Global, Environmental, and Occupational Health Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/10071

Browse

Now showing 1 - 20 of 37

AIR QUALITY ASSESSMENT OF RESIDENTIAL EXPOSURE TO PARTICULATE MATTER AND VOLATILE ORGANIC COMPOUNDS NEAR A CONCRETE BLOCK PLANT AND TRAFFIC IN BLADENSBURG, MARYLAND
(2018) Ezeugoh, Rosemary Ifeoma; Wilson, Sacoby M; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Ambient air pollution from stationary sources, industrial traffic, and commuter traffic can negatively impact air quality and human health. Ernest Maier, a concrete block plant located in Bladensburg, Maryland wants to expand to include a concrete batching plant on the same property. This expansion could further degrade air quality and impact the health of vulnerable residents. Air quality monitoring were conducted in the community at five personal sites using the Airbeam and Atmotube, which are wearable, real-time sensors that can measure PM2.5 and VOCs respectively. Sampling and traffic counts were conducted in thirty minutes’ periods to capture morning on-peak, afternoon off-peak and evening on-peak periods. Pearson’s correlation revealed that a weak correlation among the PM2.5 and VOC concentrations observed between the different sites and some of the values were found to be statistically significant. ANOVA analysis showed that the PM2.5 levels were significantly different at the different sites (p-value 0.001).
Alcohol exposure in preterm infants in neonatal isolettes
(2013) Braun, Rebecca Marie; Sapkota, Amir; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Preterm infants admitted to the NICU may spend up to 12 weeks in isolettes (incubators with controlled air temperature and humidity). Infants receive frequent contact with health-care professionals who use alcohol-based hygiene products. Ethanol is a known developmental neurotoxicant, and inhalation may have long-term effects on infant neurodevelopment. This study assessed alcohol concentration in isolette air after inserting hands cleaned with hand sanitizer, and effects of longer hand rubbing before insertion into the isolette. Each exposure consisted of two squirts (1.5 ± 0.1mL) of hand sanitizer, and hands rubbed for 10 or 20 seconds before insertion into isolettes. Air samples were collected by photoionization detector and breathalyzer. Average ethanol peaks were 387.04ppm (10s) and 104.36ppm (20s). Ethanol levels peaked within 1min, dissipated within 5min, and returned to background within 15 - 20min. Alcohol exposure from ethanol based hand sanitizer may be decreased significantly with longer duration of hand rubbing.
Antibiotic Concentrations and the Composition of Bacterial Communities in Municipal Wastewater and Reclaimed Water
(2016) Kulkarni, Prachi; Sapkota, Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Before reclaimed water is used more widely within the current United States (U.S.) wastewater treatment infrastructure, it is important to examine the potential public health impacts of this emerging, alternative freshwater resource. My dissertation evaluated antibiotic concentrations and the composition of bacterial communities in conventionally treated municipal wastewater and resulting reclaimed water. I also evaluated the efficacy of a point-of-use filtration system in reducing antimicrobials present in reclaimed water. My objectives were to: 1) Assess the fate of antibiotics and; 2) Characterize the total bacterial community structure of differentially treated wastewater, and reclaimed water that has undergone on-site treatment and storage; and 3) Evaluate zero-valent iron (ZVI)-biosand filtration as a potential point-of use treatment technology for the reduction of antimicrobials from conventionally treated reclaimed water. I extracted nine antibiotics and total genomic deoxyribonucleic acid (DNA) from differentially treated wastewater and reclaimed water samples from two Mid-Atlantic and two Midwest WWTPs, and one associated Mid-Atlantic spray irrigation site. I quantified the presence of antibiotics using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and characterized total bacterial community structure using 16S rRNA gene sequencing. I also used HPLC-MS/MS to quantify the reduction of thirteen antimicrobials from conventionally treated reclaimed water after ZVI-biosand filtration. Statistical analyses included the Kruskal Wallis test, paired Wilcoxon signed-rank test, and differential abundance using normalization achieved by cumulative sum scaling. Activated sludge treatment used at all four WWTPs resulted in the reduction of some antibiotics and the increase of genera containing potentially pathogenic bacteria (Mycobacterium and Legionella). Treatment plant chlorination and spray irrigation site ultraviolet radiation (UV) treatment and open-air storage reduced the concentration of azithromycin and increased the relative abundance of Mycobacterium. ZVI-biosand filtration achieved significant reductions in azithromycin, ciprofloxacin, erythromycin, linezolid, oxolinic acid, pipemidic acid, penicillin and vancomycin. This research provided additional scientific evidence that activated sludge treatment and chlorination alone may not be sufficient for the removal of antimicrobials and potentially pathogenic bacteria from municipal wastewater and resulting reclaimed water. However, ZVI-biosand filtration may be an efficient reuse site technology for the reduction of antimicrobials from conventionally treated reclaimed water.
Antibiotic-resistant bacteria in wastewater and potential human exposure through wastewater reuse
(2013) Goldstein, Rachel Elizabeth Rosenberg; Sapkota, Amy R.; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
As community-acquired antibiotic-resistant bacterial infections occur with increasing frequency, it is important to identify possible environmental reservoirs for these organisms. My dissertation evaluated the presence of antibiotic-resistant bacteria in U.S. wastewater intended for reuse and the related public health implications. My objectives were to: 1) Evaluate wastewater from four U.S. wastewater treatment plants (WWTPs) for the presence of methicillin-resistant Staphylococcus aureus (MRSA); 2) Evaluate the occurrence of vancomycin-resistant enterococci (VRE) at four U.S. WWTPs from which treated wastewater is reused; and 3) Determine and compare MRSA, methicillin-susceptible S. aureus (MSSA), VRE, and vancomcyin-susceptible enterococci (VSE) colonization among American reclaimed water spray irrigators and controls. Between 2009 and 2010, 44 wastewater samples were collected from four WWTPs, two in the Mid-Atlantic and two in the Midwest regions of the U.S. I analyzed samples for MRSA and VRE using standard membrane filtration. For the third objective, I collected 94 nasal and dermal swabs from 19 spray irrigators and 24 controls and analyzed them for MRSA, MSSA, VRE, and VSE. I confirmed all isolates and performed antimicrobial susceptibility testing by microbroth dilution. Statistical analyses included two-sample proportion tests and logistic regression. MRSA and VRE were detected at all WWTPs. The percentage of MRSA-positive samples and concentration of VRE decreased as treatment progressed. Neither MRSA nor VRE were identified in tertiary-treated samples, but I identified both in an un-chlorinated effluent sample. No MRSA or VRE were detected in nasal or dermal samples from spray irrigators or controls. MSSA and VSE were detected in 26% and 11% of spray irrigators and 29% and 0% of controls, respectively. The odds of MSSA, MDR MSSA, and either MSSA or VSE colonization were not significantly different between the spray irrigators and controls. My dissertation includes the first reports of MRSA at U.S. WWTPs and VRE at WWTPs whose effluent is intended for reuse. This is also the first U.S. evaluation of occupational exposure to antibiotic-resistant bacteria in reclaimed water. My findings provide additional scientific evidence that antibiotic-resistant bacteria can survive secondary-treated wastewater and may cause increased risks for infection among individuals exposed to reclaimed water.
Antimicrobial Resistance of Enterococci in Surface and Recycled Water in the Mid-Atlantic
(2018) Patterson, Rebecca; Micallef, Shirley A; Payne-Sturges, Devon C; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Increasing demands for agricultural water require identification of alternative water sources. Enterococcus species can exhibit antimicrobial resistance and transfer resistance traits to other bacterial taxa, including human pathogens. This study evaluated the distribution and antimicrobial resistance of Enterococcus faecalis and E. faecium in surface and recycled waters. In all, 365 isolates from 129 water samples collected over one year were identified by species, and 95 were selected for antimicrobial susceptibility testing. Season, water type, temperature and salinity were statistically significantly associated with species probability, and season with antimicrobial resistance of E. faecalis. 1.3% of E. faecalis and 5.0% E. faecium were pan-susceptible but 100% were susceptible to ampicillin, vancomycin, daptomycin and linezolid. Multidrug resistance was detected in 16% of E. faecalis and 70% of E. faecium isolates. Enterococcus was ubiquitous in water and exhibited resistance to multiple antimicrobials, but resistance to antimicrobials of last resort for enterococcal infections was non-existent.
Assessing the Presence of Antibiotic-Resistant Enterococcus in Reclaimed Water Used for Spray Irrigation
(2013) Carey, Stephanie Ann; Sapkota, Amy R; Turner, Paul; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Reclaiming wastewater is increasing in the US to combat dwindling freshwater supplies. This water potentially contains pathogenic bacteria; therefore, we evaluated the occurrence, concentration, and antimicrobial susceptibilities of Enterococcus spp.--an important opportunistic pathogen that remains a leading cause of nosocomial infections--in reclaimed water used for spray irrigation (SI). A total of 48 wastewater effluent and SI samples were collected in 2009 and 2010 from the Mid-Atlantic and Midwest regions of the US. Enterococci were isolated using membrane filtration, confirmed using biochemical tests and PCR, and tested for antimicrobial susceptibility using the Sensititre® dilution system. We detected total enterococci and vancomycin-resistant enterococci (VRE) in 68% (27/40) and 8% (3/40), respectively, of all SI samples. VRE and vancomycin-intermediate enterococci (VIE) represented 2% (1/41) and 10% (4/41), respectively, of the total enterococci recovered from all SI sites. Our findings show that SI workers may be exposed to enterococci during spray irrigation activities.
An Assessment of Exposure to Pollution by Recreational Users of The Anacostia Watershed: Project Recreate
(2013) Murray, Rianna Teresa; Wilson, Sacoby; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The Anacostia River, a tributary of the Chesapeake Bay, is highly contaminated with raw sewage, heavy metals, oil and grease, trash, pathogens, excessive sediments and organic chemicals. Many people use this river on a regular basis for recreational purposes, including kayaking, canoeing, rowing and sport fishing. The contaminants in the river potentially pose threats to human health for recreational users. While there has been some study of the exposure to subsistence fishers in this region there is currently little information available on the risks faced by recreational users. This work gathered pilot data on recreational users with the purpose of assessing any associated exposure risks to contaminants. The high levels of contamination in the Anacostia River and the popularity of recreation makes this an important public health issue. This study is the first to combine an evaluation of risk and risk perception for the recreational population of the Anacostia River.
Assessment of Zero-Valent Iron Capabilities to Reduce Food-borne Pathogens via Filtration and Residual Activities in Irrigation Water
(2017) Bradshaw, Rhodel; Sapkota, Ph.D., Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Inadequate disinfection of contaminated freshwater that is used to irrigate food crops that are eaten raw can result in foodborne illnesses. Therefore, in this study we assessed the efficacy of a low-cost, water treatment technology, zero-valent iron (ZVI), in reducing microbiological contamination of synthetic irrigation water. Specifically, we compared the capabilities of a ZVI-sand filter versus a sand filter in reducing levels of Salmonella Newport MDD314 and E. coli TVS 353 through filtration or residual disinfection. Our data showed that ZVI-sand filtration was more effective than sand filtration alone in reducing levels of both of these microorganisms. Our results also showed that, after filtration, there seemed to be no residual disinfection capabilities associated with either the ZVI-sand system or the sand system alone. Our findings suggest that ZVI-sand filtration can effectively reduce microbial contaminants in irrigation water; however, there seem to be no residual disinfection capabilities after filtration.
Autism Spectrum Disorder and Hazardous Air Pollutants in the U.S. and Maryland
(2010) Trousdale, Kristie; Dabney, Betty J; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The prevalence of Autism Spectrum Disorder (ASD) diagnoses in the United States has increased dramatically over the past 20 years, fueling investigations into possible environmental triggers for the disorder. Exposures to pesticides, persistent pollutants, prescription medications, and heavy metals through various routes have been examined, but very few studies have examined the potential role of chronic inhalation of hazardous air pollutants (HAPs) in the etiology of ASD. This thesis was designed to examine possible relationships between HAPs and ASD prevalence on a statewide level for the U.S., with sub-analyses on a finer, countywide level within the state of Maryland. Findings suggest consistent, positive associations between ASD prevalence and HAPs at the statewide level for the U.S. The findings do not persist at the county level in the Maryland sub-analyses. These results reinforce the concept of ASD as a spectrum of phenotypes best explained through multifactorial etiological models.
CHARACTERIZING BACTERIAL COMMUNITIES ACROSS DIVERSE TOBACCO PRODUCTS AND DYSBIOSIS IN THE ORAL MICROBIOME RESULTING FROM TOBACCO USE
(2022) Chattopadhyay, Suhana; Sapkota, Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
To evaluate the adverse health effects associated with tobacco smoking, the majority of studies have largely focused on the impact of chemical constituents in tobacco products and less on the impact of microbial contaminants within these products. Similarly, the United States (U.S.) Food and Drug Administration’s (FDA) Family Smoking Prevention and Tobacco Control Act (FSPTCA) requires tobacco manufacturers and importers to test and report on chemical constituents included on their list of harmful and potentially harmful constituents (HPHCs) in tobacco products and tobacco smoke; however, this HPHC list excludes microorganisms. Nevertheless, over the past decade, an increasing number of studies have explored the bacterial microbiome of tobacco products (e.g., cigarettes, little cigars, cigarillos, hookah and smokeless tobacco) and mainstream smoke. These studies have yielded robust data on bacterial diversity and bacterial community composition within individual tobacco product types. However, to date, there are no comparative characterizations of the bacterial microbiome across diverse tobacco products. In particular, there have been no studies that have characterized the metabolically-active (live) bacterial communities across these products; bacterial communities that might be transferred to the user’s oral cavity and cause subsequent adverse health effects. Furthermore, from an oral health perspective, while smoking/using tobacco products causes significant oral dysbiosis (bacterial community disturbances), there is a lack of data on the potential transfer of bacteria from tobacco products to user’s oral cavities or transient temporal changes in the oral microbiome that might result from smoking these tobacco products. Moreover, there are limited data comparing oral microbiome differences between cigarette smokers and smokeless tobacco users. To address these knowledge gaps, my dissertation research involved a comparative analysis of the bacterial microbiome of commercially-available tobacco products and anevaluation of the impacts of tobacco use on the oral microbiome of users. My specific aims were: 1) To evaluate the compositional differences in the bacterial microbiome between conventional tobacco products; 2) To evaluate transient changes in the oral microbiome of cigarette smokers after a single use of a little cigar; and 3) To conduct a comparative characterization of the oral microbiome between cigarette users, smokeless tobacco users, and non-users over time. Overall, I found that each type of conventional tobacco product harbored a significantly different bacterial community, with mentholation and/or flavoring being a significant driver of bacterial community changes. However, across all products the majority of the metabolically-active bacterial community was identified as Pseudomonas, along with members of the phylum Firmicutes, as well as a few pathogenic species previously associated with animal/human respiratory diseases. In analyzing the oral microbiome of cigarette smokers, I found that a singleuse of a little cigar product did not cause transient changes in the oral microbiome. In analyzing longer temporal effects of smoking on the oral microbiome, I found that, even though total bacterial diversity and composition did not change over time, multiple bacterial taxa were significantly different, with regard to their relative abundance, after four months. In addition, I found that dysbiosis of the oral microbiome was dependent on the type of tobacco product used (cigarettes or smokeless tobacco), and that tobacco smokers/users’ oral microbiomes harbored a more diverse set of bacterial species when compared to that of non-users. In summary, this work provides a comparative analysis of the total and metabolically-active bacterial microbiome of tobacco products, as well as rich findings regarding the relationship between tobacco use and oral microbiome dysbiosis. These data address major research priorities of the FDA relating to furthering our understanding of the adverse health risksassociated with tobacco smoking. Specifically, my data will add to the current body of knowledge regarding the potential role of tobacco bacterial communities in the development of smoking-related diseases. My data also can be leveraged by tobacco regulatory bodies to make future evidence-based policy changes that help reduce risks associated with microorganisms in tobacco products and protect public health.
COMPARISON OF ACRYLAMIDE EXPOSURE BIOMARKERS IN CHILDREN AND ADOLESCENTS USING NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY (NHANES) 2003-04 AND 2015-16
(2024) Vallejo, Jessica Vasquez; Turner, Paul C; Kadry, Abdel; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Acrylamide (AA) is an important industrial chemical of occupational concern due to its neurotoxicity and probable carcinogenicity; it is also a tobacco burning product and thus contributes to health concerns in smokers. More recently it was discovered to be thermally generated in the cooking of starch-rich foods, creating a potentially wider public health concern. Children and adolescents are a particularly vulnerable group because they consume more acrylamide-rich foods compared to adults. In addition, they are still going through important developmental stages. This study examines AA and its metabolite glycidamide (GA) using hemoglobin adduct biomarkers (HbAA and HbGA respectively) from the U.S. children (6-11) and adolescents’ (12-19) National Health and Nutrition Examination Survey’s 2003-04 (n=2814) and the 2015-16 (n=697). The study investigated changes in exposure over time and examined the contribution of potential modifiers including smoking status, race/ethnicity, poverty-to-income ratio, sex, and age. All HbAA and HbGA are reported as pmoL adduct per gram Hb (pmol/G Hb).Overall, HbAA biomarkers significantly (p<0.0001) declined from 2003-04, GMs (95% CI) (57.9 [55.7, 60.1] pmol/G Hb) versus (42.8 [41.4, 44.2] pmol/G Hb) in 2015-16 for all ages, with similar reductions observed in the individual children and the adolescent groups. Smokers had a higher burden of HbAA biomarkers than non-smokers, and with a significant reduction in numbers of smokers from 2003-04 to 2015-16, this likely contributes to the reduction in overall exposure. When non-smokers only were examined, a significant (p<0.0001) decrease in HbAA was still observed, from 2003-04 GMs (95% CI) (53.4 [52.0, 54.9] pmol/G Hb) versus (41.2 [40.2, 42.2] pmol/G Hb) in 2015-16, suggesting an additional contribution of changes in AA levels in food or frequency of high-risk food consumption. Similar statistically significant reductions were seen for both children and adolescent groups separately. HbGA is a marker of AA biotransformation to GA, which is a more mutagenic metabolite of AA. The ratio is of HbAA:HbGA is a phenotypic marker of mutagenic risk. In non-smokers, there was a significant (p=0.001) difference in the HbAA:HbGA ratio in children GMs (95% CI) (0.8 [0.8, 0.8] pmol/G Hb) at 2003-04 and (0.9 [0.9, 1.0] pmol/G Hb) at 2015-16 versus adolescents (1.0 [1.0, 1.1] pmol/G Hb) at 2003-04 and (1.1 [1.0, 1.2] pmol/G Hb) at 2015-16, respectively, suggesting children may be at greater risk to the mutational effects of AA exposure compared to adolescents. In multivariate regression analysis of non-smokers only, age and race significantly contributed to the HbAA biomarker levels, with higher HbAA in younger age groups and in non-Hispanic black participants, highlighting a disparity in exposure pattern. Overall, AA exposure seems to have reduced from 2003-04 to 2015-16; the reduction is driven by both changes in smoking but also diet. The young and non-Hispanic black participants remain at highest risk of exposure and potential health effects from exposure to AA.
COUPLING DNA LABELING AND NEXT-GENERATION SEQUENCING TECHNIQUES TO CHARACTERIZE METABOLICALLY-ACTIVE BACTERIA IN NONTRADITIONAL IRRIGATION WATER
(2019) Malayil, Leena; Sapkota, Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Bacteria are ubiquitous in irrigation water resources and can include pathogens that may compromise food safety and public health. However, only a small fraction of total bacterial community members in water can be identified through standard culture-based laboratory methods. 16S rRNA and shotgun sequencing techniques have improved the identification of non-culturable bacteria in water resources. Nevertheless, because sequencing approaches are nucleic-acid based, they are unable to differentiate between the proportion of bacterial communities identified that are live and metabolically-active versus those that are represented by free, relic DNA, not present in viable cells. To bridge this knowledge gap, my dissertation research coupled DNA-labeling (using 5-bromo-2’- deoxyuridine (BrdU) and propidium monazide (PMA)) with next-generation sequencing approaches to identify and comprehensively characterize metabolically-active bacteria in multiple nontraditional irrigation water sources in the Mid-Atlantic region. My aims were as follows: 1) To characterize the metabolically-active fraction of bacterial communities, as well as antibiotic resistance genes and virulence gene profiles in nontraditional irrigation water sources; 2) To evaluate culture-dependent and -independent methods in the detection of metabolically-active pathogenic and non-pathogenic Vibrio species in four nontraditional irrigational water sources; and 3) To track metabolically-active bacterial communities from rooftop-harvested rainwater to irrigated produce in Maryland. Overall, we identified diverse metabolically-active bacterial communities in all nontraditional water sources. Notably, we observed the presence of viable bacteria of importance to both human and/or animal health (Actinobacterium spp., Flavobacterium spp., Aeromonas spp. Pseudomonas spp. and Vibrio spp.). Interestingly, diverse antimicrobial resistance and virulence genes were predominantly found in non-BrdU-treated samples, indicating that these genes can persist in relic DNA and could be transferred to other environmental bacteria through transformation events. We also source-tracked viable bacteria, including Sphingomonas spp., Enterobacter spp., Enterococcus spp, and Citrobacter spp. from rooftop-harvested irrigation water to produce. In summary, this work provides the first description of total, viable, and metabolically-active bacterial communities in different nontraditional irrigation water sources. These data can be used to improve risk characterization of these water sources, and ultimately inform the selection of appropriate cost-effective remediation methods to treat these waters prior to irrigation activities in order to prevent foodborne outbreaks.
DETERMINING THE IMPACT OF WELL MAINTENANCE, CONDITION, TYPE, AND LOCATION FACTORS ON E. COLI AND TOTAL COLIFORMS IN MARYLAND FARM PRIVATE DRINKING WATER WELLS
(2023) Smith, Cameron Nicole; Rosenberg Goldstein, Rachel; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Even with the establishment of the Safe Drinking Water Act in 1974, private wells are still not regulated or monitored for drinking water quality or the presence of contaminants such as total coliform bacteria and Escherichia coli. The presence of microbiological contaminants in private wells poses a public health risk. With Agricultural Agents from the University of Maryland Extension, we collected 67 water samples from Maryland farms with private wells located in seven regions and 19 counties of Maryland. We evaluated water samples for total coliforms and E. coli to understand the risk of contamination for Maryland private well owners. We also analyzed the impact of well factors, location, and climate on the presence of total coliforms and E. coli in well water by analyzing participant survey responses and climate data. Our results found that 39% (26/67) of the well water samples were positive for total coliforms and 10% (7/67) were positive for E. coli. Region (p<0.01), county (p=0.03), previously testing for pH (p<0.01), and ambient temperature (p=0.05) were significant factors impacting total coliform concentration. Region (p<0.01) and precipitation in the last 24 hours of collection (p<0.01) were the only significant factors impacting E. coli concentration. These findings emphasize the importance of well water testing for private well owners.
THE DEVELOPMENT OF A COMMUNITY INFORMED CUMULATIVE STRESSORS AND RESILIENCY INDEX (CSRI) TO EXAMINE ENVIRONMENTAL HEALTH DISPARITIES AND DISEASE RISK IN SOUTH CAROLINA
(2017) Naney, Kristen Burwell; Wilson, Sacoby M; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Communities with environmental justice (EJ) issues usually have disparities in exposure to chemical and non-chemical stressors and health status compared to other communities without underlying EJ issues. Improving cumulative risk assessment (CRA) screening tools and models can provide the necessary information needed to reduce health disparities and create more resilient communities. To address these gaps in EJ science, this dissertation has three specific aims: 1) Identify perceptions of environmental and resilience factors that may influence health among African-Americans in North Charleston, South Carolina (SC) (Study 1), 2) Develop a Cumulative Stressors and Resiliency Index (CSRI) used to rank risk in SC (Study 2), and 3) Examine associations between CSRI scores and risk of asthma hospitalizations/emergency department (ED) visits in SC (Study 3). Community stakeholders (N=18) participated in key-informant interviews and completed a 26-item paper survey in study one. Interviews were transcribed and coded, while mode, frequencies, and percentages were calculated for each indicator based on its ability to influence health. Statistical tests performed in study two included a Principal Component Analysis (PCA), one-way analysis of variance (ANOVA), and linear regression performed in SAS Enterprise Guide 7.1. Choropleth maps were also developed in ArcMap 10.5. We concluded by calculating descriptive statistics by Environmental Affairs (EA) region, Spearman’s rank-order correlation, one-way ANOVA, and negative binomial regression analyses in study three. Many of the indicators (61%) were rated as extremely high priority items and included environmental hazards, sociodemographic attributes, and factors that may influence resiliency. CSRI scores ranged from 7.4 – 64.0 with a mean score of 29.1. Statistically significant differences in CSRI scores were evident by EA region (p <0.0001) and a one-unit increase in the percentage of non-white populations per census tract projected to increase CSRI scores by roughly 6.1%. The CSRI was not able to predict risk of asthma hospitalizations/ED visits as hypothesized. Overall, we demonstrated that identifying and addressing chemical and non-chemical stressors and resiliency gaps in areas impacted by environmental injustice may lead to overall improvements in community resilience. We anticipate this work will be used as a blueprint to build more resilient and equitable communities in SC.
ENVIRONMENTAL EXPOSURES AND CHILDREN’S HEALTH
(2024) Crnosija, Natalie; Payne-Sturges, Devon C.; Puett, Robin C.; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Climate change-driven physicochemical exposures, like extreme heat, wildfire and hurricanes are increasingly being investigated in the public health literature for their potential association with health outcomes. It is important to investigate children’s health specifically in the context of the exposures, as children’s physiological immaturity can make them uniquely vulnerable to these stressors because of their limited adaptive capacity. This dissertation investigates three distinct epidemiologic questions within this sphere, examining: 1) whether Extreme Heat Event Exposure associates with Kindergarteners’ Reading and Mathematics Performance, 2) whether wildfire smoke exposure affects respiratory/cardiovascular pediatric inpatient hospitalization in Alaska, 2015-2019, and 3) the association between exposure to Hurricane Irma and Internalizing, Externalizing and Total Problem Behaviors Among South Floridian Adolescents. Data for each of these studies was obtained from different sources, including the Early Childhood Longitudinal Study—Birth Cohort, hospital administrative data from the Alaska Department of Health and the NIH’s Adolescent Brain Cognitive Development Study. Where appropriate, external data was linked to these datasets as a means of linking exposures to health outcome data. In the first study, we found weak evidence of an association between exposure to lagged extreme heat events and children’s performance on kindergarteners’ mathematics and reading performance. In the second study, we observed a number of nonsignificant, minor associations between wildfire smoke exposure and respiratory and cardiovascular inpatient hospitalization among Alaskan children. In the third study, we observed a number of nonsignificant, minor associations between exposure to Hurricane Irma and internalizing, externalizing and total problem behaviors using data from Baseline and Wave 2 of the ABCD study. In summary, this research indicates the need for larger, more robust samples to investigate children’s health outcomes.
Environmental Impacts on Fecal Indicator Bacteria in 5 National Park Recreational Water Areas
(2012) Raspanti, Greg A.; Sapkota, Amir; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The National Park Service oversees 397 park units throughout the 50 states and US territories. Due to the high visitation, protecting the health of visitors is a top priority. Fecal contamination in recreational water can occur as a result of land use practices and weather related factors. The aim of this study is to investigate weather related factors and land use factors that contribute to fecal contamination in five National Park units. Overall, rainfall proved to be highly predictive of subsequent elevations in fecal bacteria. Specifically, same day rainfall and day prior to the sampling day rainfall showed the strongest association with elevated fecal bacteria levels. Seasonal variation of fecal bacteria was generally higher in the summer months. The land use variables were not highly predictive of fecal bacteria levels. The results of this study can be used by park managers to better predict variations in fecal contamination.
EVALUATING MALARIA AND THE IMPACT OF WATER RESOURCES DEVELOPMENT IN WESTERN ETHIOPIA THROUGH A ONE HEALTH PROSPECTIVE
(2022) Mansfield, Tavis; Turner, Paul; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
In Ethiopia, the potential to be infected with malaria may increase this decade due to the expected increases in available breeding habitats created by the filling of the Grand Ethiopian Renaissance Dam (GERD) and its reservoir as well as internal displacement and forced migration of tens of thousands of people due to the flooding of local communities by the filling of the GERD’s reservoir and ongoing civil conflict in the Tigray Region of northern Ethiopia. A One Health framework was used in this research along with refugee migration and resettlement information and, risk evaluation tools to assess the potential health effects of the construction and filling of the GERD and its reservoir in Western Ethiopia on the burden of malaria and the human population living in the same area. This thesis shows Anopheles mosquitoes that are the primary vector of malaria are present in Western Ethiopia and present an entomological surveillance tool that can be implemented in the region. The author also considers the human population movement and illustrate the current vulnerabilities of the various groups involved.
EVALUATION OF ANTIBIOTIC-RESISTANT BACTERIA IN TERTIARY TREATED WASTEWATER, RECLAIMED WASTEWATER USED FOR SPRAY IRRIGATION, AND RESULTING OCCUPATIONAL EXPOSURES
(2010) Goldstein, Rachel Elizabeth Rosenberg; Sapkota, Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Occupational exposures to vancomycin-resistant Enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) in reclaimed wastewater used for spray irrigation were evaluated. In 2009, wastewater was collected from a tertiary-treatment facility, and reclaimed wastewater, nasal and dermal swab samples from an irrigation site. Samples were evaluated for MRSA and VRE using standard methods, PCR, and susceptibility testing. MRSA and VRE were isolated from all wastewater samples except effluent. While wastewater MRSA isolates were multidrug resistant (98%), no MRSA was isolated in irrigation water or swabs. VRE was isolated in one irrigation water sample. Fewer irrigation workers were colonized with S. aureus (31%) compared to controls (46%), but they harbored more multidrug resistant S. aureus. This is the first study to 1) evaluate antibiotic-resistant bacteria (ARB) in U.S. reclaimed wastewater and resulting occupational exposures, and 2) detect MRSA in U.S. wastewater. The findings suggested that tertiary wastewater treatment effectively reduced MRSA and VRE.
EXAMINATION OF THE ASSOCIATIONS BETWEEN SELECTED PERFLUOROALKYL SUBSTANCES AND THEIR ISOMERS WITH BODY WEIGHT IN ADOLESCENTS USING NHANES 2013-2018
(2023) Snyder, Jessica A; Payne-Sturges, Devon; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
0ABSTRACT Title of thesis: EXAMINATION OF THE ASSOCIATIONS BETWEEN SELECTED PERFLUOROALKYL SUBSTANCES AND THEIR ISOMERS WITH BODY WEIGHT IN ADOLESCENTS USING NHANES 2013-2018 Jessica Snyder, Master of Science, 2023 Thesis Directed by: Professor Devon Payne-Sturges Maryland Institute for Applied Environmental Health Perfluoroalkyl substances (PFAS), a class of environmentally persistent chemicals, are suspected of having obesogenic properties, with studies thus far being inconclusive. Few past studies of PFAS toxicity have distinguished between isomer types of each PFAS group during analysis, however. In this thesis, data for non-smoking 14-19 year-olds from three cycles of the National Health and Nutrition Examination Survey was analyzed to identify potential associations in adolescents between bodyweight and two major families of PFAS: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and to additionally determine if differentiating between linear and branched isomeric groups of two major PFAS families could better elucidate any associations found. In unadjusted models, weighted linear regression of body mass index (BMI) and serum concentrations of branched, linear, and total PFAS isomer groups, all returned positive associations ranging from β (95% confidence interval) of 4.06 (3.44, 4.68) for total PFOS to 12.33 (10.39,14.28) for linear PFOA. When models were adjusted for sex, age, race/ethnic origin and income level, however, only a negative association between BMI and branched PFOS (bPFOS) was found, with β= -1.24 (-2.10, -0.39). Unadjusted weighted logistic regression models of both overweight and obese status resulted in positive associations between obesity and both branched PFOS and total PFOS with odds ratios (95% confidence intervals) of 0.45 (0.27, 0.74) and 0.86 (0.75, 0.99) respectively. After adjusting for potential confounders, the only statistically significant relationship was between branched bPFOS and obesity, with a 56% decrease in the odds of obesity for every unit increase in serum concentration of bPFOS [β =-1.06, adjusted odds ratio= 0.44 (0.26,0.76)]. There was no significant difference between the sexes in any results. The apparent protective effect that bPFOS has against obesity and elevated BMI, notable as a health outcome association in itself, also illustrates that isomeric differentiation is important in studying PFAS, as nPFOS had no statistically significant 1 association by itself while ΣPFOS, used by many studies, did. Thus, the lack of differentiation could mask which PFAS type contributes to any associations discovered.
Examining Consumer Product Use And Phthalate Exposure Among Vulnerable Populations
(2023) Boyle, Meleah; Quirós-Alcalá, Lesliam; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
One in 13 Americans have asthma, and higher rates have been reported among women and Black children.1 In addition, hairdressers who are exposed to chemicals through products used on themselves and their clients frequently report respiratory symptoms and conditions.2–10 Limited studies indicate that chemicals in personal care and consumer products (PCP) may impact respiratory health.11–14 The goal of this dissertation is to describe PCP use and exposures to recognized and suspected respiratory irritants (phthalates) among vulnerable populations who may experience disparate exposures. The aims are to: 1) characterize PCP use among 110 children with asthma, 2) examine associations between PCP use and asthma morbidity among 110 children with asthma, and 3) characterize concentrations and exposure determinants to phthalate metabolites in post-shift urine samples among 23 female hairdressers and 17 female office workers. In aim 1, participants were majority Black (87%), males (56%), and aged 8-11 years (66%). Adolescents (12-17 years) and females reported more frequent use of hair, face, and body products compared to children (8-11 years) and males. Participants used chemical treatments on their hair as young as 4 years and females 11-16 years used feminine wipes, spray, and regular deodorant in the genital area. For aim 2, use of aerosol products, hair products, and nail polish were positively associated with maximal symptom days [number of aerosol products (aOR: 1.36; CI: 1.17, 1.59), hairspray (aOR: 1.63; CI: 1.14, 2.33), perfume (aOR: 1.40; CI: 1.11,1.77); shampoo (aOR: 1.34; CI: 1.05,1.73), hair sheen (aOR: 1.41; CI: 1.00, 2.00), nail polish (aOR: 2.42; CI: 1.72, 3.41)] among children with asthma. For Aim 3, the geometric mean (GM) for monoethyl phthalate (MEP) was 10 times higher among hairdressers (161.4 ng/mL) than office workers (15.3 ng/mL). Hairdressers who provided chemical services had higher GM MEP concentrations than those who did not: texturizing (200.2 vs. 115.4 ng/mL), relaxing (181.6 vs. 92.1 ng/mL), bleaching (182.3 vs. 71.6 ng/mL), hair color (171.9 vs. 83.2 ng/mL), and Brazilian blowout (181.4 vs. 134.6 ng/mL). Hairdressers who provided natural services had lower GM MEP concentrations than those who did not: twists (129.1 vs. 215.8 ng/mL), sister locs/locs (86.0 vs. 241.9 ng/mL), and afros (94.7 vs. 203.9 ng/mL). While larger studies are needed, this dissertation provides new data on PCP use and phthalate exposure among Black children and hairdressers.