Browsing by Author "Kolivras, Korine N."

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    Application of a Mobile Flux Lab for the Atmospheric Measurement of Emissions (FLAME)
    Moore, Tim Orland II (Virginia Tech, 2009-09-08)
    According to the World Health Organization, urban air pollution is a high public health priority due its linkage to cardio-pulmonary disease and association with increased mortality and morbidity (1, 2). Additionally, air pollution impacts climate change, visibility, and ecosystem health. The development of effective strategies for improving air quality requires accurate estimates of air pollutant emissions. In response to the need for new approaches to measuring emissions, we have designed a mobile Flux Lab for the Atmospheric Measurement of Emissions (FLAME) that applies a proven, science-based method known as eddy covariance for the direct quantification of anthropogenic emissions to the atmosphere. The mobile flux lab is a tool with novel, multifaceted abilities to assess air quality and improve the fidelity of emission inventories. Measurements of air pollutant concentrations in multiple locations at the neighborhood scale can provide much greater spatial resolution for population exposure assessments. The lab's mobility allows it to target specific sources, and plumes from these can be analyzed to determine emission factors. Through eddy covariance, the lab provides the new ability to directly measure emissions of a suite of air pollutants. We have deployed the FLAME to three different settings: a rural Appalachian town where coal transport is the dominant industry; schools in the medium-sized city of Roanoke, Virginia; and the large urban areas around Norfolk, Virginia, to measure neighborhood-scale emissions of air pollution. These areas routinely experience high ozone and particulate matter concentrations and include a diverse array of residential neighborhoods and industries. The FLAME is able to capture emissions from all ground-based sources, such as motor vehicles, rail and barge traffic, refuse fires and refueling stations, for which no direct measurement method has been available previously. Experiments focus on carbon dioxide (CO₂), the principal greenhouse gas responsible for climate change; nitrogen oxides (NOx), a key ingredient in ground-level ozone and acid rain; volatile organic compounds (VOCs), a second key ingredient in ozone and many of which are air toxics; and fine particulate matter (PM2.5), a cause of mortality, decreased visibility, and climate change. This research provides some of the first measurements of neighborhood-scale anthropogenic emissions of CO₂, NOx, VOCs and PM2.5 and as a result, the first opportunity to validate official emission inventories directly. The results indicate that a mobile eddy covariance system can be used successfully to measure fluxes of multiple pollutants in a variety of urban settings. With certain pollutants in certain locations, flux measurements confirmed inventories, but in others, they disagreed by factors of up to five, suggesting that parts of the inventory may be severely over- or underestimated. Over the scale of a few kilometers within a city, emissions were highly heterogeneous in both space and time. FLAME-based measurements also confirmed published emission factors from coal barges and showed that idling vehicles are the dominant source of emissions of air toxics around seven schools in southwest Virginia. Measurements from this study corroborate existing emission inventories of CO₂ and NOx and suggest that inventories of PM2.5 may be overestimated. Despite the tremendous spatial and temporal variability in emissions found in dense urban areas, CO₂ fluxes on average are very similar across the areas in this study and other urban areas in the developed world. Nevertheless, the high level of variability in spatial and temporal patterns of emissions presents a challenge to air quality modelers. The finding that emissions from idling vehicles at schools are likely responsible for creating hot spots of air toxics adds to the urgency of implementing no-idling and other rules to reduce the exposure of children to such pollutants. Ultimately, the results of this study can be used in combination with knowledge from existing emission inventories to improve the science and policies surrounding air pollution.
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    Associations Between Drinking Water Source Watershed and Adverse Birth Outcomes in Central Appalachia
    Cornwell, Cameron Scott (Virginia Tech, 2022-06-30)
    In order to ensure clean drinking water for all, it is crucial to understand potential upland stressors that compromise the quality of source waters treated by local community water systems (CWSs). Contamination associated with specific types of land cover can result in downstream water quality degradation, which may reduce the effectiveness of treatment by CWSs. Surface mining has been hypothesized as a source of drinking water degradation within the Central Appalachian region, which may result in adverse exposures and health disparities. The purpose of this study was to identify potential correlations between land cover and adverse birth outcomes (ABOs) through the application of watershed epidemiology, an emerging environmental health paradigm. Birth records for the Central Appalachian region were acquired from their respective state health departments from 2001 to 2015: each record contained the mother's street address, outcome variables, and covariates. Records were included in later analyses if they fell within an approximated CWS service area. Contributing land cover to each CWS was determined via previously delineated watersheds that relied on CWS intake points. A binomial generalized linear model was used to compare low birth weight (LBW), term low birth rate (tLBW), and preterm birth (PTB) incidence to CWS source watershed land cover, Safe Drinking Water Act (SDWA) violations, CWS size, and covariates related to the birth records. Source watershed mining and SDWA health based (HB) violations were significantly associated with greater risks for preterm birth (PTB) and low birth weight (LBW). Future work should be conducted to explore upstream flow impacts, address missing data in the birth records, and to more accurately represent CWS service areas to better characterize exposure.
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    The Cartographic Representation of Language: Understanding language map construction and visualizing language diversity
    Luebbering, Candice Rae (Virginia Tech, 2011-03-23)
    Language maps provide illustrations of linguistic and cultural diversity and distribution, appearing in outlets ranging from textbooks and news articles to websites and wall maps. They are valuable visual aids that accompany discussions of our cultural climate. Despite the prevalent use of language maps as educational tools, little recent research addresses the difficult task of map construction for this fluid cultural characteristic. The display and analysis capabilities of current geographic information systems (GIS) provide a new opportunity for revisiting and challenging the issues of language mapping. In an effort to renew language mapping research and explore the potential of GIS, this dissertation is composed of three studies that collectively present a progressive work on language mapping. The first study summarizes the language mapping literature, addressing the difficulties and limitations of assigning language to space before describing contemporary language mapping projects as well as future research possibilities with current technology. In an effort to identify common language mapping practices, the second study is a map survey documenting the cartographic characteristics of existing language maps. The survey not only consistently categorizes language map symbology, it also captures unique strategies observed for handling locations with linguistic plurality as well as representing language data uncertainty. A new typology of language map symbology is compiled based on the map survey results. Finally, the third study specifically addresses two gaps in the language mapping literature: the issue of visualizing linguistic diversity and the scarcity of GIS applications in language mapping research. The study uses census data for the Washington, D.C. Metropolitan Statistical Area to explore visualization possibilities for representing the linguistic diversity. After recreating mapping strategies already in use for showing linguistic diversity, the study applies an existing statistic (a linguistic diversity index) as a new mapping variable to generate a new visualization type: a linguistic diversity surface. The overall goal of this dissertation is to provide the impetus for continued language mapping research and contribute to the understanding and creation of language maps in education, research, politics, and other venues.
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    Chagas Disease in the United States: the Emerging Threat and the Role Climate and Awareness Play in Its Spread
    Lambert, Rebecca Click (Virginia Tech, 2007-03-27)
    This study evaluates the roles of temperature variability and disease awareness in the emergence of Chagas disease (American trypanosomiasis). Chagas disease is endemic in Latin America and primarily spreads to humans directly via the triatomine vector. Hosts for most triatomine species are mainly rodents and occasionally dogs. The disease itself is caused by a parasitic protozoan, Trypanosoma cruzi (T. cruzi) which is found in the triatomine's feces and is often spread while the triatomine is consuming a blood meal. T. cruzi from feces enters the body via an abrasion on the skin, the mucous membranes, conjunctivae, or through consumption. To determine the risk of Chagas disease transmission one must define qualities that make the triatomine an effective disease vector as well as investigate the level of disease awareness among physicians and the population within the vector's range. This thesis maps triatomine species within the U.S. that harbor T. cruzi naturally and that exhibit qualities of domesticity. These qualities are defined by whether the species bites humans and dogs as well as reports that the species has been found in the domestic setting. Ranges illustrating temperature thresholds for increased triatomine activity for 2000 and 2030 are also depicted. Additionally, outcomes of a physician survey are presented to gauge the status of Chagas disease awareness in areas at higher risk for disease transmission. Results reveal limited consideration of Chagas disease in physician diagnosis despite the higher risk range which extends through the southern U.S. and is predicted to expand significantly by 2030.
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    Clean water for all: The demographics of urban and rural safe drinking water challenges in Virginia, USA and San Rafael Las Flores, Guatemala
    Marcillo, Cristina Elizabeth (Virginia Tech, 2020-04-14)
    The United Nations established Sustainable Development Goal 6, universal access to safely managed drinking water and sanitation service, as a global goal for 2030. In rural areas, access lags significantly and progress is rarely examined concurrently between developed and developing nations. Therefore, this dissertation focuses on rural water system challenges in a developed nation, the US, and a developing nation, Guatemala. In the US, approximately 250 million Americans receive drinking water from community water systems (CWSs), theoretically safeguarded by the Safe Drinking Water Act (SDWA). There is mounting evidence that racial, ethnic, and socioeconomic disparities persist in US drinking water access and quality, but studies are limited by the exclusion of very small CWSs and a large geographic unit of analysis. A novel geospatial methodology was created to delineate system service areas at the zip code scale in Virginia and assess the influence of demographic characteristics on compliance with the SDWA from 2006 to 2016. Results reveal that monitoring and reporting violations are concentrated in private, rural systems that serve fewer than 500 people, while health-based violations were more likely in non-white communities, specifically those with higher proportions of Black, Native Hawaiian, and other Pacific Islanders. This study was completed in parallel with a household sampling campaign in rural San Rafael Las Flores, Guatemala. In Guatemala, no public access to water system compliance or quality information currently exists. With growing investment in mining industries and recognized naturally occurring arsenic in volcanic geology, citizens are eager for drinking water information. Survey results highlighted dissatisfaction with and distrust in most tap water sources. Consequently, residents regularly buy bottled water or collect water from untreated natural springs. Water quality results indicated that tap water from the central drinking water treatment plant contained higher levels of arsenic and other contaminants, when compared to most other sources. Though the settings are quite different, parallel investigation of rural drinking water system challenges in the US and Guatemala reveal common challenges and lessons. Moving forward, all nations would benefit from standard monitoring of drinking water access, quality, and compliance that allowed for intersectional investigations of environmental health inequities.
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    Comparing Relative Convenience of Non-Commute Trips in Battery Electric Vehicles Versus Internal Combustion Engine Vehicles in the Contiguous United States
    Starner, Joshua D. (Virginia Tech, 2021-05-26)
    Technological advancements in battery electric vehicles (BEVs) have developed alongside increases in vehicle size and the introduction of vehicle styling more similar to internal combustion engine vehicles (ICEVs). Increases in the distance a BEV can travel on a single charge have been accompanied by the ability to recharge the vehicle much faster than the BEV models available just 10 years ago. The Environmental Protection Agency (EPA) reports for model year 2021 include 40 BEV models and many manufacturers have signaled plans to increase the number of battery electric vehicle models offered. As more consumers consider purchasing a battery electric vehicle the question of how well that vehicle can meet all their needs is asked more frequently. This research examines the current DC-Fast charging infrastructure to evaluate how the current distribution of chargers impacts consumer convenience for non-commute routes. No study has evaluated the impact that the current DC-Fast charging infrastructure has on the consumer driving experience and we fill this research need because it will allow consumers to understand more accurately how a (BEV) may meet their needs while also allowing BEV manufacturers to better understand the impacts of potential investments in charging infrastructure. The authors examine over 30,000 pairs of simulated BEV and ICEV routes and compare the distance and duration variations for each pair. Due to our effort to consider the suitability for long distance trips, we have ensured that more than 50% of the simulated routes have a minimum travel distance of 500 miles and over 15% of the routes exceed 1000 miles. Working from this data, 99.7% of the locations in a sample of 360 places in the contiguous U.S. can be reached without relying on the ability to charge a BEV overnight. We further identify a median increase in BEV trip duration of 13.1% and a median increase in distance of 0.06%. The differences in median travel time, particularly when trips exceed 400 miles suggests that long trips made with a BEV may result in longer total travel time, however, differences in route length between BEVs and ICEVs were minimal. These findings serve as the foundation to discuss challenges and solutions related to widespread non-commuter adoption of BEVs in a variety of geographic locations, including how and where the consumer experience may vary. The results from this work will support consumer awareness about the ability of a BEV to meet their needs as well to aid in the evaluation of infrastructure investment as it relates to improving the consumer experience. The methods employed serve as a foundation for future work to investigate the relationship between vehicle type and consumer experience as well as to advance algorithms capable of evaluating routes that require a selection to be made from a set of optional stops.
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    Development of a Spatial Decision Support System for Emergency Medical Service Facility Siting
    Muza, Matej (Virginia Tech, 2011-05-02)
    Improved strategic location of an Emergency Medical Service (EMS) facility can significantly increase EMS efficiency. Urban planners need to consider a location that satisfies multiple criteria in order to make an informed decision about a future EMS facility site. Apart from basic criteria such as parcel value and size, decision-makers need to consider area and population coverage from potential parcels. Geographic Information Systems (GIS) provide an adequate analysis environment for EMS facility siting as many considered criteria are of a spatial nature. However, urban planners making decisions about an EMS facility site often lack the necessary expertise to make full use of challenging GIS tools. In order to help urban planners in the analysis process, this research developed a Spatial Decision Support System (SDSS) for EMS facility siting. The system was developed in ESRI ArcGIS (9.3) using the Visual Basic for Applications (VBA) programming environment. The objective of the system was to integrate spatial data, analysis, and visualization in a single system to help users evaluate a facility siting problem. The system's performance was tested using data for the Town of Blacksburg, VA. In addition, the system was evaluated by local planners and GIS staff with experience in EMS facility siting. Planners agreed the system enables more comprehensive and straightforward use of GIS for EMS facility siting analysis than other available siting tools. Potential improvements include a simpler user interface, synthesis of geoprocessing techniques, reduction of analysis time through automation, and better decision-making by improved visualization of results.
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    Discerning Neighborhood Characteristics as Contributing Factors to Infant Mortality in Rural Northern Plains Communities
    Masilela, Ayanda Martha (Virginia Tech, 2014-09-11)
    American Indians are distinct in their current geographic isolation and history of exclusionary policies enacted against them. Citizenship and territorial policies from the 1700s through the early 1900s have manifested in the distinctive status of many American Indian communities as sovereign nations, a classification that no other ethnic group in the United States can claim. However, as a result of political and geographic isolation, disparities in heath and economic development have been an ongoing problem within these communities. Among the most distinctive health disparities are in infant mortality and obesity-related complications. This project will focus on South Dakota, a state that was late in its application of assimilationist policies, yet today is home to some of the least healthy reservation communities in the United States. An investigation into the making of reservation healthcare delivery systems and patterns of prenatal care utilization will hopefully reveal patterns of health and economic characteristics that predispose infant mortality.
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    Does availability of physical activity and food outlets differ by race and income? Findings from an enumeration study in a health disparate region
    Hill, Jennie L.; Chau, Clarice; Luebbering, Candice R.; Kolivras, Korine N.; Zoellner, Jamie M. (2012-09-06)
    Background Low-income, ethnic/racial minorities and rural populations are at increased risk for obesity and related chronic health conditions when compared to white, urban and higher-socio-economic status (SES) peers. Recent systematic reviews highlight the influence of the built environment on obesity, yet very few of these studies consider rural areas or populations. Utilizing a CBPR process, this study advances community-driven causal models to address obesity by exploring the difference in resources for physical activity and food outlets by block group race and income in a small regional city that anchors a rural health disparate region. To guide this inquiry we hypothesized that lower income and racially diverse block groups would have fewer food outlets, including fewer grocery stores and fewer physical activity outlets. We further hypothesized that walkability, as defined by a computed walkability index, would be lower in the lower income block groups. Methods Using census data and GIS, base maps of the region were created and block groups categorized by income and race. All food outlets and physical activity resources were enumerated and geocoded and a walkability index computed. Analyses included one-way MANOVA and spatial autocorrelation. Results In total, 49 stores, 160 restaurants and 79 physical activity outlets were enumerated. There were no differences in the number of outlets by block group income or race. Further, spatial analyses suggest that the distribution of outlets is dispersed across all block groups. Conclusions Under the larger CPBR process, this enumeration study advances the causal models set forth by the community members to address obesity by providing an overview of the food and physical activity environment in this region. This data reflects the food and physical activity resources available to residents in the region and will aid many of the community-academic partners as they pursue intervention strategies targeting obesity.
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    Ecological and Human Health in Rural Communities
    Gohlke, Julia M.; Kolivras, Korine N.; Krometis, Leigh-Anne H.; Marmagas, Susan West; Marr, Linsey C.; Satterwhite, Emily M.; Angermeier, Paul L.; Clark, Susan F.; Ranganathan, Shyam; Schoenholtz, Stephen H.; Swarup, Samarth; Thompson, Christopher K. (2017-05-15)
    Environmental exposures to chemicals and microbes in the air we breathe, the water we drink, the food we eat, and the objects we touch are now recognized to be responsible for 90% of all human illness. This suggests that well-documented health disparities within and between nations have significant geographic and ecological as well as socioeconomic dimensions that must be addressed in order to secure human well-being at local to global scales. While urbanization is a primary driver of global change, it is widely acknowledged that urbanization is dependent on large-scale resource extraction and agriculture in rural communities. Despite considerable evidence linking human industrial and agricultural activities to ecological health (i.e. health of an ecosystem including the non-human organisms that inhabit it), very little data are available directly linking exposure to environmental pollution and human health in rural areas, which have repeatedly been identified as subject to the most extreme health disparities...
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    The Effects of Land Cover Change on the Spatial Distribution of Lyme Disease in Northern Virginia Since 2005
    Stevenson, Megan N.; Kolivras, Korine N. (Virginia Tech, 2019-04-26)
    Lyme disease has been a growing problem in the United States over the last few decades, and is currently the most common vector-borne disease in the country. This research evaluates the land cover within specified counties of northern Virginia to find a correlation between forest fragmentation, suburbanization, and cases of human Lyme disease; as has been demonstrated in other Lyme endemic regions in the United States. Few studies have focused specifically on northern Virginia when considering the impacts of land cover change on Lyme disease. Discovered through the use of GIS and Geospatial Modelling Environment softwares, the cluster of Lyme disease cases in northern Virginia could be attributed to the forest fragmentation within the study region, which creates an ideal habitat for black-legged ticks and allows for an increase in Lyme disease transfer from vector to humans. The goal is for the research findings to be applicable to other regions with similar land cover types. Regions with similar characteristics would then be able to recognize the potential risk of human Lyme disease and implement ways to reduce the Lyme disease risk associated with suburban development. The purpose of this study is to answer the following research questions: 1) How has the spatial distribution of Lyme disease in Northern Virginia changed since 2005 with respect to land cover? 2) Which suburban communities are more at risk for Lyme disease when considering their land cover types and the increasing spatial distribution of Lyme disease?
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    The Effects of Land Cover Change on the Spatial Distribution of Lyme disease in Northern Virginia Since 2005
    Stevenson, Megan N. (Virginia Tech, 2019-10-11)
    Lyme disease has been a growing problem in the United States over the last few decades, and is currently the most common vector-borne disease in the country. This research evaluates the land cover within specified counties of northern Virginia to determine if a correlation exists between forest fragmentation, suburbanization, and cases of human Lyme disease as has been demonstrated in other Lyme endemic regions in the United States. Few studies have focused specifically on northern Virginia when considering the impacts of land cover change on Lyme disease. Discovered through the use of geospatial and statistical analysis, the cluster of Lyme disease cases in northern Virginia are associated with forest fragmentation within the study region, which creates an ideal habitat for black-legged ticks and the white-footed mouse, allowing for an increase in Lyme disease transfer from vector to humans. The goal is for the research findings to be applicable to other regions with similar land cover types. Regions with similar characteristics would then be able to recognize the potential risk of human Lyme disease and implement ways to reduce the Lyme disease risk associated with suburban development. The purpose of this study is to answer the following research questions: 1) How has the spatial distribution of Lyme disease in Northern Virginia changed since 2005 with respect to land cover? 2) Which suburban communities are more at risk for Lyme disease when considering their land cover types and the increasing spatial distribution of Lyme disease?
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    The Emergence of Lyme Disease in Appalachia (2000-2019)
    Otieno, Geoffrey Omondi (Virginia Tech, 2024-03-15)
    Emerging infectious diseases continue to threaten human health and healthcare resources across the world, and with the sustained emergence of some like Lyme disease, this trend is only expected to get worse. Even though some research has examined the spread of Lyme disease in different parts of the United States, focusing on its origin, spread, surveillance, and reporting, there has been minimal research on the recent spread of Lyme disease into and within Central and Southern Appalachia. This is an important gap, considering that this region is at the edge of the disease's expanding incidence and range. Considering this factor and the consequences that this disease may have on the residents of Appalachia who already face an array of underlying problems like chronic conditions, decreased access to health care, and exposure through outdoor work like resource extraction, addressing this gap will be important in understanding the current and future spatial range and impacts of the continued emergence of Lyme disease in Appalachia. This study thus sought to examine the extent of the emergence of Lyme disease in Appalachia between 2000 and 2019 using spatial scan statistic. This type of analysis uses spatiotemporal information to quantify disease emergence and diffusion using retrospective case and location data within a GIS environment; hence it helped quantify the spatial distribution and diffusion of Lyme disease into and within Appalachia and identify additional areas that can be targeted with public health prevention measures. We found five statistically significant clusters of Lyme disease across the contiguous US, indicating that the disease expanded spatially over the study period. Lyme disease has more than tripled across the US, with the number of counties with RR>1 increasing from 130 in 2000 to 453 by 2019. Lyme disease also increased more than eightfold in Appalachia, with spread southwards into and within Appalachia. The number of Appalachian counties with RR>1 increased from 16 in 2000 to 127 in 2019. These findings are important in understanding the current and future spatial range and the impacts of the continued emergence of Lyme disease in Appalachia. With this understanding, we can minimize the misdiagnosis of Lyme disease and inform public health action to reduce public vulnerability.
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    Environmental health disparities in the Central Appalachian region of the United States
    Krometis, Leigh-Anne H.; Gohlke, Julia M.; Kolivras, Korine N.; Satterwhite, Emily M.; Marmagas, Susan West; Marr, Linsey C. (De Gruyter, 2017-09-26)
    Health disparities that cannot be fully explained by socio-behavioral factors persist in the Central Appalachian region of the United States. A review of available studies of environmental impacts on Appalachian health and analysis of recent public data indicates that while disparities exist, most studies of local environmental quality focus on the preservation of nonhuman biodiversity rather than on effects on human health. The limited public health studies available focus primarily on the impacts of coal mining and do not measure personal exposure, constraining the ability to identify causal relationships between environmental conditions and public health. Future efforts must engage community members in examining all potential sources of environmental health disparities to identify effective potential interventions.
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    Environmental Justice in Virginia’ s Rural Drinking Water: Analysis of Nitrate Concentrations and Bacteria Prevalence in the Household Wells of Augusta and Louisa County Residents
    Arnold, David Frederick (Virginia Tech, 2007-06-12)
    This research studied two predominantly rural counties in Virginia to understand whether residents have equal access to uncontaminated drinking water by socio-economic status. Statistical associations were developed with the total value of each residence based on county tax assessment data as the independent variable to explain levels of nitrate, the presence of bacteria (total coliform and Escherichia coli), and specific household well characteristics (well age, well depth, and treatment). Nearest neighbor analysis and chi-square tests based on land cover classifications were also conducted to evaluate the spatial distribution of contaminated and uncontaminated wells. Based on the results from the 336 samples analyzed in Louisa County, rural residents with private wells may have variable access to household drinking water free of bacteria; particularly if lower-value homes in the community tend to be older with more dated, shallower wells. This study also suggested that, in Louisa County, the presence of water treatment devices was also significantly related to total home value as an index of socio-economic status. Analysis of the 124 samples taken from household wells in Augusta County did not result in any significant associations among selected well characteristics, total home value, and water quality. Lower community participation in Augusta County as a result of a more expensive water quality testing fee may have contributed to the lack of hypothesized relationships in that county's case study.
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    Estimating Health Risks Associated With Flooding Following Hurricane Harvey Using Earth Observations and the CDC Social Vulnerability Index
    Ramesh, Balaji (Virginia Tech, 2021-08-12)
    Increases in cases of diarrheal disease, respiratory infections and pregnancy complications have been reported in the literature following floods caused by heavy rainfall. Analyzing the association between health records of outcomes related to flooding demarcated by satellite observations will be helpful to evaluate the use of satellite observed products in the mitigation of health risks for future flood events. The Centers for Disease Control and Prevention Social Vulnerability Index (CDC SVI), a relative index assigned to census tracts, measures sociodemographic factors that may affect the ability of communities to prepare for, respond to, and recover from extreme weather events. This index, which quantifies social vulnerability is expected to have a positive relationship with health outcomes associated with flooding. This study uses an inundation map created using observations from active remote sensing satellites to classify census tracts that were flooded after the historic rainfall caused by Hurricane Harvey in Texas in 2017. The duration or period of the inundation was determined using United States Geological Survey (USGS) stream gauge data. A controlled before and after study design was used, and the relative risk (RR) of 11 cause-specific emergency department (ED) visits among the flooded census tracts compared to non-flooded tracts during and after the flood period was modelled using modified Poisson regression while adjusting for a baseline period and the age, ethnicity, race and sex of the patient. Further modification of this relationship by social vulnerability, as measured by CDC SVI quartiles, was examined. The results of this study show that flooding was associated with an increase in ED visits related to carbon monoxide poisoning, insect bites, dehydration, hypothermia, intestinal infectious diseases, and pregnancy complications during the flood period. The average rate of ED visits related to pregnancy complications and insect bites were greater among the flooded tracts compared to the non-flooded tracts in the month following the inundation. Modification of this association by CDC SVI was observed in some cases, such that ED visits were higher or lower in census tracts within higher vulnerable quartiles compared to the least vulnerable quartile. Evaluating the usefulness of earth observations and the CDC SVI in estimating the health risk associated with floods due to Hurricane Harvey has provided understanding the use of these products for future flooding events in identifying specific communities with increased health risks during and following flooding events.
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    Examining Access to Recreational Facilities in Danville, Virginia
    Sams, Lauren Kimbrell (Virginia Tech, 2012-04-26)
    Obesity is a growing issue in the United States, and it affects millions of people. Obesity-related illness accounts for billions of dollars in medical expenses each year, heightening the need for prevention and intervention strategies. Physical activity is essential in maintaining a healthy weight, yet population groups have unequal access to physical activity opportunities. This research utilizes an environmental justice framework to examine variations in access and quality of recreational facilities among different socio-demographic groups in Danville, VA. Data for this research include secondary and primary sources. Race data were obtained from the 2010 U.S. Census. The Physical Activity Resource Assessment (PARA) tool was utilized to audit all recreational facilities within the City of Danville for features, amenities, and incivilities. Telephone survey data provided individual level-BMI, physical activity minutes per week, and variables of socioeconomic status, including income, education attainment, employment status, and gender. Analysis included ANOVAs, linear, and bivariate logistic regression. Predominant block group race was a significant predictor of incivilities at physical activity outlets. Proximity to recreational facilities was not a predictor of physical activity or BMI. Interventions must be made to improve the quality of recreational facilities in black or African American block groups.
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    Examining the Modifiable Areal Unit Problem: Associations Between Surface Mining and Birth Outcomes in Central Appalachia at Multiple Spatial Scales
    McKnight, Molly Xi (Virginia Tech, 2020-06-19)
    Health studies often rely on aggregated instead of individual-level data to protect patient privacy. However, aggregated data are subject to the modifiable areal unit problem (MAUP), meaning results of statistical analyses may differ depending on the data's scale and areal unit. Past studies have suggested MAUP is context-specific and analyzing multiple spatial scales may provide richer understandings of examined phenomena. More research is needed to understand the role of scale and areal unit in health-related analyses. This study examines associations between surface mining and birth outcomes from 1989 to 2015 in Central Appalachia at the individual; postal; county; and county-sized, non-administrative scales. Evidence from previous studies suggests associations exist between health outcomes and county-level measures of mining activity. This is the first study to examine associations between mining and birth outcomes at more spatially refined exposure estimates. We identified surface mines using Landsat imagery and geocoded birth records. Airsheds, used to quantify the influence area of potential airborne pollutants from surface mining activity, were built using HYSPLIT4. The frequency values of each airshed that intersected each geocoded birth record were summed. These cumulative frequency airshed values were then aggregated. Finally, we implemented multiple regression models, each at a different scale, to examine associations between airsheds and birth outcomes. Results suggest MAUP has minimal impacts on the statistical results of examining associations between surface mining and birth outcomes in Central Appalachia. Results also indicate surface mining is significantly associated with preterm birth and reduced birthweight at each scale.
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    Examining the Relationship Between Safe Drinking Water Violations and Adverse Birth Outcomes in Virginia
    Young, Holly Ann (Virginia Tech, 2021-08-11)
    The Safe Drinking Water Act (SDWA) was established to protect consumers from potential exposure to over 90 water contaminants. Each contaminant is assigned a health-based standard meant to reflect the maximum level at which an adverse human health outcome is unlikely; measurements beyond that level have greater potential to result in an adverse health outcome. While extensive research has been done on the human health implications of water contaminants, few studies have specifically examined the risk to fetal health under real world monitoring conditions. Therefore, the objective of this study is to assess whether drinking water violations are related to fetal health in the Commonwealth of Virginia, by examining the association between SDWA violations and preterm birth (PTB), low birth weight (LBW), and term-low birth weight (tLBW). Singleton births (n=665,984) occurring between 2007 and 2015 in Virginia were geocoded and assigned to their corresponding water service area. Health-based (HB) and monitoring and reporting (MR) violations for 12 contaminants were acquired from the USEPA Safe Drinking Water System, and exposure to contaminants was defined at the service area level to limit exposure misclassification. A logistic regression model for each birth outcome was performed to evaluate potential relationships with water contaminants. When examining the relationship between individual monitoring and reporting violations and PTB, Nitrate-Nitrite and Disinfectant Byproducts Stage 2 violations were both positively associated with the birth outcome. When examining the relationship between health-based violations and birth outcomes, the total coliform rule was negatively associated with tLBW. These findings indicate that monitoring and reporting requirements may need to be more stringent to reduce MR violation occurrence.
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    Exploring the Food and Physical Activity Environments and Their Influence on Healthy Behaviors
    Waters, Clarice Nhat-Hien (Virginia Tech, 2013-11-19)
    Using a community-based participatory research (CBPR) approach, community members, community stakeholders, and academic researchers from Virginia Tech formed a community-academic partnership in 2009. In the formative months, the coalition decided to focus on reducing obesity in the region. The coalition adopted the name of The Dan River Partnership for a Healthy Community (DRPHC) with a mission to "foster community partnerships to combat obesity in the Dan River Region through healthy lifestyle initiative". During a planning workshop, the DRPHC created six causal models for the root causes of obesity in the region. Two causal models that focused on geographic and environmental influences for obesity are the foundation for this series of research. The focus of this dissertation is at the intersection of the food and physical activity environments and their characteristics that contribute to meeting fruit and vegetable intake and minutes of physical activity recommendations. The food environment is one aspect of built environment research that examines food locations for procurement and the variety, availability, and quality of different food options. To date, the vast majority of research on the food environment is based in urban, suburban, and metropolitan areas with high residential densities and populations. Rural areas are often understudied because of their dispersed and hard-to-reach populations; yet these individuals experience some of the worst health outcomes in the nation. This is due, in part, to the large overlaps of rural regions and food deserts, resulting in poor food choices and poor diets. The overall objective of this dissertation is to examine the associations of the food and physical activity environments with individual healthy behaviors. Three studies were conducted within the broader research plan to meet the overall objective. The first study systematically examined the food environment using the Nutrition Environment Measures Survey (NEMS) for all food outlets in Danville, VA, a small regional city within the health disparate region, to compare differences in healthy available food options by block group race and income. The second study expanded NEMS methodology to encompass all food outlets in the three-county Dan River region to examine if food environment and availability of healthy options was predictive of meeting fruit and vegetable intake recommendations. The last study examined the objective and perceived distance individuals must travel to reach a physical activity outlet and whether or not distance was a predictive factor of individual weekly minutes of moderate to vigorous physical activity and meeting physical activity recommendations.