This dissertation considers the economics of public health in the context of respiratory disease, a leading cause of morbidity and mortality. The pervasive nature of respiratory illness represents a significant reduction to health and longevity, but private actions to prevent illness may not consider the full-scale benefit of societal health improvement. In this thesis, I consider two determinants of respiratory illness: (1) the spread of influenza disease and (2) air pollution. In both cases, public policy aims to attenuate the effects of these factors by incentivizing or mandating preventative action. Because such interventions come at a cost, it is important to consider the magnitude of benefits associated with these actions. I consider each determinant in turn. First, I provide causal evidence on the health and economic consequences of an ongoing broad-scope vaccination program. The Ontario Influenza Immunization Campaign expanded the scope of vaccine coverage leading to a 20-percent increase in vaccination. Using the timing of this campaign and exogenous variation in vaccine quality, I link higher vaccination rates to decreases in lost-work-time, hospitalization, and death. Results indicate that, when vaccine quality is high, the program leads to higher gains for Ontario relative to other provinces and in short, an ounce of prevention is worth a pound of cure. Second, I provide evidence of the impact of air pollution on respiratory health. Recent changes in standards for air pollution are highly contentious and represent stringent constraints on economic activity. Evidence from this dissertation directly informs this debate. By linking daily pollution to hospital admissions for municipalities across Ontario, I study the impact of air pollution at levels below those historically considered. Results indicate that particulate matter has a significant effect on respiratory health of children but that ozone and carbon monoxide have little effect on respiratory hospitalizations for all age groups.

This dissertation considers the economics of public health in the context of respiratory disease, a leading cause of morbidity and mortality. The pervasive nature of respiratory illness represents a significant reduction to health and longevity, but private actions to prevent illness may not consider the full-scale benefit of societal health improvement. In this thesis, I consider two determinants of respiratory illness: (1) the spread of influenza disease and (2) air pollution. In both cases, public policy aims to attenuate the effects of these factors by incentivizing or mandating preventative action. Because such interventions come at a cost, it is important to consider the magnitude of benefits associated with these actions. I consider each determinant in turn. First, I provide causal evidence on the health and economic consequences of an ongoing broad-scope vaccination program. The Ontario Influenza Immunization Campaign expanded the scope of vaccine coverage leading to a 20-percent increase in vaccination. Using the timing of this campaign and exogenous variation in vaccine quality, I link higher vaccination rates to decreases in lost-work-time, hospitalization, and death. Results indicate that, when vaccine quality is high, the program leads to higher gains for Ontario relative to other provinces and in short, an ounce of prevention is worth a pound of cure. Second, I provide evidence of the impact of air pollution on respiratory health. Recent changes in standards for air pollution are highly contentious and represent stringent constraints on economic activity. Evidence from this dissertation directly informs this debate. By linking daily pollution to hospital admissions for municipalities across Ontario, I study the impact of air pollution at levels below those historically considered. Results indicate that particulate matter has a significant effect on respiratory health of children but that ozone and carbon monoxide have little effect on respiratory hospitalizations for all age groups.

Understanding how respiratory health risks are associated with poor housing is essential to designing effective strategies to improve children’s quality of life. The objective of this thesis is to determine the relationship between the respiratory health of children and the condition of the homes in which they reside – using both building science and health data. The thesis therefore, examines the association between self-reported mould in the home, housing conditions, and the respiratory health of children. The study contributes to both the medical and engineering research community by enabling researches, designers, and Building Code officials to focus on cost-effective target areas for improving indoor air quality and thus, the respiratory health of children. A survey designed to assess the relationship between respiratory health and housing conditions was completed by 3,424 parents of grades 3 and 4 children in Winnipeg, Manitoba, Canada. Air samples were then taken in the homes of a subset of 715 houses– one in the child’s bedroom and another in the basement – with an exterior neighborhood air sample as a control measure. Engineering audits on 715 homes were then conducted – including measurements of relative humidity, temperature, and moisture content of walls. Major findings include the following: (1) Self-reported visible mould in the home is clearly associated with the presence of air-borne mould. (2) There are fewer healthy children when mould is present in the home. (3) Cladosporium levels (CFU/m3) in the house were associated with children’s asthma in combination with persistent colds. (4) Measures taken by homeowners to increase the air-tightness of their homes, such as new windows increased the likelihood of having higher air-borne moisture and mould levels. (5) The “hygiene hypothesis” was supported, which postulates that denying children access to certain types and levels of biological contamination at a young immune-developmental age, increases their susceptibility to allergic responses at a later age.

Objective The objective of this study is to examine the exposure- response relationship between prolonged exposure to low levels of silica, uranium, radon progeny and criteria pollutants and the respiratory health of uranium workers. Method Initially two pilot studies were done on selected groups of high-risk workers to determine the prevalence of alpha-1-antitrypsin deficiency and the retained burden of uranium in the lungs of exposed workers. The value of sputum cytology was also evaluated. A cross-sectional study was conducted in 1984 to determine the prevalence of spirometric abnormalities among uranium miners. The data from non-smokers without symptoms was used to develop lung function reference values relevant for the present population. Follow up analytical cross-sectional and case control studies were done in 1996 and 1999 to determine the mean independent effect of uranium on the respiratory health of miners and to detect abnormalities in both smokers and non¬smokers. Data was collected on employment history, smoking habits, pulmonary function and chest radiographs. To determine the independent mean effect of uranium mining on the respiratory health of workers, only data of non-smokers in exposed cohorts were compared with unexposed control cohorts. Results The prevalence of alpha-1-antitrypsin appeared to be high in workers with abnormal spirometric indices. The lung burden of retained uranium in workers in the final product recovery area was within normal limits. The sputum cytology was abandoned because it was found worldwide that cytological screening had no impact on population survival rates. Lung function prediction equations derived from multiple linear regressions were calculated for the study population which differed from Schoenberg et al prediction equations. The data from the analytical cross-sectional study in1996 suggests that the level of exposure in this study group (without the confounding effect of cigarette smoking) is not associated with statistically significant impairment of lung function, increased prevalence of silicosis, tuberculosis and respiratory cancer. Only the FEF75 was found to be an indicator of early lung abnormality. Data from the 1999 study supports the hypothesis that there is a small but significant exposure-response relationship between prolonged exposure to low levels of silica dust, and lung function abnormalities (in the absence of radiologically diagnosed silicosis). The prevalence of chronic obstructive pulmonary disease (COPD) and small airways disease (SAD) was small but significantly higher in exposed workers. The risk of developing COPD was 2.7 times higher for exposed workers. The risk for non-smokers was small but significant. The incidence of tuberculosis and lung cancer was not higher than expected (probably because ex-employees were not fully investigated). Conclusion Calculation of location specific prediction equations, for different ethnic groups is advocated to enable the earliest detection of lung function abnormalities. FEF75 could be used as an early indicator of lung function impairment (provided strict quality control is maintained). Exposure to a combination of silica dust, radon progeny and smoking was associated with an increased risk of lung function abnormalities, but not with tuberculosis, silicosis and lung cancer. Conclusive assessment must await sufficient latency, and ex-employees must be investigated to establish the true magnitude and distribution of the effects of siliceous and uranium dust on the health of workers (which may continue after exposure cease). / Thesis (PhD)--University of Pretoria, 2010. / School of Health Systems and Public Health (SHSPH) / Unrestricted

Air pollution has adverse effects on human health. The respiratory system is the most exposed and short-term changes in air pollution levels have been associated with worsening of asthma symptoms and increased rates of heart attacks and stroke. Air pollution in cities due to traffic is the major concern, as many people are exposed. However, natural sources of air pollution such as natural dust storms and ash from volcanic eruptions can also compromise human health. Exposure to volcanic eruptions and other natural hazards can also threaten mental health. Air pollution has not been extensively studied in Iceland, in spite of the presence of several natural pollution sources and a sizeable car fleet in the capital area. The aim of this thesis was to determine if there was a measurable effect on health which could be attributed to air pollution in Iceland. This aim was pursued along two paths; time series studies using register data aimed to determine the short-term association between daily variation in air pollution and on one hand daily dispensing of anti-asthma medication or the daily number of emergency room visits and emergency admissions for cardiopulmonary causes and stroke. The other method was to investigate if exposure to the Eyjafjallajökull volcanic eruption was associated with adverse health outcomes, either at the end of the eruption, or 6 months later. In paper I time series regression was used to investigate the association between the daily number of individuals who were dispensed anti-asthma medication and levels of the air pollutants particle matter with an aerodynamic diameter less than 10 μm (PM10), nitrogen dioxide (NO2), ozone (O3), and hydrogen sulfide (H2S) during the preceding days. For the study period 2006-9, there were significant associations between the daily mean of PM10 and H2S and the sales of anti-asthma medication 3 to 5 days later. Giving the exposure as the highest daily one-hour mean gave more significant results. Air pollution negatively affected the respiratory health of asthma medication users, prompting them to refill their prescriptions before they had originally intended to. In paper II the main outcome was the number of individuals seeking help at Landspitali University Hospital emergency room for cardiopulmonary disease or stroke. Time series regression was used to identify the lag that gave the best predictive power, and models were run for data for 2003-9 pollutants PM10, NO2, and O3. O3 was significantly associated with the number of emergency hospital visits the same day and two days later in all models, and both for men, women and the elderly. Only emergency hospital visits of the elderly were associated with NO2, and there were no associations with PM10. In paper III the aim was to investigate if the health effects of PM10 were affected by the addition of volcanic ash from the 2010 eruption of Eyjafjallajökull and 2011 eruption of Grímsvötn to PM10 in the capital area. Time series regression of emergency hospital visits and PM10 before and after the Eyjafjallajökull eruption showed that the effect tended to be higher after the eruption, but the results were not significant. Analysis with a binary indicator for high levels of PM10 from volcanic ash and other sources showed that volcanic ash was associated with increased emergency hospital visits. There were no associations with high levels of PM10 from other sources. In paper IV, the health of the population exposed to the ongoing eruption of Eyjafjallajökull in 2010 was investigated thoroughly. Lung function in adults was better than in a reference group from the capital area, though many reported sensory organ irritation symptoms and symptoms of stress and mental unhealth, especially those with underlying diseases. Paper V report the results from a questionnaire study which was carried out six months after the Eyjafjallajökull eruption. The study population comprised a cohort of south Icelanders exposed to the eruption to varying degrees and a reference group from north Iceland. Respiratory and eye symptoms were much more common in south Icelanders than in the reference group, after adjusting for demographic characteristics. Mental unhealth rates had declined considerably. In the studies, we found that urban air pollution and natural particles have short-term effects on anti-asthma medication dispensing and emergency room visits and hospital admissions. Exposure to natural particles in the form of volcanic dust was associated with increased respiratory symptoms in a very exposed population. There were indications that volcanic ash particles were associated with increased emergency hospital visits in the following days. / <p>Statement of collaboration</p><p>This thesis and the work in it have been produced in collaboration between University of Iceland and Umeå University. The thesis was issued and defended at both institutions. Responsible</p>

"The aims of this research were to investigate the association between air pollution and respiratory health effects using a spatial approach, and to derive a composite indicator of ambient air pollution." / Master of Information Technology by Research

Children are a highly susceptible population to the effects of air pollution. To establish a current baseline of child respiratory health and associated risk factors in the Highveld Priority Area, a quantitative questionnaire was carried out among parents or guardians of children aged between 9 and 11 years in Witbank and Middelburg. Key health outcomes of interest were asthma and upper and lower respiratory tract complications. Air quality data were obtained for Witbank and Middelburg and compared with recently gazetted National Standards to establish potential risks. The prevalence of health outcomes and associated risk factors, such as indoor fossil fuel burning and parental smoking were considered and key risk factors identified. A unique method for the analysis of poor quality responses was introduced in order to derive the most meaning from the data. The study findings showed the air quality to be of concern particularly in Witbank; however, it also showed a similarity between the air quality in both towns. The health outcome with the highest prevalence was hay fever (occurring in the previous 6 months) with 31.7%. The use of non-electric heating sources, parental smoking and mould in the house were risk factors of most concern for respiratory health. During bivariate analysis mould was found to be associated with a number of health outcomes, most notably having bronchitis, with a crude OR of 4.74. An adjusted odds ratio of 4.05 was found for smoking in the house and having bronchitis. An adjusted OR of 6.32 was found for using gas or paraffin and having episodes of wheezing. These results may be used to direct future research studies as well as assist air quality management practices in the area. Finally, a technique to handle contradictions in questionnaire responses was developed to maximise use of data collected for application in under-resourced research environments. Copyright 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Albers, PN 2011, Baseline assessment of child respiratory health in the Highveld Priority Area, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02172012-162359 / > C12/4/230/gm / Dissertation (MSc)--University of Pretoria, 2011. / School of Health Systems and Public Health (SHSPH) / Unrestricted

This dissertation includes three chapters. The first and second chapters are related to economics of immigration, and the last one is about environmental economics. The first chapter studies people who work and live in the US on work visas such as H-1B, and compares them to natives. In this chapter I examine whether or not there exists any wage premium for or against college graduate immigrants who are on work visa compared to college graduate natives. I also check for any change of such a premium from 2003 to 2010. On the contrary to the common belief that foreign workers are cheap labor force, my results show that skilled immigrants holding temporary work visas on average have a significant wage premium over natives, and this premium has even increased significantly from 2003 to 2010 (from 14% to 22%). My results show that such a wage premium is different for men, women, and countries of origin, but I found no evidence supporting different premiums across different fields of study. The second chapter of this dissertation studies the dynamics of the earnings gap between those immigrants and US-born individuals with bachelor's degrees or higher in science and engineering fields. The research question is that in case a gap exists for or against immigrants, how is it changing with the amount of time immigrants reside in the United States? I employ cross-sectional and longitudinal approaches to answer this question, and study the earnings gap between three groups of immigrants (based on the current residency status) and natives at entry and over time. I also compare natives with immigrants who migrated to the United States on different types of visas (permanent residence visa, work visa, study visa, and dependent visa). Results show that, upon arrival, immigrants on average have a considerable premium over the US-born, and this gap, surprisingly, even gets bigger with an approximate rate of 0.25% for the first 5-10 years of immigrants' residence in the US. This phenomenon could be due to the higher level of abilities and motivation among immigrants compared to natives. Another reason can be the selectivity among immigrants, meaning that more successful stays and others return. Unfortunately, due to the lack of information in data regarding these issues, they could not be controlled for in my models. The last chapter is about environmental economics. This chapter exploits a daily time series data on pollen count and PM2:5 level from 2009 to 2015 to study the separate impacts of PM2:5 and pollen on the number of total, in-patient, and out-patient respiratory hospital admissions within different age groups in the Reno/Sparks metropolitan area in Northern Nevada. The results show that although PM2:5 has a positive impact on the number of out- patient admissions in most of the age groups, there is no evidence that shows any relationship between the pollen count and the number of in-patient or out-patient respiratory admissions. / Ph. D.

Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = -0.43, p = 0.001, R-2 = 0.08), water (b = -0.22, p = 0.07, R-2 = 0.03), house dust (b = -0.37, p = 0.07, R-2 = 0.04), and dust loading (b = -0.21, p = 0.04, R-2 = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = -0.42, p = 0.02, R-2 = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities.

Purpose: The substantial impact of indoor air quality and environmental hazards in the home on one’s health has long been recognized in the field of public health. This cross-sectional study investigates the risk between home based hazards, specifically lead, and respiratory health in children. The objective of this study is to examine the extent to which children testing positive for blood lead exposure are at an increased risk for having poor respiratory health. Methods: A nationally representative sample of 977 children ages 1- 6 years was obtained from the 2005-2006 National Health and Nutrition Examination Survey (NHANES). Information from the demographic, blood lead level, and respiratory health questionnaire databases were combined to assess the impact of lead exposure on respiratory health. Blood lead exposure (BLL) was assessed at the following cut-off values: 1, 2, 3, 4, 5 and 10ug/dL. Respiratory health status was dichotomized as good and poor respiratory health based on the study participant’s answers to the questionnaire. Logistic regression was used to determine the relationship between blood lead levels and respiratory health status while controlling for the following potential confounders: race, age, sex, and annual family income. Results: This study was unable to establish a relationship between lead exposure and poor respiratory health in children ages 1-6 years, and the lack of relationship held for increasing levels of lead exposure. However, this study did reveal the significant impact of low level lead exposure in children with approximately 77% exposed at BLL ≥ 1ug/dL and 39% at BLL ≥ 2ug/dL. It is important to note that this is only a snapshot of the amount of lead exposure within this population; it is very likely that the levels fluctuate. Conclusion: While the percentage of study population decreases as the lead exposure increases, it is still alarming at the number of children exposed to low levels of lead. A large and growing body of literature documents the adverse health effects associated with low levels of lead exposure in children. This finding further supports the need for continuing research in examining the true impact of low level lead exposure and in determining a threshold dose level. In addition, a stronger study with a larger sample size and a more clearly defined respiratory health variable would allow for the relationship to be more closely examined before a definitive “no association” result can be made.