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Exposure to volatile organic compounds (VOCs) has critical health implications for developing fetuses and subsequently for infants and young children. Research has suggested that this ambient air pollutant can be found indoors in quantities that may be hazardous to human health. In low-income neighborhoods in New York City such as northern Manhattan and the South Bronx, where there are disproportionately high rates of asthma and asthma-related hospitalizations, high rates of indoor exposure to VOCs persist. Simultaneously, as mobile devices expand, applications on mobile devices may be used to educate parents of children who reside in these geographic regions about indoor VOC emission sources and subsequently how to reduce exposure.Therefore, this study sought to assess the role of mobile device applications in reducing household VOCs by assessing the feasibility of existing health applications on both Apple and Android OS mobile devices without the use of a household air monitoring unit. An online survey assessed awareness of VOCs and identified knowledge of both emission sources and reduction methods of household VOCs among a sample of (N = 57) parents/guardians residing in the Northern Manhattan and Southern Bronx regions with children under the age of 5. A series of focus groups were conducted among a subset of participants to assess the adaptability of a mobile application prototype that specifically targets the reduction of VOCs. Lastly, a preliminary mobile device application mockup was created with potential features. The key findings of this study included the following: (a) the author identified no existing mobile device applications that could be utilized as a method for VOC reduction without the use of a physical in-home air monitor; (b) while parents had some baseline awareness of VOCs, there were gaps within their knowledge of VOCs, particularly with emission sources; (c) the feasibility of this proposed application as a potential source of intervention for indoor VOC mitigation was apparent through parent willingness to explore its possible use, while providing ample recommendations for optimal mobile device application design; and (d) the exploratory mockup of the proposed mobile device application was generated with suggested features.

published_or_final_version / Urban Planning and Environmental Management / Master / Master of Science in Urban Planning

published_or_final_version / Community Medicine / Master / Master of Philosophy

Age-related cognitive decline is a growing public health issue as increases in life expectancy are expected to substantially raise the prevalence of cognitive impairment and dementia. An estimated 46.8 million individuals are currently living with dementia, with the global prevalence expected to double every 20 years. Emerging evidence suggests that ambient air pollution from traffic and other sources may be an important risk factor for cognitive decline in addition to its association with other cardiovascular and neurological outcomes. The aim of this dissertation was to first investigate the association between long-term exposure to ambient air pollution and cognitive decline among older adults in an urban population within Northern Manhattan. I then set out to assess specific mechanisms involved in the association between long-term exposure to ambient air pollution and cognitive decline, specifically investigating the ApoE4 allele, age, and current smoking behavior as effect modifiers of the association between long-term exposure to ambient air pollution and cognitive decline. I found evidence of an adverse effect of ambient air pollution on the cognitive functioning of older adults. Overall, exposure to higher levels of ambient air pollution was highly predictive of lower cognitive scores, but at baseline only. Contrary to the current hypothesis, limited evidence was found for an association between estimates of air pollution and trajectories of cognitive decline. The patterns of effect were similar across pollutant types and cognitive domains in this aging, urban population. I found strong evidence of effect modification by smoking status, where contrary to the hypothesis; the overall effects of ambient air pollution on cognition and cognitive decline were stronger among individuals who never smoked. The impact of effect modification by age category was most prominent in the memory and language cognitive domains. Among individuals less than 75 years old at baseline, there was a stronger association between a one IQR increase in air pollutants and cognitive domain scores at baseline as compared to individuals 75 years and older. I did not observe conclusive evidence of an association between air pollution and cognition in models stratified by APOE-4 status. To my knowledge, this is the largest study to analyze the association of ambient air pollution on cognition and cognitive decline over time in a racially and ethnically diverse sample. These results further support the current evidence on the role of air pollution on accelerated cognitive aging and brain health.

Background: Three billion individuals worldwide rely on biomass fuel (crops, dung, wood) for cooking and heating, mostly in the developing world. Incomplete combustion of these biomass fuels in inefficient cookstoves leads to high levels of household air pollution (HAP). Health conditions resulting from HAP are responsible for approximately 1.6 million premature deaths each year. Of the diseases associated with HAP exposure, lower respiratory infections (LRIs) are the leading cause of death for children under five worldwide. There is a great need to understand the etiology of HAP-associated LRIs to inform health interventions and to improve treatments. Ultimately, however, the only way to prevent the disease burden from HAP is to stop exposure. Policies and programs to promote the use of clean fuels for cooking are a pivotal prevention strategy. Methods: All three studies draw from an established cohort in Ghana. The Ghana Randomized Air Pollution and Health Study (GRAPHS), was a cookstove intervention trial in Kintampo, Ghana. Participants were randomized to a more efficient biomass cookstove arm, a liquefied petroleum gas (LPG) stove arm, or the traditional cookstove arm (baseline). The principal outcome of GRAPHS was childhood pneumonia. The first chapter utilizes banked nasal swabs from GRAPHS to assess the relationship between HAP exposures and a panel of known respiratory pathogens. In the second chapter we leverage data on stove use during GRAPHS, and then follow a sub cohort 6 months prior to and 6 months after the GRAPHS termination date. We employ a novel construct, suspended use, to understand the factors associated with people stopping LPG use. The third chapter tests a new randomized intervention on a subset of the GRAPHS participants. We provide free cookstoves, and allocate participants to one of four arms: a behavior change intervention, an intervention where LPG fuel is directly delivered to their home, a dual intervention of behavior change and fuel delivery, or a control arm. We track their stove use to identify the most effective intervention on sustained use. Results: In Chapter 1, we find that the traditional cookstove users had a higher mean number of microbial species than the LPG (LPG: 2.71, 3-stone: 3.34, p<0.0001, n = 260). This difference was driven by increased bacterial (p<0.0001) rather than viral species presence (non-significant). Adjusted exposure-response analyses, however, produced null results. Chapter 2 identifies several factors associated with reduced or suspended LPG use of intervention cookstoves, including: experience of burns, types of food made, and access to biomass fuels. Finally, in Chapter 3 results show increased use for all three intervention arms, the largest for the direct delivery arm with an increased weekly use of 4.7 minutes per week (p<0.001). Conclusions: Transition away from traditional biomass stoves is projected to curb the health effects of HAP by mitigating exposure, but the full benefits of newer clean cookstove technologies can only be realized if use of these new stoves is absolute and sustained. This work enhances our understanding of the etiology of HAP-associated pneumonia, the drivers of clean cookstove suspension, and informs policies designed to promote clean cookstove sustained use, thus reducing the burden of disease associated with exposure. We recommend future use of the suspended use paradigm in research to inform future household energy interventions. Additionally, we encourage policymakers to incorporate health behavior change theory and approaches in cookstove intervention and promotion efforts.

In 1990, the Clean Air Act (CAA) Amendments authorized the regulation of 188 hazardous air pollutants (HAP). Exposure to HAPs at sufficient concentrations and durations can increase both cancer and serious adverse non-carcinogenic effects. The purpose of this study was to conduct a human health risk assessment using data of 43 HAPs from five monitor sites in Portland, Oregon during July 1999-August 2000. HAP concentrations were compared to carcinogenic and non-carcinogenic (health) benchmark concentrations; and emission sources were determined for HAPs that exceeded health benchmark concentrations. Additionally, cancer risks were determined for subpopulations and compared to cancer risks generated for the general population. Results of this study indicate that 20 HAPs exceeded carcinogenic benchmark concentrations (corresponding to a risk level of 1 x 10������) in at least one location. Chromium compounds posed the highest cancer risk (3.5 x 10������). Seventeen HAPs exceeded carcinogenic benchmark concentrations at all five sites. Seventy-five percent (%) of the total cumulative cancer risk was contributed by chromium compounds, 1,3-butadiene, formaldehyde and 1,1,2,2-tetrachloroethane. Three HAPs, chromium compounds, acrolein, and formaldehyde, exceeded non-carcinogenic hazard ratios of 1.0. Releases from area sources accounted for the largest percentage of HAPs that exceeded health benchmark concentrations. With respect to subpopulations, asthmatics teenagers (age 11-16) and asthmatic adults (age 18-50), had slightly elevated cancer risks of 1.4 x 10������ and 1.2 x 10������. respectively, compared to the general population risk level of 1 x 10������. Results of this study indicate that several HAPs pose a potential human health concern in Portland and that efforts should be made to reduce their emissions. Additional studies are warranted to further assess potential human health risks and the extent of HAPs in Portland, Oregon. / Graduation date: 2003

Poor indoor air quality in schools is associated with diminished learning, health risks to students and staff, and economic costs. This dissertation reports findings from the Texas Elementary School Indoor Air Study (TESIAS). The objective of this investigation is to establish a baseline for indoor environmental parameters. The investigation selected 30 elementary schools from 2 school districts. One school district was located along the Texas/Mexico border in a hot-humid climate region. The other school district was located in central Texas in a mixed-humid climate region. Phase I of the study was a questionnaire completed by 1336 teachers and other school staff. Phase II of the study collected both qualitative and quantitative data in 120 classrooms including continuous monitoring of comfort parameters (carbon monoxide, carbon dioxide, temperature, and relative humidity). Phase III collected more in-depth quantitative data, including fungi and bacteria concentrations, in 12 classrooms. This dissertation investigates potential differences in the study data between school districts and between portable and traditional classrooms. The two major findings of this study concern water leakage from roofs and inadequate ventilation. Roof leaks were the highest reported source of water incursion and correlated with health symptoms. Free-standing small footprint classrooms had fewer roof and wall leaks than traditional classrooms. The simple low pitch roof design and sufficient overhangs typically found on the small footprint buildings studied likely result in less reported roof leaks. The measured carbon dioxide concentrations (both average and peak values) were well in excess of the recommended maximums and fewer than 15% of the classrooms met the recommended maximum concentrations. Relatively higher CO2 concentrations and relative humidity in the border school district were attributed to a greater frequency of blocked outdoor air intakes. Further investigation of novel HVAC systems, such as low velocity displacement ventilation, is needed. Ultimately, this study enables the development of best practices for school design for improved indoor air quality. / text

Background: Air pollution is a serious concern all over the world, and there have been numerous studies showing its adverse effects on health outcomes including disease-specific hospitalization and mortality. Most of these studies were conducted in Western settings and focused on NO2, SO2, PM10 and black smoke; limited results on PM2.5 in Asia have been published. Objectives: This study attempted to identify association between PM2.5 concentration and daily mortality due to all-natural causes, cardiovascular diseases, and respiratory diseases in Hong Kong, a tropical city in Asia from 2008 to 2011. Methods: The study used a case-crossover study design with time-stratified referent selection strategy. The referents were selected on the same day of the week of the same month and year as the event day. In this way, biases due to autocorrelation, time trend, and seasonal pattern were controlled for by study design. Covariates including temperature, humidity, and gaseous pollutants (NO2, SO2, O3 and CO) were adjusted for by statistical modelling. The statistical method applied was Conditional Logistic Regression. Sensitive analyses using matched by month strategy were also conducted to check the robustness of the main analyses. The health outcome variables included were mortality due to all natural causes, cardiovascular disease, and respiratory disease. Each model was examined for effects of PM2.5 at each lag 0 through lag 5 day and, for the current and lag 1 day moving average (lag 0-1). Effects were measured in Excess Risks (ER) associated with 10 μg/m^3 increase in PM2.5. Results: Significant associations with PM2.5 were observed for mortality from all natural causes and cardiovascular disease at lag 0, lag 1, and lag 0-1; and from respiratory disease only at lag 1. At lag 0-1, PM2.5 was associated with mortality from all natural causes, cardiovascular disease, and respiratory disease with the ER (95% confidence interval) of 0.74% (95% CI: 0.29, 1.19), 1.4% (95% CI: 0.52, 2.27), and 0.67% (95% CI: -0.30, 1.64), respectively. After adjusting for each of the co-pollutants in two-pollutant model, the effect magnitude dropped except that one adjusting for CO. The ERs of mortality in co-pollutant models from all natural causes ranged from 0.23% to 1.72%, from cardiovascular disease ranged from 1.00% to 2.93%, and from respiratory disease ranged from -0.10% to 1.83%. The results were robust in sensitivity analyses. Conclusion: My study provides some information to support formulation of air quality control strategies and policies, and for updating air quality standards. Such information includes the overall and seasonal patterns of air pollutants and mortality in Hong Kong, as well as the excess risks of mortality associated with increase in PM2.5. Studies with individual data stratified for subgroups can be conducted in the future to investigate effect modification of lifestyle factors for the individuals and population. / published_or_final_version / Public Health / Master / Master of Public Health

Low-income communities are potentially more vulnerable to physical, social and environmental hazards than wealthier communities. The lack of services associated with these communities (such as water supply, sanitation facilities and electrification) has increased the exposure of households to health hazards. These households also lack the coping mechanisms and resources to deal with the stress that these hazards impose on them. This study is concerned with the potential health hazards imposed from indoor air pollution. Traditional health risk assessments are used to determine the level of risk to human health from a variety of chemical or biological hazards. What these assessments do not include however, is a measure of the vulnerability of the household. The aim of this study therefore, was to develop a methodology for generating a vulnerability index for the inclusion of factors underlying urban poverty and vulnerability into a risk assessment of indoor air pollution. The approach adopted in this study followed an iterative and inductive pathway. Theories on risk assessment and urban vulnerability were explored in order to understand the manner in which risk to human health is assessed and compounded by vulnerability. Secondary data sources as well as a household survey provided information that aided the selection of a number of vulnerability indicators. These indicators were chosen as measures of vulnerability specifically for low-income households in South African settlements. The findings of the research show that there are a number of factors or issues which underlie vulnerability. The issues are related to demographics, livelihoods, physical exposures, externalities, services and general health. This study used a four-tiered selection approach to sift through the issues of vulnerability and to transform the key issues into a set of vulnerability indicators which make up the vulnerability index. / Thesis (M.Sc.)-University of Natal, Durban, 2003.