1,4-Dioxane is an emerging groundwater contaminant and a probable human carcinogen. Its biodegradation was investigated in microcosms prepared with groundwater and soil from an impacted site in Alaska. In addition to natural attenuation conditions (i.e., no amendments), the following treatments were tested: (a) biostimulation by addition of 1-butanol (a readily available auxiliary substrate) and inorganic nutrients; and (b) bioaugmentation with Pseudonocardia dioxanivorans CB1190, a well-characterized dioxane degrading bacterium, or with Pseudonocardia antarctica DVS 5a1, a bacterium isolated from Antarctica. Biostimulation enhanced the degradation of 50 mg L-1 dioxane by indigenous microorganisms (about 0.01 mg dioxane d-1 mg protein-1) at both 4 and 14°C, with a simultaneous increase in biomass. A more pronounced enhancement was observed through bioaugmentation. Microcosms with 50 mg L -1 initial dioxane (representing source zone contamination) and augmented with CB1190 degraded dioxane fastest (0.155 +/- 0.038 mg dioxane d-1 mg protein-1) at 14°C, and the degradation rate decreased dramatically at 4°C (0.021 +/- 0.007 mg dioxane d-1 mg protein-1). In contrast, microcosms with DVS 5a1 degraded dioxane at similar rates at 4 and 14°C (0.018 +/- 0.004 and 0.015 +/- 0.006 mg dioxane d-1 mg protein-1, respectively). DVS 5a1 outperformed CB1190 when the initial dioxane concentration was low (500 microg L-1). This indicates differences in competitive advantages of these two strains. Natural attenuation microcosms also showed significant degradation over 6 months when the initial dioxane concentration was 500 microg L-1. This is the first study to report the potential for dioxane bioremediation and natural attenuation of contaminated groundwater in sensitive cold-weather ecosystems such as the Arctic.

Utilizing a randomized phone survey of coastal Louisiana residents, this study will focus on identifying which influences from a residents exposure, socio-economic vulnerability and adaptive capacity are the best indicators of an individuals resilience. Two binary logistic regression models were developed to test the associations of resident response to: 1) acute hazards via household emergency plan adoption and 2) chronic hazards represented by behavior modification in response to daily air quality reporting where adoption of these two risk-reducing behaviors are viewed as increased individual resilience. Bivariate correlation analysis found that a north south grouping of coastal Louisiana was significantly correlated with 26 of the survey predictor variables. The two binary logistic regression model results include: as an individuals current level of environmental hazard knowledge increases by 1-increment they are 53% more likely to engage in the risk-reducing behavior, adoption of an emergency plan and almost 5 in 10 residents of the southern region reported altering their behavior on poor air quality days. This self-reported mitigation effort is associated with an increase in their personal level of concern for overall environmental pollution. Overall the results indicate when residents are provided with relevant environmental hazard information and, more importantly, when residents understand and have confidence in the hazard information, they are more likely to take anticipatory and pre-emptive measures to reduce their risk. While this study found less optimal risk-reducing adoption rates, the finding suggests immediate opportunities for government agencies and public-interest organizations to increase public education efforts to target audiences who are willing and receptive to increased environmental hazard information. Future research improvements should include increased survey questions, new survey administering methods, broadening the geographical scope of the research project, and, thus, increasing the sampling population size.

<p>Polycyclic aromatic hydrocarbons (PAHs) are prevalent contaminants in aquatic environments, and exposure can elicit a variety of toxic effects including teratogenicity, genotoxicity and carcinogenicity. Many PAHs are agonists for the aryl hydrocarbon receptor (AHR), which is involved in mediating their teratogenic and carcinogenic effects by unknown mechanisms of action. When activated, the AHR initiates the transcription of a variety of genes involved in both phase I and phase II metabolism, including the monooxygenase cytochrome P4501s (CYP1A, CYP1B1, CYP1C1). The biotransformation of PAHs is necessary for their detoxification and excretion; however, oxidation by CYP1A results in the conversion of the parent PAH to reactive metabolic intermediates that can covalently bind to nucleic acids and proteins, or cause oxidative stress. There is a population of killifish (Fundulus heteroclitus) from a PAH contaminated site on the Elizabeth River (ER) in Portsmouth, Virginia whose embryos, larvae, and adults are refractory to the induction of CYP1A activity, protein or message when exposed to AHR agonists. The embryos and larvae of the ER population are resistant to acute PAH-induced teratogenicity and lethality. However, wild caught ER adults at the site have a high prevalence of hepatic and pancreatic neoplasms, suggesting that their resistance to intermediate and chronic PAH toxicity requires further investigation. The contaminated sediment at the ER is comprised of a complex mixture of PAHs with different mechanisms of action. Although there is limited information concerning PAH mixtures, the current assumption for risk assessors is that their toxicity is additive. In studying the effects of the mixture of PAHs at the Elizabeth River, research has shown that co-exposure of reference site killifish embryos to PAH-type CYP1A inhibitors causes a synergistic increase in the embryotoxicity of PAH-type AHR agonists and PAH-contaminated sediment extract. This dissertation utilized the resistant Elizabeth River killifish, chemical inhibitors, and morpholino technology to determine how the chemical and molecular inhibition of CYP1 enzymes affects the biotransformation of PAHs and ultimately their teratogenicity, genotoxicity, and carcinogenicity. Toward these objectives, the mRNA inductions of the newly sequenced metabolic enzymes, CYP1B1 and CYP1C1, were characterized in embryos born to ER and reference site killifish after exposure to multiple AHR agonists. Embryos from both populations were also co-exposed to the PAHs benzo[a]pyrene (BaP; AHR agonist) and fluoranthene (FL; CYP1A inhibitor). Reference site embryos were injected with an antisense morpholino to knockdown translation of CYP1A and exposed to BaP. After chemical exposure, embryos were examined for CYP1 activity, teratogenesis, and BaP biotransformation. To examine the effects of early-life exposure on the chronic toxicity of PAHs, larval offspring of ER and reference site killifish were exposed to BaP, and examined for CYP1 activity, mitochondrial and nuclear DNA damage, and BaP biotransformation. Three and nine months after exposure, livers of exposed juveniles were analyzed histologically. The mRNA inductions of the metabolic enzymes, CYP1A, CYP1B1, and CYP1C1, were significantly reduced in ER embryos exposed to AHR agonists compared to those from a reference site. CYP1 enzymatic activity was also reduced in these embryos, and they were resistant to the teratogenic effects of PAH both in single and combined exposures. These data suggest that the ER population have adapted an altered responsiveness of the AHR signaling pathway. Higher concentrations of parent BaP were recovered from the embryonic and larval offspring of the ER killifish. Additionally a higher concentration of the metabolite BaP-9,10-dihydriodiol was recovered from ER embryos, suggesting that the adaption alters PAH biotransformation and excretion in this population. ER larvae and juveniles were more resistant to PAH-induced genotoxicity and carcinogenicity compared to the reference site population, indicating that the adaptive resistance of the ER population to PAH-induced teratogenicity has also resulted in a resistance to both genotoxicity and carcinogenicity. Co-exposure of the reference site embryos to the PAH mixture and morpholino knockdown of CYP1A did increase teratogenicity; however, no interpretable alterations in BaP biotransformation were observed. Chemical and molecular alterations of metabolic enzymes can dramatically affect the toxic outcomes of exposure to PAHs. The study of biotransformation is an important step in understanding the mechanisms of PAH-induced toxicity, and evaluating the risks in aquatic ecosystems.</p> / Dissertation

Title IV of the Clean Air Act Amendments of 1990 (CAAA 1990) created the first large scale cap-and-trade program as a means to control acid rain in the United States. The program regulated the emission of sulfur dioxide (SO2) and nitrous oxide (NOx) in the atmospherethe precursor to acid rain (formerly acid deposition). Economists have long argued for the use of market-based incentive approach as oppose to the traditional command-and-control methods for its ability to be efficient and cost-effective. Title IV went into full effect in 1995 and has been lauded among one of the most successful regulation as it was efficient in reducing SO2 at lower cost than other program. Market based or incentive based programs work by providing incentives for individuals and firms to alter polluting behavirors. This is accomplished by inposing opportunity cost through pricing. The altering of polluting bvehaviors is achieved by changes in the regulatory environment in which firms operate. However, when prices are low there is the potential for the loss of incentive. Such loss in the regulatory environment occurred in 2008 when the D.C. Circuit overturned the Clean Air Interstate Rule (CAIR) and remanded the dispute to EPA to develop new rules for its replacement. This thesis found regulatory uncertainty to contribute significantly to the decline in the price of emission permits. However, the contribution is relatively small. The adoption of technology appears to be the driving factor behind the decline in the price of emission permits. In the context of the Clean Air Act, there was the expectation of more stringent SO2 standards and impending regulation of mercury emissions. Scrubber technology used to control the emission of SO2 has also shown to be effective in limiting the emissions of oxidized mercury. Since the announcement of these standards there has been a statistically significant increase in the number of control technologies being implemented.

Multitudes of pathogenic and infectious microbes are known to spread via contaminated aerosols. Dental personnel have an increased incidence of respiratory infections. Ultrasonic scaling procedures are reported to produce the largest amounts of contaminated aerosols of any dental procedure. The goal of the current study was to see if dental hygienists are at an increased risk of respiratory infections during the performance of their job and to see if certain dental procedures had a significant effect on this risk. This study was conducted at the Dental Hygiene Clinic of the Louisiana State University School of Dentistry in New Orleans, LA. An air monitor collected air composition data during various dental hygiene procedures, and a survey was given to dental hygiene students. The current study found significant increases in particle counts, aerosols and particulates, during ultrasonic scaling procedures. This significant increase in particle counts for a range of particles, 0.5-5.0 micron in diameter, was shown at the onset (p=0.0002) as well as throughout ultrasonic scaling procedures (p=0.0063). Aerosols of the 0.5-1.0 micron size range produced by dental procedures presents an important transportation mechanism since pathogenic bacteria and viruses can easily be carried by these size particles. Therefore, these results clarify the potential for significant risk of respiratory infection in dental hygienists. Recommendations are provided to help reduce this increased risk of aerosol mediated pathogen exposure during dental procedures. Survey analysis determined that receiving a flu shot the previous year had a significant effect on the likelihood of experiencing respiratory symptoms.

Understanding and assessing the spatial and temporal changes of quality of life and environment of a community is critical to its sustainable development, especially after a disaster strikes. This study explores an approach that integrates remote sensing with socioeconomic data to assess the temporal changes in quality of life and environment (QOL) using Orleans Parish as an example. Hurricane Katrina, which struck New Orleans in 2005, has had vast implications economically, socially, and environmentally for this city and the surrounding area. Empirically quantifying these concepts will help to rebuild the city more sustainably. This study investigated change in environmental quality pre- and post-Katrina using Landsat-TM imagery. Environmental quality was measured by means of vegetation productivity as an indicator, using the Normalized Difference Vegetation Index (NDVI) and Tasseled Cap Index (T-cap) of greenness, wetness, and brightness derived from the Landsat images. Factor analysis was employed to create a QOL index at the zip code level that incorporated both environmental (vegetation, flood depth) and socioeconomic variables. The factor analysis yielded four factors with 95.3% of the variance explained. A weighted QOL index was created that included seven variables from the four factors: NDVI, median household income, population density, housing density, median home value, educational attainment, and flood depth. Validation of the QOL indices with households receiving mail post-Katrina resulted in correlations of 0.546 and 0.510 for the pre- and post-Katrina QOL indices, respectively. The QOL index maps demonstrated spatial contiguity pre- and post-Katrina. Areas that exhibited high QOL included Downtown, Uptown, Garden District, West Bank, and Lakefront. Low QOL was found in New Orleans East, Lower Ninth Ward, and Central Business District. Four years after Katrina, much of the city experienced a decrease in QOL. Zip codes with high wealth tended to maintain or even increase their high QOL, such as in Uptown and the Garden District. This study suggests that higher values of income, education, home value, and vegetation contribute to higher QOL and increase resilience to natural disturbances. These QOL indices link human and natural systems and provide an effective means for comparing changes in a region after a disaster.

Sea level rise (SLR) is directly influenced by climate change through the processes of temperature affecting the growth and decay of continental ice (Barron and Thompson 1990). It is a significant environmental challenge that threatens coastal areas of many nations throughout the world. The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report issued in 2007 states that SLR poses a serious challenge to sustainable development along many coastal areas. The objectives of this thesis are to examine the SLR management issue both in the P.R.C. and the U.S, identify the government agencies that are concerned with SLR issues in the two countries and the specific programs that have been conducted by these agencies, analyze the key obstacles to managing risks associated with SLR, and recommend actions to address some of these challenges. The research methods include reviewing the monitoring efforts, laws, and administrative systems dealing with SLR in the U.S. and the P.R.C., surveying a panel of experts consisting of government agency administrators and researchers in the two countries, and performing vulnerability analysis through case studies of two significant coastal areas in the U.S. and the P.R.C. The research findings indicate that the SLR monitoring efforts of the two countries are very similar, both in terms of technology used and the density of monitoring stations along the coastlines. However, different stages of policy development related to SLR were evident, with the U.S. having established a more integrated federal and state-level policy framework for incorporating SLR issues into coastal planning through the Coastal Zone Management Act of 1972. Currently, risk assessments and some planning activities similar to those conducted in the U.S. are being implemented or are under development by policy makers in the P.R.C.. The main obstacles reported by the experts in both countries to systematically incorporating SLR risks into coastal zone planning were limited budgets, public apathy and the presence of other pressing coastal management issues. Public education efforts designed to convey the potential risk of SLR to stakeholders of specific coastal communities, including possible socioeconomic and environmental consequences, would appear to be a logical strategy to address key reported obstacles to integration of SLR risks into long-term coastal planning.

Environmental pollution has become a steadily growing problem in todays society. East Baton Rouge alone has 13 chemical plants in the parish. The goal of this research is to find out if the chemical releases in the parish are having an effect on the cancer rates in East Baton Rouge Parish. I gathered data from all 64 parishes in Louisiana. The four chemicals I chose to study specifically, Benzene, Dioxin, Formaldehyde, and Xylene. Chemical release data was taken from the Toxic Release Inventory (TRI) website and software from the years1988 to 2009, which was the last reporting year. The cancers I chose to study were Nasopharynx, Non Hodgkin Lymphoma, Leukemia, Lung and bronchus Cancer, and Soft Tissue Sarcomas. The cancer data was taken from the Surveillance Epidemiology and End Results (SEER) programs software called SEERStat. Those data range from 1995 to 2009. I estimated a time lag of 10 years. Stata was used for the statistical analysis. I found that there is evidence that the chemical releases across the state have an effect on the cancer rates especially dioxin and formaldehyde. There were not enough cancer observations in East Baton Rouge parish to perform the analysis by parish and statistically say that chemicals in East Baton Rouge parish are having an effect on the cancer rates.

Due to the destruction of the damaging hurricanes of 2005, Katrina and Rita, more effort has gone into the rebuilding and prevention of future disasters along the Louisiana coast than ever before. This research focuses on the use of wetlands, in the ten coastal parishes of Louisiana, as a mitigation effort aiding in the protection of coastal communities. Using content analysis and decision support software, a wetland ranking was created that represents how wetlands are utilized and protected within each parish. Criteria gathered from the plans include how many times wetlands were mentioned, collaboration with the state and other agencies, and the occurrence of wetland mitigation projects within the plan or parish. This ranking shows Lafourche Parish having the highest wetland involvement and St. Bernard Parish the lowest. The next objective was to determine what factors may influence the wetland ranking. Collected data included 2000 socioeconomic, 2005 wetland, and 46 year hazard data for the ten parishes which was run against the wetland ranking in the SPSS program. The number of hazards the parish experienced over a 46 year period was the only factor shown to significantly impact the wetland involvement. Other interesting relationships include the percentage of wetlands in the parish and number of hazards along with hazard data and voting percentages. This research brings together protective and restorative measures in regards to wetlands along the coast. It is the first step in seeing how communities are adapting hazard mitigation plans to the specific needs of each area and opens the door to future research in which wetlands may be utilized as a way to decrease the vulnerability of coastal populations.

Oyster reefs have recently been identified as one of the most endangered coastal ecosystems, fueling efforts to restore and enhance these systems. Oyster reefs located in the northern Gulf of Mexico have been identified as some of the healthiest of reefs globally, and current efforts focus on devising an approach to Gulf-wide restoration of these reefs. As with all natural resource management and restoration, success is dependent on more than simply understanding the biological requirements of the resource; rather, they are equally dependent on understanding and working within the social and political context in which these management and restoration activities must occur. This project has developed a framework for setting Gulf-wide oyster reef restoration goals by identifying the geo-political, socio-economic, and spatial context in which restoration will occur. Specifically, this project assesses key political and socio-economic factors affecting oyster reef restoration in the Gulf by 1) exhibiting differences and similarities in state requirements for oyster reef restoration, and view points among oyster reef restoration project leaders in each state 2) determining stakeholder and various user groups perception of oyster reef restoration and 3) providing a spatial tool to aid decision making regarding oyster reef restoration in the Gulf. Results show that there are currently differences among the states in their oyster reef restoration policies and requirements, and differences in project leader goals that may make it difficult to create a region wide oyster reef restoration plan. There is also variation in how various stakeholder groups prefer for oyster reef restoration to occur, though there is unanimous stakeholder support for oyster reef restoration. Important biological and socio-economic spatial information identifies areas that are suitable for oyster reef restoration, allowing decision makers to more fully understand the potential success or effects of restored reefs. These studies show that there are socio-economic, geo-political and biological differences across the northern Gulf of Mexico that can ultimately create constraints as well as opportunities for a regional oyster reef restoration plan. This knowledge can help inform oyster reef restoration planners by guiding their restoration actions more efficiently and effectively, enabling them to achieve their desired outcomes.