This research examines the efficient control of SO₂ from ships, a topic that has been discussed at the International Maritime Organization (IMO). The focus is on the economic evaluation of this problem, involving the concept of efficient abatement costs of controlling environmental externalities. The task is to derive an economic framework for quanlifying the costs and benefits of emissions control and then to evaluate environmental regulations on the basis of resource and environmental economic efficiency. For this purpose, this study includes a theoretical consideration of optimal emission in the case of multiple emitting agents as an appropriate framework for discussion of the SO₂ problem from ships, the derivation of an abatement cost function of SO₂ emissions, and a cost-benefit analysis for the optimal regulation of SO₂ by employing an appropriate economic model containing an abatement cost function and an environmental damage function. Theoretical consideration and cost-benefit analysis indicate that more efficient solutions can be achieved than the currently proposed IMO mandates. This will depend on the extent to which (1) variation in damage among affected areas is evidenced, (2) variation in abatement cost functions among emitting agents is effected, and (3) the range of potentially effective countermeasures is employed according to agent's choice. Based on the theory, a simple cost-benefit assessment is derived under the assumptions and conditions implied by the IMO to define their varied regulatory mandates and concerns. The method is to derive abatement cost engineering and environmental damage functions from pseudo-data for a representative case (Rotterdam). The derived formulation shows that the short-run optimal level of sulfur content regulation is 3.0% for bunker oil and 2.0% for land-based heavy oil in Rotterdam. Major conclusions of this research are that the regulation of SO₂ from ships should be considered on a region or area specific basis, and that the regulation should extend not only to ships but also to all relevant SO₂ emitting agents causing environmental damage, including land-based facilities.

Solid waste is a global issue. As developing countries strive to improve their economic situations and standings in the world community, they face extreme underfunding in vital areas of local infrastructure, especially solid waste management. As populations continue to grow, solid waste and its management will become a very serious issue. This dissertation addressed the problems of insufficient available data and inadequate funding in an urban center in a small developing country with respect to future solid waste management. The aim was to develop a quick, simple and cost-effective check-list that could be used by decision-makers in developing countries of similar characteristics, in dealing with current and future planning for improved solid waste management. Residential municipal solid waste (RMSW) was analysed from three main locations, which where Georgetown, Guyana and Tucson and Sells, Arizona in the United States. Due to the lack of data available in Guyana, several other locations were used for lesser comparisons. These were Miami, Florida, and the Kaibab-Paiute Indian Reservation and Patagonia, Arizona. The waste streams of each were compared, as were the physical, social and economic situations of the main three locations. Past and current solid waste management practises were also compared. Results indicated that RMSW in all places contained little hazardous component. The waste in Georgetown comprised mostly of organic food waste, as has been found in other developing nations. Based on reports of foreign consultants, many solutions and improvements suggested for solid waste management in Georgetown have not been feasible and technologies brought from developed countries have been too high-tech. Solutions in developing countries need to be low-tech and those who try to solve problems must take into consideration local limiting factors and work within their constraints. Since data are seldom available, it is important to communicate with those who work in solid waste management as they are an invaluable source of information.

4-Phenylcyclohexene (4PC), a contaminant released from latex adhesives used to produce carpet, is structurally similar to the ovarian toxicant, 4-vinylcyclohexene (VCH). VCH causes depletion of primary ovarian follicles in mice. Our aim was to determine if the related compound, 4PC, also causes ovarian damage. Groups of B6C3F1 mice were given either: sesame seed oil (vehicle control), 3 mmole/kg 4PC (4PC-3), 6 mmole/kg 4PC (4PC-6), or 6 mmole/kg VCH (positive control), ip, daily for 30 days. Vaginal smears were done daily to determine the stage of estrus. On day 31, the mice were killed and the ovaries were fixed and stained. The numbers of primary and secondary follicles were significantly reduced in the VCH treated mice, but not in 4PC treatment groups. The number of estrous cycles/30 days was significantly reduced in VCH and 4PC-6 treated groups. This study suggests that although the substitution of a phenyl group (4PC) for a vinyl substituant (VCH) on the cyclohexene ring appears to eliminate the follicular loss, monitoring of the estrous cycles may be an early indication of an adverse reproductive effect for 4PC.

Colloid filtration theory was utilized to estimate the sticking coefficient (α) of bacteria in filter media. Determination of bacterial cell numbers was facilitated by incorporation of [³H] leucine into cells prior to filtration. Large changes in retention of bacteria within porous material correlated with different stages in the bacterial growth cycle. This was due primarily to changes in cell size and not due to a change in α. The effects of ionic strength, pH, nutrient status, surfactant concentration and filter material on α were also evaluated. Various filtration models predicted similar trends in the magnitude of bacterial α with changes in experimental conditions. Experiments were performed with two gram negative and one gram positive bacterial species, Pseudomonas fluorescens, Pseudomonas JS6, and Bacillus pumilus. Small reductions in α were observed in cultures that were carbon-limited. Oxygen limitation produced no change in alpha. Bacterial α's were a function of ionic strength and filter material.

In this study volatile organic compounds (VOCs) emitted during carpet installations employing water-based adhesives were characterized. The potential impacts of 4 adhesives on indoor air quality were evaluated. Headspace sampling and analysis by gas chromatography/mass spectrometry were used to qualitate VOC emissions. Adhesives and carpet/adhesive composite samples were prepared for quantitative analysis of VOC emissions by gas chromatography with flame ionization detection. Volatiles were concentrated using a monitoring device and collected on charcoal adsorption tubes. Sampling intervals ranged from 30 minutes to 21 days. The adhesives emitted primarily aromatic, alicyclic and aliphatic compounds as toluene, m-xylene, 1,2-dimethylcyclohexane, alpha-pinene, 2-methylheptane, octane, nonane, decane and undecane. Emission profiles depended on performance characteristics and manufacturer. A carpet boundary layer slowed VOC decay by acting as a sink. Potential overexposure within 24 hours to specific and total VOCs was indicated for one of the adhesives. This study suggests that water-based carpet adhesives are a potential source of indoor air pollutants.

This study was conducted to determine emission rates of nitrous oxide (N₂O) gas from arid region locations. Fluxes were measured at an effluent-irrigated turfgrass location in Arizona, a Sonoran desert location, and a savannah location in Africa. Fluxes were measured by a closed chamber method at the Arizona locations on a weekly basis during the summer of 1991, and at the African location during two separate three day studies during the summer of 1992. Soils were sampled at each location during each sampling period and analyzed for water content, nitrate, pH, and total organic carbon content. Nitrous oxide fluxes in Arizona averaged approximately 13 and 0.7 kg N₂O-N ha⁻¹ yr⁻¹ for the turfgrass and desert locations respectively. The average fluxes from the African sites were 1.3, 1.6, and 1.3 kg N₂O-N ha⁻¹ yr⁻¹ for a millet field, fallow field, and "tigerbush" plateau, respectively. Diurnal and seasonal variability was observed.

Hydraulic fracturing has become a hot topic in Americas growing, domestic, oil and natural industry. This new technology has provided an economic way to extract resources from tight oil and gas shale formations found deep underground, but this new way of drilling does not come without environmental and human health effects. Among these health effects are water usage, water quality, and air quality. In this paper, data from Frac Focus.org was used to get the average amount of water used per well, and the average amount of chemicals, and what those chemicals are, for each well in the Haynesville Shale. An extensive literature review was used to get average air emission data from drilling and hydraulic fracturing. Data from the Louisiana Department of Natural Resources SONRIS was used to find average drilling statistics associated with Haynesville Shale wells and used to determine drilling and hydraulic fracturing efficiency. These parameters were then used estimate air emissions, water usage, and chemical use in the Haynesville Shale. It was found that on average an unconventional well in the Haynesville Shale used 6.5 million gallons of water. The top three chemicals used in fracking fluid were found to be: Hydrochloric Acid, Phenol, and Quaternary Ammonia Salts, used at an average concentration of 0.21%, 0.086%, and 0.02%, respectively. Air emissions from unconventional drilling processes were estimated for NOx, CO, VOC, PM, SOx, CO2, and CH4. Overall, the drilling process in the shale was found to emit the most amount of emissions, except for CH4 where fracturing emitted the most. Lastly, using the drilling parameters and water use calculations, evidence was shown that learning by doing was taking play in the Haynesville Shale and that efficiency, in some aspects of the well development activities, was being achieved.

Similar to passive exposure to cigarette smoke, building occupants, in homes and in offices, are passively exposed to volatile organic compounds that are being emitted form surfaces of interior finishes and furnishings. Identifying emissions from surfaces of interior finishes and furnishings requires in-situ sampling. Interior finishes and furnishings used in homes and offices are many and varied. Current available methods used for sampling surface emissions from interior finishes and furnishings require the use of environmental chambers in laboratory settings. The in-situ applications of these lab-based chambers are limited. A novel method for in-situ surface emission sampling is needed. This thesis presents the development and validation of a novel surface emission sampler, the Kappa. Emissions from an interior carpet sample were captured using three different samplers, an ASTM-based chamber, a Field and Laboratory Emission Cell (FLEC) and the novel Kappa. Results were compared qualitatively and quantitatively. Based on the results obtained, the Kappa and the FLEC were comparable in their relative responses with each other and against the ASTM chamber. The Kappa, however, sampled emissions in-situ, whereas the ASTM and the FLEC sampled emissions under laboratory settings. As an in-situ surface emission sampler, the Kappa was able to estimate the contribution of an interior finish such as a carpet to indoor air pollution in real indoor conditions. The Kappa could thus provide representative, appropriate and necessary field data that are required to justify implementation of site-specific remedial action. The latter would help reduce the burden of, and occupants' exposure to emissions from interior finishes and furnishings in non-industrial microenvironments.

Dallas, Texas is located in North Texas and sits above the eastern portion of the Barnett Shale natural gas formation. Hydraulic fracturing, or fracking, was introduced to the region as a means to access previously inaccessible natural gas within the formation. This fracking concerns many because it requires large amounts of fresh water, an average of over 4 million gallons per well within Dallas Water Utilities service area. This thesis examines whether water use for fracking will have a negative effect on the water supply for the city of Dallas and its wholesale water customer cities. The water is typically removed from the water cycle because chemical additives required for fracking are difficult to remove and the water is often disposed of underground. Methods of recycling and treating this water are being pursued but are not currently employed at a high rate in the Barnett Shale area. Water is of special concern in this region due to drought, increasing population, and the recent discovery of Zebra Mussels in the water supply. Texas is experiencing the worst drought other than the 1950s drought of record which is reducing the available water supply, through both evaporation and lack of recharge. The population in the area is also projected to nearly double by 2060 which will lead to increased water demand. Zebra Mussels have been found in Dallas supply system and these mussels are impossible to remove and can clog pipes, reducing the flow of water and so potentially reducing the available supply. Future water plans are prepared to address these issues, focusing on conservation as well as increasing available supplies. Based on this analysis, hydraulic fracturing in Dallas, Texas and within Dallas Water Utilities wholesale customers should not significantly affect Dallas water supply in the near term. Other methods of conservation, such as limiting landscape watering, should be considered as more beneficial ways to save water.

<p> As replacement and removal of undersized culverts gains momentum as an effective technique for restoring natural stream flows and removing fish passage barriers, it is important to evaluate the benefits of these efforts on the in-stream and adjacent riparian habitat for other species of potential concern. This study compares stream-associated amphibian (SAA) occurrence in streams adjacent to different road crossing structures on unpaved forest roads in the Wilson River watershed located within the Tillamook State Forest, Oregon. Surveys were conducted at road crossing structures for three taxa of SAA; Pacific giant salamander (<i>Dicamptodon tenebrosus</i>), coastal tailed frog (<i>Ascaphus truei</i>), and Columbia torrent salamander (<i>Rhyacotriton kezeri</i>). Statistical models were created to analyze the effect of habitat variables on SAA occupancy, and determine whether those variables changed relative to road crossing structures. </p><p> Results showed that coastal tailed frog occupancy was positively associated with dissolved oxygen and crayfish presence, negatively associated with longitude, and had a slight quadratic relationship to channel confinement. Because all sites were highly saturated with oxygen, percent dissolved oxygen was likely a surrogate for one or more other covariates, such as in-stream habitat or substrate size. Detection rates of Pacific giant salamander were too high and detection rates of Columbia torrent salamander were too low to provide reliable models, but they did provide some insight into the factors affecting occupancy in the study area, including information about their interactions with road crossing structures. Occupancy rates of Pacific giant salamanders in the study area appear to be unaffected by road crossings, fish passable or otherwise. Conversely, torrent salamanders seemed to be mostly absent from the study sites altogether, but based on the one stream where they were detected, they are not excluded from occupying fish barrier culvert sites. </p><p> Top weighted habitat covariates, including dissolved oxygen, channel confinement, crayfish and fish presence, and flow constriction are all indicators of disturbance that can be linked to road crossings. Although the size and structure of road crossings did not prove to significantly influence SAA occupancy, indicators of stream disturbance that can be related to road crossings were included in the best models for predicting occupancy, demonstrating the importance of reducing disturbance related to road crossings on streams.</p>