Browsing by Author "Peel, Jennifer, committee member"
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Item Open Access Anthropometric indicators of obesity and their link to lifestyle and cardiovascular risk in Colorado firefighters(Colorado State University. Libraries, 2011) O'Toole, Lorin, author; Nelson, Tracy, advisor; Lipsey, Tiffany, committee member; Peel, Jennifer, committee memberCardiovascular disease (CVD) is the leading cause of death in firefighters as it is in the general population. Despite data promoting Colorado as the leanest state in the nation and the image of firefighters as healthy and physically fit, obesity is evident in Colorado firefighters and continues to be an important CVD risk factor. PURPOSE: To determine obesity prevalence, depending on measurement and classification, and its association with lifestyle factors and cardiovascular (CV) risk in a cohort of Colorado firefighters. METHODS: Analysis was conducted on data from 466 Colorado firefighters (41 females; 425 males). Using standard classification cut-points, prevalence of obesity was determined using body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), sagittal abdominal diameter (SAD), and percent body fat (%BF) from skin fold (SF) and hydrodensitometry (H) measurements. Lifestyle factors used in the analysis included diet, physical activity, sleep, tension and depression. Lipids, C-reactive protein (CRP) levels, predicted maximal oxygen consumption and fitness measures were also included. CV risk was assessed using the Cooper Risk Profile. Correlation statistics were run for each anthropometric measure with the above variables. RESULTS: Obesity prevalence varied by measurement: BMI=9.8% females, 19.1% males; WC=19.5% females, 18.9% males; WHR=19.5% females, 8.0% males; SAD=31.6% females, 43.5% males; %BF(SF)=17.1% females (7.3% for >35%BF), 15.1% males; %BF(H)=23.7% females (13.2% for >35%BF), 28.6% males. In both sexes, all anthropometric measures were positively correlated with triglycerides and CRP and inversely associated with high-density lipoprotein cholesterol (except BMI in females), the sit and reach test and estimated maximal oxygen consumption (except BMI in females) (p≤0.05). All anthropometric measures were significantly correlated with CV risk (p≤0.05) except WHR in females. The strongest link to CV risk was %BF(SF) in females and WHR in males. CONCLUSIONS: The prevalence of obesity in Colorado firefighters varies depending on the measure used. There are significant associations between obesity and lifestyle factors that should be further explored. Percent BF(SF) and WHR may be appropriate in assessing CV risk in populations of female and male firefighters, respectively, of similar demographics.Item Open Access Combustion phenomena in biomass gasifier cookstoves(Colorado State University. Libraries, 2016) Tryner, Jessica, author; Marchese, Anthony J., advisor; Willson, Bryan, committee member; Yalin, Azer P., committee member; Peel, Jennifer, committee memberApproximately 2.8 billion people (~40% of the global population) rely on solid fuels, such as wood, charcoal, agricultural residues, and coal, for cooking. Exposure to emissions resulting from incomplete combustion of solid fuels leads to many adverse health impacts. These health impacts have motivated the development of solid-fuel cookstoves that reduce user exposure to carbon monoxide (CO) and fine particulate matter (PM2.5). In recent years, rating systems and emission rate targets for solid-fuel cookstove performance have been proposed. The aspirational targets included in these systems (e.g., Tier 4 in the ISO IWA tiers) have encouraged the development of cookstoves that reduce emissions of CO and PM2.5 by more than 50% and 95%, respectively, compared to a baseline three-stone fire. In a top-lit up draft (TLUD) gasifier cookstove, solid biomass fuel is gasified and the resulting gaseous fuel is mixed with secondary air above the fuel bed to produce the flame that heats the cooking surface. Household biomass cookstoves that utilize gasifier designs have attracted interest due to their demonstrated ability to emit less CO and PM2.5 per unit of energy delivered to the cooking surface than other cookstove designs. Unfortunately, highly variable performance has also been observed among gasifier cookstoves, and some have been found to emit more CO and PM2.5 than a three-stone fire. Accordingly, three studies were conducted to: (1) identify the sources of the observed variability; (2) characterize the manner in which stove design, fuel properties, and operating mode influenced performance; (3) gain insight into how secondary air velocity affected fuel-air mixing and the flame dynamics in the secondary combustion zone; and (4) evaluate whether or not the reductions in emission rates that are sought could be achieved with the TLUD design. In the first study, five natural draft TLUD design configurations were tested with two fuels (corn cobs and Lodgepole pine pellets) to investigate the variability in performance that had been observed in previous studies. The results indicated that stove design, fuel type, and operator behavior all influenced emissions. Four of the five configurations exhibited lower emissions when fueled with Lodgepole pine pellets than when fueled with corn cobs. Furthermore, large transient increases in CO emission rates were observed when stoves were refueled during operation by adding fresh biomass on top of the hot char bed that was left behind after the previous batch of fuel had gasified. An energy balance model was also developed, using temperature data collected from thermocouples mounted on each configuration, to identify the factors that contributed the most to sub-unity efficiency. The results illustrated that up to 60% of the energy input to the stove as fuel could be left over as char at the end of the test, and whether or not the energy in this char was subtracted from the energy in the fuel consumed during the test when calculating the thermal efficiency of a given configuration had a large effect on the calculated efficiency value. The manner in which cookstove design, fuel properties, and operator behavior affected TLUD performance was investigated in more detail in a second study. Seventeen different stove geometries, 4 primary air flow rates, 4 secondary air flow rates, 5 secondary air temperatures, 4 fuel moisture contents, and 4 different sfuel types were tested in a modular test bed using a procedure specifically designed to capture the low emissions observed during normal operation and the high emissions observed during refueling and char burnout. The lowest high-power emissions measured during normal operation were 1.6 g/MJd-1 CO (90% confidence interval (CI) = 1.1-2.1) and 18 mg/MJd-1 PM2.5 (90% CI = 17-19). These values were well below the Tier 4 targets of 8 g/MJd-1 CO and 41 mg/MJd-1 PM2.5, but post-refueling emissions were always above the Tier 4 targets. Higher secondary air velocities resulted in lower emissions. Changes in fuel type influenced the composition of the producer gas entering the secondary combustion zone during normal operation and sometimes resulted in order of magnitude changes in PM2.5 emissions. Temperature measurements taken in the fuel bed indicated that the stove operated as an inverted downdraft gasifier during normal operation and as a conventional updraft gasifier after refueling. Overall, the results suggest that efforts aimed at reducing users' exposure to CO and PM2.5 emissions from solid fuel combustion need to take fuel type and operator behavior, in addition to stove design, into consideration. The third study was designed to investigate the effects of secondary air velocity on the fuel-air mixing process and flame dynamics in the secondary combustion zone by employing high-speed imaging techniques. Images of OH* chemiluminescence, acetone (which served as a fuel tracer) planar laser-induced fluorescence (PLIF), and OH PLIF were collected at multi-kHz repetition rates in a burner designed to generate a two-dimensional replica of the secondary combustion zone in a gasifier cookstove. This burner featured two opposed planar jets that formed an inverse non-premixed flame in which the air and fuel were in cross flow. Images were collected for various air and fuel velocities. Regular deflecting oscillation of the jets, which has been reported previously for isothermal, non-reacting, unconfined opposed planar jets, was observed in some cases but appeared to be suppressed by convection in the vertical direction and buoyancy effects in other cases. The acetone PLIF images revealed that a high air jet velocity resulted in more extensive mixing of the air and fuel below the height of air injection. As a result, the reaction zone was located further below the top of the burner in comparison to the low air velocity case. These results suggest that higher air jet velocities may lead to lower emissions from gasifier cookstoves as a result of better fuel-air mixing and a lower reaction front location that allows more time for CO and PM to be oxidized before reactions are quenched by the cold cooking surface; however, the literature suggests that unconfined opposed axisymmetric jets do not exhibit deflecting oscillation behavior and, as a result, there are limitations associated with the use of opposed planar jets as a model for the secondary air jets in a gasifier cookstove.Item Open Access Development of paper-based analytical devices for particulate metals in welding fume(Colorado State University. Libraries, 2015) Cate, David M., author; Henry, Charles S., advisor; Volckens, John, advisor; Dandy, David, committee member; Peel, Jennifer, committee member; Lear, Kevin, committee memberExposure to metal-containing particulate matter places a tremendous burden on human health. Studies show that exposures lead to cardiovascular disease, asthma, flu-like illnesses, other respiratory disorders, and to increased morbidity. Individuals who work in occupations such as metalworking, construction, transportation, and mining are especially susceptible to unsafe exposures because of their proximity to the source of particle generation. Despite the risk to worker health, relatively few are routinely monitored for their exposure due to the time-intensive and cost-prohibitive analytical methods currently employed. The current paradigm for chemical speciation of workplace pollution is outdated and inefficient. Paper-based microfluidic devices, a new type of sensor technology, are poised to overcome issues associated with chemical analysis of particulate matter, specifically the cost and timeliness of exposure assessment. Paper sensors are designed to manipulate microliter liquid volumes and because flow is passively driven by capillary action, analysis costs are very low. The objective of this work was to develop new technology for rapidly measuring Ni, Cu, Fe, and Cr in welding fume using easy-to-use paper devices. This dissertation covers the development of two techniques for quantifying metal concentration: spot integration and distance-based detection. Metal concentrations as low as 0.02 ppm are reported. A method for controlling reagent deposition as well as a new interface for multiplexed detection of metals, is discussed.Item Open Access Epidemiology and prevention of Salmonella enterica in veterinary hospitals(Colorado State University. Libraries, 2014) Burgess, Brandy Ann, author; Morley, Paul S., advisor; Peel, Jennifer, committee member; Lunn, Paul, committee member; Weese, Scott, committee memberTo view the abstract, please see the full text of the document.Item Open Access Extreme precipitation and flooding: exposure characterization and the association between exposure and mortality in 108 United States communities, 1987-2005(Colorado State University. Libraries, 2017) Severson, Rachel, author; Anderson, Brooke, advisor; Peel, Jennifer, committee member; Grigg, Neil, committee memberThere is substantial evidence that extreme precipitation and flooding are serious threats to public health and safety. These threats are predicted to increase with climate change. Epidemiological studies investigating the health effects of these events vary in the methods used to characterize exposure. Here, we compare two sources of precipitation data (National Oceanic and Atmospheric Administration (NOAA) monitor-based and North American Land Data Assimilation Systems (NLDAS-2) Reanalysis data-based) for estimating exposure to extreme precipitation and two sources of flooding data, based on United States Geological Survey (USGS) streamflow gages and the NOAA Storm Events database. We investigate associations between each of the four exposure metrics and short-term risk of four causes of mortality (accidental, respiratory-related, cardiovascular-related, and all-cause) in the U.S. from 1987 through 2005. Average daily precipitation values from the two precipitation data sources were moderately- to well-correlated (rho = 0.74); however, values from the two data sources were less correlated when comparing binary metrics of exposure to extreme precipitation days (J = 0.35). Binary metrics of daily flood exposure were generally poorly correlated between the two flood data sources (rho = 0.07; J = 0.05). There was generally little correlation between extreme precipitation exposure and flood exposure in study communities. We did not observe evidence of a positive association between any of the four exposure metrics and risk of any of the four mortality outcomes considered. Our results suggest, due to the observed lack of agreement between different extreme precipitation and flood metrics, that exposure to extreme precipitation might not serve as an effective surrogate for exposures related to flooding. Furthermore, it is possible that extreme precipitation and flood exposures may often be too localized to allow accurate exposure assessment at the community level for epidemiological studies.Item Open Access Household air pollution among women using biomass stoves in Honduras: exposure characterization and associations with exhaled nitric oxide and markers of systemic inflammation(Colorado State University. Libraries, 2018) Benka-Coker, Megan Leigh, author; Clark, Maggie, advisor; Peel, Jennifer, committee member; Volckens, John, committee member; Wilson, Ander, committee memberTo view the abstract, please see the full text of the document.Item Open Access Indoor hockey officials' noise exposure, temporary hearing loss, and effect of helmet visor length on exposure to whistle noise(Colorado State University. Libraries, 2016) Adams, Karin L., author; Brazile, William, advisor; Reynolds, Stephen, committee member; Peel, Jennifer, committee member; Legare, Marie, committee member; Lipsey, Tiffany, committee memberTo view the abstract, please see the full text of the document.Item Open Access Laboratory evaluation of a microfluidic electrochemical sensor for aerosol oxidative load(Colorado State University. Libraries, 2012) Shapiro, Jeffrey, author; Volckens, John, advisor; Henry, Charles, committee member; Peel, Jennifer, committee memberHuman exposure to particulate matter (PM) air pollution is associated with both human morbidity and mortality. The mechanisms by which PM impacts human health are yet unresolved, but evidence suggests that PM intake leads to cellular oxidative stress through the generation of reactive oxygen species (ROS). Therefore, reliable tools are needed for estimating the oxidant generating capacity, or oxidative load, of PM. The most widely reported method for assessing PM oxidative load is the dithiothreitol (DTT) assay. The traditional DTT assay utilizes filter-based PM collection in conjunction with laboratory analysis. However, the traditional DTT assay suffers from poor time resolution, loss of reactive species during sampling, and high limit of detection. Recently, a new DTT assay was developed by coupling a Particle Into Liquid Sampler with microfluidic-electrochemical detection. This 'on-line' system allows continuous monitoring of PM reactivity (~three minute measurement resolution) from substantially reduced sample masses (nanograms). This study reports on a laboratory evaluation of the on-line DTT approach. A standard urban dust sample was aerosolized in a laboratory test chamber at three atmospherically-relevant concentrations allowing comparison of the on-line and traditional DTT methods. The on-line system gave a stronger correlation between DTT consumption rate and PM mass (R2 = 0.93) than the traditional method (R2 = 0.29). The on-line system also reported ~1.4 times greater relative reactivity for a given PM sample compared to the traditional method (p = 0.022) indicating improved efficiency for the capture and detection of redox-active species. These results suggest that on-line methods for PM sampling and reactivity analysis may improve our ability to study impacts of PM exposure on human health.Item Open Access Multilocus genetic associations with obesity outcomes in Hispanic and non-Hispanic whites using a principal components regression approach: the San Luis Valley Diabetes Study(Colorado State University. Libraries, 2013) Booth-Kalajian, Andrea D., author; Nelson, Tracy, advisor; Melby, Chris, advisor; Hokanson, John, committee member; Peel, Jennifer, committee member; Bellows, Laura, committee memberIntroduction: The overweight and obesity crisis in America has reached alarming rates with little progress of reversing the trend, despite much effort. Heritability has been estimated at up to 70%, though it is still unclear how genetics respond to environmental pressures. Evaluating groups of genes that are known to influence metabolic pathways has given some insight into the variation we see in body composition and prevalence of metabolic diseases. Methods: Data from the San Luis Valley Diabetes Study's third examination were utilized (1997-1998, n=837). One hundred seven single nucleotide polymorphisms (SNP) were selected from 22 genes that have previously been associated with obesity and type 2 diabetes (T2D) in a cohort of Hispanic and non-Hispanic white (NHW) individuals. Genetic data were reduced to a smaller set of derived factors using principal components analysis (PC). Associations were determined between factors and obesity outcomes. Results: Hispanics were more likely to have T2D than NHW (19% vs. 11%). Sample minor allele frequencies for 100 analyzable SNPs varied between the two groups with the minor alleles of rs8059937 (A2BP1) and rs6822807 (UCP1) being significantly more prevalent in Hispanics and rs11724758 (FABP2) and rs2239179 (VDR) significantly more prevalent in NHWs. SNP variance was redistributed into orthogonal components and 32 were retained for analysis, accounting for 77% of the total variance in genetic data. The combined genetic information increased predictive power of increases in body mass index (BMI) from the study baseline by 5.6% in Hispanics. Genetic data increased predictability of BMI and waist circumference (WC) in NHWs by 7.5% and 5.1%, respectively. Both groups had a significant increase in knowledge gained (18%) for the prevalence of T2D when genetic information was added to the base model. SNPs from UCP1 loaded strongly onto PC4, which was associated with BMI change in Hispanics and BMI, WC, and T2D in NHWs. PC7 represented SNPs from RBP4 and FABP2, which was associated with diabetes status in both groups. All obesity outcomes were associated with PC15 in Hispanics, symbolizing SNPs on the PPARD and RBP4 genes. NHWs showed additional associations with components having strong loadings from SNPs on multiple genes, including ADIPOQ, GC, VDR, PPARG, PPARGC1A, PPARD, UCP2, UCP3, and AlOX15. Conclusions: When combined together, multilocus genetic data show a larger influence on obesity outcomes than single polymorphisms alone. Base variations in UCP1, RBP4, and FABP2 gene sequences are associated with change in BMI and diabetes status in Hispanics and BMI, WC, and diabetes status in NHWs.Item Open Access One health in the U.S. military: a review of existing systems and recommendations for the future(Colorado State University. Libraries, 2014) Evans, Rebecca I., author; Salman, Mo, advisor; Lappin, Michael, committee member; Hayne, Stephen, committee member; Peel, Jennifer, committee memberBackground: The merging of the former U.S. Army Veterinary Command (VETCOM) with the former U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) into the U.S. Army Public Health Command (USAPHC) in 2011 created an opportunity for the military to fully embrace the One Health concept. That same year, the USAPHC began work on a Zoonotic Disease Report (ZDR) aimed at supporting critical zoonotic disease risk assessments by combining zoonotic disease data from human, entomological, laboratory, and animal data sources. The purpose of this dissertation is to facilitate the creation of a military Zoonotic Disease Surveillance program that combines disease data from both military human and animal sources. Methods: Five of the most commonly used human military medical data systems were systematically reviewed using a standardized template based on Centers for Disease Control and Preventive Medicine (CDC) guidelines. The systems were then compared to each other in order to recommend the one(s) best suited for use in the USAPHC ZDR. The first stage of the comparison focused on each system's ability to meet the specific goals and objectives of the ZDR, whereas the second stage applied capture-recapture methodology to data system queries in order to evaluate each system's data quality (completeness). A pilot study was conducted using Lyme borreliosis to investigate the utility of military pet dogs as sentinel surveillance for zoonotic disease in military populations. Canine data came from 3996 surveys collected from 15 military veterinary facilities from 1 November 2012 through 31 October 2013. Surveys simultaneously collected Borrelia burgdorferi (Bb) seroprevalence and canine risk factor data for each participating pet dog. Human data were obtained by querying the Defense Medical Surveillance System for the same 15 military locations and the same time period. The correlation of military pet dog Bb seroprevalence and military human Lyme disease (borreliosis) data was estimated using the Spearman Rank Correlation. The difference between military pet dog data and civilian pet dog data was examined through the use of the chi-squared test for proportions. Multivariable logistic regression was then used to investigate the potential for identified risk factors to impact the observed association. Results: The comparison of human military medical data systems found the Military Health System Management Analysis and Reporting Tool (M2) data system most completely met the specific goals and objects of the ZDR. In addition, completeness calculation showed the M2 data source to be the most complete source of human data; 55% of total captured cases coming from the M2 system alone. The pilot study found a strong positive correlation between military human borreliosis data and military pet dog Bb seroprevalence data by location (rs = 0.821). The study showed reassuring similarities in pet dog seroprevalence by location for the majority of sites, but also showed meaningful differences between two locations, potentially indicating military pet dogs as more appropriate indicators of Lyme disease risk for military populations than civilian pet dog data. Unfortunately, whether canine Bb seroprevalence is influenced by the distribution of identified risk factors could not be determined due to limited study power. Conclusions: Based on this study M2 was recommended as the primary source of military human medical data for use in the Public Health Command Zoonotic Disease Report. In addition, it was recommended that Service member pet dog data be incorporated as a sensitive and convenient measure of zoonotic disease risk in human military populations. The validity of the data, however, should be evaluated further with either larger sample sizes and/or a zoonotic disease with higher prevalence.Item Open Access Personal, spatiotemporal exposure assessment: method development and application(Colorado State University. Libraries, 2013) Adams, Colby D., author; Volckens, John, advisor; Reynolds, Stephen, committee member; Peel, Jennifer, committee member; Brazile, William, committee member; Laituri, Melinda, committee memberTo view the abstract, please see the full text of the document.Item Open Access Quantifying commuter exposures to volatile organic compounds(Colorado State University. Libraries, 2014) Kayne, Ashleigh, author; Volckens, John, advisor; Peel, Jennifer, committee member; Collett, Jeffrey L., committee memberMotor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the laboratory using standard BTEX gases. The LODs for the Tenax TA sampling tubes (determined with a sample volume of 1,000 standard cubic centimeters which is close to the approximate commuter sample volumes collected) were orders of magnitude lower (0.04 to 0.7 parts per billion (ppb) for individual compounds of BTEX) compared to the PIDs' LODs (9.3 to 15 ppb of a BTEX mixture), which makes the Tenax TA sampling method more suitable to measure BTEX concentrations in the sub-parts per billion (ppb) range. PID and Tenax TA data for commuter exposures were inversely related. The concentrations of VOCs measured by the PID were substantially higher than BTEX concentrations measured by collocated Tenax TA samplers. The inverse trend and the large difference in magnitude between PID responses and Tenax TA BTEX measurements indicates the two methods may have been measuring different air pollutants that are negatively correlated. Drivers in Fort Collins, Colorado with closed windows experienced greater time-weighted average BTEX exposures than cyclists (p: 0.04). Commuter BTEX exposures measured in Fort Collins were lower than commuter exposures measured in prior studies that occurred in larger cities (Boston and Copenhagen). Although route and intake may affect a commuter's BTEX dose, these variables are outside of the scope of this study. Within the limitations of this study (including: small sample size, small representative area of Fort Collins, and respiration rates not taken into account), it appears health risks associated with traffic-induced BTEX exposures may be reduced by commuting via cycling instead of driving with windows closed and living in a less populous area that has less vehicle traffic. Although the PID did not reliably measure low-level commuter BTEX exposures, the Tenax TA sampling method did. The PID measured BTEX concentrations reliably in a controlled environment, at high concentrations (300-800 ppb), and in the absence of other air pollutants. In environments where there could be multiple chemicals present that may produce a PID signal (such as nitrogen dioxide), Tenax TA samplers may be a better choice for measuring BTEX. Tenax TA measurements were the only suitable method within this study to measure commuter's BTEX exposure in Fort Collins, Colorado.Item Embargo Quantitative health impact assessments as a tool for exploring public health dimensions of environmental exposures(Colorado State University. Libraries, 2024) Dean, Daniel, author; Rojas-Rueda, David, advisor; Anderson, G. Brooke, advisor; Peel, Jennifer, committee member; Hurrell, James, committee memberPublic health is influenced by a population's built and natural environment in both negative (e.g., natural disasters or ongoing stress from heat) and positive (for instance, heat-moderating effects of vegetation) ways, as well as interactively with behavioral and social dynamics. One framing of policy priorities and urban resilience is a "triad" consisting of exposure reduction (limiting the extent to which community members are exposed to environmental hazards—including "ambient" ones like stressful temperatures), vulnerability reduction (mitigating the impacts of sustained hazards), and hazard reduction (actively reducing the frequency or intensity of hazards) (Hoegh-Guldberg et al. 2018). Because any such measures carry tradeoffs in financial and other resources, it is important that policymakers and other stakeholders weigh comparative benefits of potential environmental hazards or interventions with consistent, quantifiable metrics. In this body of work, we applied quantitative health impact assessments, an epidemiology framework that provides a valuable tool here, allowing researchers to project health outcome changes for a population of interest given predicted changes in a relevant exposure and using epidemiological evidence, including exposure-response functions (exposure-response functions), which link exposure and health outcomes. In this body of work, we use HIAs to explore three different resilience-relevant systems spanning a range of intervention types, environmental systems, and spatiotemporal scales: Project 1: Health Impacts of Future Tropical Cyclones in the Eastern United States: While tropical cyclones are among the most damaging natural disasters faced by the United States, the temporal and spatial rarity of these events impedes traditional frequency-based estimates for public health and related risk projections, leading to potential oversights in risk characterization. In addition, mortality associated with tropical cyclones may not be readily apparent between delayed onset and indirect causes (e.g. stress, disrupted medical care, infections), meaning that immediate mortality counts often underestimate full attributable mortality. In this project, we performed a pilot quantitative health impact assessment designed to address aspects of these limitations. First, we tested extending the historical tropical storm dataset using a pool of 10,000 simulated, or "synthetic" tropical cyclone seasons from the widely used and open-source STORM algorithm, trained from and intended to represent the "gold standard" of historical International Best Tracks Archive for Climate Stewardship (IBTrACS) data. To the extent that STORM represents real-world conditions, this vastly expanded 'sample population provided information on potential tropical cyclone exposure risk than would be possible from historical data alone. For the second challenge of accounting for delayed and indirect attributable mortality, we combined the synthetic data with a recently-developed exposure-response function: an integrated Bayesian causal-predictive model trained on Medicare Claims data (simplified to Americans aged 65 and older), featuring an integrated model approach to combine a whole-population causal inference model for central trends with county-specific predictive models for give county-specific estimates. This model also tracked up to 21 days of "lag time" in health outcomes after a TC exposure to capture delayed mortality. This combination of methodologies promises a comprehensive, county level picture of tropical cyclone-associated all-cause mortality risk among older adults. This approach provided insights including regions of the country at the greatest risk for tropical cyclone-related exposures among older adults. However, as our study represented a new application of the STORM algorithm (in particular, our emphasis focusing on post-landfall behavior of tropical cyclones), we also assessed the level of agreement between STORM and the historical dataset, finding some discrepancies including lower overall frequency, and considerably 'smoother' spatial distribution in exposures; some discrepancies were in line with previously noted limitations. This project used recent innovations in atmospheric science and epidemiology modeling to explore the utility of a quantitative health impact assessment framework for present-day risk and could inform policy and planning decisions in terms of tropical cyclone preparedness and response measures. Project 2: Health impacts of Urban Tree Canopy policy scenarios in Denver and Phoenix: We explored potential health impacts (in terms of all-cause mortality, stroke, and dementia) of standing policy goals in Denver, Colorado and Phoenix, Arizona, for increasing the urban tree canopy coverage in these relatively arid cities. We projected health benefits (in terms of reduced attributable all-cause mortality, stroke, and dementia incidence) at a census block group level using several existing exposure-response functions based on the widely used Normalized Difference Vegetation Index (NDVI). Because the cities expressed policy goals in terms of percentage urban tree canopy, we generated predictive models to "translate" between this metric used in policy goals and the NDVI metric. We modeled the public health impacts of proposed real-world policies for near-future policy interventions in the form of increasing urban tree canopy, using current populations, and modeling an "overnight" change in exposure, with policy scenario benefits modeled for populations in year 2020, rather than demographic projections for the 2030 (Phoenix) and 2050 (Denver) dates in the policy goal timelines. We also considered socioeconomic dimensions by using the census-based Social Vulnerability Index to trace the equity of current UTC and NDVI exposures, as well as of potential benefits. We determined that each city could, by reaching its standing policy goals, could avert hundreds of all-cause mortality cases, with even a partial attainment scenario (halfway between current and desired UTC levels) having appreciable benefits, with roughly half the captured mortality prevention; with respect to equity of UTC access, more-vulnerable communities in the cities saw lower access to current canopy cover, and consequently greater potential per-capita benefits under successful intervention scenarios. Project 3: Health Impacts of Future Temperature Extremes Under a Solar Climate Intervention Scenario. In this project, we explored potential all-cause mortality implications of a proposed climate intervention effort intended to counteract anthropogenic warming, modeling the years 2050-2060 under alternate climate scenarios. Specifically, we projected temperature-associated mortality under a stratospheric aerosol injection (SAI) intervention scenario, as well as a corresponding scenario of "middle-of-the-road" climate change. We used a study population of 65-and-older Americans in eight major US cities (Seattle, Chicago, New York, Philadelphia, Los Angeles, Phoenix, Houston, and Miami) spanning a range of local climates. We built our analysis on widely used models and the shared socioeconomic pathway platform, allowing our two scenarios to be compatible, differing only in the SAI intervention itself. We focused on two age groups (65-75, and 75+) to reflect elevated heat- and cold-associated mortality risks among this population, finding broadly similar trends between age groups. We explored city-specific exposure-response functions for the temperature-mortality association, using a widely used modeling, comparing the anticipated number of cold- and heat-related deaths under each scenario, and highlighted tradeoffs for either policy scenario, finding considerable heterogeneity in trends between these cities. To make our analysis more specific to the mid-21st century, we incorporated existing estimates for population growth and mortality rate changes based on the same climate modeling scenarios as the SAU exposure scenarios. We observed dramatic variability in minimum mortality temperatures and temperature-attributable mortality between cities and found that SAI was not associated with decisive reductions in all-cause mortality among either age group. While SAI did effectively reduce heat-attributable mortality, lower cold-attributable mortality under the warmer, non-SAI scenario counterbalanced this effect, yielding a weak net impact in central tendencies. This observation could help inform planning and resilience efforts as far as types of temperature-related stress under each scenario, as well as provide insights for larger cost-benefit analyses for the overall proposition of SAI. Together, these projects demonstrated how quantitative health impact assessments can help form a methodological foundation for exploring epidemiology and resilience-relevant systems. The variety of projects covered demonstrated the utility of this methodology in a variety of spatial scales, ranging from census block groups (comparable to neighborhoods) in Project 2 to county-level characterizations of tropical cyclone-associated risk for much of the eastern United States in Project 1. We also explored a range of time periods, ranging from Project 1's focus on characterizing tropical cyclone risk representative of the past several decades (as represented by the STORM resampling algorithm), through our attempts to explicitly model mid-21st century populations and temperature-related mortality trends using both climate and demographic projections. The modularity of the quantitative health impact assessment framework enabled our projects to leverage of existing research and datasets for low-cost, comparatively rapid assessments, as well as to lay infrastructure for future research and introduce several specific innovations in their respective designs.Item Open Access Respiratory morbidity in susceptible populations: the role of joint exposure to multiple environmental chemicals and pollutants(Colorado State University. Libraries, 2019) Benka-Coker, Wande, author; Magzamen, Sheryl, advisor; Peel, Jennifer, committee member; Wilson, Ander, committee member; Anderson, Brooke, committee memberExposure to ambient pollution from environmental chemicals and pollutants has been associated with a range of adverse respiratory outcomes; susceptible populations are disproportionately affected. Children with asthma are particularly at risk for adverse respiratory effects of environmental agents. The recent increase in US and worldwide pediatric asthma prevalence has encouraged new lines of inquiry focusing on environmental factors, rather than genetic factors, as the main etiologic agent in asthma-related morbidity; the complex relationship between individuals and their environment requires improved characterization and quantification.Item Open Access Toward the understanding and optimization of chimneys for buoyantly driven biomass stoves(Colorado State University. Libraries, 2013) Prapas, Jason, author; Willson, Bryan, advisor; DeFoort, Morgan, advisor; Marchese, Anthony, committee member; Peel, Jennifer, committee memberThe vast majority of indoor combustion devices in the developed world make use of stacks (flues, vents, chimneys, smokestacks) to channel flue gases out of the operator space. In the developing world, where indoor air pollution kills several million people every year, the use of chimneys with biomass cooking and heating stoves has been met with limited success and a high level of controversy. Due to a lack of theoretical understanding, design criteria, poorly executed installation practices, and/or insufficient maintenance routines, many chimney stoves have exhibited inadequate indoor emissions reductions in addition to low thermal efficiencies. This work aims (a) shed light on the physical phenomenon of the "stack effect" as it pertains to dynamic, non-adiabatic, buoyancy-driven stoves (b) apply new understanding toward the optimization of two types of biomass chimney stoves: plancha or griddle type stoves popular in Central America and two-pot stoves common in South America. A numerical heat and fluid flow model was developed that takes into account the highly-coupled variables and dynamic nature of such systems. With a comprehensive physical model, parameter studies were conducted to determine how several field-relevant variables influence the performance of stack-outfitted systems. These parameters include, but are not limited to: power/wood consumption rate, chimney geometry, stove geometry, material properties, heat transfer, and ambient conditions. An instrumented experimental chimney was built to monitor relationships between air flow, differential pressure, gas temperatures, emissions, and thermal efficiency. The draft provided by chimneys was found to have a strong influence over the bulk air-to-fuel ratio of buoyantly-driven cookstoves, greatly affecting the stove's overall performance by affecting gas temperatures, emissions, and efficiency. Armed with new information from the modeling and experimental work, two new stoves were designed and optimized to have significant reductions in fuel use and emissions.