Browsing by Author "Gohlke, Julia M."
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- Adverse Health Outcomes Following Hurricane Harvey: A Comparison of Remotely-Sensed and Self-Reported Flood Exposure EstimatesRamesh, Balaji; Callender, Rashida; Zaitchik, Benjamin F.; Jagger, Meredith; Swarup, Samarth; Gohlke, Julia M. (American Geophysical Union, 2023-04)Remotely sensed inundation may help to rapidly identify areas in need of aid during and following floods. Here we evaluate the utility of daily remotely sensed flood inundation measures and estimate their congruence with self-reported home flooding and health outcomes collected via the Texas Flood Registry (TFR) following Hurricane Harvey. Daily flood inundation for 14 days following the landfall of Hurricane Harvey was acquired from FloodScan. Flood exposure, including number of days flooded and flood depth was assigned to geocoded home addresses of TFR respondents (N = 18,920 from 47 counties). Discordance between remotely-sensed flooding and self-reported home flooding was measured. Modified Poisson regression models were implemented to estimate risk ratios (RRs) for adverse health outcomes following flood exposure, controlling for potential individual level confounders. Respondents whose home was in a flooded area based on remotely-sensed data were more likely to report injury (RR = 1.5, 95% CI: 1.27-1.77), concentration problems (1.36, 95% CI: 1.25-1.49), skin rash (1.31, 95% CI: 1.15-1.48), illness (1.29, 95% CI: 1.17-1.43), headaches (1.09, 95% CI: 1.03-1.16), and runny nose (1.07, 95% CI: 1.03-1.11) compared to respondents whose home was not flooded. Effect sizes were larger when exposure was estimated using respondent-reported home flooding. Near-real time remote sensing-based flood products may help to prioritize areas in need of assistance when on the ground measures are not accessible.
- Aging in Flood-Prone Coastal Areas: Discerning the Health and Well-Being Risk for Older ResidentsBukvic, Anamaria; Gohlke, Julia M.; Borate, Aishwarya; Suggs, Jessica (MDPI, 2018-12-18)Coastal communities are increasingly exposed to more intense and frequent hurricanes, accelerated sea-level rise, and prolonged tidal inundation, yet they are often a preferred retirement destination for older adults vulnerable to flooding and extreme weather events. The unique physical and psychosocial challenges of older population age 65 and over may affect their level of preparedness, capacity to cope with, and ability to respond and recover from a hazard event. Despite the clear vulnerabilities of older residents living in high-risk areas when compared to younger coastal populations, there is a lack of empirical research on the integrated flood risks to this population group in the coastal context. This paper provides a holistic assessment of this emerging problem along the U.S. East Coast by measuring the exposure of older population to sea level rise and storm surge in coastal counties. It further evaluates how age-related vulnerabilities differ between rural and urban settings using the case study approach and geospatial and statistical analysis the paper also conducts a review of scientific literature to identify gaps in the current understanding of health and well-being risks to aging populations in coastal communities. The results show that older populations are unevenly distributed along the U.S. East Coast with some states and counties having significantly higher percent of residents age 65 and older living along the shoreline. Many places with larger older populations have other attributes that further shape the vulnerability of this age group such as older housing stock, disabilities, and lower income and that often differ between rural and urban settings. Lastly, our study found that vast majority of research on aging in high-risk coastal locations has been conducted in relation to major disasters and almost none on the recurrent nuisance flooding that is already affecting many coastal communities.
- Antimicrobial Resistance Mitigation [ARM] Concept PaperVikesland, Peter J.; Alexander, Kathleen A.; Badgley, Brian D.; Krometis, Leigh-Anne H.; Knowlton, Katharine F.; Gohlke, Julia M.; Hall, Ralph P.; Hawley, Dana M.; Heath, Lenwood S.; Hession, W. Cully; Hull, Robert Bruce IV; Moeltner, Klaus; Ponder, Monica A.; Pruden, Amy; Schoenholtz, Stephen H.; Wu, Xiaowei; Xia, Kang; Zhang, Liqing (Virginia Tech, 2017-05-15)The development of viable solutions to the global threat of antimicrobial resistance requires a transdisciplinary approach that simultaneously considers the clinical, biological, social, economic, and environmental drivers responsible for this emerging threat. The vision of the Antimicrobial Resistance Mitigation (ARM) group is to build upon and leverage the present strengths of Virginia Tech in ARM research and education using a multifaceted systems approach. Such a framework will empower our group to recognize the interconnectedness and interdependent nature of this threat and enable the delineation, development, and testing of resilient approaches for its mitigation. We seek to develop innovative and sustainable approaches that radically advance detection, characterization, and prevention of antimicrobial resistance emergence and dissemination in human-dominated and natural settings...
- Assessing Human Exposure to Emissions from Ultrasonic HumidifiersYao, Wenchuo (Virginia Tech, 2021-09-14)Portable ultrasonic humidifiers add moisture into room air, but they simultaneously add exposure risks of aerosolized metals from drinking water used as fill water. The inhalation exposure from emitted metals can be overlooked, and thus, co-exposure of inhalation and ingestion and co-exposure to multiple inorganic metals is investigated. The objectives of this work are: 1) predict airborne metal concentrations and particle sizes in four realistic room scenarios (33 m3 small or 72 m3 large, with varying ventilation rates from 0.2/hr -1.5/hr), and the investigated metals are arsenic, cadmium, chromium, copper, lead, and manganese; 2) characterize exposure doses and consequent risks for adults and 0.25, 1, 2.5, and 6 yr old children, when using identical drinking water ingested and as fill water, including inhalation of fine, respirable particles generated at the frequency of 8 hrs/day (equals 121.67 days/yr) and daily ingestion, under four realistic room scenarios. The risk assessment includes non-cancer [calculation of average daily dose (ADD) and hazard quotient (HQ)] and cancer risk evaluation; 3) quantify deposition fraction and deposited doses of multiple metals in human adult's and children's respiratory tract, using multi-path particle dosimetry (MPPD) model. Results show airborne-particle-bound metal concentrations increase proportionally with water metals, and a poorly ventilated room causes greater exposure. Ingestion ADDs are 2 magnitudes higher than inhalation ADD, at identical water metal concentrations and daily exposure frequency. However, in the worse-case scenario of 33 m3 small room with low air exchange rate, the consequent inhalation HQs are all greater than 1 for children and adults, except for lead, indicating significant non-cancer risks when exposed to humidifier particles under the worse-case scenario. The cancer risks for arsenic, cadmium, chromium, and lead metals reveal are greater than acceptable one case in a million population (1E-6) produced from inhalation of the humidifier emitted metal-containing particles only. The MPPD model results indicate inhaled metal-containing airborne particles deposit primarily in head and pulmonary regions, and a greater dose (unit in µg/kg body weight/day) deposits in children than adults. Inhalation of ultrasonic humidifier aerosolized metals results in additional, and potentially greater risks (indicated by HQinhalation >1, and greater deposited dose) than ingestion at the same aqueous metal concentration, especially for children. Room conditions (i.e. volume and ventilation) influence risks. Both inhalation and ingestion exposures require consideration for eliminating multiple metal exposures and health-based environmental policy making. Consumers should be aware that they may be degrading their indoor air quality by using ultrasonic humidifiers even when filling with acceptable water quality for drinking.
- Associations Between Drinking Water Source Watershed and Adverse Birth Outcomes in Central AppalachiaCornwell, 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.
- Building Interdisciplinary Partnerships for Community-Engaged Environmental Health Research in Appalachian VirginiaSatterwhite, Emily M.; Bell, Shannon Elizabeth; Marr, Linsey C.; Thompson, Christopher K.; Prussin, Aaron J. II; Buttling, Lauren G.; Pan, Jin; Gohlke, Julia M. (MDPI, 2020-03-05)This article describes a collaboration among a group of university faculty, undergraduate students, local governments, local residents, and U.S. Army staff to address long-standing concerns about the environmental health effects of an Army ammunition plant. The authors describe community-responsive scientific pilot studies that examined potential environmental contamination and a related undergraduate research course that documented residents’ concerns, contextualized those concerns, and developed recommendations. We make a case for the value of resource-intensive university–community partnerships that promote the production of knowledge through collaborations across disciplinary paradigms (natural/physical sciences, social sciences, health sciences, and humanities) in response to questions raised by local residents. Our experience also suggests that enacting this type of research through a university class may help promote researchers’ adoption of “epistemological pluralism”, and thereby facilitate the movement of a study from being “multidisciplinary” to “transdisciplinary”.
- Clean water for all: The demographics of urban and rural safe drinking water challenges in Virginia, USA and San Rafael Las Flores, GuatemalaMarcillo, 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.
- A community-engaged approach to understanding environmental health concerns and solutions in urban and rural communitiesWang, Suwei; Richardson, Molly B.; Evans, Mary B.; Johnson, Ethel; Threadgill-Matthews, Sheryl; Tyson, Sheila; White, Katherine L.; Gohlke, Julia M. (2021-09-24)Background Focus groups and workshops can be used to gain insights into the persistence of and potential solutions for environmental health priorities in underserved areas. The objective of this study was to characterize focus group and workshop outcomes of a community-academic partnership focused on addressing environmental health priorities in an urban and a rural location in Alabama between 2012 and 2019. Methods Six focus groups were conducted in 2016 with 60 participants from the City of Birmingham (urban) and 51 participants from Wilcox County (rural), Alabama to discuss solutions for identified environmental health priorities based on previous focus group results in 2012. Recorded focus groups were transcribed and analyzed using the grounded theory approach. Four follow-up workshops that included written survey instruments were conducted to further explore identified priorities and determine whether the priorities change over time in the same urban (68 participants) and rural (72 participants) locations in 2018 and 2019. Results Consistent with focus groups in 2012, all six focus groups in 2016 in Birmingham identified abandoned houses as the primary environmental priority. Four groups listed attending city council meetings, contacting government agencies and reporting issues as individual-level solutions. Identified city-level solutions included city-led confiscation, tearing down and transferring of abandoned property ownership. In Wilcox County, all six groups agreed the top priority was drinking water quality, consistent with results in 2012. While the priority was different in Birmingham versus Wilcox County, the top identified reason for problem persistence was similar, namely unresponsive authorities. Additionally, individual-level solutions identified by Wilcox County focus groups were similar to Birmingham, including contacting and pressuring agencies and developing petitions and protesting to raise awareness, while local policy-level solutions identified in Wilcox County included government-led provision of grants to improve septic systems, and transparency in allocation of funds. Workshops in 2018 and 2019 further emphasized water quality as the top priority in Wilcox County, while participants in Birmingham transitioned from abandoned houses as a top priority in 2018 to drinking water quality as a new priority in 2019. Conclusions Applying a community-engaged approach in both urban and rural locations provided better understanding of the unique opportunities and challenges for identifying potential interventions for environmental health priorities in both locations. Results can help inform future efforts to address locally defined environmental health issues and solutions.
- Development and Evaluation of the Planetary Health Diet Index for the United States and Assessment of Dietary Constructs Associated with SustainabilityParker, Molly Kathryn (Virginia Tech, 2023-05-09)Dietary choices present an important avenue for promoting food system sustainability. Research suggests that plant-based dietary patterns can have positive health effects and reduce environmental impacts. The Planetary Health Diet was proposed by the EAT-Lancet Commission as a reference healthy and sustainable dietary pattern. A Planetary Health Diet Index (PHDI) was developed for Brazil to measure adherence to Planetary Health Diet recommendations; however, a PHDI has not been developed and evaluated for the United States (U.S.) population. Additionally, relatively few studies have assessed dietary constructs related to sustainability among U.S. adults, including the construct of meat attachment (i.e., a positive bond toward eating meat) and willingness to reduce meat intake. These gaps informed three primary research objectives. First, develop and evaluate the PHDI for the U.S. (PHDI-US). Second, use the PHDI-US to measure American adherence to the Planetary Health Diet. Third, analyze differences in meat attachment and willingness to reduce meat intake by sociodemographic and socioeconomic characteristics in a southern U.S. population. Cross-sectional data from 4,741 participants of the National Health and Nutrition Examination Survey 2017-2018 were used for analyses. Validity and reliability tests were acceptable, with total PHDI-US and Health Eating Index-2015 scores being positively associated; concurrent-criterion validity analyses identifying significantly lower scores among males, everyday smokers, and younger adults; and Cronbach's alpha equaling 0.51. The average PHDI-US score was 38.7 out of 150, indicating that American diets are far from meeting Planetary Health Diet recommendations. Using the Meat Attachment Questionnaire (MAQ), levels of meat attachment, meat intake frequency, and willingness to reduce meat intake and follow a more plant-based diet were compared by gender, educational attainment, income, and age among 328 American adults. The two characteristics most associated with differences in MAQ scores were age and educational attainment, with younger adults and those with higher educational attainment having lower MAQ scores and greater willingness to follow a more plant-based diet. The results of these studies can help improve the design of interventions by providing a tool to quantitatively measure American adherence to the Planetary Health Diet and identifying that younger adults and those with higher educational attainment may be more receptive to adopting sustainable dietary patterns.
- Ecological and Human Health in Rural CommunitiesGohlke, 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...
- Effect Modification by Environmental Quality on the Association between Heatwaves and Mortality in Alabama, United StatesJian, Yun; Wu, Connor Y. H.; Gohlke, Julia M. (MDPI, 2017-09-28)Background: Previous studies have shown that heatwaves are associated with increased mortality. However, it remains unclear whether the associations between heatwaves and mortality are modified by the environmental quality. Methods: We used the United States (US) Environmental Protection Agency’s Environmental Quality Index (EQI) and its five domain indices (air, water, land, built, and sociodemographic) to represent the cumulative environmental quality. We applied a time-stratified case-crossover design to analyze the disparities in the association between heatwaves and non-accidental deaths (NAD) among counties with different environmental qualities, in metropolitan areas in Alabama (AL), United States. Results: We found significant associations between heatwaves and NAD and a significant effect modification of this relationship by EQI. There were higher odds ratios in counties with the worst cumulative environmental qualities compared to counties with the best cumulative environmental qualities. For example, the percent change in odds ratio (mean and (95% CI)) between heatwave days and non-heatwave days was −10.3% (−26.6, 9.6) in counties with an overall EQI of 1 (the best overall environment) and 13.2% (4.9, 22.2) in counties with an overall EQI of 3 (the worst overall environment). Among the five domains, air quality had the strongest effect modification on the association. Conclusion: Our findings provide evidence that the associations between heatwaves and NAD vary among areas with different environmental qualities. These findings suggest that integration of air quality and heatwave warning systems may provide greater protection to public health.
- Effect of an Additional 30 Minutes Spent Outdoors during Summer on Daily Steps and Individually Experienced Heat IndexWang, Suwei; Richardson, Molly B.; Wu, Connor Y. H.; Zaitchik, Benjamin F.; Gohlke, Julia M. (MDPI, 2020-10-17)Spending time outdoors is associated with increased physical activity; however, high ambient temperature/humidity, together with built environment features in urban versus rural environments, may influence physical activity. We conducted an intervention trial with 89 urban and 88 rural participants performing normal activities on Days 1–2 (baseline) and spending an additional 30 min outdoors on Days 3–7 (intervention) in the summer. Participants wore a pedometer with real-time visual feedback to track daily steps taken and a thermometer clipped to their shoe to track temperatures experienced individually. Hygrometer–thermometers were deployed in participants’ neighborhoods to collect finer resolution ambient heat indexes in addition to regional weather station measurements. Using linear mixed effects models and adjusting for ambient conditions and individual-level factors, participants on average walked 637 (95%CI (83, 1192)) more steps and had a 0.59 °C (95%CI (0.30, 0.88)) lower daily mean individually experienced heat index during intervention days compared to baseline days. The intervention benefit of increased physical activity was greater in rural residents who were less active at baseline, compared to urban residents. Our results suggest adding a small amount of additional time outdoors may improve physical activity without increasing participants’ heat exposure, even during summer in a humid subtropical climate.
- Environmental health disparities in the Central Appalachian region of the United StatesKrometis, 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.
- Environmental Heat Exposure Among Pet Dogs in Rural and Urban Settings in the Southern United StatesMoon, Katherine E.; Wang, Suwei; Bryant, Kaya; Gohlke, Julia M. (2021-10-05)With advancing global climate change, heat-related illnesses and injuries are anticipated to become more prevalent for humans and other species. Canine hyperthermia is already considered an important seasonal emergency. Studies have been performed on the risk factors for heat stroke in canine athletes and military working dogs; however there is limited knowledge on environmental risk factors for the average pet dog. This observational study explores variation in individually experienced environmental temperatures of pet dogs (N = 30) in rural and urban environments in central Alabama. Temperature data from dogs and their owners was collected using wearable personal thermometers. Demographic data on the dogs was collected using a brief survey instrument completed by their owners. Dogs included in the study varied in signalment, activity level, and home environment. Linear mixed effects regression models were used to analyze repeated measure temperature and heat index values from canine thermometers to explore the effect of environmental factors on the overall heat exposure risk of canine pets. Specifically, the heat exposures of dogs were modeled considering their owner's experienced temperatures, as well as neighborhood and local weather station measurements, to identify factors that contribute to the heat exposure of individual dogs, and therefore potentially contribute to heat stress in the average pet dog. Results show hourly averaged temperatures for dogs followed a diurnal pattern consistent with both owner and ambient temperature measurements, except for indoor dogs whose recordings remained stable throughout the day. Heat index calculations showed that owners, in general, had more hours categorized into the National Weather Station safe category compared to their dogs, and that indoor dogs had a greater proportion of hours categorized as safe compared to outdoor dogs. Our results suggest that the risk of the average pet dog to high environmental heat exposure may be greater than traditional measures indicate, emphasizing that more localized considerations of temperature are important when assessing a dog's environmental risk for heat-related injury or illness.
- Environmental Predictors of US County Mortality Patterns on a National BasisChan, Melissa P. L.; Weinhold, Robert S.; Thomas, Reuben; Gohlke, Julia M.; Portier, Christopher J. (PLOS, 2015-12-02)A growing body of evidence has found that mortality rates are positively correlated with social inequalities, air pollution, elevated ambient temperature, availability of medical care and other factors. This study develops a model to predict the mortality rates for different diseases by county across the US. The model is applied to predict changes in mortality caused by changing environmental factors. A total of 3,110 counties in the US, excluding Alaska and Hawaii, were studied. A subset of 519 counties from the 3,110 counties was chosen by using systematic random sampling and these samples were used to validate the model. Step-wise and linear regression analyses were used to estimate the ability of environmental pollutants, socio-economic factors and other factors to explain variations in county-specific mortality rates for cardiovascular diseases, cancers, chronic obstructive pulmonary disease (COPD), all causes combined and lifespan across five population density groups. The estimated models fit adequately for all mortality outcomes for all population density groups and, adequately predicted risks for the 519 validation counties. This study suggests that, at local county levels, average ozone (0.07 ppm) is the most important environmental predictor of mortality. The analysis also illustrates the complex inter-relationships of multiple factors that influence mortality and lifespan, and suggests the need for a better understanding of the pathways through which these factors, mortality, and lifespan are related at the community level.
- Estimating Health Risks Associated With Flooding Following Hurricane Harvey Using Earth Observations and the CDC Social Vulnerability IndexRamesh, 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.
- Examining the Modifiable Areal Unit Problem: Associations Between Surface Mining and Birth Outcomes in Central Appalachia at Multiple Spatial ScalesMcKnight, 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.
- Examining the Relationship Between Safe Drinking Water Violations and Adverse Birth Outcomes in VirginiaYoung, 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.
- Functional Labeling of Individualized Post-Synaptic Neurons using Optogenetics and trans-TangoCastaneda, Allison Nicole (Virginia Tech, 2023-07-11)Neural circuitry, or how neurons connect across brain regions to form functional units, is the fundamental basis of all brain processing and behavior. There are several neural circuit analysis tools available across different model organisms, but currently the field lacks a comprehensive method that can 1) target post-synaptic neurons using a pre-synaptic driver line, 2) assess post-synaptic neuron morphology, and 3) test behavioral response of the post-synaptic neurons in an isolated manner. This work will present FLIPSOT, or Functional Labeling of Individualized Post-Synaptic Neurons using Optogenetics and trans-Tango, which is a method developed to fulfill all three of these conditions. FLIPSOT uses a pre-synaptic driver line to drive trans-Tango, triggering heat-shock-dependent expression of post-synaptic optogenetic receptors. When heat shocked for a suitable duration of time, optogenetic activation or inhibition is made possible in a randomized selection of post-synaptic cells, allowing testing and comparison of function. Finally, imaging of each brain confirms which neurons were targeted per animal, and analysis across trials can reveal which post-synaptic neurons are necessary and/or sufficient for the relevant behavior. FLIPSOT is then tested within Drosophila melanogaster to evaluate the necessity and sufficiency of post-synaptic neurons in the Drosophila Heating Cell circuit, which is a circuit that functions to drive warmth avoidance behavior. FLIPSOT presents a new combinatory tool for evaluation of behavioral necessity and sufficiency of post-synaptic cells. The tool can easily be utilized to test many different behaviors and circuits through modification of the pre-synaptic driver line. Lastly, the success of this tool within flies paves the way for possible future adaptation in other model organisms, including mammals.
- Global Health Impacts for Economic Models of Climate Change: A Systematic Review and Meta-AnalysisCromar, Kevin R.; Anenberg, Susan C.; Balmes, John R.; Fawcett, Allen A.; Ghazipura, Marya; Gohlke, Julia M.; Hashizume, Masahiro; Howard, Peter; Lavigne, Eric; Levy, Karen; Madrigano, Jaime; Martinich, Jeremy A.; Mordecai, Erin A.; Rice, Mary B.; Saha, Shubhayu; Scovronick, Noah C.; Sekercioglu, Fatih; Svendsen, Erik R.; Zaitchik, Benjamin F.; Ewart, Gary (American Thoracic Society, 2022-07)Rationale: Avoiding excess health damages attributable to climate change is a primary motivator for policy interventions to reduce greenhouse gas emissions. However, the health benefits of climate mitigation, as included in the policy assessment process, have been estimated without much input from health experts. Objectives: In accordance with recommendations from the National Academies in a 2017 report on approaches to update the social cost of greenhouse gases (SC-GHG), an expert panel of 26 health researchers and climate economists gathered for a virtual technical workshop in May 2021 to conduct a systematic review and meta-analysis and recommend improvements to the estimation of health impacts in economic-climate models. Methods: Regionally resolved effect estimates of unit increases in temperature on net all-cause mortality risk were generated through random-effects pooling of studies identified through a systematic review. Results: Effect estimates and associated uncertainties varied by global region, but net increases in mortality risk associated with increased average annual temperatures (ranging from 0.1% to 1.1% per 1 degrees C) were estimated for all global regions. Key recommendations for the development and utilization of health damage modules were provided by the expert panel and included the following: not relying on individual methodologies in estimating health damages; incorporating a broader range of cause-specific mortality impacts; improving the climate parameters available in economic models; accounting for socioeconomic trajectories and adaptation factors when estimating health damages; and carefully considering how air pollution impacts should be incorporated in economic-climate models. Conclusions: This work provides an example of how subject-matter experts can work alongside climate economists in making continued improvements to SC-GHG estimates.