This study examines the transport of atrazine, an herbicide used in Kentucky to control grassy and broad-leaf weeds in corn fields, on suspended sediments. Atrazine is a known carcinogen and endocrine disruptor and has been shown to be toxic at low environmental concentrations. Atrazine has the capacity to adsorb to soil particles, which in karst areas such as those found in south central Kentucky can be transported directly into the groundwater. Suspended sediments and water were collected from a well at the Hawkins River in Mammoth Cave National Park during a spring storm and tested for atrazine. Atrazine was found in concentrations exceeding 3 |ig/l in all of the sediment samples collected. Concentrations of atrazine in the cave stream's water were low, ranging from nondetectable traces to 0.1 (j.g/1. These results indicate that, in some cases, adsorption to sediments may be a major mechanism for atrazine transport in karst regions. The relatively high levels of atrazine present on the suspended sediments raise serious concerns, since this mode of transport has received little attention in karst environments.

Congested roadways and declining air quality standards are major concerns for many communities faced with the challenges of suburban growth and city decay. How each community chooses to fight the problems created by urban sprawl depends greatly on individualized characteristics of the community. Analyzing and understanding unique values of each community provides a sound foundation for measures designed to promote sustainable growth initiatives. The Evansville, Indiana, region is experiencing many of the growing pains associated with increased residential, commercial, and industrial development. Many roadways are currently strained near capacity, and traffic problems are anticipated to increase over the next 20 years. Evansville was ranked 68 out of the 271 worst sprawling MPOs, and Vanderburgh County will be designated as "non-attainment" with the next EPA air quality ruling. This research demonstrates that the Evansville region has problems with urban sprawl, air quality, and roadway congestion. Local air quality data, roadway congestion, employer and employee surveys, and commute patterns are all analyzed to determine the existing characteristics of the community. As a means to mitigate current and future concerns, Travel Demand Management (TDM) strategies such as park and ride facilities should be utilized. Implementing shared used park and ride facilities will provide an effective and relatively inexpensive method of congestion reduction by providing motorists with a different commute option.

The Mammoth Cave System of south central Kentucky encompasses more than 560 km of surveyed cave passages. The largest groundwater basin (244 km2) found within this cave system emerges from the Turnhole Bend Spring on the Green River. During high flow conditions, water from this groundwater basin will spill over into the Echo River section of the cave. Previous research, including cave mapping and dye tracing (Quinlan and Ray, 1989; Currens and Ray, 1998; Coons, 1994), has delineated the boundaries of spring groundwater basins for numerous springs along the Green and Barren Rivers. These data showed that 60% of the water that flows through the Turnhole Bend Aquifer comes from beyond the boundaries and protection of Mammoth Cave National Park. This area outside the park is crossed by several major transportation routes, including Interstate 1-65, U.S. Highway 31 -W, and CSX Railroad. Because the Turnhole Bend Aquifer is crossed by these major transportation routes, the aquifer is vulnerable to contamination from accidental spills of hazardous materials. Dye tracing methods were utilized to better delineate the boundaries and sub-basins of the Turnhole Bend Groundwater Basin along Interstate Highway 1-65. The approximate boundaries developed by previous research by others were first used to located areas that had not been previously dye traced. Fluorescent dyes were used as tracers and were detected by both qualitative (yes/no) methods and by quantitative (discrete water sampling) methods. Data from quantitative dye traces performed during this research provided additional information on the behavior of water flow into and through the maturely karstified limestones found in the south central Kentucky karst. Dye traces performed during the wet season, late winter and spring, have shown that average flood pulse groundwater flow velocities often exceed 1 km/hr. These high flow rates are contrasted by flow rates in the order of 0.5 km/day during the summer when evapotranspiration is high and rainfall is less frequent. Data from the quantitative dye traces also indicate a significant difference in the residence times of the dye between the wet and dry seasons. Dye that was injected during the wet season had a relatively short residence time in the cave streams of approximately 2 to 3 days. Dry season quantitative dye traces are very different with residence times of over 12 days being recorded. This information is vital in determining the consequences of a sudden release of hazardous materials within the drainage basin of Mammoth Cave and demonstrates that emergency planning is crucial.

For a long time, fish is regarded as an important food source beneficial for human health. But there’s nowadays an increasing concern of fish consumption for increasing existence of mercury (Hg) and methylmercury (MeHg), which can be accumulated upon fish intake and pose health threats to human.  It is suggested that children and pregnant women are more vulnerable to effects due to accumulation of Hg. There have been continuous efforts done by governments and researchers all over the world, e.g. publishing national and regional advisories on fish consumption, in order to inform public related risks aroused by excess fish consumption. Sweden, as one of the earliest countries abandons the use of Hg (Regeringskansliet, http://www.sweden.gov.se), has published a national advisory on fish consumption for pregnant and breastfeeding women (Swedish National Food Agency, SLV, http://www.slv.se/). Hg level in edible fish organs is also limited for safe consumption.  In order to picture a better image of this, we investigated existed databases in Sweden on Hg levels in fish, fishery statistics, consumption data, and observed Hg level in human in recent decades for human exposure to Hg in Sweden. Though mercury emission decreased, the exposure to mercury via fish consumption is still high. We believe there’s a potential risk for Swedish inhabitants, especially pregnant women and women in breastfeeding, as well as young children. It is strongly recommended a safer limit of Hg in fish products for consumption in Sweden.             We hope for more synthesized knowledge of safe fish consumption that benefit for the public and promote regional/national policy in having an up-to-date fish consumption advisory in Sweden.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vi, 67 p. : maps (part col.). Vita. Includes abstract. Includes bibliographical references (p. 53-56).

published_or_final_version / Community Medicine / Master / Master of Public Health

Biomonitoring has become an important component in bioassessment programs. It is used to maintain high water quality standards, and determine contaminant levels and biological affects in areas that have been heavily disturbed. The objectives of this research were 1) to improve and apply certain modern biomonitoring techniques and 2) to locate possible contaminant sources affecting the flora and fauna of the Green River and of Mammoth Cave. Actinonaias ligamentina (Lamarck, 1819), a freshwater mussel, was used for interpretation of these impacts as well as refinement of biomonitoring techniques. The mussels were collected in the Lawler Bend region of the Green River, an area upstream from the Mammoth Cave System, and from Haynes Shell Midden (dating 4000 - 6000 years before present) 45 miles downstream. Analyzing the shell nacre of these mussels, and the soft tissue of recently collected specimens, produced an abundance of information including high tissue concentrations of organochloride pesticides, significant concentrations of several metals including Cadmium, Copper, Mercury, Nickel, Silver and Zinc (with Mercury and Silver being found at the impact site), and numerous shell nacre stains. These results indicated possible impact from agriculture in the region and past and present contamination from local industries, and demonstrated the importance of the nacreous shell to biomonitoring programs.

<p> Urban air pollution is responsible for high levels of morbidity and mortality in exposed populations due to its effects on cardiovascular and respiratory function. Transportation-related air pollutants account for the majority of harmful air pollution in urban areas. Forests are known to reduce air pollution through their ability to facilitate dry deposition and atmospheric gas exchange. This work characterizes the interactions between transportation air pollutants and urban forests in Hillsborough County, Florida. A highly spatially resolved passive air sampling campaign was conducted to characterize local concentrations of nitrogen oxides, benzene, toluene, ethylbenzene, and xylenes (BTEX) in Hillsborough County, Florida. Sampling locations included a proportion of densely forested urban areas in order to determine the effects of Hillsborough County's urban forest resources on localized concentrations of selected transportation pollutants. Recommended approaches for the use of urban forests as an effective air pollution mitigation technique in Hillsborough County were generated based on results from the sampling campaign. Results show mean concentrations of 2.1 parts per billion and 6.5 &micro;g/m3 for nitrogen oxides and total BTEX, respectively. High spatial variability in pollutant concentrations across Hillsborough County was observed, with the coefficient of variation found to be 0.61 for nitrogen oxides and 0.79 for total BTEX. Higher concentrations were observed along interstate highways, in urban areas of the county, and near select point sources in rural areas. Differences in concentrations within forested areas were observed, but were not statistically significant at the 95% confidence level. These results can be used to identify elements of urban design which contribute to differences in concentrations and exposures. This information can be used to create more sustainable urban designs which promote health and equity of the population.</p>

<p> Millions of people are exposed to arsenic in the United States and worldwide. Commonly found arsenic species in human urine are AsIII (arsenite), AsV (arsenate), MMA (monomethyl arsenic acid), DMA (dimethylarsinic acid) and AB (arsenobetaine). Evidence has shown that these species vary in toxicity, and since each of these metabolites can be detected through analysis, they have the potential to be used as biomarkers for human exposure. For human exposure assessments in areas that have naturally occurring arsenic contaminated sources, or those who live or work near contaminated environmental sites where arsenic has been used, it is important to fully understand what species of arsenic residents are being exposed to in order to grasp the risk of arsenic exposure specifically and in its entirety.</p><p> Since it is difficult to determine direct human exposures, a swine model was used as a surrogate. Swine urine was collected from two different swine studies where animals were given non-toxic doses of arsenic contaminated soil and another group receiving a soluble reference dose using sodium arsenate for comparison. The urine samples from these studies were used to modify an arsenic speciation method using high-performance liquid chromatography and inductively coupled plasma mass spectrometry (LCICPMS). It is evident that when comparing the percent of arsenic species found in swine urine samples with what is found in humans a correlation can be made. There was a range of 64&ndash;74% DMA in swine samples for all test soils where a range of 60&ndash;75% DMA has been reported in human urine samples. This further illustrates the importance of arsenic speciation in swine urine since it does appear that it could correlate to human exposure. If proper measurement systems are utilized to quantify As species of health concern, dosed swine can be used to assess and predict human toxicological effects of arsenic exposure.</p>

There is little information available on the relationship between the chemical composition and toxicity of South African paraffin. The aim of this study was therefore to determine an association, if any, between the chemical composition and toxicity of South African paraffin. The objectives were to analyze the chemical composition and potential toxicity of paraffin using an A549 lung cell line. There were two phases to the study. In the first phase of the study the chemical composition of seven (7) paraffin samples was tested at accredited InterTek Testing Services (ITS) according to SABS protocol. In the second phase of the study toxicology studies were conducted using the MTI and Annexin assays to establish the toxicity of the samples. The experiments included dissolving paraffm in a constant volume of ethanol. Results of the chemical analysis of paraffin from local refineries indicated that the major components were aliphatic hydrocarbons (>75%, v/v), olefins (1-8%, v/v), aromatics (1-20%, v/v) and sulphur «0.1%, v/v). Cytotoxicity tests indicated that there were significant (p<0.001) differences in the level of toxicity of the paraffin samples. The chemical composition or formulation was the single most important factor, which determined the degree of toxicity. The toxicity of paraffin dissolved in ethanol was significantly (p<0.001) more toxic when compared to that of undissolved paraffin. Paraffin samples also induced apoptosis and necrosis. It is therefore recommended that the chemical composition of paraffin must be standardized to a consistent less toxic product to ensure the safety of the South African public. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2007.