Surface-bound particulates containing radionuclides in the environment can become airborne through the process of resuspension. Once airborne, these radionuclides can be inhaled or ingested to deliver an internal dose of ionizing radiation. To that end, the resuspension factor method is a powerful tool for predicting a person's exposure to airborne particles from surface contaminations, and therefore is used to determine protective and intervening measures. The resuspension factor is calculated as the ratio measured airborne to surface mass concentration and has been found to generally decrease exponentially with time. Current models of the resuspension factor are empirical and have failed to predict recent measurement, motivating a stronger basis and physical model for the system. Additionally, federal guidances conservatively suggest an unphysical model of particulate radioactivity impact wherein the entirety of the radiation is absorped. For this dissertation, two- and three-compartment catenary models were derived which build on measured resuspension rate constants under various influences. These models were fit to a set of historic observations of resuspension factors using an instrumental uncertainty-weighting to resolve the large variances early in time which otherwise inflate calculations. When compared to previous resuspension models, our physical models better fit the data achieving reduced-chi-squared closer to 1. An experiment was undertaken to validate our basic environment resuspension models in an urban environment without wind. A resuspension chamber is constructed by placing an acrylic tube atop a poured concrete surface and lowering a low-volume air sampler head from above. Europium oxide powder was dispersed upon the surface or from above the air sampling height to emulate ideal compartmentalized release scenarios, and air is sampled on an hourly, daily, or weekly basis. Sampler filters then were evaluated for Europium content using neutron activation and gamma spectroscopy. Hourly measurements following airborne release are within an order of magnitude of early-timeframe historic resuspension factors (~10^−6 m^−1), whereas daily and weekly measurements from surface release demonstrate a gradual decrease in resuspension factor (∼10^−8 m^−1). These results support a need to critically assess the resuspension factor definition and its relationship to "initial suspension" and the indoor background, non-anthropogenic resuspension. Finally, a simulated model was generated to demonstrate loss of alpha radiation from relevant transuranic radioparticles. This was accomplished using the Geant4 Monte Carlo particle transport code. This basic model demonstrated a clear loss of average intensity and energy of exiting particles which are both directly related to the absorped dose. The data shows a loss from 10 to 90% of intensity to occur at particle sizes approaching the range of alphas within them, and a loss of roughly half the initial alpha energy at around the same particle sizes. The results establish a first-order baseline for a particulate self-absorption model which complement existing dosimetry models for inhaled radionuclides.

Philosophiae Doctor - PhD / In South Africa there are currently 44.8 million people under the age of 20 years accounting for approximately 44% of the total South African population. Literature has indicated a number of lifestyle behaviors which account for most of the mortality, morbidity and social problems in adolescents. These behaviors include tobacco uses, unhealthy dietary behaviors, physical inactivity, alcohol and other drug use, risky sexual behaviors, and behaviors that result in unintentional and intentional injuries. Adolescent women are profoundly affected by a number of health risks related to their behavior. Many of these also affect their male peers such as smoking, drinking, use of other drugs, and violence, but have a special effect on women because of either higher prevalence or a relationship to other risks. Another set of risky behaviors are those uniquely linked to women's reproductive potential. The health of young people today, and the adults they will become, is critically linked to the health related behaviors they choose to adopt. It is thus vitally important for health professionals to address adolescent health issues with targeted health-related interventions and effective health-promoting programmes. The heightened adverse health effects of many risk behaviors for adolescent women and the unique risks associated with being female point to the need for gender-specific prevention efforts. The purpose of this study was to investigate health risk behaviours among black female high school learners. The study used a mixed method approach, specifically the sequential explanatory strategy. Quantitative data was collected using two self-administered questionnaires assessing six domains of health risk behaviours including cigarette use, alcohol use, drug use, sexual activity, behaviours leading to violence and behaviours related to physical activity.

The thesis is focused on the identification, analysis and assessment of risks in three key areas (quality, environment, occupational safety and health). The paper made a risk analysis according to ISO 31000: 2010 Risk Management - Principles and guidelines. The risk assessment of selected construction technologies were chosen following methods - analysis methods and consequences of failures (FMEA), Pareto diagram, analysis of the causes and consequences (Ishikawa) and analysis of the type of butterfly. Using these methods are evaluated selected risks to propose action to reduce its value and impact. The aim of this thesis is to identify, assess and analyze the risks and handle simple tools for the management and elimination.

Master of Public Health - MPH / The HIV incidence among young people aged 15 to 24 years remains a global health concern. Sub-Saharan Africa (SSA) is the home of approximately four million young people living with HIV, and young people in the region account for about 70% of new infections annually. Over 85% of HIV infections among young people in SSA is sexually transmitted. Therefore, the aim of the study was to understand young people’s experiences and perspectives on HIV prevention in four communities in Zambia.

Abstract This research focuses on developing former mining sites situated in the south of the City of Johannesburg that are contaminated with radon gas. This well-located land would be suitable for development of houses for low – to – moderate-income earners, preferably those living +10km away from the city centre. Former mining land has been developed in other countries both in Europe and in America. The results from international experience shows that houses had been developed on sites contaminated with radon and people had lived longer than 35 years without contracting lung cancer. The literature reviewed reveals that radon is the world’s second greatest cause of lung cancer after cigarette smoke. There are local and international norms and standards that development of land contaminated with radon should adhere too. In South Africa, the National Nuclear Regulator (NNR) sets the norms and standards for development of land contaminated with radon in which compliance with international norms and standards has been predetermined. Utilisation of the former mining land south of the City of Johannesburg will reduce development of houses at the periphery and will bring people closer to employment opportunities, amenities, transportation, services and facilities required for sustainable housing environment. Radon-contaminated land was visited, and surveys were administered to get different opinions from people who are close to mine dumps and those who are far from the Central Business District. The results show that people are interested and prepared to take the risk of living in areas contaminated with radon. The City of Johannesburg’s former mining land should therefore be considered to meet the goals of housing units. Therefore, former mining land should in future be developed for housing purposes, provided approval has been granted by the relevant government departments.

No description available.

Although not all hazardous effects on human health have been clearly defined so far, the health risks of particulate matter can be considered evident. Pulmonary and cardiovascular diseases, in particular, are caused or aggravated by inhaled particulate matter. The aim of this article is to describe the incorporation and the effects on organ function of inhaled particles. Furthermore, the potential risks of de novo synthesised nanoparticles are discussed in the context of the public controversy regarding environmental particulate matter pollution. / Obwohl die schädlichen Auswirkungen inhalierbarer Partikel auf unseren Organismus bisher noch nicht vollständig geklärt sind, kann eine Gesundheitsgefährdung durch Feinstäube als erwiesen angesehen werden. Insbesondere pulmonale und kardiovaskuläre Erkrankungen werden durch Feinstaubexposition ausgelöst oder verschlimmert. Dieser Artikel stellt Aufnahme und Auswirkungen inhalierter Partikel im menschlichen Organismus dar und erörtert potenzielle Gefahren de novo synthetisierter Nanopartikel im Kontext der auch in der breiten Öffentlichkeit kontrovers geführten Feinstaubdiskussion.

No description available.

Abstract available in the Annals of Behavioral Medicine.

Health Risk Behavior (HRB) is defined as behavior that increases the likelihood of adverse outcomes: injury, morbidity, or mortality. University students are particularly susceptible to HRB due to their age, academic pressures, social environment, and newly unsupervised lifestyle. Despite major efforts by university campaigns to make students aware of the potential health risks of HRB, students continue to consistently engage in behavior that risks both their short-term and long-term health. Previous literature indicates the importance of self-esteem in positive decision-making and the inhibiting role of shame in increasing withdrawal and social isolation. Shame and guilt are distinct self-conscious emotions often evoked in similar circumstances: shame often debilitative, and guilt adaptive. This study utilizes a cross-sectional design to examine the associations between HRB and the affective emotions of shame, guilt, and self-esteem to better understand HRB determinants. Data was collected from students using a Qualtrics form containing demographic and HRB questions. The Personal Feelings Questionnaire-2 (PFQ2) and the Rosenberg Self-Esteem Scale (RSES) assessed shame and guilt proneness, and global self-esteem, respectively. Mean data analyses, frequency tests, and one-way ANOVA analyses revealed associations between HRB and the three tested affective emotions. Results of this study indicated HRB is associated with higher negative emotion: higher shame and guilt proneness and lower self-esteem. With further research, this information can guide more effective clinical and educational interventions in reducing HRB and subsequent preventable diseases by targeting emotional risk factors in the university population.