Thesis (Ph. D.)--Duke University, 2008.

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves i-xvi).

<p> The use of pharmaceutical products has steadily increased in the United States from 2 billion prescriptions in 1999 to 3.9 billion in 2009. Half of patients do not comply with the recommended prescription regimen and dispose of unused drugs in the environment. The U.S. Environmental Protection Agency and many researchers have highlighted the human-health risks associated with improperly disposing of pharmaceutical products. This quantitative cross-sectional study examined the potential correlations between people&rsquo;s actual disposal practices and their knowledge of the impact of disposal practices on the environment and human health, and availability of disposal options. The conceptual framework selected for this study comprised 2 models: the health belief model and the theory of planned behavior. Respondents to an online survey were 485 residents of the northeast United States, polled from the general population. Descriptive statistics and logistic regression were used to model responses from the dependent variable actual disposal practice (ADP) across the independent variables, and analysis of variance explored whether ADP differed across demographic variables. Statistically significant associations emerged among individuals&rsquo; knowledge of environment and human-health impact, recommended disposal practices, disposal options, and that person&rsquo;s likelihood to practice recommended disposal. Demographic variables did not impact disposal behavior. To promote positive social change, it is recommended that policymakers plan and implement the expansion of convenient drug disposal options, as well as information campaigns on proper disposal practices. In parallel, health care professionals should stress to their patients the importance of complying with prescribed regimens, thus minimizing the amount of unused or expired medications.</p><p>

Environmental research is increasingly using citizen scientists in many aspects of projects, such as data collection and question design. To date, only a limited number of co-created citizen science projects where community members are involved in most or all steps of the scientific process have been completed, and few comparing community engagement methods and efficacy and learning outcomes across demo- and geographic data. This study compares two citizen science programs, evaluating what motivates citizen scientists to participate in environmental health research and whether participation affects scientific knowledge and environmental behavior and efficacy. Participants in the Gardenroots: A Citizen Science Garden Project completed sample collection training and submitted soil, water, vegetable, and dust samples for analysis and received their environmental monitoring results. In the Facilitating Community Action to Address Climate Change and Build Resiliency in Southern Metropolitan Tucson project, Spanish speaking community members of South Tucson underwent training in climate change and environmental quality and sample collection, and worked with families in the South Tucson community, collecting soil and water samples and providing environmental health education. For both projects, participants completed a pre- and post-survey with a variety of qualitative and quantitative questions. These survey instruments were used to evaluate differences in environmental self-efficacy and motivations. In addition, select Gardenroots participants were involved in focus groups and semi-structured interviews to understand and gauge changes in knowledge and to further explore changes in motivation and self-efficacy. The participants were primarily internally motivated and saw increases in both efficacy and knowledge as a result of participation in the program. This information is critical to moving citizen science efforts forward and determining whether such projects: 1) co-produce environmental monitoring, exposure assessment, and risk data in a form that will be directly relevant to the participant's lives, 2) increase the community’s involvement in environmental decision-making, and 3) improve environmental health education and literacy in underserved communities.

The groundwater supply in the Valcartier area of Quebec is contaminated with trichloroethylene (TCE) from multiple sources, and hydrogeologic characterization is being carried out to understand its origin and migration patterns. A geochemical investigation was undertaken to independently verify groundwater flow and TCE transport in Valcartier groundwater to improve a numerical model that is currently being developed. 3H-3He ages were obtained along flow paths stemming from two main source zones and compared with advective model ages produced at corresponding locations. Ages obtained above and below a prodeltaic silty aquitard in the eastern part of the study area were used to calculate an average vertical hydraulic conductivity (Kv) of 1.3-3.1x10-8 m/s. 3H-3He ages were compared with modelled ages at different values of porosity (n) and recharge; the bestcorrespondence was found to be at 0.35 and 300 mm/yr, respectively. Anomalously high concentrations of terrigenic He and unexpectedly old 3H-3He ages in some areas indicate areas where groundwater in the underlying proglacial aquifer may flow upward into the deltaic sand aquifer. Geochemical parameters measured in groundwater along the flow paths as well as in Shannon and in the proglacial aquifer were examined for patterns. Multivariate statistics (Principal components analysis and cluster analyses) were applied to the data to distinguish different types of groundwater; the geochemistry of each group reflects recharge origin and lithology encountered. The groups verify flow paths delineated by the groundwater model, and help distinguish groundwater of different origins downgradient of source zones. One facies in particular is associated with high TCE concentrations and occurs where groundwater upflow from the proglacial aquifer in Shannon inferred from the 3H-3He data. This appears to be TCE coming from a previously unrecognized source in the south part of the study area, possibly an old bedrock dump. This study demonstrates the value of integrating geochemical information in groundwater characterization programs with existing information to refine the understanding of groundwater flow, especially in the development of numerical models.

Ultraviolet B radiation (UVBR) and chemical pollutants are environmental stressors that may affect amphibian populations. While adverse effects of UVBR and chemicals on amphibians are documented, few studies examined the effects of interactions between stressors on amphibian health. Gosner stage 25 Rana pipiers tadpoles were chronically exposed to environmentally relevant levels of UVBR (0.15-0.22 W/m2) and the estrogenic chemical 4-tert-octylphenol (OP) (0.01 nM or 10 nM) alone and in combination. Tadpoles exposed to UVBR and/or OP exhibited significantly delayed development at stage 29. Significantly fewer UVBR-treated tadpoles developed past stage 34 and metamorphosed. Effects of UVBR/OP on the thyroid system were assessed because it is the main regulator of amphibian metamorphosis. Stage 29 and 34 tadpoles were collected for gene expression analysis in tail and T3 (triiodothyronine) whole body levels (minus tail). Moreover, we examined whether pre-exposure to UVBR/OP affected the molecular and morphological responses of tadpoles to exogenous T3. OP increased the expression of several genes in tail and brain and/or their response to T3 (e.g., deiodinase 2), and the addition of UVBR can alter the effect of OP. Although UVBR had no observable effect on gene expression, developmentally delayed UVBR-treated stage 31 tadpoles exposed to T3 exhibited slowed tail resorption and accelerated hind limb development. UVBR and/or OP did not affect T3 levels of stage 29 and 34 tadpoles. However, a decrease and increase in deiodinase 2 and 3 (D2 and D3) mRNA levels, respectively, were observed in groups of tadpoles with slowed developmental rates at those stages. Since D2 activates and D3 inactivates thyroid hormones (TH), UVBR/OP mediated disruptions in development are likely caused by dysfunctions in the localized metabolism of THs. These results indicate that environmental levels of UVBR and/or OP can affect metamorphosis, potentially by disrupting the biological action of T3 and deiodinases in peripheral tissues, which could contribute to population declines.

Research continues to show that pharmaceutical environmental contamination has caused adverse environmental effects, with one of the most studied effects being feminization of fish exposed to pharmaceutical endocrine disruptors. Additionally, there are also public health risks associated with pharmaceuticals because in-home reserves of medications provide opportunities for accidental poisoning and intentional medication abuse. Pharmaceutical take back programs have been seen as a remedy to these concerns; however a thorough review of peer-reviewed literature and publicly available information on these programs indicates limited research has been conducted to validate these programs as a purported solution. Furthermore, there are significant data gaps on key factors relating to take back program participants. The purpose of this dissertation was therefore to address these gaps in knowledge and ultimately determine if take back programs could actually improve public and environmental health. This was accomplished by conducting social and scientific research on a take back program called Denton Drug Disposal Day (D4). Socioeconomic, demographic, and geographic characteristics of D4 participants were investigated using surveys and geographic analysis. Impacts on public health were determined by comparing medications collected at D4 events with medications reported to the North Texas Poison Center as causing adverse drug exposures in Denton County. Impacts to environmental health were determined by monitoring hydrocodone concentrations in wastewater effluent released from Denton’s wastewater treatment plant before and after D4 events. Data collected and analyzed from the D4 events and the wastewater monitoring suggests D4 events were successful in contributing to improvements in public and environmental health; however there was insufficient evidence to prove that D4 events were exclusively responsible for these improvements. An additional interesting finding was that willingness to travel to participate in D4 events was limited to a five to six mile threshold. This geographic information, combined with other findings related to socioeconomic, demographic, and risk perception characteristics of D4 participants, has the potential to help improve the effectiveness of future take back events. This would allow these programs to better meet their common goals of improving both public and environmental health, which this study has shown is achievable to some degree.

This dissertation contributes to the fields of medical sociology, environmental health, and public health by examining the effects of social stratification on environmental exposures and physical morbidity. Although previous conceptual models suggest that the unequal distribution of environmental exposures may help to explain race/ethnic and socioeconomic differences in physical health, there is little to no empirical evidence to support these processes. Building on previous research, I use data from the National Health and Nutrition Examination Surveys (2007-2008) to formally assess the following questions: 1) Does exposure to environmental toxins vary according to race/ethnicity and socioeconomic status? 2) Do race/ethnic and socioeconomic differences in environmental exposures help to explain race/ethnic and socioeconomic differences in physical health? The results of this research extend the literature by revealing empirically the unequal exposures to environmental toxins by race/ethnicity and socioeconomic status. Specifically, race/ethnic minorities (Blacks and Hispanics) and individuals with lower levels of socioeconomic status are disproportionately exposed to environmental toxins. Although overall toxin exposure and lead were unrelated to self-rated health, cadmium was found to partially mediate race/ethnic and socioeconomic differences in self-rated health. / A Dissertation submitted to the Department of Sociology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2016. / July 27, 2016. / Health, Race/ Ethnicity, Socioeconomic status, Toxins / Includes bibliographical references. / Amy M. Burdette, Professor Directing Dissertation; Chris J. Coutts, University Representative; Miles G. Taylor, Committee Member; John R. Taylor, Committee Member.

Investigations of environmental hormone contamination commonly utilize solidphase extraction (SPE) followed by high-performance liquid chromatography / (electrospray ionization) tandem mass spectrometry (HPLC/(ESI)MS2) in the detection of estrogens. Matrix interference is widely reported. In this study, androgens were targeted alongside estrogens as environmentally co-introduced endocrine disrupting chemicals. Analytical methods were developed in parallel for detection of several hormones from each class, with comparison of protocols and instrumental parameters. Ultraperformance LC (UPLC®), an emerging technology advertised for reduced retention times, was used in place of HPLC for hormone separation. Applicability to diverse aqueous samples was tested. Matrix interference was combated with two rarely used techniques: atmospheric pressure chemical ionization (APCI) MS2 and extract purification by size exclusion chromatography (SEC). Infusion and spiking tests were performed in (ESI)MS2 and (APCI)MS2, demonstrating relative matrix disruption of hormone signals. An SEC fractionation protocol was developed and applied to extracted wastewater samples prior to UPLC/MS2 analysis. Hormone recoveries were compared to those obtained without SEC purification. In accordance with these experiments, it was found that estrogen and androgen contaminants can be simultaneously extracted using C18 SPE. This approach reduces the amount of sample, supplies, and time required in preparation for instrumental analysis. In UPLC separation, a broader gradient, slower flow rate, and increased run time were used for the androgens to counteract structural similarity and reduced polarity. The androgens were most readily detected using positive (ESI)MS2, versus negative for the estrogens, with modifier addition for signal enhancement. Electron delocalization in the estrogen and testosterone molecular structures facilitated ionization, permitting MS2 detection at or below 23 pg on-column versus 500 pg for the androgens lacking bond conjugation. Recoveries of all analytes from deionized water were 67-112% using UPLC/(ESI)MS2. Use of UPLC reduced retention times and solvent usage in comparison to HPLC, permitting adequate resolution of the hormones within 7 min in the presence of clean solvents. In environmental samples, the rapid analyses proved susceptible to matrix interference, with lack of signal resolution amidst unresolved complex mixtures. The application of (APCI)MS2 to complex samples showed promise in combating matrix interference, permitting detection of hormones spiked into wastewater that were not observed using (ESI)MS2. The ionization methods tended toward opposite matrix effects, with 140-410% recoveries (i.e. ion enhancement) from effluents using APCI and 5-120% (i.e. ion suppression) using ESI. Application of SEC prior to instrumental analysis removed some interfering compounds, allowing recoveries of 48-98% for several hormones using UPLC/(APCI)MS2.

No description available.