Typescript. Includes vita and abstract. Includes bibliographical references (leaves 110-120). Also available online in Scholars' Bank.

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.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1988. / Bibliography: leaves 520-551. / Photocopy. / Microfilm. / xxi, 551 leaves ill. 29 cm

This study examines the adoption of clean cooking technologies in developing countries with a focus on the ACE-1 advanced biomass stove (ABS). Marginalized communities in rural environments are often exposed to high levels of Household Air Pollution (HAP) due to the common use of traditional cookstoves. The United Nations (UN) has recognized the adoption of clean cooking technology like the ABS as a key driver and high-impact opportunity in the context of the 2030 Agenda for Sustainable Development. Nonetheless, the context for adoption is complex. Adoption depends on numerous variables, that can enable or hinder the uptake of modern cookstoves. This study is based on the assumption, that adoption starts with the decision-making process and acquisition of the stove. Based on a field study in rural Cambodia, this research focuses on users at the initial stage of adoption. By means of questionnaire-based interviews, this study identifies how variables related to ‘fuel and technology’ and ‘household and setting’ affect the likeliness of adoption and what opportunities can be identified to facilitate the process of adoption. The study finds, that ABS-suitable biomass fuels are available and accessible in rural Cambodia. Besides, the production of renewable biomass fuels like pellets is growing, which provides opportunities for collaboration with stove distributors. The study confirms the common practice of stove stacking and points out the strong market presence of Liquefied Petroleum Gas (LPG) stoves. Market activities need to consider these factors and highlight the competitive advantages of AB, namely fuel efficiency and cost savings. Finally, the impact of social influence and peer relations should be further researched and taken into consideration for sales and marketing activities.

Household air pollution (HAP) is responsible for almost 4 million premature deaths every year, a burden that is primarily carried by women and children in developing countries. The mortality and morbidity impact of HAP can be significantly alleviated through clean cookstove interventions. However, for these interventions to be effective, the new intervention stove must be a substantially cleaner technology and adoption should be high and sustained over time. Woody biomass is the fuel of choice in many developing communities, and contributes substantially to HAP. Several organizations have launched clean cooking interventions to address this issue. However, the majority of those interventions do not address adoption related challenges, that they often face. This thesis explores previous studies on Human-Centered Design (HCD) and the impact of feedback and data access on behavior change. It details a HCD process and methodology applied during the design process of an air quality feedback system, to improve adoption of liquefied petroleum gas (LPG) cookstoves in Rwanda. The feedback system is intended to provide real-time air quality information to stove users and potentially encourage them to abandon traditional biomass cookstoves in favor of the cleaner LPG stoves.

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.

The use of biomass as a renewable fuel source can help the United States reduce its dependence on fossil fuels, especially in providing affordable heat for many middle- and low-income households. However, residential wood combustion (RWC) releases pollutants that can negatively impact the environment and human health, especially for those living in the vicinity of wood-burning locations. Current compliance testing methods are insufficient in capturing the actual in-use emissions of residential wood heaters because they do not represent real-life use, leading to higher emissions during actual use. This thesis investigates emissions during realistic operations of wood-fired heaters to identify and quantify the majority of emissions and ways to minimize such emissions. The study focuses on investigating eight different woody biomass fired heaters, including three pellet stoves, a pellet boiler, two wood chip-fired hydronic heaters, and two outdoor cordwood fired hydronic heaters. This research contributes a new knowledge on the impact of combustion strategies, fuel type, and control strategies to minimize emissions. The obtained data can provide information to manufacturers, policy makers, and consumers, guiding low-emission and more efficient use of wood-fired heating devices. In all chapters, variability was evident due to burn phase, fuel type, and operation. The results from the pellet stoves showed that even while using a homogeneous fuel, different burn phases produce different emissions than the overall period. For the pellet boiler studies, the highest efficiencies were achieved during the high load, steady state tests. The burn phase also affects emissions from woodchip boilers, where low output periods are significantly higher in terms of emissions compared to high output periods. Each individual burn phase of the duty cycle produced different emissions in cordwood testing, with steady-state phases having the lowest emissions and highest efficiency. The variability in emissions from different burn phases is a crucial factor in evaluating the performance of wood-burning appliances. Lower moisture content fuels were found to have better performance in terms of PM emissions and efficiency. Fuel type can impact emissions, but it may be overshadowed by burn phase and technology. Relatively high emissions were often related to low or incorrect air-to-fuel ratios. Gasification techniques used in some woodchip boilers during low output periods significantly increased efficiency and reduced CO emissions. Additionally, gasification techniques used during high burn steady states with wet fuel chips resulted in a 77% reduction in PM emissions. Comparing all the primary heaters studied in this thesis, in terms of PM emission output, showed the units that used gasification, integrated catalysts, or thermal storage had the lowest emissions. The results of the study are compiled into data sets that give a more accurate picture of real-world operation of wood-fired heaters that will benefit air quality modelers and policy makers. Such emission data for various biomass heaters in EPA’s AP-42, under realistic operating conditions, currently either does not exist or is limited. Additionally, this research identifies the most important parameters that need to be included in the development of high-resolution models, optimizing the performance of wood-fired devices and supporting the transition from current compliance testing to more realistic testing. In conclusion, this work provides new insights into the performance and emissions of wood-fired heaters during realistic operation. The results of the study can help manufacturers optimize their products for real-life performance and help policy makers and consumers make informed decisions regarding low-emission and more efficient use of wood-fired heating devices. The study highlights the importance of capturing transient phases and the impact of fuel type and control strategies on minimizing emissions.

The recovery boiler in a pulp and paper mill plays a dual role of recovering pulping chemicals and generating steam for either chemical processes or producing electricity. The efficiency of producing steam in the recovery boiler is limited by the first melting temperature of ash deposits that accumulate on the superheater tubes. Above the first melting temperature, the molten salt reacts with the protective oxide film that develops and dissolves it. The most protective oxide is determined by evaluating how little it dissolves and how its solubility changes in the molten salt. Solubility tests were done on several protective oxides in a known salt composition from a recovery boiler that burns hardwood derived fuel. ICP-OES was used to measure concentration of dissolved metal in the exposure tests while EDS and XRD were used to verify chemical compositions in exposure tests. NiO was found to be the least soluble oxide while Cr₂O₃ and Al₂O₃ had similar solubility with Fe₂O₃ being less soluble than Cr₂O₃ but more soluble than NiO. Exposure tests with pure metals and selected alloys indicated that even though Fe₂O₃ has little solubility, it is not a protective oxide and causes severe corrosion in stainless steels. The change in performance of iron based alloys was due to the development of a negative solubility gradient for Fe₂O₃ where Fe₂O₃ precipitated out of solution and created a continuous leaching of oxide. Manganese was found to be beneficial in stainless steels but its role is still unknown. Nickel based alloys were found to be least corroded due to nickel's low solubility and because it did not form a negative solubility gradient.

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.