Browsing by Author "Miranda, Marie Lynn"
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Item Open Access A Cost-Benefit Analysis of In-Plant Waste Recycling at Scaw Metals Group(2011-04-29) Mbazima, NandiThe procurement of new landfill sites for in-plant waste disposal presents certain challenges to companies in the steel manufacturing industry. These include the increased costs of the acquisition of land space, as well as the potential adverse environmental and social impacts associated with landfill activities. Scaw Metals Group, an international steel-manufacturing organisation, is currently seeking a recycling initiative for its in-plant waste materials. This is a proposal developed in efforts to shift the company away from its current custom of landfill disposal of all of its in-plant waste materials. This would not only reduce the costs of waste disposal to the company and render it economically beneficial, but it would also provide environmental and social benefits. This study investigates the economic viability of a nine-month recycling trial that transpired at Scaw Metals Group’s operations in Johannesburg, South Africa, and examines the potential costs and benefits that would be incurred and accrue to the company over time. To buttress the reliability of the cost and benefit estimates obtained, further analyses are undertaken to account for variability in the purchasing price of steel scrap, for the economic outcomes that would arise under different waste diversion scenarios, and for factors that would influence Scaw Metals Group’s decision to adopt or abandon in-plant waste recycling efforts. The results suggest that the project would be financially worthwhile for Scaw to pursue, and would be robust under the various scenario analyses examined. Further discussion on the limitations of the study and on the critical issues that should be taken into consideration for future analysis concerning this project have been included.Item Open Access ASSESSING THE IMPACT OF LOWER NATIONAL MERCURY AND LEAD REPORTING THRESHOLDS(2007-05) Fiffer, MelissaAfter a pair of toxic releases in Bhopal, India and Institute, West Virginia in the 1980s, environmental groups and members of the public demanded more information on toxic chemical releases into the community. As a result, United States facilities that manufacture, use, or process above-threshold amounts of one of 650 listed toxic chemicals must publicly report their releases and transfers via the annual Toxics Release Inventory (TRI). In 2000 and 2001, the EPA lowered the reporting thresholds for mercury and lead, respectively. This project assesses how the increased TRI reporting for mercury and lead changes our understanding of the geographic distribution and industry composition of mercury and lead-releasing facilities, as well as the demographic characteristics of the areas surrounding the facilities. Through a geospatial analysis of mercury and lead TRI reporting before and after the threshold changes, this project evaluates the effectiveness of the TRI program at achieving its founding purpose: to provide information to empower communities. The findings suggest evidence of an overall geographic and industry diversification across the threshold changes, but point to specific states and industry types that tend to account for larger than average portions of releases. Reporting was found to be concentrated in working poor block groups, with no change in income distribution across the threshold changes. Further geospatial and statistical analysis of income and other demographic variables is recommended in order to confirm reporting and release trends. Given the limitations to interpretation of TRI data, more outreach and education would be prudent in order to maximize communities’ utility of the increased mercury and lead data available after the threshold changes.Item Open Access Bayesian Spatial Quantile Regression(2010) Lum, KristianSpatial quantile regression is the combination of two separate and individually well-developed ideas that, to date, has barely been explored. Quantile regression seeks to model each quantile of an outcome distribution, whether separately or jointly, conditional upon covariates. Spatial methods have been developed for instances when spatial dependence ought to be incorporated into the model, whether to adjust for the decreased e ective sample size that comes with highly correlated data or to allow the ability to create a model-based spatial surface that interpolates between the data collected. Combining the spatial methods with quantile regression, this dissertation proposes and studies the properties of several process models for quantile regression that incorporate spatial dependence. In each chapter, we present an application for the model presented therein. In all cases, we are able to achieve improved check loss by incorporating a spatial component into the model.
In Chapter 1, the introduction, we motivate this work by exploring several examples that demonstrate the utility of both quantile regression and spatial models separately.
In Chapter 2, we present the asymmetric Laplace process (ALP), a process model suitable for quantile regression. We derive several covariance properties of various speci cations of this model and discuss the advantages and disadvantages of each option. As an example, we apply this model to real estate data.
In Chapter 3, we extend the ALP to accommodate large data sets by incorporating a predictive process covariance structure and sampling scheme into the ALP. By doing so, we create the asymmetric Laplace predictive process (ALPP), which we apply to a data set of approximately 3,000 births in the state of North Carolina in the year 2000. Here, interest lies primarily on the relationship between various maternal covariates and the lower tails of the distribution of birth weights.
In Chapter 4, we again extend the ALP, this time to incorporate a temporal component. We discuss several ways in which both continuous and discrete time can be included in the model. We further develop and outline the details of a discrete time spatial dynamic model. We apply this model k to a data set of spatially and temporally indexed temperatures, given elevation.
In Chapter 5, we propose an alternative to the ALP, which re-scales a Gaussian process using two separate scale parameters. We investigate the properties of this double normal process (DNP), and present a simulation example to illustrate the utility (and disutility) of this model.
Item Open Access Blood Lead Levels Among Pregnant Women: Historical Versus Contemporaneous Exposures(2012-11-01) Edwards, Sharon E; Miranda, Marie Lynn; Neelon, Brian Hugh; Paul, Christopher J; Swamy, Geeta KrishnaBlood lead among pregnant women, even at modest levels, may impair offspring cognitive development. We examine whether blood lead levels (BLLs) result from current versus historic exposures, among a cohort of pregnant women. Cumulative logit models were used to characterize the relationship between maternal risk factors and higher BLLs. Maternal blood lead levels more likely result from lead remobilization from historic versus contemporaneous exposures. Even if all lead sources were abated immediately, women and their fetuses would experience lead exposure for decades. This work emphasizes the importance of addressing sources of environmental lead exposure in the United States and internationally.Item Open Access Blood lead levels among pregnant women: historical versus contemporaneous exposures.(Int J Environ Res Public Health, 2010-04) Miranda, Marie Lynn; Edwards, Sharon E; Swamy, Geeta K; Paul, Christopher J; Neelon, BrianBlood lead among pregnant women, even at modest levels, may impair offspring cognitive development. We examine whether blood lead levels (BLLs) result from current versus historic exposures, among a cohort of pregnant women. Cumulative logit models were used to characterize the relationship between maternal risk factors and higher BLLs. Maternal blood lead levels more likely result from lead remobilization from historic versus contemporaneous exposures. Even if all lead sources were abated immediately, women and their fetuses would experience lead exposure for decades. This work emphasizes the importance of addressing sources of environmental lead exposure in the United States and internationally.Item Open Access Community assessment project: understanding the built environment within a neighborhood health context(2009-04-24T20:51:00Z) Kroeger, GretchenPurpose: Research shows evidence of associations between the built environment (BE)—housing, commercial buildings, community resources, and infrastructure—and health outcomes. However, there is less research describing the spatial variation of BE conditions. This master’s project demonstrates the impact of this variation with a database describing the BE within a neighborhood health context. Hypothesis: The hypothesis tested is two-fold: 1) the assessment tool enables the quantification of BE conditions, and 2) the data generated offer a comprehensive index for relating the BE to public health. Methods: Trained assessors canvassed over 17,000 tax parcels in Central Durham, NC using a standardized visual assessment of 40 distinct BE variables. Data were summed into 8 indices—housing damage, property damage, security level, tenure, vacancy, crime incidents, amenities, and nuisances. Census blocks were assigned an index based on the summary score of primarily and secondarily adjacent blocks. Results: The indices describe the spatial distribution of both community assets and BE conditions that are likely to affect the health of residents. Housing damage, property damage, security level, vacancy, crime incidents, and nuisances all contained higher scores for blocks located in areas characterized by high minority and low socioeconomic status. Similarly, a low tenure score described those same blocks, indicating that the majority of residential properties within those blocks are renter-occupied. Conclusions: The community assessment tool offers a comprehensive inventory of the BE, facilitating the generation of indices measuring neighborhood health. These resulting data are useful to community members, researchers, and government leaders.Item Open Access Environmental Equity: Socio-Historical Context of Industrial Siting in Riceboro, Georgia(2008-04-23T11:55:40Z) Devendorf, MeredithRiceboro is a small, rural, and predominantly African-American community in coastal Liberty County, Georgia. With two resident manufacturing industries producing over 75% over the county’s Toxic Release Inventory (TRI) emissions, Riceboro is plagued by public health concerns, and residents have raised questions about environmental and social equity. This master’s project explores several components critical to characterizing, documenting and resolving possible environmental injustice.
A key component in environmental justice case studies is the qualification of the sociopolitical context in which both the impacted community and the environmental risk factor(s) arose. In completing the picture of environmental justice issues, social sciences frame biological and natural scientific inquiry. A community’s specific history is critical to the accurate assessment and understanding of environmental justice issues. Not only can such a study help mitigate immediate environmental concerns, but it also enables a community help articulate its own identity and inform the policy process. As environmental management involves the management of people, such sociological perspective is critical to advancing essential elements of environmental justice.
This case-study uses anthropological, historical and sociological methods to characterize Riceboro and Liberty County, Georgia, in socio-historical terms and to trace the evolution of local political and economic systems within the context the of the American South’s transition from agrarianism to industrialization in the mid-20th century. The project further analyzes the existing environmental concerns to verify suspected environmental inequity, examines the paradigm in which it arose, and suggests policies for the fostering of environmental justice in the community. The findings may be used in tandem with other lines of scientific inquiry to develop policies for alleviating adverse conditions and circumventing future environmental injustice. Finally, this project provides a working model for similar socio-historical surveys for application in environmental justice assessments.
Publicly-available TRI emissions, health and census data reveal high risk factors in Liberty County are unequally distributed across ethnic and income levels. Further, as Riceboro has been a demographically and cultural stable community for over 200 years, patterns of economic, social and political behaviors including risk aversion and political passivity are entrenched and need careful consideration in initiating successful environmental justice policies.
Item Open Access Local Food Production and Institutional Purchasing: Assessing Producer Consumer Relationships at Duke University(2011-04-29) Chamberlin, CarlGreen purchasing policies are one aspect of campus sustainability that has been receiving increasingly more interest at Duke University in the past three years. Concurrently, locally supported food systems have been developing in the Research Triangle area, represented by farmers’ markets, community supported agriculture, and retail cooperatives. Furthermore, within the Duke Dining Services office, increased purchasing of locally produced food has been identified as one of the top three opportunities being pursued by the Dining Director. This study utilizes a farm-based survey to develop knowledge of the producer subsystem of the local food system, and interviews of dining operators at Duke to understand the current use of local food in purchasing policies. Local, small farmers are still relying heavily on farmers’ markets as their main source of income, but many are branching out into other markets such as retail and restaurants. Of the dining operators with the ability to use local food in their operations, six out of ten were currently choosing to purchase locally, although some more than others. This provides the university with a strong base to develop future policies to encourage increased relationships between farmers and operators.Item Open Access Local Government Recycling Program Attributes Associated with Recyclable Material Recovery(2009-04-23T20:42:47Z) Bullman, HollyThis study was designed to describe the relationship between specific local government solid waste and recycling program attributes and recyclable material recovery. The characteristics of solid waste and recycling programs vary greatly across North Carolina, achieving variable levels of recyclable material recovery rates. Given that solid waste disposal is increasing at a significant rate in North Carolina and approximately 20 years of landfill space remain in the state’s landfills, solid waste directors and recycling coordinators face an enormous amount of pressure to divert as much materials as possible to recycling programs. Through a survey of North Carolina solid waste and recycling program managers, this study collected vital data regarding characteristics of waste and recycling collection programs including pickup frequencies, weekly waste and recycling collection capacities, recycling separation requirements, and other variables presumed to be related to recyclable material recovery rates. Using correlation analyses and significance tests, the study revealed which solid waste and recycling program characteristics are most closely related to recyclable materials recovery. The study showed the three variables most closely related to recyclable materials recovery are recycling pickup frequency, separation methods and provision of recycling equipment. Solid waste and recycling program managers interested in maximizing recyclable material recovery rates should evaluate these three program attributes first to determine if improvements could be made. Recycling pickup frequency should be maximized, separation methods should be minimized and local governments should increase convenience for residents to obtain recycling bins or carts.Item Open Access Process Evaluation of a Community-Based Microbial Larviciding Intervention for Malaria Control in Rural Tanzania.(International journal of environmental research and public health, 2020-10-07) Berlin Rubin, Nina; Mboera, Leonard EG; Lesser, Adriane; Miranda, Marie Lynn; Kramer, RandallMicrobial larviciding can be an effective component of integrated vector management malaria control schemes, although it is not commonly implemented. Moreover, quality control and evaluation of intervention activities are essential to evaluate the potential of community-based larviciding interventions. We conducted a process evaluation of a larval source management intervention in rural Tanzania where local staff were employed to apply microbial larvicide to mosquito breeding habitats with the aim of long-term reductions in malaria transmission. We developed a logic model to guide the process evaluation and then established quantitative indicators to measure intervention success. Quantitative analysis of intervention reach, exposure, and fidelity was performed to assess larvicide application, and interviews with larviciding staff were reviewed to provide context to quantitative results. Results indicate that the intervention was successful in terms of reach, as staff applied microbial larvicide at 80% of identified mosquito breeding habitats. However, the dosage of larvicide applied was sufficient to ensure larval elimination at only 26% of sites, which does not meet the standard set for intervention fidelity. We propose that insufficient training and protocol adaptation, environment and resource issues, and human error contributed to low larvicide application rates. This demonstrates how several small, context-specific details in sum can result in meaningful differences between intervention blueprint and execution. These findings may serve the design of other larval source management interventions by demonstrating the value of additional training, supervision, and measurement and evaluation of protocol adherence.Item Open Access Risk Factors for Sudden Infant Death in North Carolina.(Frontiers in pediatrics, 2021-01) Yamada, Merick M; Rosamilia, Michael B; Chiswell, Karen E; D'Ottavio, Alfred; Spears, Tracy; Osgood, Claire; Miranda, Marie Lynn; Forestieri, Nina; Li, Jennifer S; Landstrom, Andrew PBackground: Sudden infant death syndrome (SIDS) is the sudden, unexplained death of infants <1 year old. SIDS remains a leading cause of death in US infants. We aim to identify associations between SIDS and race/ethnicity, birth weight/gestational age, and socioeconomic/environmental factors in North Carolina (NC) to help identify infants at risk for SIDS. Methods and Results: In this IRB-approved study, infant mortality 2007-2016 and death certificate-linked natality 2007-2014 were obtained from the NC Department of Health and Human Services. General, NC natality statistics 2007-2016 were obtained from CDC Wonder. Association between SIDS/total infant death and covariates (below) were calculated. Total infant mortality decreased 2007-2016 by an average of 14 deaths/100,000 live births per year, while SIDS incidence remained constant. Risk ratios of SIDS/total infant deaths, standardized to Non-Hispanic White, were 1.76/2.41 for Non-Hispanic Black and 0.49/0.97 for Hispanic infants. Increased SIDS risk was significantly and independently associated with male infant sex, Non-Hispanic Black maternal race/ethnicity, young maternal age, low prenatal care, gestational age <39 weeks, birthweight <2500 g, low maternal education, and maternal tobacco use (p < 0.01). Maternal previous children now deceased also trended toward association with increased SIDS risk. Conclusions: A thorough SIDS risk assessment should include maternal, socioeconomic, and environmental risk factors as these are associated with SIDS in our population.Item Open Access The Social Context of Environmental Exposures: an Application to Swine CAFO Air Effluent and Pregnancy Outcomes in North Carolina(2012) Tosiano, Melissa AnnCompared to full weight infants, low birth weight infants are at greater risk for short and long term health consequences. Maternal exposure to air pollution is associated with low birth weight, although these studies did not extend to rural sources of air pollution[1]. The aim of this study was to investigate the association of maternal exposure to swine CAFO air emissions with birth weight. Information on all North Carolina births from 2004-2008 was extracted from the NCDBR. Maternal exposure to swine CAFO air emissions were estimated using NC CAFO water release permitting in a geographic information system. Using ordinary least squares regression modeling, this study implicates a statistically, but not clinically significant association with exposure to swine CAFO emissions and a decrease in birth weight. As the metric of estimated maternal exposure to swine CAFO air emissions became more refined (binary< interaction< exponential decay) the association between swine CAFO exposure and decreased birth weight was increased. Prior studies have found associations between swine CAFOs and poor health in proximate communities, but none have addressed birth weight [2-8]. The results of this research indicate rural sources of air pollution could potentially adversely impact birth outcomes of especially sensitive mothers.