Approximately 3 billion people in developing countries rely on solid fuels for their cooking, heating and lighting needs (Smith 2000). Household air pollution (HAP) from the incomplete combustion of these fuels constitutes the fourth leading risk factor for death and morbidity worldwide, and the number one risk factor for disease burden in some developing nations, including Ghana (Lim et al. 2013; Institute for Health Metrics and Evaluation 2016). While research shows biomass fuel combustion presents a significant global health and environmental burden, no regional, national or global policies have been enacted to reduce fine particulate matter (PM2.5) and black carbon (BC) emissions from cooking with biomass fuels. More data on personal exposures to particulate matter and BC from cooking with biomass are needed across geographic areas to assess whether exposure is mediated by (cultural) cooking customs, practices and behaviors. These data are critical in informing improved cookstove design as well as policies aimed at reducing harmful emissions and exposures from biomass smoke. The overall objective of this proposal is to examine personal exposures to cooking and non-cooking sources of HAP, characterize the elemental composition of the fine particulate matter across two common biomass fuels (charcoal and wood), and assess acute respiratory symptoms in pregnant women cooking with biomass fuels in rural Ghana. Through aerosol monitoring of PM2.5, our goal is to identify and apportion sources of personal exposures borne by cooks in rural Ghana, in order to inform mitigation policies and intervention design to alleviate health burden associated with cooking with biomass fuels. Specifically, in Aim 1 we propose to measure personal exposures and kitchen air concentrations of PM2.5 and BC across cooking locations, (i.e. enclosed, semi-enclosed, outdoor) and assess cooking characteristics (e.g. fuel, kitchen type, ethnicity) as possible determinants of exposure. In Aim 2, we will characterize the elemental composition of personal and kitchen air samples across fuel and kitchen types. These two aims will allow us to assess cooking and non-cooking sources of personal HAP exposure based on air monitoring data, composition of the filters, and survey-based cooking characteristics/demographics. In Aim 3, we propose to characterize the prevalence of adult respiratory symptoms in 1183 pregnant women in the region, and assess associations between personal exposure, measured by personal carbon monoxide (CO), and other cooking and non-cooking determinants of personal exposure, including fuel type, years cooked, kerosene lamp, mosquito coils, and charcoal production.

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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.

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

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.

Chapter 1. Background: Asthma is the most common chronic childhood disease and is characterized by recurrent airway obstruction, bronchial hyper-responsiveness, and airway inflammation. Asthma is the leading cause of childhood hospitalization and school absenteeism in the United States. The associations between adverse respiratory effects and exposure to indoor nitrogen dioxide (NO2) and other byproducts of combustion such as particulate matter (PM) in particular ultrafine particulates (UFP), Ozone (O3) and Sulfur Dioxide (SO2), have been the focus of many epidemiological studies in recent years. Indoor exposure to NO2 and other pollutants from combustion may increase the risk of acute and chronic respiratory disease, reduce lung function, initiate and exacerbate asthma in children. The levels of exposure to NO2 indoors are of public health concern because children spend nearly 70% of their time indoors at home. According to the 2010 US Census report, approximately 39% of US households use natural gas for cooking, and the primary source of residential NO2 is a gas-fuel cooking appliance. Indoor levels of NO2 where NO2 sources are present can be much higher than outdoors, where the primary source of NO2 is vehicular traffic. Epidemiological studies in developed countries suggest that gas stoves used for cooking and/or heat are associated with an increased risk of asthma and respiratory symptoms in children. While there are numerous, epidemiological studies supporting an association between increased NO2 levels and gas stoves and asthma symptom severity in children, there are other studies that have examined the relationship in homes that did not observe significant associations. A better understanding of how NO2 and other indoor environmental (e.g., environmental tobacco smoke (ETS), allergens) exposures contribute to asthma morbidity in inner city preschool children will allow interventions to more effectively designed and implemented. To date, there are conflicting results on the role of exposure to indoor NO2 and its association with new-onset asthma in young inner-city children. The recent studies assessing the effects of indoor NO2 on asthma morbidity were limited to inner-city children, largely older, who were diagnosed with asthma. A gap in knowledge remains regarding the role indoor NO2 plays on the development of asthma in children not previously diagnosed. The scientific and public health rationale for conducting this dissertation was to describe the association of exposure to indoor NO2 and primary sources with the initiation and exacerbation of asthma symptoms among pre-school children with and without diagnosed asthma. The data analyzed in the current research come from a larger study of Endotoxin, Obesity, and Asthma (EOA) in the New York City Head Start Program, funded in the summer of 2002. The primary research objective of that study was to identify modifiable risk factors associated with asthma and asthma persistence among preschool children from low-income families living in select New York City neighborhoods with high pediatric asthma hospitalization rates. We conducted a cross-sectional analysis of data collected from the study questionnaire and home visit sampling at study enrollment. The analyses were performed in two phases: the first phases used data collected at study enrollment and the second phase used data collected 12-months after study baseline. Henceforth, the dissertation will refer to the first analyses as the baseline study and the second as the follow-up study. The research evaluated the association of NO2 exposure with asthma status among New York City Head Start children with and without asthma at study enrollment and with respiratory symptoms among children with asthma at 12-month follow-up. Chapter 2. Baseline Study: We conducted a cross-sectional analysis of data collected from the study questionnaire and home visit sampling at study enrollment. Specifically, the research sought to evaluate the association of NO2 exposure with asthma status among New York City Head Start children with and without asthma at study enrollment and with respiratory symptoms among children with asthma at enrollment. A total of 503 children were included in the baseline study. A total of 105 children (20.9%) met the criteria for both asthma and allergy, and 67 (13.3%) met the criteria for asthma alone. Girls made up 51.7% and boys, 48.3% of the 503 study participants. Descriptive analyses suggested that asthma/allergy status was associated with: male gender, non-Mexican ethnicity/national origin, presence of a smoker in the child’s home, number of smokers in the child’s home, self-reported parental history of asthma, mother’s education level and sensitization to one or more of the four allergens. Logistic regression models were used to investigate the magnitude and direction (as well as trend) of the association between childhood asthma and indoor NO2 sources in the child’s home. Chapter 3. Follow-up Study: Our follow-up study involved the analysis of the 12-month follow-up data from the study of Endotoxin, Obesity, and Asthma in the New York City Head Start Program funded in the summer of 2002. We focused on assessing the magnitude and direction of the associations of exposure to indoor NO2 levels (based on baseline NO2 measurements) with children’s asthma status and with symptom severity among asthmatics at 1-year follow-up. For the follow-up study, we categorized children by whether their asthma status had changed since baseline. Descriptive analyses were performed looking at key characteristics by “change in asthma status.” Children’s asthma status at baseline and at follow-up, were based on responses to the questionnaire. We analyzed indoor NO2 level measurements at baseline in relation to asthma outcomes on follow-up. We did not have enough data on NO2 levels at follow-up to analyze them in relation to asthma status on follow-up. Unless the family had relocated since baseline and/or reported changes since baseline in the use of gas appliances or the number of smokers in the home, we assumed that baseline NO2 levels in the participating children’s homes were reasonable proxies for current exposures. We looked at the number of children who moved since baseline and whether the move (for example, looking at gas stove status, age of new building) may have impacted indoor NO2 levels. Of the 503 children who were included in the baseline analyses, 47.3% had data on asthma status on follow-up. A total of 238 children (111 male, 127 female) were grouped into the four mutually exclusive outcome categories: 122 (51.3%) did not have asthma at baseline or on follow-up, 34 (14.3%) had asthma on follow-up but not at baseline, 65 (27.3%) had asthma at baseline but not on follow-up, and 17 (7.1%) had asthma at baseline and on follow-up. The mean age at 1-year follow-up was 59.5 months (6.95), and neither age nor gender was associated with asthma. The distribution of ethnicity/national origin among the 238 children remained the same as at baseline; no one ethnicity group experienced disproportionate loss to follow-up, and asthma status remained associated with non-Mexican ethnicity/national origin, although 44.1% with new-onset asthma were of Mexican background. Asthma was also associated with self-reported parental history of asthma and allergy in children, but nearly 80% of children with new-onset asthma had no such parental history of asthma. More parents of children with new-onset (35.3%) or persistent asthma (23.5%) than of other children reported making efforts to reduce risk factors or triggers for asthma exacerbations in the past 12 months. Chapter 4. Dissertation Conclusion : The primary objective of the dissertation research was the examination of the relationship between asthma and asthma severity and exposure to gas cooking and residential NO2. In both our baseline and 12-month follow-up studies, exposure to indoor NO2 was represented by the baseline measurement of NO2 and the NO2 surrogate, gas stove. Asthma status of children was based on parental responses on the questionnaire regarding asthma symptoms and urgent care visits due to respiratory distress over the course of each 12-month period prior to the conducting study questionnaires. For both studies, we did not find an association between exposure to NO2 levels at baseline and asthma status or severity. Our findings contradict the results of most recent studies of both NO2 levels and residential sources of NO2 and their effects on asthma symptoms in very young children. However, it remains difficult to compare our results we those of previous published studies because those studies primarily focused on children who were diagnosed with asthma, whereas our research included preschool aged children with and without asthma. Based on our findings and the fact they conflict with other epidemiological studies, of which there were also conflicting results, we feel that the relationship between asthma symptoms and NO2 exposures remains ambiguous. The lack of consistent results of epidemiological research raises questions that should be the focus of future epidemiological studies. What are the roles of co-pollutants and co-risk factors? Does NO2 work alone or in concert with other indoor pollutants? There exists a real lack of understanding on the possible synergistic effects of exposure to NO2 and other combustion byproducts. Important to furthering our knowledge of the role of exposure to indoor NO2 and asthma is determining whether NO2 acts as a surrogate for co-pollutants that are considered risk factors for asthma and other respiratory conditions. Another focus of future indoor pollution studies should be the development of effective methods and technologies for measuring the constituents of the complex mixture of pollutants in indoor air; these methods and technologies can then be applied in personal monitoring of exposure to indoor pollutants in epidemiological studies that would help to determine with much more accuracy the effects of individual indoor pollutants on asthma and other respiratory symptoms. This knowledge would help in the development of more effective public health and environment policies towards reducing the burden of childhood asthma.

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.

Indoor air quality has become an important health concern due to the number of indoor pollutants and the realization that even minimal exposures to volatile organic compounds may produce direct or indirect adverse health outcomes. Young people are most vulnerable to these poisonous chemicals as they spend much of their times indoors at homes, schools, nurseries and in day care centers. Exposure to volatile organic compounds indoors has been related to asthma and other respiratory symptoms. The adverse effects of air pollution on respiratory health in South Durban have been described in a number of studies. In 2000, a study in the South Durban Basin at Settlers Primary School demonstrated both a high prevalence of respiratory diseases amongst schoolchildren as well as an association between ambient air pollutants and other adverse health outcomes. The South Durban Health Study subsequently undertook a health risk assessment and an epidemiological study investigating this association further on behalf of the eThekwini Municipality. The study highlighted that relatively moderate ambient concentration of N02, NO, PMIO and S02 were strongly and significantly associated with a reduction in lung function among children with persistent asthma. Moreover, attending primary school in South Durban was significantly associated with increased risk from persistent asthma when compared to schools in North Durban. METHODS The descriptive study measured the total volatile organic compound levels within selected homes and schools of asthmatic children in South and North Durban. Recommendations for reducing or mitigating indoor total volatile organic compound exposures were made. The study involved a secondary analysis of data obtained from the South Durban Health Study. The monitoring for total volatile organic compounds within homes and classrooms was undertaken using passive samplers during a 72-hour period and analyzed using a gaschromatography/ mass spectrometry method. Temperature and humidity was assessed using temperature and humidity sensors. Statistical analysis was performed using SPSS version 13. The dataset comprised 140 total volatile organic compound samples from homes and 14 from classrooms. Total volatile organic compounds were measured in microgram per cubic meter (g/m3), temperature in degrees Celsius and relative humidity in percentage of moisture. RESULTS Total volatile organic compounds with levels in households ranging from 17g/m3 to 1440g/m3 and in classrooms ranging from 48g/m3 to 5292g/m3 were measured. The mean levels detected were significantly different in homes and classrooms / Thesis (MMed.)-University of KwaZulu-Natal, Durban, 2008.

Background: This dissertation comprises research conducted on two distinct projects. Project I focuses on the connection between household air pollution (HAP) from cooking with biomass fuels and blood pressure (BP); this research is situated in the context of a large randomized trial of a cookstove intervention in Ghana, West Africa. The setting of Project II, meanwhile, is the residential environment of New York City, where we explore temperature and humidity conditions in homes and relate these conditions to summertime heat wave risk and to the survival and transmission of respiratory viruses in the winter. Although these projects are quite distinct, each relates to the complex relationship between climate change and health. Reducing HAP to improve health (the focus of Project I) will simultaneously reduce climate change through a reduction in emissions of short-lived climate pollutants into the atmosphere. Meanwhile, furthering our understanding of heat and humidity levels inside urban residences (the focus of Project II) is crucial to our ability to protect health in light of projections for a changing climate. Domestic activities associated with heating, cooling, and cooking are thus very relevant both to human health and to climate change mitigation and adaptation. Objectives and Methods: Our overall objective for Project I was to investigate exposure- response relationships between HAP and BP in a cohort of pregnant women taking part in the Ghana Randomized Air Pollution and Health Study (GRAPHS). We first explored this association in a cross-sectional study (Chapter 1), in which we used 72-hour personal monitoring to ascertain levels of exposure among the GRAPHS women to carbon monoxide (CO), one of the pollutants emitted by traditional wood-fed cooking fires. These exposure data were collected at enrollment into the GRAPHS study, prior to the initiation of cooking with improved cookstoves. We investigated the association between these “baseline” CO exposure levels and the women’s blood pressure at enrollment into GRAPHS. A limitation of this study was that BP was only measured once. We followed this with a second study of 44 women drawn from the same cohort (Chapter 2), for whom we designed BP protocols using 24-hour ambulatory blood pressure monitoring (ABPM), the current gold standard for clinical diagnosis of hypertension. As we were not aware of any prior research in Africa that had employed ABPM, we also designed a parallel BP protocol using home blood pressure monitoring (HBPM) equipment for comparison with ABPM. The use of ABPM with concurrent personal CO monitoring enabled us to investigate hourly associations between CO exposure and changes in BP. We also evaluated BP in these women both before and after the cookstove intervention; this allowed us to investigate whether any changes in BP were associated with switching to an improved cookstove. Our objectives for Project II were to understand the distribution of temperature and humidity conditions in a range of New York City homes during the summer and winter seasons, to evaluate the impact of structural and behavioral factors (e.g. building size, use of air conditioning, and use of humidifiers) on these conditions, and to build models that could help predict indoor conditions from more readily available outdoor measurements. We conducted this research in two ways. We first analyzed a set of indoor temperature and humidity measurements that were collected in 285 New York City apartments during portions of summers 2003-2011 and used these data to simulate indoor conditions during two heat wave scenarios, one of which was more moderate and the other of which was more extreme (Chapter 3). Second, we designed and conducted a new study in which temperature and humidity were monitored in a set of 40 NYC apartments between 2013 and 2015 (Chapters 4-6). This second study enabled us extend our research into the winter season, and also to explore how factors such as air conditioning and humidifier use impacted indoor temperature and humidity. We also investigated relationships between the monitored conditions, self-reported perceptions of the indoor environment, and symptoms that were experienced among household members. Results: In the cross-sectional analysis of CO and BP in the GRAPHS cohort (Chapter 1), we found a significant positive association between CO exposure and diastolic blood pressure (DBP): on average, each 1 ppm increase in exposure to CO was associated with 0.43 mmHg higher DBP [0.01, 0.86]. A non-significant positive trend was also observed for systolic blood pressure (SBP). In our study of the acute relationship between CO exposure and BP (Chapter 2), we determined that peak CO exposure (defined as above the 90th percentile of the exposure distribution, or an average of 4.1ppm) in the two hours prior to BP measurement was associated with elevations in hourly systolic BP (4.3 mmHg [95% CI: 1.1, 7.4]) and diastolic BP (4.5 mmHg [95% CI: 1.9, 7.2]), as compared to BP following lower CO exposures. We also observed a non-significant trend toward lower BP following initiation of cooking with an improved cookstove. Lastly, we demonstrated that ABPM was a feasible and well-tolerated tool for BP assessment in a rural West African setting. For Project II in New York City, we first determined that there was a great deal of variability in indoor summer heat index (HI) between homes in association with similar outdoor conditions, and that this variability increased with increasing outdoor heat (Chapter 3). Our simulation of a moderate heat wave led us to conclude that the hottest 5% of the homes would reach peak indoor heat index (HI) values of 39°C. In a more extreme heat wave simulation, HI in the hottest 5% of homes reached a peak of 41oC and did not drop below 34oC for the entire nine- day simulated heat wave period. Our second indoor monitoring study yielded the following findings: in the summer season (Chapter 4), we found significant differences in indoor temperature and heat index according to the type of air conditioning (AC) in the home. Homes with central AC were the coolest, followed by homes with ductless AC, window AC, and no AC. Apartments on the top floor of a building were significantly hotter than other apartments regardless of the presence of AC. During the winter season (Chapter 5), median vapor pressure in our sample of apartments was 6.5mb. Comparing humidity levels in the apartments to a threshold of 10mb vapor pressure that has been proposed as protective against influenza virus transmission, levels of absolute humidity in the homes remained below this threshold for 86% of the winter: a total of over three months. Residential use of humidifiers was not associated with higher indoor humidity levels. Larger building size (above 100 units) was significantly associated with lower humidity, while the presence of a radiator heating system was non-significantly associated with higher humidity. Lastly, perceptions of indoor temperature and measured temperature were significantly associated in both the summer and the winter (Chapter 6), while sleep quality was inversely related to measured indoor temperature in the summer season only. Reports of heat- stress symptoms were associated with perceived, but not measured, temperature in the summer season. Conclusions: The work presented in this dissertation adds to a growing body of evidence on the importance of exposures in the domestic environment to health and well-being. The research reported here on household air pollution in Ghana documents an exposure-response relationship between air pollution from cookstoves and elevations in blood pressure, on both a chronic and an acute basis. As elevated BP is a known risk factor for cardiovascular disease (CVD), our research provides support for a plausible factor linking HAP exposure to CVD. Meanwhile, our research on temperature and humidity in New York City residences provides concrete data to supplement the very slim literature to date documenting these conditions in the home environment, where Americans spend over half their time. We conclude, first, that AC may not be fully protective against summertime heat risk, and second, that the levels of humidity we observed in residential environments are consistent with levels that have been shown to promote enhanced survival and transmission of respiratory viruses in experimental settings. We suggest that interventions that can reduce exposure to household air pollution and excess indoor heat can also mitigate climate change, and that with thoughtful planning we can improve health at the same time as we foster resiliency in the face of a changing climate.