BACKGROUND: Exposure to extreme heat and heat waves has detrimental effects on human health, and with increasing predictions of climate change and global warming, it is of the utmost importance to further understand how our bodies will react. There is a high risk of increasing hospital admissions, especially among the elderly, with increasing heat events. Most studies of the health effects of heat waves have focused on a few pre-selected diseases, such as heat stroke and dehydration, and most notably mortality in specified regions and cities. However, the full range of medical diagnoses associated with heat wave exposure has not been identified. OBJECTIVE: This study investigated multiorgan and system consequences of heat waves on the human body. The purpose of this study was to further analyze statistically significant disease categories, and attempt to get a broad spectrum of medical diagnoses and their trends during heat wave events among older adults. METHODS: This study is a follow-up study of a prior investigation that looked broadly at 283 disease categories to determine which diseases had higher rates of hospitalization on heat wave days as compared to matched non-heat wave days. The study population consisted of 23.7 million Medicare enrollees residing in 1,943 counties in the United States, aged 65 years or older. This population represents roughly 85% of all Medicare enrollees. Data were collected between the years of 1999-2010, where data for 5 summers of near-complete daily temperatures were available1. Diagnoses were measured with 6 different heat wave definitions, starting with the baseline definition of a heat wave as a period of at least 2 days of average daily temperature beyond the 99th percentile for that specific county. Of the disease categories that were previously analyzed, 5 showed statistically significantly elevated risk during heat wave days (urinary tract infections, septicemia (except in labor), heat stroke and other external causes, and fluid and electrolyte disorders, and acute and unspecified renal failure), and one was shown to be statistically significantly lower on heat wave days (congestive heart failure; nonhypertensive). The current study evaluated these statistically significant categories to determine which specific medical diagnoses within each were statistically significantly associated with exposure to heat wave days. Using ICD-9-CM codes as diagnosis identification, a log-linear mixed-effects regression model was used to the multisite time series data of hospital admissions (1). RESULTS: Of the 6 disease categories, 12 unique medical diagnoses had statistically significant log relative risks (logRR) on heat wave days as compared to matched non-heat wave days. Seven of the twelve (12) diagnoses came from the disease categories "Other injuries and conditions due to external causes" and "Fluid and electrolyte disorders". Medical diagnoses that had a greater risk of hospital admissions on heat wave days included heat stoke and sunstroke, heat exhaustion (unspecified), heat exhaustion (anhydrotic), hyperosmolality and or/hypernatremia, hypovolemia, other specified septicemias, dehydration, hypoosmolality and/or hyponatremia, acute kidney failure (unspecified), urinary tract infection (site not specified), and unspecified septicemia. One medical diagnosis had a lower risk of hospital admissions, which was unspecified congestive heart failure (logRR: -0.062 (95% CI, -0.085 -- -0.039)). Within the baseline definition of a heat wave, the relative risk values ranged from 22.646 (95% CI, 14.865--34.192) for heat stroke and sunstroke to 1.055 (95% CI, 1.017--1.095) for unspecified septicemias. DISCUSSION: The results from this study indicate a higher risk of hospital admissions among 11 different medical diagnoses during heat wave days and a lower risk of hospital admissions for congestive heart failure. These diagnoses primarily came from two of the broad disease categories: "Other injuries and conditions due to external causes" and "Fluid and electrolyte disorders". It can be concluded from these results that among older adults, there are various specific medical diagnoses that can be associated with heat wave events, leading to a large excess of hospital admissions. However, heat waves may have some potential protective affect on unspecified congestive heart failure. It is important for clinicians and hospitals to be aware and prepared for the predicted increase in reasons for hospital admissions during heat wave events.

Phthalate plasticizers are found in consumer products and home furnishing materials. Phthalate urinary metabolites are detected in nearly every sample in population-based studies indicating widespread exposure. Prior epidemiologic studies have associated vinyl flooring, a proxy for phthalate exposure, or house dust concentrations of phthalates with eczema and asthma in children. However, these studies lack adequate exposure measurements, consideration of the early life period, and prospective designs. In light of these gaps in the literature, we designed epidemiologic analyses to address our overarching hypothesis that early life exposure to a mixture of phthalates will have associations with adverse allergic and respiratory health outcomes in children. We tested this hypothesis in five self-contained manuscripts that characterize sources of exposure to phthalates in early life, demonstrate the application of new statistical methods for estimating effects of these highly correlated biomarkers, and test the association between early life exposure to phthalates and eczema and airway inflammation in children. Participants were enrolled from the longitudinal birth cohort of the Columbia Center for Children's Environmental Health (CCCEH) in New York City. Phthalate metabolites were measured in prenatal and child urine samples at the Centers for Disease Control and Prevention. Questionnaires and visual inspections were combined with phthalate measurements from personal and indoor air sampling and urinary metabolite concentrations to examine sources and patterns of phthalate exposure associated with personal care product use and flooring materials in the home. The use of perfume and personal care products was associated with higher exposure to the metabolite of diethyl phthalate (DEP) but not di-n-butyl phthalate (DnBP). Vinyl flooring in the home was associated with higher indoor air and urinary metabolite concentrations for butylbenzyl phthalate (BBzP) but not di(2-ethylhexyl) phthalate (DEHP). Because some phthalates share exposure sources and have multiple metabolites, the urinary biomarker concentrations can be highly correlated. Using a reanalysis of the association between prenatal phthalate metabolites and reduced gestational age, we demonstrate that simple Bayesian models can estimate effects for highly correlated exposure measures without the instability of conventional modeling approaches. We found that prenatal concentrations of the metabolite of butylbenzyl phthalate were associated with the report of early-eczema but not atopy among children in the cohort. In a cross-sectional analysis, children's urinary concentrations of metabolites of diethyl phthalate and butylbenzyl phthalate were both associated with higher fractional exhaled nitric oxide, a marker of airway inflammation. These findings suggest several important sources of exposure to phthalates and demonstrate new methods for highly correlated exposures that have not been widely applied in the environmental health sciences. The association of biomarkers of exposure to butylbenzyl phthalate and eczema extend the findings of previous studies. Our results include the first report of an association between phthalates and airway inflammation in children.

In my dissertation, I examine the impacts of the local urban environment on health in the developed and developing world. By 2008, more than half the global population resided in urban areas, yet many questions regarding the health impact of urban environmental factors remain unanswered. I use large, unique micro data sets on fetal health in New York City, where 8 million people reside, to observe the impacts of air pollution and extreme weather events on birth outcomes. Previous work has shown that fetal health can affect long-run outcomes, like educational attainment or income, so it is necessary to understand how exposure to various environmental factors might affect fetal health. In contrast to the U.S. where air quality regulations have been implemented since the 1960's, I also observe air pollution in Nairobi, the capital of Kenya and home to 3.1 million residents. Currently, there are no air quality regulations enforced in Kenya, nor any long-term consistent pollution monitoring, though by 2020, more than half of Kenya's population is expected to reside in urban areas. Additionally, few studies have examine urban air pollution in sub-Saharan Africa. So in another chapter, I measure occupational exposure levels of fine particulate matter (PM2.5) for individuals who work by roadways and inside informal settlements. These chapters incorporate elements from economics, public health, and atmospheric science to better understand these issues and the potential policies needed to reconcile problems of urban development and sustainability. In my first chapter, "Transit buses and fetal health: Evaluating the impacts of bus pollution policies in New York City," I provide the first estimates of the impacts of diesel vehicles on fetal health using quasi-experimental analysis. The U.S. Environmental Protection Agency (EPA) re- duced emission standards for transit buses by 98% between 1988 and 2010. I exploit the variation induced by these policy changes over time to evaluate the impacts of transit bus pollution policies on fetal health in New York City (NYC). I use bus vintage as a proxy for street-level bus emis- sions and construct a novel panel data set for the NYC Transit bus fleet that allows me to assign maternal exposure to bus pollution at the census block level. Results show a 10% reduction in emission standards for particulate matter and nitrogen oxides during pregnancy increased infant Apgar 5 scores by 0.003 points and birth weight by 6.2 grams. While the impacts on fetal health are modest, the sensitivity of later-life outcomes to prenatal conditions suggests improved emission standards between 1990 and 2009 increased total earnings for the 2009 birth cohort by at least $51 million. In my second chapter, "Occupational exposure to PM2.5 from roadways and inside informal settlements in sub-Saharan Africa: A pilot study in Nairobi, Kenya," I observe the impacts of exposure to PM2.5 for at-risk populations. Few studies examine urban air pollution in sub-Saharan Africa (SSA), yet urbanization rates there are among the highest in the world. In this study, we measure 8-hr average occupational exposure levels of fine particulate matter (PM2.5), black carbon, UV-PM, and trace elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, and Pb) for individuals who work along roadways in Nairobi, specifically bus drivers, garage workers, and street vendors. As a comparison group we also measured exposure levels for women who reside and work inside informal settlements in Nairobi and who may also be exposed to high levels of urban air pollution. First, we find strong correlations among sources of roadside dust and vehicle exhaust across all groups. Second, we find bus drivers in Nairobi experienced 2 to 5 times the PM2.5 levels as bus or truck drivers in U.S. or European cities. Additionally, exposure levels for garage workers, street vendors, and women in Mathare were not statistically different from each other, suggesting residents in informal settlements in SSA also experience high exposure levels. These results suggest major health benefits from regulations targeting diesel exhaust emissions and roadside dust for the large portion of Nairobi residents who walk and work along roadways. We also find that improved cook stove programs could reduce PM2.5 exposure levels for informal settlement residents, particularly women. This is the first study to measure occupational exposure to urban air pollution in SSA and results from this suggest that roadway emissions are a serious concern. In my third chapter, "The relationship between temperature and fetal health in cities," I observe the impact of extreme weather events on fetal health in New York City. Climate change is projected to increase the duration, intensity and frequency of heat waves, but few studies have examined this relationship, which is of particular concern in cities where the urban heat island effect could exacerbate impacts. In this study, I combine average daily temperature from 1985-2010 with detailed birth certificate data in New York City and flexibly estimate the impact of an increase in maternal exposure to moderate and extreme temperatures. I find exposure to a day where temperature is greater than 85 degrees F is associated with a 0.37 to 1.14 g reduction in birth weight. However, I find no effect on gestational age. The effect on birth weight is modest, but using projections on how climate change might affect future heat waves, I find birth weight could reduce by 8.5 to 26.2 grams in the future, or about six times the current impact.

<p> Cause-specific mortality (CSM), among other global health estimates, has garnered prominence in the contemporary public health field. CSM has been associated with several factors, however, research comparing CSM for prefracking versus postfracking periods is sparse. Hydraulic fracturing or fracking is a technique of extracting oil and gas from deep underground. The purpose of this study was to evaluate the difference among mean CSM scores from 1975 through 2015 in the available cities and counties of residence in Colorado and to determine the impact of gender, marital status, county of residence, and city of residence on CSM scores (prefracking period 1975-1977 versus postfracking period 1999-2015) among adults aged 45-70 years. In this retrospective quantitative study, the socioecological model of health was used to analyze 73,251 cases obtained from the Colorado Department of Public Health and Environment. One-way analysis of variance and multiple regression were used to analyze data. Results showed that Denver County had a higher mean CSM score compared to other counties in Colorado. Regression results revealed a significant but weak association between CSM scores and gender, marital status, city of residence, and county of residence. If gender, marital status, and county of residence can be significant predictors of CSM, this information could have social change implications by influencing decisions regarding CSM and fracking.</p><p>

The use of community-based participatory research (CBPR) methods to conduct environmental exposure assessments provides valuable insight about disparities in fish consumption and contaminant exposure. Ninety-five community-specific fish consumption surveys were administered to low-income African American women (ages 16--49) residing in the Southeast community of Newport News, Virginia, USA, in 2008. The mean fish consumption rate for the women surveyed was 147.8 g/day (95% CI: 117.6-185.8), a rate substantially higher than the mean fish consumption rate reported for U.S. women (1.8 g/day 95% CI: 1.51-2.04). Through collaborative partnerships established between current researchers and The Moton Community House (a local community center), African American women (ages 16--49 yrs) from the same community were surveyed in 2010 to assess the reproducibility and consistency of fish consumption patterns (ingestion rates, exposure frequencies, weight, and fish consumption rates), and the reliability of the survey responses. Fish consumption patterns were reproducible and the survey responses were reliable. Comparison between years revealed that fish consumption patterns remained consistent over time. In addition, the high fish consumption rate estimated in 2008 was reaffirmed in 2010 with a rate (134.9 g/day; 95% CI: 88--207 g/day) not materially different and still considerably higher than mean fish consumption rates reported for U.S. women. Daily mercury intake rates were estimated using consumption data from 2008 and three consumption scenarios (canned white, canned light, and no tuna) due to confirmed differences in mercury concentration between canned white and light tuna. Arithmetic mean daily mercury intake rates were 0.284 ug/kg-bw/day (95% CI: 0.229 - 0.340 ug/kg-bw/day) using canned white tuna, 0.212 ug/kg-bw/day (95% CI: 0.165 - 0.259 ug/kg-bw/day) using light tuna, and 0.197 ug/kg-bw/day (95% CI: 0.151 - 0.243 ug/kg-bw/day) using no tuna. Probabilistic estimations of dietary mercury exposure for African American women (ages 16--49) from the Southeast Community were generated and compared to point estimates. Four different consumption scenarios were assumed, representing 1) no, 2) light, 3) both light and white, and 4) white tuna consumption. The probabilistic models generated lower dietary mercury intake rates than the point estimations, under these consumption scenarios. Arithmetic mean daily mercury intake rates (95% Cl) for the probabilistic models were 0.149 (+/-0.003), 0.148 (+/-0.003), 0.172 (+/-0.004), and 0.202 (+/-0.004) ug/kg-bw/day, respectively for no, light, both, and white tuna consumption. Reducing the amount of fish consumed in probabilistic models resulted in lower dietary mercury exposures for each consumption scenario. at a rate that was a quarter of what was normally consumed, the percentages of exposures that exceeded the US EPA's oral RfD for mercury were 14%, 13%, 18%, and 25% respectively for no, light, both, and white tuna consumption. In this community we learned that even though African American women in Southeast Newport News, Virginia are not subsistence fishers, they consume seafood at a subsistence fisher rate. In addition, estimates of dietary mercury exposure were high enough to warrant concern.

This project tested the hypothesis that non-experts' rankings of ergonomic stressors differ from those of health professionals. Tennessee ranks fifth in the production of tomatoes, an industry in which stoop labor, hand harvesting, and packing predominate. Specific parts of tomato workers' bodies are at risk of ergonomic injury such as, shoulders (loads), backs (stoop labor), lower extremities (posture), and upper extremities (repetitive motion). Of equal importance is our expectation that the scores assigned by non-experts will correlate with those of experts, leading to a community consensus for action and practical intervention research. Video footage of harvesting and sorting was analyzed using the Rapid Entire Body Assessment method, revealing movements and postures likely to be injurious. A panel of 13 health professionals (“experts”) and industry personnel (“non-experts”) were assembled to rate job task video segments in tomato harvesting and packing using the REBA method. Analysis of variance (ANOVA) was used to analyze the extent to which raters agree on the major body parts at risk of cumulative trauma disorders. Agreement and variation among professional groups, as well as intra-rater variability, were assessed . The possibility of achieving consensus among various professional groups with respect to the most dangerous tasks is discussed.

This thesis covers the use of chemistry in the automotive industry with emphasis on environmental compliance via chemical reporting by database and internal Energy Dispersive X-ray Fluorescence (XRF) screening, third party laboratory material testing, and the future of the chemist in the United States (U.S.) automotive industry. The third party testing was performed at Western Kentucky University (WKU) via the Materials Characterization Center (MCC), Institute for Combustion Science and Environmental Technology (ICSET) Thermodynamics Laboratory, and using the Scanning Electron Microscope/Energy Dispersive X-ray Spectrometer (SEM/EDX) managed by the WKU Biotechnology Center. Furthermore, the tests conducted were used to investigate material defects, provide solid third party quantitative results to support our XRF screenings to ensure environmental compliance, and determine cost effective material replacements. The company for which the testing was performed and information obtained is involved with the production of electronics for many of the major automotive companies throughout the world. The company specializes in the production of wiring harnesses, electrical control units (ECU), boxes (junction, fuse, relay, etc), and electrical components. These four areas control everything from the vehicle's lights, CD/DVD player, and heater to windows, locks, and navigation system. The automotive industry is extremely competitive; therefore, each company must continually change and improve in order to survive. New materials are constantly required to meet the reduced costs implemented by the customer, as well as, improve the function and quality of the components, while maintaining compliance with global environmental standards.

Consumption of fish contaminated with mercury is the primary exposure pathway by which humans are exposed to mercury. Mercury is known to be a neurological toxin that can cause attention and language deficits, impaired memory, and impaired visual and motor function, especially in children under the age of six. In addition, mercury exposure can lead to other health problems in adults, such as damage to the kidney and increased risk of coronary heart disease. This study assesses the exposure to mercury through consumption of fish from Kentucky surface waters. The exposure assessment is based on data collected by the Kentucky Department for Environmental Protection (KDEP), Division of Water, from different streams and lakes in Kentucky and average consumption rates defined by the U.S. Environmental Protection Agency (EPA). The design of this study is established to determine if people in Kentucky are at risk of mercury contamination and whether the Kentucky fish advisory protects the population from this threat. The exposure analysis presented examines mercury in different fish species from different streams and lakes in Kentucky. Fillet samples of fish were examined by KDEP and the quantity of methylmercury was determined in micrograms per kilogram (ppm). These data were used to estimate the exposure under various scenarios for methylmercury. Exposure assessment is a major component of the risk assessment process and is used here to assess the magnitude of methylmercury contamination for people in Kentucky that consume fish. EPA has been determined the maximum contaminant level of mercury in fish to be 1 ppm, and stated that the general consumer should be advised to eat no more than 1 meal/week of noncommercial fish in the U.S. at this level. Also, they determined the reference dose of methylmercury to be 0.1 (J.g/kg of body weight/day. The result of categorizing Kentucky fishes according to EPA monthly risk-based fish consumption limits indicated that 22.8% of the fishes caught from lakes and 31.44% of the fishes from streams had a greater risk than the current Kentucky advisory would indicate. The calculated daily intakes of methylmercury have shown that the consumption of certain types of fish from lakes and streams will lead to ingestion of methylmercury that exceeds the acceptable level as determined by EPA.

Lead in soil has been shown to be a significant pathway of lead exposure in children. Several factors including age of housing units, exterior composition, and paint loading may affect the amount of lead present in the soil. The purpose of this study was to analyze soil lead levels on properties located in an historic district and relate those levels to the variables previously mentioned. A total of 30 soil samples were collected from housing units in a nationally recognized historic district. Concentrations of lead in the soil were analyzed using a NITON X-ray Fluorescence Spectrum Analyzer, following EPA Method 6200 and the instrument protocol. Significant differences were found between the soil lead levels and paint loading (fully painted vs. non-painted). Significant differences were also found between soil lead levels and exterior surface (frame, brick, and other). A correlation analysis revealed there was no correlation between housing age and soil lead levels. Soil lead can be used as a predictor of blood lead levels in children. Using the information regarding soil lead concentration, the relative risk of exposure to lead and the subsequent health effects can be estimated for children living in the study area. The results from this study can also be used to initiate other studies and develop educational strategies for the district.

This study examines the variation in the distribution of the concentration of atrazine, a triazine herbicide used in Kentucky to control weeds primarily in corn fields. Atrazine is known to have carcinogenic properties and is an endocrine disruptor in aquatic species even at low concentrations. Atrazine has the ability to be transported through the environment into water bodies due to its physical and chemical properties favoring its occurrence and distribution. Raw and Finished drinking water samples were collected from the Lewisburg water treatment plant which derives its drinking water supplies from a source water intake namely Spa Lake, which has a direct run-off from the fields with abundant atrazine application. Atrazine was analyzed in the collected water samples and was found in both the raw and finished drinking water in concentrations exceeding the Maximum Contaminant Level (MCL) of 3 ppb as established by the US Environmental Protection Agency (US E.P.A).The Safe Drinking Water Act (SDWA) methodology requires quarterly sampling strategy to be implemented by all small community water systems to monitor and control the concentrations of atrazine in finished drinking water. The presence of missing high concentrations of atrazine in finished water which are not measured in the regular quarterly sampling protocol is of concern for exposures and protection of public health and environment.