conclusion: H&NC risk factors varied by site and HPV-status.Objectif: Étudier les facteurs de risque du cancer des voies aérodigestives supérieures (CVADS), et selon le site anatomique ou l'infection au VPH. Méthode: Les données concernant 150 cas de CVADS et 161 témoins (étude cas-témoin hospitalière « HeNCe ») comprenaient : caractéristiques sociodémographiques, comportementales, environnementales recueillies par entrevue; détection du VPH des cellules buccales. Résultats: Les facteurs de risque du CVADS identifiés par régression logistique étaient : tabagisme [Rapport de cotes (RC=1.01, 95%IC:1.00-1.02)/paquet-année], éducation [(RC=2.58, 95%IC:1.28-5.20) secondaire vs.université], VPH [(RC=4.84, 95%IC:2.56-9.14)] et nombre de dents manquantes [(RC=2.25, 95%IC:1.22-4.17) >9 vs.0-9]. Quarante-trois pourcent des cas étaient infectés au VPH, majoritairement VPH-16. Les facteurs de risque principaux différaient par site (pharynx, larynx, cavité buccale). Les CVADS VPH-négatifs étaient associés au tabagisme et nombre de dents manquantes; les CVADS VPH-positifs étaient liés au comportement sexuel et à l'éducation. Conclusion: Les facteurs de risque du CVADS différaient selon le site et l'infection au VPH.
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PALUMBO, ROBERTA. "HUMAN AND ANIMAL HEALTH RISK ASSESSMENT OF MYCOTOXIN MIXTURES IN MAIZE: FROM FUNGAL PRODUCTION AND OCCURRENCE TO HARMONISED RISK CHARACTERISATION." Doctoral thesis, Università Cattolica del Sacro Cuore, 2020. http://hdl.handle.net/10280/73545.
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Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. Dietary (co)-exposure to mycotoxins is associated with human and animal health concerns as well as economic losses. The present thesis aims to apply a holistic approach for the risk assessment of mycotoxin mixtures in food and feed, i.e. from fungal production and occurrence to harmonised risk characterisation. This was done in three folds. Firstly, available environmental, ecological, and agronomic factors that may affect the relative abundance of co-occurring mycotoxins in the contaminated crops were collected from peer-reviewed literature, with focus on maize (Chapter I). Secondly, (co-)occurrence data on mycotoxins in core cereals was extracted from available articles in the scientific literature and analysed to estimate potential pattern of co-exposure in humans and animals (Chapter II). Finally, Chapter III investigates the applicability of the EFSA guidance to multiple mycotoxins through a scenario of possible co-exposure in humans and animals, using maize as a case study. In particular, a human and animal risk assessment to mycotoxin mixture in maize was conducted using a modelled component-based approach for selected mixture of mycotoxins, that, according to our data, co-occur in maize based feed and food products.Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. Dietary (co)-exposure to mycotoxins is associated with human and animal health concerns as well as economic losses. The present thesis aims to apply a holistic approach for the risk assessment of mycotoxin mixtures in food and feed, i.e. from fungal production and occurrence to harmonised risk characterisation. This was done in three folds. Firstly, available environmental, ecological, and agronomic factors that may affect the relative abundance of co-occurring mycotoxins in the contaminated crops were collected from peer-reviewed literature, with focus on maize (Chapter I). Secondly, (co-)occurrence data on mycotoxins in core cereals was extracted from available articles in the scientific literature and analysed to estimate potential pattern of co-exposure in humans and animals (Chapter II). Finally, Chapter III investigates the applicability of the EFSA guidance to multiple mycotoxins through a scenario of possible co-exposure in humans and animals, using maize as a case study. In particular, a human and animal risk assessment to mycotoxin mixture in maize was conducted using a modelled component-based approach for selected mixture of mycotoxins, that, according to our data, co-occur in maize based feed and food products.
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PALUMBO, ROBERTA. "HUMAN AND ANIMAL HEALTH RISK ASSESSMENT OF MYCOTOXIN MIXTURES IN MAIZE: FROM FUNGAL PRODUCTION AND OCCURRENCE TO HARMONISED RISK CHARACTERISATION." Doctoral thesis, Università Cattolica del Sacro Cuore, 2020. http://hdl.handle.net/10280/73545.
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Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. Dietary (co)-exposure to mycotoxins is associated with human and animal health concerns as well as economic losses. The present thesis aims to apply a holistic approach for the risk assessment of mycotoxin mixtures in food and feed, i.e. from fungal production and occurrence to harmonised risk characterisation. This was done in three folds. Firstly, available environmental, ecological, and agronomic factors that may affect the relative abundance of co-occurring mycotoxins in the contaminated crops were collected from peer-reviewed literature, with focus on maize (Chapter I). Secondly, (co-)occurrence data on mycotoxins in core cereals was extracted from available articles in the scientific literature and analysed to estimate potential pattern of co-exposure in humans and animals (Chapter II). Finally, Chapter III investigates the applicability of the EFSA guidance to multiple mycotoxins through a scenario of possible co-exposure in humans and animals, using maize as a case study. In particular, a human and animal risk assessment to mycotoxin mixture in maize was conducted using a modelled component-based approach for selected mixture of mycotoxins, that, according to our data, co-occur in maize based feed and food products.Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. Dietary (co)-exposure to mycotoxins is associated with human and animal health concerns as well as economic losses. The present thesis aims to apply a holistic approach for the risk assessment of mycotoxin mixtures in food and feed, i.e. from fungal production and occurrence to harmonised risk characterisation. This was done in three folds. Firstly, available environmental, ecological, and agronomic factors that may affect the relative abundance of co-occurring mycotoxins in the contaminated crops were collected from peer-reviewed literature, with focus on maize (Chapter I). Secondly, (co-)occurrence data on mycotoxins in core cereals was extracted from available articles in the scientific literature and analysed to estimate potential pattern of co-exposure in humans and animals (Chapter II). Finally, Chapter III investigates the applicability of the EFSA guidance to multiple mycotoxins through a scenario of possible co-exposure in humans and animals, using maize as a case study. In particular, a human and animal risk assessment to mycotoxin mixture in maize was conducted using a modelled component-based approach for selected mixture of mycotoxins, that, according to our data, co-occur in maize based feed and food products.
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Godin, Stephen Joseph DeVito Michael J. "Species differences in the metabolism of pyrethroid pesticides potential implications for human health risk assessment /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,2168.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Feb. 26, 2009). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Curriculum in Toxicology." Discipline: Toxicology; Department/School: Medicine.
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Serra, Stefania <1985>. "Air Pollution and Human Health Risk: Evaluation of Carcinogenic Potential of Urban Airborne Particulate Matter." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7364/6/serra_stefania_tesi.pdf.
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Urban airborne particulate matter (PM) is known to increase morbidity and mortality due to cardiopulmonary diseases related to inflammatory processes and genotoxic effects.
The aim of this thesis is to highlight the toxic and carcinogenic potential of airborne particulate matters collected during different seasons at a site that is located in the northern area of the city of Bologna by using alternative in vitro tests, such as the cell transformation assay with BALB/c 3T3 A31-1-1 and Bhas 42 cells. The purpose is also to evaluate the lifetime cancer risks associated with air inhalation in different sites (rural and urban), by using the relative potency of compounds belonging to the same chemical class (PAHs and nitro-PAHs) and the specific unit of carcinogenic risk.
None of the organic or inorganic extracts of PM2.5 and PM1 induced a significant increase in the average number of transformed foci/plate or in the transformation frequency of BALB/c 3T3 A311-1 cells, whereas the results obtained by Bhas 42 cell transformation showed a significant increase in the average number of transformed foci/plate. All the analyzed organic extracts showed promoting effects in Bhas 42 cells.
The application of the UR cancer risk to the transformed value of B(a)P equivalents in the winter– autumn campaigns leads to estimate an increase in the cancer risk similar to that defined in the literature (1 x 10-4 for exposure to 1 ng/m3). The calculated cancer risk was about one order of magnitude lower in the summer campaigns.
In conclusion, the proposed approach, based on the integration of the data derived from in vitro testing and cancer risk assessment, could represent a reliable model for investigating environmental mixtures and predicting their effects on toxicological relevant endpoints.
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Serra, Stefania <1985>. "Air Pollution and Human Health Risk: Evaluation of Carcinogenic Potential of Urban Airborne Particulate Matter." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7364/.
Full textAbstract:
Urban airborne particulate matter (PM) is known to increase morbidity and mortality due to cardiopulmonary diseases related to inflammatory processes and genotoxic effects.
The aim of this thesis is to highlight the toxic and carcinogenic potential of airborne particulate matters collected during different seasons at a site that is located in the northern area of the city of Bologna by using alternative in vitro tests, such as the cell transformation assay with BALB/c 3T3 A31-1-1 and Bhas 42 cells. The purpose is also to evaluate the lifetime cancer risks associated with air inhalation in different sites (rural and urban), by using the relative potency of compounds belonging to the same chemical class (PAHs and nitro-PAHs) and the specific unit of carcinogenic risk.
None of the organic or inorganic extracts of PM2.5 and PM1 induced a significant increase in the average number of transformed foci/plate or in the transformation frequency of BALB/c 3T3 A311-1 cells, whereas the results obtained by Bhas 42 cell transformation showed a significant increase in the average number of transformed foci/plate. All the analyzed organic extracts showed promoting effects in Bhas 42 cells.
The application of the UR cancer risk to the transformed value of B(a)P equivalents in the winter– autumn campaigns leads to estimate an increase in the cancer risk similar to that defined in the literature (1 x 10-4 for exposure to 1 ng/m3). The calculated cancer risk was about one order of magnitude lower in the summer campaigns.
In conclusion, the proposed approach, based on the integration of the data derived from in vitro testing and cancer risk assessment, could represent a reliable model for investigating environmental mixtures and predicting their effects on toxicological relevant endpoints.
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Esber, Allahna Lauren. "HPV risk factors and screening among Malawian women." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1458645591.
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Mallya, Shruti. "Modelling Human Risk of West Nile Virus Using Surveillance and Environmental Data." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35734.
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Limited research has been performed in Ontario to ascertain risk factors for West Nile Virus (WNV) and to develop a unified risk prediction strategy. The aim of the current body of work was to use spatio-temporal modelling in conjunction with surveillance and environmental data to determine which pre-WNV season factors could forecast a high risk season and to explore how well mosquito surveillance data could predict human cases in space and time during the WNV season. Generalized linear mixed modelling found that mean minimum monthly temperature variables and annual WNV-positive mosquito pools were most significantly predictive of number of human WNV cases (p<0.001). Spatio-temporal cluster analysis found that positive mosquito pool clusters could predict human case clusters up to one month in advance. These results demonstrate the usefulness of mosquito surveillance data as well as publicly available climate data for assessing risk and informing public health practice.
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Roa, Nadia C. "Human Health Risk Assessment for Petroleum Refining Industry of the Remaining Air Toxics after MACT I Emissions Reductions." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/849.
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Inhalation risks on human health for hazardous air pollutants emitted from MACT I petroleum refining industry were determined using EPA HEM-3 Program. Methodology included compiling vertical and fugitive emissions from 2002 National Emissions Inventory for sources inside two facilities in Louisiana, 'Motiva Norco' and 'Valero St. Charles' refineries. Six cases were modeled applying EPA criteria, where cancer risks are 'low' if the probability is. 1/1, 000, 000, and non-cancer risks are harmful when hazard quotient is > 1. It was demonstrated that fugitive emissions have more impact on human health than the verticals because of their significant portion of the total refining emissions. HAPs can cause moderate adverse effects in humans living nearby refineries, as 113 people resulted in high risk of respiratory problems with Valero emissions, 4571 people resulted in 'moderate' risk of getting cancer with Motiva emissions, 2702 people with Valero emissions, and 11, 282 people with both refineries' emissions.
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HACON, BIANCA DE SOUZA. "INFLUENCE OF THE SOIL PHYSICAL PARAMETERS IN RISK TO HUMAN HEALTH IN AREAS CONTAMINATED BY PAHS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33908@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
No Brasil, os riscos à saúde humana resultantes da exposição a compostos químicos vêm sendo abordados há poucos anos. Em 2009 foi publicada a Resolução CONAMA 420 que deu início à regulamentação desta prática e em 2013 o procedimento de avaliação de riscos à saúde humana em áreas contaminadas foi normatizado através da NBR 16209. Esta dissertação apresenta um estudo de avaliação de risco à saúde humana a partir de um estudo de caso de uma área contaminada com hidrocarbonetos policíclicos aromáticos (HPAs), considerando a exposição de futuros trabalhadores da área. Diante dos resultados obtidos foi realizada uma análise de sensibilidade dos parâmetros do meio físico da área de estudo para que fosse possível determinar e recomendar quais devem ser melhor investigados em estudos de áreas contaminadas com HPAs. Os resultados de risco à saúde humana mostraram que a rota de exposição mais crítica para o estudo de caso é a inalação de vapores em ambientes fechados, devido à ocorrência de compostos de baixo peso molecular, como o naftaleno. A análise de sensibilidade mostrou que o parâmetro do meio físico que exerceu maior influência nos resultados de risco à saúde humana foi a fração de carbono orgânico (FOC). Quanto maior a FOC menor foi o risco por inalação em ambientes abertos, fechados ou contato direto com a água subterrânea.
In Brazil, the risks to human health from exposure to chemical compounds have been discussed since few years ago. In 2009 federal resolution CONAMA 420 was published, starting the regulation of this practice, and in 2013 the procedure of human health risk assessment (HHRA) in contaminated areas was regulated by the Brazilian Regulatory Standard (NBR) 16209. This dissertation presents a HHRA for a case study of an area contaminated with Polycyclic Aromatic Hydrocarbons (PAHs), considering the exposure of future workers in the area. Based on the results a sensitivity analysis of the soil physical parameters of the study area was performed to determine and recommend which of the parameters should be further investigated in studies of areas contaminated with PAHs. The results of the HHRA showed that the most critical exposure pathway to case study is the inhalation of indoor air due to the occurrence of low molecular weight compounds such as naphthalene. The sensitivity analysis showed that the soil physical parameter that had greater influence on the risk results was the fraction of organic carbon (FOC). The higher the FOC the lower was the risk for inhalation in outdoor spaces, enclosed spaces or direct contact with groundwater.
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Louw, E. J. M. "Climate change in the Western Cape : a disaster risk assessment of the impact on human health." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1158.
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Thesis (DPhil (Geography and Environmental Studies))—University of Stellenbosch, 2007.Background The Disaster Management Act (Act 57 of 2002) instructs a paradigm shift from preparedness, response and recovery towards risk reduction. In order to plan for and mitigate risks, all spheres of government must firstly assess their hazards, vulnerabilities, capacity to cope and therefore risks. Studies in this regard, in South Africa, have however only focussed on current risks. Climate Change has now been accepted by leading international studies as a reality. Climate change can impact upon many aspects of life on earth. Studies to quantify the impact of climate change on water resources, biodiversity, agriculture and sustainable development are steadily increasing, but human health seem to have been neglected. Only general predictions, mostly regarding vector-borne disease and injury related to natural disasters are found in literature. Studies in South Africa have only focussed on malaria distribution. Most studies, internationally and the few in South Africa, were based on determining empirical relationships between weather parameters and disease incidence, therefore assessing only the hazard, and not the disaster risk. Methodology This study examines the impact of climate change on human health in the Western Cape, within the context of disaster management. A qualitative approach is followed and includes: · A literature overview examining predicted changes in climate on a global and regional scale, · A discussion on the known relationships and possible impacts climate change might have on human health, · A disaster risk assessment based on the status quo for a case study area, the Cape Winelands District Municipality, · An investigation into the future risks in terms of health, taking into account vulnerabilities and secondary impacts of climate change, resulting in the prioritisation of future risks. · Suggestions towards mitigation within the South African context. Results The secondary impacts of climate change were found to have the larger qualitative impact. The impact of climate change on agriculture, supporting 38% of the population can potentially destroy the livelihoods of the workforce, resulting in poverty-related disease. Other impacts identified were injuries and disease relating to temperature, floods, fire and water quality. Conclusion Risk is a function of hazard, vulnerability and capacity to cope. The impact of an external factor on a ‘spatial system’ should be a function of the impacts on all these factors. Disasters are not increasing because of the increase in the frequency of hazards, but because of the increasing vulnerability to hazards. This study illustrated that the major impacts of the external factor could actually be on the vulnerabilities and the indirect impacts, and not on the hazard itself. Climate change poses a threat to many aspects of the causative links that should be addressed by disaster management, and its impacts should be researched further to determine links and vulnerabilities. This research also illustrates that slow onset disasters hold the potential to destroy just as much as extreme events such as Katrina, Rita or a tsunami. It also reiterates that secondary impacts may not be as obvious, but are certainly not of secondary importance.
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Aldaihani, Humoud Melfi Zayedd. "A geotechnical, geochemical and human health risk assessment of a dry oil lake site in Kuwait." Thesis, University of Portsmouth, 2017. https://researchportal.port.ac.uk/portal/en/theses/a-geotechnical-geochemical-and-human-health-risk-assessment-of-a-dry-oil-lake-site-in-kuwait(97d404f4-4b60-4a92-b82d-1a7996bb0729).html.
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The main contribution of this study is to evaluate the effects of hydrocarbon contamination of soil with respect to geotechnical and geochemical properties and their impact on human health resulting from the Iraqi invasion of Kuwait in 1990. To fulfil this goal, the geotechnical and geochemical characteristics of soil at a dry oil lake have been investigated. The Human Health Risk Assessment (HHRA) was investigated utilising Risk Integrated Software for Soil Clean-up Version-5 (RISC-5) to evaluate the effects of hydrocarbon contamination on human health via ingestion of soil, dermal contact with soil, ingestion of vegetables, inhalation of outdoor air and inhalation of particulates pathways. In order to study these variations, two neighbouring sites at Al-Magwa area on the Greater Burgan Oil Field were selected. The first was chosen for a dry oil lake scenario, and the other adjacent site as an uncontaminated baseline control. Geotechnical tests were implemented on samples taken at different depths from both sites. These included Atterberg Limit, Particle Size Distribution (PSD), permeability and shear strength. Electronic micrographs were also taken for the upper layer (0.0 m depth). The geochemical investigations included Hydrogen Ion Concentration (pH), water soluble Chloride and Sulphate content, Vario Macro Elemental Analysis (EA) and Gas Chromatograph Mass Spectrometry (GC-MS). GC-MS was carried out to determine the specific hydrocarbon compounds and their concentrations within the soil. These values formed the basis of a HHRA. The geotechnical results show that hydrocarbon contamination modifies the PSD together with a decrease in the angle of internal friction (φ). The geochemical results confirm that the hydrocarbon contamination causes a change in the pH, with the Chloride and Sulphate contents and hydrocarbon concentrations decreasing with depth. The HHRA demonstrated that certain hydrocarbon compositions at elevated levels encountered in the dry oil lake site had potential effects with regard to non-carcinogenic risks. The geotechnical and geochemical characterisation data used in this study are also analysed quantitatively using IBM SPSS Statistics in order to support robust results. The statistical analysis confirms that all the results are solid and compatible.
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Pokhrel, Lok R., Brajesh Dubey, and Phillip R. Scheuerman. "Pharmaceuticals in the Aquatic Environment: A Critical Appraisal of Uncertainty and Knowledge Gaps in Human Health Risk Assessment." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etsu-works/2882.
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Weddell, Chad Allen. "Evaluation of Soil as a Risk Indicator for Human Leptospirosis in Coastal, Rural Ecuador." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5795.
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Leptospirosis, a zoonotic disease caused by pathogenic spirochete bacteria (family Leptospiraceae, genus Leptospira), is endemic in developing tropical regions of the world. It occurs in epidemics and is endemic in Ecuador where environmental conditions are ideal for maintenance. The role of soil as a long term reservoir has been previously been documented. Geographic Information System (GIS) and Remote Sensing (RS) technology was used in our study to further explore the role of soil as an environmental reservoir and its potential use as a static risk indicator for disease. Red, Green, Blue (RGB) spectral band data from known leptospire positive soil sites were extracted from high resolution satellite images and used to construct the first ever remotely dependent soil-based model. The soil co-variates failed to demonstrate statistical significance; however, elevation was found to be statistically significant. The soil type most associated with soil samples where leptospire DNA was detected using real-time PCR analysis was cambisol, a soil type with a common distribution in Ecuador and Africa. This exploratory analysis presented a novel idea of combining environmental microbiological sampling and GIS/RS technology to better examine static risk indicators such as soil. Further analysis is warranted based on spatial relationships noted.
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Ricci, Christiana Lea. "ASSESSING THE INFLUENCE OF PARENT/GUARDIAN VARIABLES ON SELECT TYPE 2 DIABETES RISK FACTORS AMONG 10 TO 14 YEAR OLD NORTHERN PLAINS INDIAN YOUTH." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-06112009-173623/.
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Type 2 diabetes (T2DM) is a growing health concern among American Indian populations. Many behavioral risk factors for T2DM are influenced by the family unit. Purpose: The purpose of this study was to assess the influence of certain parent/guardian variables on youth type 2 diabetes risk factors. Methods: The parents/guardians of 10-14 year old Northern Plains American Indian youth (n=37) were surveyed regarding their knowledge for physical activity and nutrition, support behaviors for physical activity and nutrition in their youth, and their individual physical activity and nutrition behaviors. Youth variables including physical activity behavior, dietary behavior, and body mass index percentile-for-age (BMI %ile) were also collected. Results: Higher levels of parent/guardian physical activity support were correlated with higher youth BMI %ile (r= 0.433, p=0.013). Parent/guardian nutrition support was also significantly correlated with higher youth BMI %ile as well (r=0.406, p=0.021). Parent/guardian physical activity support and nutrition support were not significantly correlated (p>0.05) with youth physical activity behavior or dietary behavior. Parent/guardian knowledge about physical activity and nutrition was not associated with youth physical activity, youth dietary intake, or youth BMI %ile. Parent/guardian nutrition behaviors and physical activity behaviors were also not significantly correlated with youth physical activity, dietary intake, or BMI %ile. Discussion: The results for parent/guardian support to be associated with higher youth BMI %ile were unexpected and deserve attention in future research to evaluate the motivating forces behind parent/guardian support of youth physical activity and nutrition. Although parents/guardians have an influential role in the lives of adolescents, this role did not translate broadly to measurable outcomes concerning T2DM risk factors for the 10-14 year old Northern Plains American Indian youth in the study. While this study was not conclusive regarding the influence of parent/guardian factors on youth disease risk factors, this topic merits further research in light of the increasing incidence of T2DM among American Indian youth.
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Altaner, Stefan [Verfasser]. "Cyanobacterial microcystins and human health : First steps towards a congener dependent risk assessment of microcystins / Stefan Altaner." Konstanz : KOPS Universität Konstanz, 2019. http://d-nb.info/1199266515/34.
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Lee, Robert F. "Human health and coastal ecosystem risk assessment of the Massachusetts Military Reservation main base landfill groundwater plume." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/41358.
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Hines, James J. (James Joseph). "Uncertainty of risk to human health from groundwater impacted by the Massachusetts Military Reservation Superfund site landfill." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39060.
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Phan, Kim Anh, and Thanh Giao Nguyen. "Groundwater quality and human health risk assessment related to groundwater consumption in An Giang province, Viet Nam." Technische Universität Dresden, 2018. https://tud.qucosa.de/id/qucosa%3A33342.
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Groundwater is one of the main sources for water supply for domestic use, irrigation, aquaculture and industry in Mekong Delta. With rapidly increasing in human population, groundwater becomes more important for social and economic activities. This study evaluated the quality of groundwater using data from the eight monitoring wells over the period of 2009 - 2016. Human health risk was assessed for the population consuming groundwater contaminated with arsenic. The findings indicated that groundwater wells in An Giang province were contaminated with microorganisms. The total dissolved solids (TDS) and hardness in Phu Tan (PT) and Cho Moi (CM) wells were significant higher than the national technical regulations on groundwater quality (QCVN 09-MT:2015/BTNMT). In addition, groundwater wells in some small islands of An Giang were seriously contaminated with organic matters and arsenic. The mean arsenic concentration was up to 0.55 ± 1.21 mg/L. Estimation of carcinogenic risk for human population showed that the cancer risks ranged from medium (8.66 x 10-4) to high (8.26 x 10-2) for both children and adults. Alternative water supply sources should be offered for the population at risk. Besides, regular health check is essential for local people in the arsenic contaminated groundwater.Nước ngầm là một trong những nguồn cung cấp nước chính cho sinh hoạt, tưới tiêu, nuôi trồng thủy sản và công nghiệp ở Đồng bằng sông Cửu Long. Cùng với sự gia tăng dân số, nước ngầm ngày càng đóng vai trò quan trọng hơn trong các hoạt động phát triển kinh tế - xã hội. Nghiên cứu đã tiến hành đánh giá diễn biến chất lượng nước ngầm thông qua số liệu của tám giếng quan trắc trong giai đoạn từ năm 2009 – 2016. Kết hợp với đánh giá rủi ro sức khỏe của người dân khi sử dụng nước ngầm chứa arsenic. Kết quả nghiên cứu cho thấy các giếng nước ngầm ở tỉnh An Giang đã bị nhiễm vi sinh. Tổng chất rắn hòa tan (TDS) và độ cứng ở trạm Phú Tân và Chợ Mới phân tích được cao hơn quy chuẩn cho phép (QCVN 09-MT:2015/BTNMT). Các giếng nước ngầm ở một số khu vực cù lao của tỉnh An Giang đã bị ô nhiễm hữu cơ và arsenic nghiêm trọng. Nồng độ arsenic trong nước ngầm có thể dao động lên đến 0.55 ± 1.21 mg/L. Rủi ro ung thư ở hai đối tượng người lớn và trẻ em khi sử dụng nước ngầm nhiễm arsenic dao động từ trung bình (8 người trong 1.000 người) tới cao (8 người trong 100 người). Cung cấp nguồn nước thay thế là giải pháp khả thi để giảm rủi ro sức khỏe cho con người trong trường hợp này. Ngoài ra, người dân địa phương cần được khám sức khỏe thường xuyên để kịp thời phát hiện và sớm điều trị bệnh.
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Majnemer, Annette. "The prognostic significance of multi-modality evoked response testing in high risk newborns /." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74333.
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In a previous prospective study from our laboratory, the prognostic significance of the auditory brainstem evoked response (ABR) was assessed in high risk neonates. An abnormal ABR predicted neurologic sequelae at 1 year; however there were false negatives. In this study, somatosensory evoked responses (SER) were performed together with the ABR so that a wider distribution of the nervous system could be evaluated. Testing was carried out on healthy and high risk neonates in the newborn period and in infancy. Infants were subsequently evaluated in a blind fashion at 1 year of age by a pediatric neurologist and psychologist. As part of this study, normative data and reliable testing procedures needed to be established. The effect of gestational age on evoked responses performed in the newborn period was also determined.The results demonstrated that the ABR and SER can be reliably recorded in newborns. Latency and morphological changes on serial testing reflected maturation of the nervous system. Chi square analysis revealed that an abnormal SER or ABR predicted neuromotor impairment at 1 year of age. The type of SER abnormality further delineated the degree of disability. A normal SER and ABR predicted normal neurodevelopmental outcome. In conclusion, multi-modality evoked response testing yielded valuable prognostic information for the newborn at high risk for neurologic sequelae.
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Johnstone, Kelly Rose. "Organophosphate exposure in Australian agricultural workers : human exposure and risk assessment." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16345/1/Kelly_Johnstone_Thesis.pdf.
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Organophosphate (OP) pesticides, as a group, are the most widely used insecticides in Australia. Approximately 5 000 tonnes of active ingredient are used annually (Radcliffe, 2002). The OP pesticide group consists of around 30 identifiably distinct chemicals that are synthesised and added to approximately 700 products (Radcliffe, 2002). OP pesticides are used on fruit, vegetable, grain, pasture seed, ornamental, cotton, and viticultural crops, on livestock and domestic animals, as well as for building pest control.
OP pesticides all act by inhibiting the nervous system enzyme acetylcholinesterase (AChE) and as such are termed anticholinesterase insecticides. The phosphorylation of AChE and the resultant accumulation of acetylcholine are responsible for the typical symptoms of acute poisoning with OP compounds. In addition to acute health effects, OP compound exposure can result in chronic, long-term neurological effects.
The traditional method of health surveillance for OP pesticide exposure is blood cholinesterase analysis, which is actually biological effect monitoring. However, there are several drawbacks associated with the use of the blood cholinesterase test, including its invasive nature, the need for baseline levels and a substantial exposure to OP pesticide before a drop in cholinesterase activity can be detected. OP pesticides are metabolised fairly rapidly by the liver to form alkyl phosphates (DAPs). Approximately 70% of OP pesticides in use in Australia will metabolise into one or more of six common DAPs. During the last 30 years, scientists have developed a urine test that detects these six degradation products. However, unlike the blood cholinesterase test, there is currently no Biological Exposure Index (BEI) for the urine DAP metabolite test.
Workers in the agricultural industry - particularly those involved with mixing, loading and application tasks - are at risk of exposure to OP pesticides. It is therefore important that these workers are able to assess their risk of health effects from exposure to OP pesticides. However, currently in Queensland, workplace health and safety legislation exempts the agricultural industry from hazardous substance legislation that incorporates the requirement to perform risk assessments and health surveillance (blood cholinesterase testing) for OP pesticide exposure.
The specific aim of this research was to characterise OP pesticide exposure and to assess the feasibility of using urine DAP metabolite testing as a risk assessment tool for agricultural and related industry workers exposed to OP pesticides. An additional aim among farmers was to conduct an in-depth evaluation of their knowledge, attitudes and behaviours related to handling OP pesticides and how they assess the risks associated with their use of OPs.
A cross-sectional study design was used to assess exposure to OP pesticides and related issues among four groups: fruit and vegetable farmers, pilots and mixer/loaders, formulator plant staff and a control group. The study involved 51 farmers in the interviewer-administered questionnaire and 32 in urine sample provision. Eighteen pilots and mixer/loaders provided urine samples and 9 exposed formulation plant staff provided urine and blood samples. Community controls from Toowoomba Rotary clubs provided 44 urine samples and 11 non-exposed formulation plant staff provided blood and urine samples; all groups also provided responses to a self-administered questionnaire.
Participant farmers were drawn from the main cropping areas in south-east Queensland - Laidley/Lowood, Gatton, and Stanthorpe. The farmer group was characterised by small owner-operators who often had primary responsibility for OP pesticide mixing and application. Farmers had good knowledge of pesticide-related safety practices; however, despite this knowledge, use of personal protective equipment (PPE) was low. More than half of the farmers did not often wear a mask/respirator (56%), gloves (54%) or overalls (65%). Material Safety Data Sheets were never or rarely read and 88.2% of farmers never or rarely read OP pesticide labels before application. There were also problems with chemical suppliers providing farmers with MSDSs. The majority of farmers (90.2%) reported that they had never had any health surveillance performed and three-quarters had never read about or been shown how to perform a formal risk assessment.
The main inhibitors to the use of PPE in the farmers' group included the uncomfortable and cumbersome nature of PPE, especially in hot weather conditions, and the fear of PPE use triggering neighbours' complaints to Government authorities. Factors associated with better PPE use included having positive attitudes and beliefs toward PPE use, higher knowledge scores and low risk perception.
Farmers' use of OP pesticides was infrequent, of short duration and involved application via a boom on a tractor, a lower risk application method. Consequently, urine DAP metabolite levels in this group were generally low, with 36 out of 96 samples (37.5%) containing detectable levels. Detectable results ranged from 9.00-116.00 mol/mol creatinine.
Formulators exposed to OP pesticides were found to have the highest urine DAP metabolite levels (detectable levels 13.20-550.00 mol/mol creatinine), followed by pilots and mixer/loaders (detectable levels 8.40-304.00 mol/mol creatinine) and then farmers. Despite this, pilots and mixer/loaders (particularly mixer/loaders) had the greatest number of samples containing detectable levels (94.4% of samples). The DAP metabolite most frequently detected across all groups was DMTP, which was the only metabolite found in control samples.
Levels found in this study are similar to those reported in international research (Takamiya, 1994, Stephens et al., 1996, Simcox et al., 1999, Mills, 2001, Cocker et al., 2002). The observed DAP levels were not associated with a drop in cholinesterase activity among the formulation plant workers, as expected from the literature. Such exposure also is unlikely to be associated with acute health effects. In contrast, there is insufficient scientific knowledge to know whether levels recorded in this study and elsewhere may be associated with long-term, chronic health effects.
Notably, DMTP levels also were observed among the presumably 'unexposed' comparison groups. Environmental background level exposures to OPs producing the DAP metabolite DMTP are therefore of potential significance and may be related, at least in part, to consumption of contaminated fruit and vegetables. There is also emerging evidence to suggest that exposure to DAP metabolites themselves through diet and other sources may contribute to the concentration of DAPs, including DMTP in urine, potentially complicating assessment of occupational exposures. Nevertheless, the urine DAP metabolite test was a useful, sensitive indicator of occupational OP pesticide exposure among agricultural workers and may be of use to the industry as part of the risk assessment process. Future research should aim to establish a BEI for the urine DAP test.
48
Johnstone, Kelly Rose. "Organophosphate exposure in Australian agricultural workers : human exposure and risk assessment." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16345/.
Full textAbstract:
Organophosphate (OP) pesticides, as a group, are the most widely used insecticides in Australia. Approximately 5 000 tonnes of active ingredient are used annually (Radcliffe, 2002). The OP pesticide group consists of around 30 identifiably distinct chemicals that are synthesised and added to approximately 700 products (Radcliffe, 2002). OP pesticides are used on fruit, vegetable, grain, pasture seed, ornamental, cotton, and viticultural crops, on livestock and domestic animals, as well as for building pest control. OP pesticides all act by inhibiting the nervous system enzyme acetylcholinesterase (AChE) and as such are termed anticholinesterase insecticides. The phosphorylation of AChE and the resultant accumulation of acetylcholine are responsible for the typical symptoms of acute poisoning with OP compounds. In addition to acute health effects, OP compound exposure can result in chronic, long-term neurological effects. The traditional method of health surveillance for OP pesticide exposure is blood cholinesterase analysis, which is actually biological effect monitoring. However, there are several drawbacks associated with the use of the blood cholinesterase test, including its invasive nature, the need for baseline levels and a substantial exposure to OP pesticide before a drop in cholinesterase activity can be detected. OP pesticides are metabolised fairly rapidly by the liver to form alkyl phosphates (DAPs). Approximately 70% of OP pesticides in use in Australia will metabolise into one or more of six common DAPs. During the last 30 years, scientists have developed a urine test that detects these six degradation products. However, unlike the blood cholinesterase test, there is currently no Biological Exposure Index (BEI) for the urine DAP metabolite test. Workers in the agricultural industry - particularly those involved with mixing, loading and application tasks - are at risk of exposure to OP pesticides. It is therefore important that these workers are able to assess their risk of health effects from exposure to OP pesticides. However, currently in Queensland, workplace health and safety legislation exempts the agricultural industry from hazardous substance legislation that incorporates the requirement to perform risk assessments and health surveillance (blood cholinesterase testing) for OP pesticide exposure. The specific aim of this research was to characterise OP pesticide exposure and to assess the feasibility of using urine DAP metabolite testing as a risk assessment tool for agricultural and related industry workers exposed to OP pesticides. An additional aim among farmers was to conduct an in-depth evaluation of their knowledge, attitudes and behaviours related to handling OP pesticides and how they assess the risks associated with their use of OPs. A cross-sectional study design was used to assess exposure to OP pesticides and related issues among four groups: fruit and vegetable farmers, pilots and mixer/loaders, formulator plant staff and a control group. The study involved 51 farmers in the interviewer-administered questionnaire and 32 in urine sample provision. Eighteen pilots and mixer/loaders provided urine samples and 9 exposed formulation plant staff provided urine and blood samples. Community controls from Toowoomba Rotary clubs provided 44 urine samples and 11 non-exposed formulation plant staff provided blood and urine samples; all groups also provided responses to a self-administered questionnaire. Participant farmers were drawn from the main cropping areas in south-east Queensland - Laidley/Lowood, Gatton, and Stanthorpe. The farmer group was characterised by small owner-operators who often had primary responsibility for OP pesticide mixing and application. Farmers had good knowledge of pesticide-related safety practices; however, despite this knowledge, use of personal protective equipment (PPE) was low. More than half of the farmers did not often wear a mask/respirator (56%), gloves (54%) or overalls (65%). Material Safety Data Sheets were never or rarely read and 88.2% of farmers never or rarely read OP pesticide labels before application. There were also problems with chemical suppliers providing farmers with MSDSs. The majority of farmers (90.2%) reported that they had never had any health surveillance performed and three-quarters had never read about or been shown how to perform a formal risk assessment. The main inhibitors to the use of PPE in the farmers' group included the uncomfortable and cumbersome nature of PPE, especially in hot weather conditions, and the fear of PPE use triggering neighbours' complaints to Government authorities. Factors associated with better PPE use included having positive attitudes and beliefs toward PPE use, higher knowledge scores and low risk perception. Farmers' use of OP pesticides was infrequent, of short duration and involved application via a boom on a tractor, a lower risk application method. Consequently, urine DAP metabolite levels in this group were generally low, with 36 out of 96 samples (37.5%) containing detectable levels. Detectable results ranged from 9.00-116.00 mol/mol creatinine. Formulators exposed to OP pesticides were found to have the highest urine DAP metabolite levels (detectable levels 13.20-550.00 mol/mol creatinine), followed by pilots and mixer/loaders (detectable levels 8.40-304.00 mol/mol creatinine) and then farmers. Despite this, pilots and mixer/loaders (particularly mixer/loaders) had the greatest number of samples containing detectable levels (94.4% of samples). The DAP metabolite most frequently detected across all groups was DMTP, which was the only metabolite found in control samples. Levels found in this study are similar to those reported in international research (Takamiya, 1994, Stephens et al., 1996, Simcox et al., 1999, Mills, 2001, Cocker et al., 2002). The observed DAP levels were not associated with a drop in cholinesterase activity among the formulation plant workers, as expected from the literature. Such exposure also is unlikely to be associated with acute health effects. In contrast, there is insufficient scientific knowledge to know whether levels recorded in this study and elsewhere may be associated with long-term, chronic health effects. Notably, DMTP levels also were observed among the presumably 'unexposed' comparison groups. Environmental background level exposures to OPs producing the DAP metabolite DMTP are therefore of potential significance and may be related, at least in part, to consumption of contaminated fruit and vegetables. There is also emerging evidence to suggest that exposure to DAP metabolites themselves through diet and other sources may contribute to the concentration of DAPs, including DMTP in urine, potentially complicating assessment of occupational exposures. Nevertheless, the urine DAP metabolite test was a useful, sensitive indicator of occupational OP pesticide exposure among agricultural workers and may be of use to the industry as part of the risk assessment process. Future research should aim to establish a BEI for the urine DAP test.
49
Jeffries, Anne. "Cervical Infection with high risk Human Papillomavirus Anogenital Subtypes in Indigenous Women in Alta and Baja Vera Paz Guatemala." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3754.
Full textAbstract:
Cervical cancer, caused by oncogenic (high risk [hr]) human papillomavirus (HPV) subtypes, is the most common cancer in women in Guatemala and the most common cause of cancer mortality in women aged 15-44 years. Visual inspection with acetic acid (VIA) with onsite cryotherapy “test-and-treat” is recommended for underserved Guatemalan indigenous rural women. This research assessed: 1) hrHPV infection prevalence in women screened by VIA; 2) Sensitivity and specificity of VIA in detecting hrHPV infection and cytologically identified precancerous and cancerous lesions; and 3) Factors associated with hrHPV infection. Analysis of anonymous data collected during VIA clinics in 2013 (N = 205) and 2017 (N = 234) for indigenous women aged 21-65 years in six villages showed 22.6% (95% confidence interval [CI]=18.7%-27.2%) had hrHPV cervical infection. VIA results were abnormal in 5.9% (95%CI=3.8%-8.8%). Only nine VIA exams in 89 women with hrHPV were abnormal (Sensitivity=10.1%, 95%CI=4.7%-18.3%), although abnormal VIA was associated with hrHPV (Prevalence Ratio [PR])=1.8; 95%CI=1.1-3.1; P=.05). Of 221 women who had VIA, hrHPV nucleic acid testing and liquid preparation cytology (equivalent to Papanicolaou or “Pap”) testing, 10 (4.7% [95%CI=2.3%-8.5%]) had abnormal cytological results, including one cancer, four high- and five low-grade squamous intraepithelial lesions. VIA sensitivity and specificity for detection of precancerous cytological abnormalities and cancerous lesions were 20.0% (95%CI=2.5%-55.6%) and 96.0% (95%CI=92.3%-98.3%) respectively. In contrast, hrHPV sensitivity and specificity were 100% (95%CI=71.7%-100%) and 88.7% (95%CI: 83.9%-92.7%). In both years combined, women aged fewer than 29 years or reporting fewer than four pregnancies were more likely to have hrHPV cervical infection (36.8%, 27.3%, respectively) than those who were older or reported more pregnancies (18.7; P=.025, respectively); 60.0% reported some form of modern contraception. Progesterone injections or implant users were more likely to have hrHPV infection (31.9%) than women using other or no contraceptives (19.5%); PR=1.6; 95%CI=1.1-2.4; P=.01). These data suggest that VIA may not be sufficiently sensitive for use in cervical cancer screening. “Test-and-treat” screening using hrHPV real-time testing, as recommended by the World Health Organization may be preferable to VIA, and may be acceptable using self-collected specimens.
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Du, Toit Willem Johannes. "The relationship between health and safety and human risk taking behaviour in the South African electrical construction industry." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1009529.
Full textAbstract:
Mankind, and the development of people, exists due to risk-taking behaviour. It is not that humans should not take risks, but rather the ability to identify the magnitude of risk exposure in order that mankind‟s actions would be so selected as to mitigate exposed risk factors, that no harm should befall them. The approach to health and safety (H&S) has always been to manage H&S environmental factors that could have a negative impact on people, capital, and organisational systems. However, the critical component of human risk-taking behaviour that would have a far greater impact has rarely been acknowledged as part of the drivers that increase risk exposure. Human behaviour is a major contributing factor in accident causation. Although human error cannot be completely eliminated, it should be identified and correctly managed according to each individual‟s risk-taking profile. The reason people decide to take certain risks under certain conditions and the effect it has on H&S management systems is a key component to managing organisational risk exposure. To quantify the value of individual risk-taking behaviour could provide management with better opportunities of lowering the organisational risk exposure. Human risk-taking behaviour is influenced by each individual‟s perception of risk. Such perception of risk will influence decisions on risk-taking behaviour, which in turn is influenced by the individual‟s psychological profile and environmental factors, including character and the impact of a cultural environment. The electrical construction and maintenance industry differs from other similar industries in that the physical entity of electricity requires not only sensory perception for the identification and evaluation of risk factors, but also requires specialised knowledge and testing equipment to evaluate the parameters of electrical installation, plant or equipment. Without such competence, direct exposure to most electrical installations could be fatal. The optimum human resource (HR) solution for managing the risk potential of high risk-taking behaviour is the rating and allocation of specific job tasks that can match and limit the individual potential for risk-taking behaviour and the impact on organisational incident statistics. Maintaining and optimising employee job performance enables organisations to better achieve pre-set goals and missions. Such improvements being a catalyst for better job performance by setting limitations on high risk-taking behaviour, that will improve H&S performance by lowering incident rates.