Agricultural land use in areas that are located in karst groundwater basins negatively impact groundwater quality because karst terrains provide multiple, direct hydrologic connections from the surface into karst aquifers. The connections and rapid velocities associated with surface and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in areas located downstream of the spring or springs. The purpose of this study was to identify the source and movement of agricultural contaminants in a karst groundwater basin within the context of local climate, hydrogeology and land use. The study area is a fluvio-karst groundwater basin located in the Corn Belt of northeast Iowa and southeast Minnesota. Land use is predominantly agricultural in nature. Dye tracing, both qualitative and quantitative, resulted in the delineation of the Coldwater Cave Groundwater basin and illustrated that the boundaries of the basin could change as a result of precipitation events. Investigation of basin and aquifer characteristics, stream water temperature monitoring, and evaluation of cave map data and karst feature inventories determined that the surface and subsurface hydrogeology in the study area was very well integrated. Water sampling and analysis documented that agricultural contaminants, specifically nitrates, bacteria, and atrazine impact the quality of the surface water and groundwater within the basin. A ribotyping project that was done in conjunction with the thesis work showed the source of bacteria to be from cattle and humans. Nitrogen isotope analyses indicated that the source of nitrates was from ammonium fertilizers and from septic system wastes. Atrazine, at levels well below the MCL standards established by EPA, and its metabolite deethylatrzine (DEA) were detected in the groundwater year round. Contaminant load was calculated for nitrates, bacteria, and atrazine. Lowest contaminant loads occurred during the winter months of November, December, and January, when freezing temperatures minimized groundwater recharge. Contaminant load varied between high and low concentrations during the months of February and March reflecting the diurnal change between above and below freezing surface temperatures. Contaminant loads were highest during May through October when storm events are common. Contaminant load and transport are a function of the interaction of local hydrogeology and climate.

In 1998, Western Kentucky University (WKU) worked in collaboration with the Environmental Protection Agency (EPA), Drinking Water Protection Division, to investigate methods to improve source-water quality for rural-water supply systems (RWSS). Through partial funding from the EPA, WKU developed a Technical Assistance Center for Water Quality (TACWQ), which focused resources and expertise toward assisting RWSS in achieving and maintaining capacity development goals and protecting public health. The TACWQ established the Source Water Protection Initiative (SWPI) to assist RWSS in acquiring and monitoring the technical, financial and managerial capacity needed to provide safe drinking water and achieve the public health protection goals of the EPA Safe Drinking Water Act (Technical Assistance Center, July 1998). The SWPI also provided technical assistance toward identifying and reducing source water impacts throughout Kentucky. Monthly sampling during 2000 from seven watersheds in western and south central Kentucky showed that levels of several pesticides and herbicides were elevated above Maximum Contaminant Levels (MCLs) in their source waters. Of the MCL exceedences, three commonly used pesticides (atrazine, alachlor, and simazine) were repeatedly being detected at several sites. Of the three compounds, atrazine, a triazineclass herbicide widely used in Kentucky to control broad leaf and grassy weeds in row crops such as corn, drew the most interest. Atrazine has been classified as a spring use only, "Restricted Use Pesticide due to its potential for groundwater contamination." (EXTOXNET, 1996) It is regulated as a compound with class III (slight) toxicity. In 1994, EPA took atrazine under special review to evaluate the ecological and biological effects it may cause. EPA later deemed atrazine not to significantly increase the risk of cancer in humans and went as far as lifting its use restrictions. Independent researchers still dispute EPA claims. The exceedences of the MCLs by many compounds in source water do not immediately result in violations. The source water must go through treatment processes. Water-supply operators must strive to meet National Primary Drinking Water Standards (EPA, 1999) prior to going to the consumer. However, the fundamental concept driving the SWPI is that the technical and financial challenges faced by RWSS are proportional to the quality of their source water. At several sites, even treated water that was distributed to customers exceeded federally mandated MCLs. Levels of atrazine in finished water reached 17 parts per billion (ppb) in Lewisburg, Kentucky. The MCL for atrazine is currently 3.0 ppb.

X-ray contrast media such as diatrizoate and iohexol have been found in wastewater and drinking water and are difficult to remove because they are resistant to water treatment processes. A removal process can be started with ultraviolet photocatalytic degradation of X-ray contrast media in the presence of titanium dioxide or other catalysts. Raman spectra of diatrizoate and iohexol were taken in an aqueous solution in the presence and absence of titanium dioxide during exposure to ultraviolet radiation. Raman intensity is directly proportional to concentration; therefore, we can measure the rate of the reaction based on changes in the Raman spectrum. Changes were monitored for eight hours. Evidence of photoreaction is observed, indicating that the degradation of X-ray contrast media can be measured using Raman spectra. To our knowledge, this represents the first use of Raman spectroscopy to monitor photocatalytic degradation in real time, opening a potentially powerful approach to studying the removal of pollutants in the environment.

In this research, a novel approach that utilizes Moran’s I statistical analyses to examine the spatio-temporal dispersal patterns of the White-Nose Syndrome currently affecting North American bat species is undertaken to further understand the disease transmission mechanism(s) of this emerging wildlife epidemic. White-Nose Syndrome has been responsible for in excess of five million bat deaths to date and has the potential to alter the ecological landscape significantly; however, due to a variety of factors, little research has been conducted into the patterns of infection on a national scale. Global and Local Moran’s I analyses were performed on the spatial-temporal variable of month and location from the initial outbreak site in order to address the spread of the Geomyces destructans fungus that causes White-Nose Syndrome. A comprehensive dataset of outbreak confirmation sites has been compiled and statistical analysis using ArcGIS reveals a complex pattern of disease dispersion since initial discovery of the disease, and shows important policy and management implications, in particular the need for more standardized and rigorous data collection and reporting procedures.

Working below the threshold limit value (TLV) for heat stress is not always feasible. When work above the TLV is required, an exposure method is needed that can help protect workers from time limiting heat stress by calculating a safe time for work at certain heat exposures. The purpose of this paper is to determine whether the USARIEM Heat Strain Decision Aid (HSDA) can be used to predict time limiting heat stress exposure in an occupational setting. Twelve adults participated in time limited heat stress exposures. A range of heat stress conditions were designed using three different ensembles and five different heat stress levels. Safe exposure times were assigned based on limiting criteria for core temperature (38.5°C), high heart rate (90% of age-estimated maximum), or willingness to continue. The HSDA process was adapted to an Excel function using Visual Basic for Applications (VBA) and trial data were input data to the HSDA function. A second HSDA function was used to find a predicted core temperature for fixed a standard person using a height of 170cm, a weight of 70kg, and an initial core temperature of 37°C. The logistic regression and probability of the individual data as well as the fixed data were compared. We found that the HSDA could be used to assess time limiting exposures in an occupational setting when workers are working above the TLV.

Manufactured nanomaterials (MNMs) from the rapidly increasing number of consumer products that contain MNMs are being discharged into waste streams. Increasing evidence suggests that several classes of MNMs may accumulate in sludge derived from wastewater treatment and ultimately in soil following land application as biosolids. Little research has been conducted to evaluate the impact of MNMs on terrestrial ecosystems, despite the fact that land application of biosolids from wastewater treatment will be a major pathway for the introduction of MNMs to the environment. To begin addressing this knowledge gap, we have conducted a series of experiments designed to test how bioavailable MNMs are to terrestrial ecoreceptors when exposed through a variety of pathways. First, we used the model organisms Nicotiana tabacum L. cv Xanthi (tobacco) and Triticum aestivum (wheat) to investigate plant uptake of 10, 30 and 50 nm diameter gold (Au) MNMs coated with either tannate (T-MNMs) or citrate (C-MNMs). Both C-MNMs and T-MNMs of each size treatment bioaccumulated in tobacco, but no bioaccumulation of MNMs was observed for any treatment in wheat. In a second exposure, we investigated the potential for bioaccumulation of MNMs from contaminated plant surfaces by a terrestrial secondary consumer, tobacco hornworm (Manduca sexta). We found that hornworms bioaccumulate Au MNMs, but that the assimilation efficiency of bioaccumulation was low. Hornworms eliminate ingested Au MNMs rapidly from 0-24 h, but very slowly from 1 d to 7 d. Finally, we used the model organisms tobacco and tobacco hornworm to investigate the potential for trophic transfer of Au MNMs. Biomagnification of Au MNMs was observed in the hornworms. We have demonstrated that MNMs of a wide range of size and with different surface chemistries are bioavailable to plants, that MNMs resuspended by wind, rain, biota, and mechanical disturbance from soil onto plant surfaces are bioavailable to terrestrial consumers, and that trophic transfer and biomagnification of plant accumulated MNMs can occur. These results have important implications for risks associated with nanotechnology, including the potential for human exposure.

The collection of fecal coliform (FC) monitoring data in shellfish growing waters is primarily to assess public health risks from consumption of contaminated product. The data is also commonly used to assess the potential sources and loads of bacteria entering the aquatic system. This project is intended to extend traditional methods of developing these assessments, by applying an inverse modeling approach to improve the estimation of FC loads in the small watersheds typically contributing to shellfish growing waters in Virginia. Many fecal contamination studies in lower Chesapeake Bay, Virginia, have conveniently focused on analyses over relatively small spatial and temporal scales. The potential sources of bacteria are numerous and the magnitude of their contributions is commonly unknown (Hyer and Moyer, 2004). The effects of stochastic events merely complicate the already difficult task of quantifying sources and loads in an inherently variable system (White et al., 2008). Instead of identifying and quantifying individual fecal bacteria sources, like deer or raccoons or domestic animals, it is herein proposed to analyze spatial and temporal patterns of fecal contamination on relatively large scales and quantify FC loadings based on land cover. The result would make it easier for managers to assign land-cover-based accountability to restore fecal contaminated environments. Monitoring of FC concentrations throughout Virginia by the Division of Shellfish Sanitation (DSS) provided an opportunity to analyze FC levels from 1984 to the present and quantify FC loadings by type of land cover. There are three aspects in this study---spatial analysis of FC data, temporal analysis of FC data, and FC loadings quantification based on the findings from spatial and temporal analyses. GIS tools and a variety of statistical methods are used in combination with an inverse modeling approach. The modeling method was based on some basic concepts incorporated in the Watershed Management Model and the Tidal Prism Model currently used to develop Total Maximum Daily Load (TMDL) models for Virginia waters. The core contributions of this dissertation are: (1) This study provided a thorough examination of FC monitoring data in Virginia coastal waters and described how contamination levels are expressed at different spatial and temporal scales. Analyses examined tidal effects, regional effects, land condition effects, and climate effects. Results not only inform management decisions, but also provide guidance for the subsequent quantification of fecal bacteria loadings. (2) Fecal bacteria loadings are quantified as a function of land cover. The model developed in this study avoids the problems associated with using highly varied and poorly documented FC production rates and population numbers. Although the model is simple, the magnitude of Fecal Coliform Event Mean Concentration (FCMC) values based on land covers effectively distinguished the seasonal FC loadings.

ABSTRACT Current glove guides attempt to assist in recommending which type of glove is appropriate for handling chemicals; however, they include information on less than 1% of the 89 million chemical products available today. This study offers a solution by testing five durable polymer materials against 50 chemicals, using two rapid chemical degradation assessment techniques. The first technique involves gravimetric analysis of the weight change following constant immersion against the chemical mixture. The second method uses tensile strength to assess molecular changes in the polymer structure. This study is focused on addressing three issues of concern. First, this study examines if current degradation testing methods are adequate to determine chemical resistance against complex mixtures. Secondly, this study will be used to determine if current degradation information on pure chemicals is effective in predicting degradation of complex chemical mixtures, based on the major ingredient(s). Lastly, this study will start a chemical resistance index for complex mixed chemicals. The results of this study clearly show that glove recommendations of pure and mixed chemicals are frequently different. In more than 58.4% of the cases, the mixed chemical requires a different glove than that of its pure chemical components. Results also show that glove recommendations based solely on weight change and/or permeation results are missing important information on tensile test performance. There are several instances (15.2%) in which the initial glove recommendation would be changed to a lower recommendation rating if the results of a tensile test were included.

In 2015 Dr. Pratiksha Vaghela started the “Stop Poking Me” campaign which was aimed at curbing the increase in the number of needlesticks at the James A. Haley Veteran Affairs Hospital (JAHVA). The data for needlesticks was collected by the Occupational Medicine Clinic (OMC) between Oct 2013 and Oct 2016. We then obtained the original data from Dr. Vaghela’s project and compared the data to assess whether the new implementations have truly decreased the number of needlesticks. There was a 23.6% reduction in the number of needlesticks between 2013 and 2016 and even more importantly a 60.1% reduction between 2015 and 2016. Our project shows that the decrease correlates to the implementation of the “Stop Poking Me” campaign.

Many organic compounds, although beneficial, are associated with negative health and ecological impacts. It is therefore imperative to understand the environmental fates of these contaminants. Whereas the fates and health impacts of many persistent organic pollutants have been extensively examined, there is limited research characterizing the fates of these and the less persistent organic compounds in tropical multi-use watersheds. This study therefore aimed to evaluate the roles of forests and climate change on the environmental fates and health impacts of select organic chemicals in the Rio Cobre watershed, a tropical river basin in Jamaica. A total of 16 organic compounds were selected for this assessment, including some polybrominated diphenyl ethers (PBDEs), dioxins, furans and current-use pesticides. In the first portion of the assessment, field measurements of the concentrations of select PBDEs (PBDE-28, -47, -99, -100, -153, -154, -183 and -209) in the deposition, soil, litterfall and atmosphere of a forest and nearby clearing in the aforementioned watershed were evaluated. The mean air and litterfall concentrations of the PBDEs were lower in the forest than in the clearing, whereas the deposition flux rate and soil concentrations were higher in the forest. It was therefore concluded that the tropical forest filtered the PBDEs by transferring them from the atmosphere to the soil. In the next segment of the assessment, a multimedia environmental model of contaminant fate and transport, reflective of a region with three vegetative covers – urban, agricultural/grassland and forests – was developed to assist with the evaluations. This model, RioShed, was used to compute and compare fate metrics, including persistence and long range transport potential, for the aforementioned 16 organic compounds given varying forest parameters and climatic conditions. The atmospheric long range transport potentials and overall persistence of the organics were generally lower in the forested tropical watershed than in the un-forested tropical watershed, especially when the forests were fully evergreen. In this tropical watershed, the fate metrics were particularly responsive to precipitation rates. The atmospheric long range transport potentials and overall persistence of the evaluated organics increased and decreased, respectively, under the climate change condition of decreased precipitation rates. However, the effects of precipitation on the atmospheric long range transport potentials and overall persistence were more varied for the current-use pesticides. It was therefore concluded that the fates of the evaluated chemicals differed in forested versus un-forested tropical watersheds and that such differences were influenced by forest parameters, climate drivers and the chemical properties of the organics. The results and methods described in this dissertation are applicable in environmental multi-media model development and can be used to inform land management practices, as well as assist in decision-making for environmental sustainability in tropical developing countries.