Triazine herbicides are the most heavily used pesticides in the United States. Atrazine and Simazine are the primary triazine herbicides used for broadleaf weed control in the production of corn, sugarcane, and sorghum. Recent monitoring studies of surface waters in the Upper Terrebonne Basin of Louisiana indicate elevated amounts of triazines are running off fields and entering drinking water supplies. Atrazine has been classified as a possible carcinogen by the United States Environmental Protection Agency. Recent epidemiological studies have revealed increases in breast cancer and pre-term births following exposure to triazines at levels detected in drinking water. Non-point source pollution is a major problem affecting the water quality in the United States. Agriculture contributes a large percentage of non-point source water pollution, with sediment, pesticides and animal waste transported into waterways with surface runoff. Recent amendments to the Clean Water Act require that States identify impaired waters and develop Total Maximum Daily Load Budgets for these waters. Best Management Practices have been advocated as a method to reduce non-point pollution to meet these new regulations. Data were collected in the Upper Terrebonne Basin of Louisiana before and after the farmers were advised to follow Best Management Practices to reduce Atrazine runoff . Samples of finished and raw water were collected from Iberville Water District Three and analyzed for atrazine concentration by the Louisiana Department of Agriculture and Forestry. Atrazine concentration data were evaluated using Dynamic Linear Models, with stream flow from Bayou Grosse Tete as a regressor. This analysis revealed that stream flow has a significant influence and accounts for most of the change in atrazine concentrations at the Iberville water facility. The trend in acreage of crops planted in the UTB had a decrease in the number of crop acres that could utilize Atrazine. The sale of Atrazine in the UTB also increased for the years at the beginning and end of this study. From the results of the time series analysis, it appears that Best Management Practices had less effect than stream flow on Atrazine concentrations at Iberville Water District Three.

Through intense studies of agency audits, EPA policies and documents, state environmental compliance data and state agency issued documents, I have evaluated the enforcement programs of Region Six state environmental agencies. The four elements utilized to perform this evaluation were listed in EPA compliance assurance program documents. The analysis was conducted by comparing state program performance in each element. Element 1 is the appropriate identification of violations. Element 2 is the timely issuance of enforcement actions. Element 3 is the escalation of enforcement actions when violations continue. Element 4 is the ability to assess and collect penalties. These elements are interdependent. Their success depends on the perception of their success by the regulated community. A lack of success in one element will prevent the effectiveness of all elements. The community must perceive a high likelihood of being inspected, and a high likelihood of receiving enforcement orders and penalties for existing violations. Without this perception, an enforcement program cannot effectively deter the regulated community from subsequent violations. Because each agency needed to improve in some area of enforcement, it was determined that none of the Region Six state agencies were completely efficient in all elements. Because a successful program relies upon all elements, there is no best or worst program. Each agency contains strengths and weaknesses among the elements, and each agency can improve their environmental enforcement procedures.

This study evaluated the PCR inhibition and toxic effects by sediment samples exposed to drilling muds. This information was gathered in an attempt to identify what effect, if any, drilling muds had on the microbial community structure in sediments around four specific oil-drilling platforms in the Gulf of Mexico. Sediment samples were taken before and after drilling had taken place around two platforms (GB516 and VK916), and sediment samples were taken after drilling had taken place around two other platforms (MC292 and GB602). After using traditional, non-selective DNA extraction methods, successful amplification took place via PCR with all pre-drilling samples that were tested. Post-drilling samples, however, failed to amplify using the same procedure. Many experiments were conducted to identify the cause of PCR inhibition in the post-drilling samples. It was clearly demonstrated that an abundance of humic substances was being carried through the extraction procedure and caused the PCR inhibition. The Lumitox assay showed that the toxic effects of exposed sediments ranged from very toxic to non-toxic.

A quality assurance testing of the ECLOX-M, a rapid water quality indicator used in potential terrorist attacks, was evaluated for its adequacy in nine regional Louisiana water systems. The ECLOX-M system uses enhanced chemiluminescence to measure toxicity in water by integration of a mixture of luminol (C₈H₇O₃N₃), and an oxidant in the presence of a catalyst enzyme - horseradish peroxidase (HRP). Water samples were tested for chemiluminescence, chlorine content, pH, and arsenic and/or nerve agent/pesticide contamination. In addition, three toxic industrial chemical standards were evaluated (mercury, a volatile liquid mixture, and a volatile gas mixture) and two nerve agent/pesticide standards (atrazine, and a regulated pesticide mixture). Additional tests included: three replicates of each contaminant at two concentration levels; three replicates of each regional water sample; and chemical standard spikes on each water sample. A metal mixture and a volatile organic compound (VOC) mixture were evaluated to determine the machine's sensitivity to chemical mixtures. Lastly, two ECLOX-M's were tested simultaneously to determine their precision and accuracy. Testing revealed a significant difference in the inhibition % for the nine regional water samples. A one-way ANOVA and a student T-test revealed a significant difference in inhibition % between concentrations for all chemical standards tested. A trend was seen with chemicals and water samples in which the standard deviation for inhibition % increases as the toxicity of the sample decreases. An additive effect on inhibition % was hypothesized for the chemical mixtures. Instead an inhibitory effect was seen for the metal mixture, and a synergistic effect was seen for the VOC mixture. This suggests that the ECLOX-M is not capable of detecting components or interactions between components within a mixture. The simultaneous testing revealed no significant difference between the performances of the two machines. Lastly, there was a significant difference between the regional water sample pH levels, (p ≤ 0.01). It is suggested that water systems with complex water matrices consider using multiple testing methods, as ECLOX-M alone is not an accurate indicator of contamination. Detection of added contaminants is difficult to ascertain if clean water produces high light inhibition.

Eutrophication is a process by which a waterbody progresses from its origin to its extinction. During this period, there is a gradual accumulation of nutrients and organic biomass, accompanied by a decrease in average depth of the water due to sediment accumulation, and an increase in primary productivity, usually in the form of dense algal blooms. Cultural eutrophication occurs when humans, through their various activities, greatly accelerate this process. Eutrophication can cause loss in species diversity, fish kills, and decrease the aesthetic value of a waterbody. The EPA is trying to prevent cultural eutrophication by setting standards for water quality criteria for each of the fourteen ecoregions in the United States. Nutrients are the most common pollutants affecting waterbodies. The EPA considers total phosphorous and total nitrogen as the two causal variables and chlorophyll a and Secchi depth as the two early indicator response variables. There are models that predict the relationship of chlorophyll a to phosphorous and chlorophyll a to nitrogen, but there are very few that combine phosphorous and nitrogen to predict chlorophyll a at a cross-sectional level. This study is concerned with fitting a linear model for the prediction of chlorophyll a, using phosphorous and nitrogen, for the fourteen ecoregions. Six combinations of the three variables have been tested (because of the different methods used to obtain each variable) to find out which model is the best with respect to model fit, number of observations, and geographical coverage. The best model can then be used in further studies to determine eutrophication end points at smaller and more homogeneous divisions of the ecoregion for better management of water quality in lakes.

The intersection of science and law is very complex. The two disciplines frequently interact due to environmental issues. Expert testimony is most often the method used to introduce scientific data into the legal system. Advances in technology have allowed scientists to increase the preciseness and reliability of data produced. The development of the gas chromatograph and the recent microFAST gas chromatograph has greatly increased the amounts of data available to the legal system. The legal system has relatively recently developed a set of guidelines with which to evaluate scientific evidence and determine whether it should be admitted into trial. Previously novel scientific evidence such as the microFAST gas chromatograph would not have been admitted because it was not generally accepted. The new guidelines in admissibility, however, require that the relevance and reliability of the evidence be examined. A comparison of the mechanics of a conventional gas chromatograph to the microFAST gas chromatograph reveals that the two machines operate on the same basic theoretical principles. Since data produced by a conventional gas chromatograph is readily accepted by the legal system, this same standard of admissibility should be applied to the microFAST gas chromatograph. The increased rate of data production by the microFAST machine will help establish causation in trial and improve the relevancy of the scientific evidence. Reliability is established by adherence to quality control procedures and repeatability. This thesis examines the relationship between law and science and projects that data produced by the microFAST gas chromatograph will ultimately be accepted into the legal system.

The Environmental Protection Agency appropriates 400 million dollars in grant funding under the authority of Title X: Residential Lead-based Paint Hazard Reduction Act of 1992. The education mandate of Title X states that the federal government must build an infrastructure to educate the public, real estate professionals, and contractors, to name a few, on the hazards of lead-based paint. A survey was developed to assess the effectiveness of the Title X education mandate. Contractors in the City of New Orleans were surveyed to assess their knowledge of the act and the hazards of lead-based paint before attending an 8-hour training course used to training contractors in accordance with a city ordinance. The citys ordinance was passed to ensure that contractors performing remodeling or renovation activities in the city limits are properly trained on the hazards of lead-based paint and hazard control methods known as interim controls. It requires contractors to attend a minimum 8-hour course approved by the Department of Housing and Urban Development (HUD). <p> The results of this study indicate that the contractors in the New Orleans area are not being educated on the hazards of lead-based paint and the requirements of Title X as mandated. The training course the contractors attended requires attendees to pass a post-course test in order to receive a notice of completion to prove certification. The scores from the test were also analyzed and assessed. The analysis demonstrated the contractors benefited from specialized training as average scores of the group increased by approximately 20% over the survey scores. This study recommends policy mandating training and education with a need for additional research. Contractors should be required to attend specialized education.

The usefulness of detecting genomic instability in the form of microsatellite instability (MSI) has been examined in a number of cancers. Squamous cell carcinoma (SCC) and adjacent normal and lichen sclerosis (LS) samples were taken from patients with radical vulvectomies. Vulvar SCC samples were compared with adjacent normal samples using four oligonucleotide markers (BAT-25, BAT-26, D10S208 and D10S587) found to be informative with other carcinomas. Using polymerase chain reaction techniques, 30 vulvar SCC DNA samples were examined for MSI. BAT-26 displayed the highest level of MSI and was considered to be the most sensitive marker in studying vulvar SCC. There was not a statistically significant difference between adjacent normal and LS samples analyzed. The level of MSI discovered in three loci (BAT-26, D10S208 and D10S587) was statistically significant when compared to adjacent normal samples and indicates a dysfunction in mismatch repair genes. Genomic instability pathways of carcinogenesis, characterized by mismatch repair defects and MSI, appear to have a role in the genesis of vulvar SCC, based on the high incidence of MSI in association with BAT-26.

Epigenetics is defined as the study of heritable changes of DNA. One such component of epigenetic regulation is DNA methylation in humans. In neoplastic cells epigenetic controls are often dysregulated, especially in the promoter region of CpG islands. Global hypomethylation along with region specific hypermethylation of CpG islands in the promoter region of tumor suppressor is often indicative of neoplastic cells. In cancer, CpG island cytosine hypermethylation has been observed in more than fifty genes, including known tumor suppressor and DNA repair genes. Squamous cell carcinoma (SCC), lichen sclerosis (LS), and adjacent normal tissues were obtained by radical vulvectomies of over one hundred patients. Normal unassociated tissues were also collected in the same manner. The disease process of LS provides an environment conducive to oxidative damage and increases in free radicals. Increased methylation in the promoter regions of specific tumor suppressor and DNA repair genes were anticipated to display a progression to malignancy from normal tissue to LS to SCC. Hypermethylation patterns of p16, p15, O⁶ methyl guanine methyl transferase (MGMT), glutathione S-transferase pi (GSTP1) were examined by methylation specific polymerase chain reaction (MSP) to obtain an etiological model of vulvar cancer. SCC samples exhibited 26% and 34% methylation in p16 and p15 genes. LS samples displayed 22% and 31% methylation in p16 and p15. The level of hypermethylation in SCC and LS associated samples was significantly different from normal samples in both p16 and p15 genes, suggesting that silencing of these two genes is an early and important event in vulvar squamous cell carcinoma. GSTP1 and MGMT were not found to have a statistically significant difference in any of the tissues tested.

Nitroglycerin, used in propellant formulations and ignition cartridges in military weapons, has been found as a surface soil contaminant on military installations. Concerns have arisen since the fate and mobility of nitroglycerin is not understood in these natural environments. The objective of this study was to determine the fate of nitroglycerin in natural field soils. Nitroglycerin degradation was examined using a surface soil and an aquifer soil under aerobic and anaerobic conditions at three pH levels. Studies were also performed to determine the influence of a supplemental carbon source on degradation. Radiolabeled 14C-nitroglycerin was used to trace the partitioning between aqueous and soil phases. The only nitroglycerin remaining in solution appeared at pH 6 under aerobic conditions in both test soils. The addition of glucose as a carbon co-substrate did not exert a substantial effect on the rate of nitroglycerin degradation. Mass balance studies revealed partitioning differences between the two test soils with unidentified derivatives in both water and soil phases. Results from this study demonstrate nitroglycerin will not remain in parent form in anaerobic or aerobic environments (except in acidic locations), with carbon content having little influence on degradation rates.