Master of Science (MS), Wright State University, 2007, Earth and Environmental Sciences

Due to their distinctive environments, constructed wetlands are utilized to remediate groundwater that has been contaminated with chlorinated ethenes (i.e. perchloroethene) and other such contaminants. This research focuses on vertical flow mesocosm reactors housed in a greenhouse at Wright State University, which simulate a constructed wetland on Wright-Patterson Air Force Base. These reactors were studied to investigate the effects of vegetation and seasonal changes on the redox parameters present. Water samples were collected from six different reactors from late September/early October 2006 until August 2007. The reactors were sampled three days in a row and this sampling was done once a month. The triplicate sampling was done to promote accuracy in the data by averaging the three days together. Colorimetric analysis of ammonia and iron found anoxic/oxic redox zones apparent in the reactor. These zones were soil and plant specific. In control reactors, where no plants were present, anoxic/oxic boundaries were found in the lower portions. The same was found in reactors planted with the Carex comosa. An anoxic/oxic boundary was found at the bottom of the reactor as well as the top of the reactor where plant roots were present. Those reactors planted with Scirpus atrovirens also showed similar boundaries. The rhizosphere present in these reactors introduces oxygen and bacteria that is not available in control reactors so intensified Fe(III) is able to occur. The profiles of ammonia and nitrite coincide well together. It was found that where ammonia concentrations were high nitrite was low and as ammonia values began to decrease nitrite values began to increase. This suggests ammonia oxidation is causing the nitrification that takes place near the rhizosphere. There are lower ammonia values found in SA reactors as compared to CC reactors, which indicates that the SA plant roots extend further into the reactor than CC roots. More oxygen is being introduced which inhi (open full item for complete abstract)

Committee: Abinash Agrawal (Advisor) Subjects: Environmental Sciences

Doctor of Philosophy (PhD), Wright State University, 2002, Biomedical Sciences PhD

Laboratory and field tests were conducted to evaluate the hypothesis that factors such as the total organic carbon (TOC) contents and groundwater-surface water interactions (GSI) in the sediments can affect chemical desorption, bioavailability and benthic organism exposure. Laboratory studies were conducted with the polycyclic aromatic hydrocarbon fluoranthene (FLU) and the herbicide trifluralin (TF). Toxicokinetic parameters were determined for Lumbriculus variegatus and Hyalella azteca in water-only exposures to 0, 5, 20 and 50 µg/L of the compounds and bioaccumulation was measured during exposures to 0, 100 and 200 mg/kg of FLU and TF spiked onto sediments from Lakes Erie and Huron. Mean uptake clearance rates ranged from 150-180 mL/g wet animal/h for FLU and 84-120 mL/g/h for TF, and elimination rates were 0.12-0.18 and 0.067-0.10/h for FLU and TF, respectively. The uptake clearances in sediments (ks) ranged from 0.021 to 0.070 g dry sed/g wet animal/h for FLU and 0.013 to 0.041 g/g/h for TF. The desorption kinetics of FLU and TF from spiked sediments were measured over 34 d by extraction with Tenax®. The rapidly desorbing fraction for FLU and TF ranged from 31.3 to 54.9% of the initial concentrations and rates of the rapidly (krap), slowly (kslow) and very slowly (kvs) desorbing fractions were on the order of 10-1/h, 10-2–3/h and 10-4/h, respectively. The influence of GSI on contaminant bioavailability was demonstrated with in situ exposures of benthic invertebrates to river sediments that were contaminated primarily with chlorobenzenes (CBs). Hydrologic and chemistry data from nested mini-piezometers explained the exposure-effects relationships. Overall, downwelling conditions reduced the in situ exposure of organisms in surficial sediments, and hence, the toxicity and bioaccumulation of CBs. Data from these field and laboratory investigations were combined with literature values of contaminant partitioning (i.e., Koc values), and L. variegatus feeding rates a (open full item for complete abstract)

Committee: G. Burton (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

Robert A Kehoe, M.D., founder and director of The Kettering Laboratory from 1930 to 1965, urged in 1933 that "strenuous efforts must be devoted to eliminating lead from their [the children's] environment." The history of lead poisoning in the United States can be termed as tragic. Today, we find lead in old buildings and contaminated soil, have passed laws to minimize this hazard, and work to clean up our cities and our industrial sites. Yet, we still have cases of childhood lead poisoning. In 1953, Dr. Kehoe suggested to the Lead Industries Association to implement "a concerted and well organized program of education and control on the part of the paint manufacturers, and distributors, to eliminate the use of paints (and putty) of more than very minor lead content for all inside decoration in the household and in the environment of young children." (32) It was not until 1955 that the American Academy of Pediatrics sponsored the American Standard Association's guideline (American Standard Z66.1-1955) titled "Minimize Hazards to Children from Residual Surface Coating Materials" that industry adopted voluntary guidelines. Meanwhile, Dr. Kehoe continued to inform the public, serve on committees, assist agencies in preventive efforts, and champion legislation at local and national levels. Cincinnati city ordinances were imposed in 1960 for the prevention of childhood lead poisoning, but it was not until 1971 that the federal government passed the first law to reduce the risk of childhood lead poisoning in children. Today, as an outgrowth of Dr. Kehoe's efforts, continuing research and medical activities at the University of Cincinnati contribute to strengthening those efforts in preventing childhood lead poisoning.

Committee: James Donovan, M.D. (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2001, Engineering : Environmental Science

Two constructed wetlands of differing designs were evaluated for the removal of non-point source pollutants over a study period of nine months. The basins were evaluated during low-flow periods for the removal of total suspended solids, ammonia, nitrate, orthophosphate and turbidity. The effect of the basins on the following parameters was also evaluated during low-flow conditions: dissolved oxygen, temperature, pH and bacteria. The basins were also evaluated during storm-flow conditions for all the above parameters excluding bacteria. Lastly, the basins were compared, during low-flow and storm-flow conditions to each other and to a traditionally designed stormwater retention basin. The traditionally designed basin removed or neutralized greater percentages of constituents than the two treatment basins for all parameters excluding temperature during non-storm events. This is most likely due to the longer flow path of the traditionally designed basin. Under storm conditions, with higher loading amounts of the constituents under study, the two treatment basins removed higher percentages of pollutants. It is surmised that physical, rather than chemical or biological, processes dominate in these two treatment basins.

Committee: Dr. Pasquale Scarpino (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

The goal of this study was to evaluate the ability to detect irritant smoke in the presence of a known exhalation valve leak using a RespiFit TM Respirator Qualitative Fit Test Kit. The OSHA protocol for the irritant smoke test mandates the use of a low flow air pump or aspirator squeeze bulb. Many commercial test kits include an aspirator bulb, which is subject to variation from depth of squeeze, fatigue and individual hand strength. The RespiFit TM is designed to prevent these variables by emitting a continuous smoke stream via a battery-operated pump. Twenty subjects wearing North 7600 series full-face respirators equipped with P100 filters were fit tested with a Portacount Plus to ensure adequate fit. The exhalation valve was replaced with a damaged valve and rotated approximately 90° as needed to produce a fit factor below 100. Having induced an exhalation valve leak, the irritant smoke test was performed using the OSHA irritant smoke protocol. The RespiFit TM did not detect 40% of respirators with leaking exhalation valves. Sixty percent of the subjects were able to detect the irritant smoke. Results of the ANSI Draft Z88.10 sensitivity calculation indicate that the irritant smoke test performed with the RespiFit TM did not meet the 95% criterion for identifying an inadequate fit. Of the 12 subjects that failed the smoke test, none detected the smoke in less than a minute; the average detection time was 3:05 minutes. Five subjects who detected the irritant smoke did so after suppressing a reaction. These subjects indicated an ability to ignore the effects of the irritant smoke for a period of time. Only one of the eight subjects who were instructed to break the face to face-piece seal after passing the fit test detected the irritant smoke. The remaining seven subjects did not detect the irritant smoke until given the second sensitivity test. These findings suggest that qualitative fit testing using an irritant smoke fit test with a 200 mL/min continuous flow p (open full item for complete abstract)

Committee: Dr. Roy T. McKay (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

Smoking is a strong independent environmental risk factor for stroke. The purpose of this prospective study was to determine changes in smoking behavior at three months in patients with acute stroke. Patients who were admitted to one of 16 hospitals in the Greater Cincinnati area, with a confirmed diagnosis of stroke, were interviewed in the acute period after their event. A standardized questionnaire was utilized to collect a detailed smoking history. Risk factor reduction was discussed with the patient and/or family members and printed risk-reduction information was provided. Patients or their proxies were then contacted at three months and current smoking status was recorded. Of the 405 available stroke patients 112 (28%) were smokers at the time of stroke. The only significant differences found at baseline between smokers and non-smokers were age with patients under the age of 65 more likely to be smokers (p<0.001) and race with African Americans being more likely to smoke than Caucasians or other ethnic group (p=0.005). At three months 48 (43%) of the baseline smokers had quit smoking (p<0.001), and the overall amount of daily cigarette use had decreased (p <0.001). Conclusions: As with other life altering diagnoses, about half of patients are motivated to change smoking behavior after a stroke. This change of behavior was independent of baseline characteristics, and was not associated with the level of post-stroke disability. Longer follow-up is needed to see if this change in behavior continues. Additional interventions need to be undertaken to see if this positive lifestyle change can be affected in more subjects.

Committee: M. Brown (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2007, Medicine : Industrial Hygiene (Environmental Health)

Air monitoring was performed on an aircraft deicing fluid collection system at the Cincinnati/Northern Kentucky International Airport (CNKIA). The goal of the study was to determine employee exposure to ethylene glycol and the target compounds of decomposition as maintenance was performed on the system. The maintenance work involved performing confined space entries to repair and maintain various diversion chambers, pump stations and storage tanks used to collect and convey spent aircraft deicing fluid. The collected deicing fluid during the period of the study was primarily ethylene glycol based. The study included low flow area air sampling of selected diversion valve pits, pump stations and storage tanks for the presence of ethylene glycol as well as ethanol, formaldehyde, and acetaldehyde which are suspected end products of decomposition of ethylene glycol. The study also included the collection of weekly samples using Draeger Tubes to test for ethylene glycol. Samples were collected in the spring, summer and winter months. The results of the study revealed that the target compounds of decomposition were detected in various concentrations throughout the sample study. All results for the decomposition compounds were well below established regulatory and recommended levels. The weekly analysis for ethylene glycol revealed the potential for exposure to ethylene glycol at the diversion valves and to a lesser extent at the deicing pad pump stations during periods of heavy deicing. Ceiling limits for ethylene glycol at deicing fluid collection valves appear to be exceeded during periods of deicing fluid use greater than 750 gallons per day.

Committee: Dr. Scott Clark (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2006, Engineering : Environmental Engineering

Publicly Owned Treatment Works (POTWs) have come to be examined by the EPA as a major source of Hazardous Air Pollutant (HAP) emission. The 1990 Clean Air Act Amendments as well as state and local regulations, has required POTWs to implement maximum achievable control technologies, MACT, to meet the new regulations. A majority of the HAPs that are emitted are Volatile Organic Compounds (VOCs). Many of these HAPs are considered to be carcinogens or precursors to ozone formation. VOC emission from wastewater treatment plants can occur through a variety of mechanisms including volatilization, evaporation, biodegradation, and photodecomposition; of which, volatilization being the most significant occurring largely in the aeration basins. HAPs are stripped from wastewater in low concentrations over a large surface area. The low concentration and large area make it extremely inefficient and costly to treat polluted air using conventional methods. Recent studies have shown that off gas can be greatly reduced by using a circulating aeration system (CAS). A circulating aeration system requires the capture of off-gas at the aeration basin by an enclosure and the circulation of a percentage back through the system. Fresh air would be mixed; in proportion to the wasted off-gas, with the circulated gas, while only a fraction of the off-gas would be emitted to the atmosphere. Circulating aeration system recycles a percentage of the off-gas back into the system. The use of a CAS lengthens the retention time and increases the possibility for further biodegradation breakdown of compounds. The off gas control also becomes more manageable. With a higher off gas concentration, conventional methods of pollutant control become more economical and efficient. Effects of a CAS are compound specific, however biodegradation rates appear to improve and emissions are reduced drastically. Compounds of high degradability and high volatility, biodegradation are significantly improved. Compounds, s (open full item for complete abstract)

Committee: Dr. Tim Keener (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2006, Engineering : Environmental Engineering

Recently, 16S rDNA Bacteroidetes-targeted PCR assays were developed to discriminate between ruminant and human fecal pollution. These assays are rapid and relatively inexpensive but have been used in a limited number of environmental applications. In this study, we evaluated the efficacy of human- and ruminant-specific 16S rDNA Bacteroidetes assays in determining the primary sources of fecal pollution in Plum Creek (NE) watershed. The sensitivity and specificity, as well as the temporal and spatial application of these assays were challenged against feces from different animals, water, and sediment samples from this watershed. Phylogenetic analyses of 981 fecal and environmental 16S rDNA clones were also performed to study the diversity of Bacteroidetes in this watershed. On average, the host specific assays indicated that ruminant feces were present in more than one-third of the water samples and in all sampling seasons, with increasing frequency in downstream sites along Plum Creek. The human-targeted assay indicated that only 5% of the water samples were positive for human fecal signals, although a higher percentage of human-associated signals (i.e., 24%) were detected in sediment samples. Phylogenetic analysis of Bacteroidetes 16S rDNA sequences derived from fecal and environmental samples demonstrated the presence of a high level of sequence diversity, with nearly half of the recovered sequences showing less than 97% identity to sequences found in publicly available databases. Approximately, 60% of all clones clustered with yet to be cultured Bacteroidetes species associated with sequences obtained from ruminant feces, further supporting the prevalence of ruminant contamination in this watershed. The preponderance of clones affiliated with uncultured Bacteroidetes strongly suggests that the bacterial diversity of this group is not sufficiently represented by the culturable members for which sequence data are available. The sequencing data also indicated that ot (open full item for complete abstract)

Committee: Dr. Daniel Oerther (Advisor) Subjects: Environmental Sciences

MA, University of Cincinnati, 2004, Design, Architecture, Art and Planning : Architecture (Master of)

Aircraft noise effects on its environs have been a subject of discussion since the first aircraft jet took off into the skies some decades ago. To this end, airlines, aircraft and engine manufacturers, airports, and Federal, state and local governments have made substantial efforts to find ways to either reduce aircraft noise, or at best, make its impact manageable and acceptable to the airport neighbors. Hence, substantial resources have been devoted to the research and development of quieter aircraft engines, in addition to establishment of programs for existing engines and to develop noise compatibility projects. Also, to provide methods and formulae for predicting the annoyance effect of aircraft noise on the airport communities and to adequately study the health and other effects of aircraft noise on both humans and the environment. However, most of the these efforts were directed to major commercial airports with little or no consideration for reliever airports, as the latter was thought to be far away from major populated urban areas, with nothing but “cornfields and cows” as neighbors. As suburban sprawl continues to plague America, these airports that were once in the middle of nowhere are now experiencing the fast residential growth encroaching on them. Thus, the reliever airports are now becoming a source of major aircraft noise complaints. This thesis will examine aircraft noise abatement programs at reliever airports. It will use four reliever airports as a case study and to determine the effectiveness of the programs at each airport. In addition, it will examine the overall impact, if any, of the noise abatement programs on the individual airport community.

Committee: Roget Barry (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2004, Medicine : Epidemiology (Environmental Health)

This study examined infants' risk for developing upper respiratory symptoms (URS) in relation to their exposure to environmental tobacco smoke (ETS) and mold. Eligible infants (n=633) were identified by birth records and had one parent that was atopic by positive skin prick test (SPT). Exposure information was collected at the time of parent SPT, and the average age of the infants was seven months. Parents were asked to complete monthly diaries related to their infants' URS. Our analysis included two models, one using parental report of mold/mildew and a sub-analysis (n=342) using in-home assessor report of none, low or high mold exposure. When controlling for race, gender and socioeconomic status, multivariate logistic regression showed an increased risk of sinus infection with parental report of mold/mildew (OR 1.91; 95%CI 1.14-3.23) and exposure to >20 cigarettes/day (2.38; 1.26-4.49); in the in-home assessor report, high mold was even more significant (6.7; 2.27-19.79). Ear infection was also associated with assessor report of mold, in both the low (1.77; 1.17-2.67) and high (3.07; 1.32-7.12) categories. Rhinitis was significantly associated with parental report of mold/mildew (1.32; 1.31-1.47) and exposure to >20 cigarettes/day (1.74; 1.14-2.65). Although significant associations were not observed with allergic rhinitis, elevated odds ratios were observed with both parent and assessor report of mold. This analysis suggests that mold is a risk factor of sinus infection, ear infection and rhinitis, while ETS is a risk factor of sinus infections and rhinitis. This analysis suggests that mold exposure and not ETS is associated with ear infections in infants. The sub-analysis findings also may suggest that mold exposure is a stronger risk factor than ETS for sinus infection, while ETS may be more closely associated with rhinitis.

Committee: Dr. Grace LeMasters (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2004, Engineering : Environmental Science

Benthic sediment and pore water from the Little Miami River (LMR) near Spring Valley, Ohio was sampled before and after three storm events to determine the zone of influence for soluble reactive phosphorus (SRP). The zone of influence is the area in a vertical cross section through the streambed where the pore water SRP concentration changes during the passage of a runoff event. Benthic sediment samples (d < 0.85 mm sieved coarse sand and finer) from three depths (z=0, 15, 30 cm) and five in-stream locations at a single transect were analyzed for their ability to adsorb and desorb SRP. The LMR stream bottom was surveyed during each sampling event to detect changes in the cross-sectional shape of the river. Laboratory analysis of benthic sediment and pore water showed a significant decrease (α =5%) in benthic SRP concentrations with the passage of storm events at all sample points except the 15 and 30 cm near-bank samples. The zone of influence for the SRP concentration was found to extend throughout the benthic zone examined except in areas that are "protected" by a layer of depositional silts near the edge of the LMR. The river cross-section profiles taken during sampling events showed a scouring and re-shaping of the river bottom. Following the storm event, water column SRP concentrations increase from upstream sources and subsequently benthic sediment SRP increases in the zone of influence. The benthic sediments may confound future improvements from TMDL controls and watershed improvements with regards to nutrient removal. While fine benthic material serves as a sink during periods of high SRP in the water column, it may also serve as a source of SRP as the river column phosphorus concentrations decline.

Committee: Steven Buchberger (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2003, Engineering : Environmental Science

This study was performed to determine the efficiency of aerosolized chemical treatments to inactivate fungal and bacterial organisms contaminating the surface of gypsum board materials. The commercially available treatments were administered in the form of aqueous solutions using a Collison Nebulizer directed into a sterile growth chamber housing inoculated gypsum board. Surface swab samples were collected before and after chemical exposures to determine the effects of the treatments. The 0.05% chlorine dioxide and 0.6% sodium hypochlorite treatments after eight hours successfully inactivated the Stachybotrys chartarum. The 0.6% sodium hypochlorite solution was successful in reducing the total concentration of Bacillus subtilis endospores after twelve hours of exposure by 98%; complete disinfection of the endospores was not achieved for the exposure times used.

Committee: Dr. Pasquale V. Scarpino (Advisor) Subjects: Environmental Sciences

PhD, University of Cincinnati, 2002, Engineering : Environmental Science

The U.S. EPA's drinking water Distribution System Simulator (DSS) was used to assess a long-term wastewater cross-connection's effect on the biofilm of a simulated water distribution system. Initial experimentation determined that wastewater injected into the DSS at 0.6% wastewater to system volume over a 24-hour period with 0.1% wastewater to system volume injected every eight hours resulted in continual detection of microorganisms with only slight measurable aesthetic problems (turbidity) within the DSS water column. The DSS was operated with a direct cross-connection of 0.3% wastewater to system volume per day for 90 days. During the cross-connection, tap water, wastewater, and system discharge water were monitored to ensure that the source of indicator organisms was only the wastewater cross-connection and that indicator organisms were present in the water column of the DSS. Following elimination of the cross-connection, samples showed that indicator organisms were removed from the water column within 24 hours, which was the hydraulic retention time of the system. Higher numbers of heterotrophic organisms were detected in the pipe discharge following the cross-connection. Similar results were obtained for the system biofilm. The effectiveness of free chlorine levels of 0, 1, 2, and 5 mg/L to inactivate microbes in biofilms growing on PVC and cast iron sample coupons following a wastewater cross-connection was determined. A significant reduction in all indicator organisms (total coliforms, Escherichia coli, Enterococcus spp., Salmonella spp., Aeromonas spp., aerobic endospores, and total culturable heterotrophic organisms) occurred in the biofilm after 12 hours for both non-chlorinated PVC and cast iron coupons. The indicator organisms were inactivated both in the biofilm and in the water column. Water column data showed that biofilm sloughing resulted in release of culturable heterotrophs and endospores into the previously water column throughout the evaluation (open full item for complete abstract)

Committee: Dr. P.V. Scarpino (Advisor) Subjects: Environmental Sciences

PhD, University of Cincinnati, 2002, Engineering : Environmental Science

This study investigates the potential for biodegradation of methyl tert-butyl ether (MTBE), a prevalent gasoline additive and groundwater contaminant, under various substrate and oxidation-reduction (redox) conditions. Porous pot reactors designed for biomass retention were operated aerobically under the following conditions: MTBE only, MTBE and ethanol, MTBE and di-isopropyl ether, MTBE and diethyl ether, and MTBE with benzene, toluene, ethylbenzene, and p-xylene (BTEX). In all reactors, optimal performance was achieved when operated without biomass wasting. Mineralization of MTBE and the alternative substrates was observed in all reactors, with an average stable effluent concentration of all compounds being at or below 1 ppb (0.001 mg/l). Anaerobically, MTBE degradation was investigated in porous pot reactors and in batch systems. After a 180 day acclimation period, conversion of MTBE to its intermediate, tert-butyl alcohol (TBA), was observed in both batch and continuous-flow iron-reducing systems, and one instance of degradation was observed in the denitrifying porous pot reactor. No degradation of MTBE under methanogenic or sulfate-reducing conditions was observed after over 1 year of incubation. A molecular tool, denaturing gradient gel electrophoresis (DGGE) was used to monitor and profile the bacterial community structure of all reactors. Members of the Flexibacter-Bacterioides-Cytophaga (F-B-C) group of bacteria were most represented among all aerobic reactors, while delta-Proteobacteria were found to be prevalent in the iron-reducing system. Beta-Proteobacteria with high similarity to the known MTBE degrader, PM1, were detected by DGGE late in operation of the MTBE only and the MTBE and BTEX reactors. Two pure MTBE-degrading cultures with high similarity to PM1 were also isolated from the MTBE only reactor. Studies in pure culture also indicated no significant effect of alternative substrate (BTEX) on MTBE degradation. Results indicate that aerobic degrada (open full item for complete abstract)

Committee: Dr. Makram T. Suidan (Advisor) Subjects: Environmental Sciences

MS, University of Cincinnati, 2002, Medicine : Environmental Health Sciences

Two computer models for predicting the aerial dispersion from chemical releases were compared. The U.S. Environmental Protection Agency's (EPA) Aerial Location of Hazardous Atmospheres (ALOHA) model and the RITE Emergency Response Software model's predictions were compared. A sector of Cincinnati, which most closely resembles the coastal, urban terrain of Singapore, was chosen to test the models. Two chemicals, chlorine and propane, were used to simulate accidental releases. Release data for a range of meteorological conditions were input to both models. The plume travel directions and maximum plume travel distances at Immediately Dangerous to Life and Health (IDLH) values from source, were predicted by the models. Results were compared by paired t-Test and Analysis of Variance methods. Analysis showed statistically significant difference ( p=0.001) between the predicted angles of the ALOHA and RITE models. The Analysis of Variance (ANOVA) for the RITE predicted angles showed that stability class will significantly affect the predicted angle for both chemicals. Chemical type, temperature and humidity were not significantly related to the RITE model's predicted plume direction. Analysis also showed statistically significant difference ( p=0.001) between the ALOHA and RITE models in predicting maximum distances at IDLH values. The ANOVA for the RITE model predicted distances at IDLH values showed that both stability class and chemical type were statistically significant predictors of distances at IDLH values. Temperature and humidity were not significantly related to the RITE model's predicted maximum plume distances.

Committee: Dr. Scott Clark (Advisor) Subjects: Environmental Sciences

PhD, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

Lead is a toxic substance and a ubiquitous environmental contaminant. Many studies have shown its negative health effects on psychological development, neuromotor system and many other body organs. Lead was added to paint in the form of white lead to reinforce the paint and produce a tough and flexible film. It is estimated that more than 3 million tons of lead have been used in the form of lead-based paint in the U.S. during the past 100 years. As a result, about 38 million homes still contain leaded paint. For this reason, hundreds of millions of dollars have been spent in the U.S. for lead hazard control. The leaded particles aerosolized during lead hazard reduction work are a health hazard for the workers. Significant levels of leaded particles representing health hazards are aerosolized during lead abatement. Few studies regarding these aerosols have been performed. The two main goals of the research described in this dissertation were 1) to characterize the airborne leaded particles and 2) to apply the acquired knowledge to the evaluation of various lead hazard control procedures. The first goal was to investigate the fundamental characteristics of the particles aerosolized during lead abatement. An Environmental Test Chamber was designed and constructed in the Kettering building at the University of Cincinnati. Wood doors coated with lead-based paint were abated in the chamber by dry scraping, wet scraping, or dry machine sanding. The airborne particle concentration was measured with the Grimm particle size spectrometer. The size distribution of the airborne particles changed substantially with time. The airborne particle concentration for each specific size was found to decay exponentially in calm air condition. Size selective air sampling on filters and subsequent laboratory lead analysis of them showed no significant effect of particle size on the percent lead. The second goal was achieved by the following three studies. The first study was to investigate (open full item for complete abstract)

Committee: Dr. Sergey A. Grinshpun (Advisor) Subjects: Environmental Sciences

Doctor of Philosophy, The Ohio State University, 2008, Natural Resources

China suffers from a host of environmental problems which have worsened over the past three decades of economic reform. Non-point source pollution in freshwater has become a striking issue around the country. The objectives of the research were to explore the knowledge and perceptions of the residents about non-point source pollution and community-based watershed management policies within Nansihu Lake watershed of China, their attitudes toward non-point source pollution control and watershed management, the amount of their willing to pay for water quality improvement, the differences among different groups of the residents regarding their knowledge, perceptions, attitudes towards non-point source pollution and watershed management policies, and their willingness to pay for improving water quality, and finally, the socio-economic factors affecting the residents' willingness to pay. The results indicated that the residents in Nansihu Lake watershed had low level of knowledge and perceptions of non-point source pollution, eutrophication, and community-based watershed management policies. Their attitudes toward non-point source pollution control were very positive. There was no direct cause and effect between respondents' knowledge and their attitude. With the combination of two major CVM formats, the survey results indicated that the urban respondents' median WTP was ¥157.5 (U.S. $19.69), while suburban and rural respondents' median WTPs were ¥100 (U.S. $12.5) and ¥50 (U.S. $6.25), respectively. The total amount of WTP per year in Nansihu Lake watershed was estimated to be ¥562.63 million (U.S. $70.33 million). The survey revealed that residents' yearly income and geographic locations were the main factors affecting residents' willingness to pay for non-point source pollution control in this area. Overall, there was no significant difference between urban and suburban residents in their knowledge, perceptions, and attitudes, but rural residents were significantly diff (open full item for complete abstract)

Committee: Joe Heimlich (Advisor) Subjects: Environmental Sciences

Doctor of Philosophy, The Ohio State University, 2007, Environmental Science

Ecological treatment systems (ETS) are promising, sustainable alternatives to conventional wastewater treatment. These systems consist of anaerobic reactors, aerobic reactors, clarifiers and wetlands. Microbes and plants perform the majority of treatment through the utilization of carbon, nitrogen and phosphorus present in the wastewater. Through the reliance on renewable resources, ETS have successfully treated municipal and industrial effluents with reduced costs compared to conventional methods. However, their capacity to treat livestock wastewater is unknown. Additional gaps in ETS knowledge include the ability of the systems to remove coliforms from wastewater, and the role of plant roots in wastewater treatment. The impact of three strengths of dairy wastewater on effluent water quality was assessed. Influent and effluent water samples were analyzed for PO4, TP, TN, NH4, NO3, total suspended solids (TSS), and carbonaceous biochemical oxygen demand (CBOD5). Influent volumetric loading rates were much greater than those of a similar system treating municipal wastewater. Regardless of wastewater strength, concentrations of all measured variables were significantly reduced between the influent and effluent of the ETS. This dissertation also assessed the ability of an ETS to reduce concentrations of total coliforms and Escherichia coli from dairy wastewater. Regardless of wastewater strength, average total coliform and E. coli concentrations were consistently reduced by at least 99% from influent to effluent, with the majority of the removal (76%) occurring in the first two reactors. Relationships between internal concentrations of solids and coliforms indicated that increased removal of solids may further reduce coliform concentrations. The substantial reductions achieved indicate that ETS have the potential to successfully reduce coliforms in wastewater to meet discharge limits. Finally, this research identified plant species that promote greater nitrogen removal (open full item for complete abstract)

Committee: Jay Martin (Advisor) Subjects: Environmental Sciences

Doctor of Philosophy, The Ohio State University, 2006, Natural Resources

The United States faces a daunting challenge. The country's current economic wealth and prosperity is largely based on the use of its considerable natural resources. Unfortunately, there is a well-recorded history of callous and poorly planned use of these resources by the government, industry and individual citizens that has led to the deterioration and pollution of the natural environment. Compounding this problem for many citizens, the country also has a well-recorded history of social and economic marginalization of racial and ethnic minority groups, which has only begun to be addressed in the last fifty years. These two trends—the misuse of the natural environment and segregation of minority populations to the fringes of society—are not always isolated from each other; in many cases, they conspire to create a single, large problem. Marginalized and minority groups' exposure to a disproportionate amount of the environmental waste produced by society is often higher than it is for the non-minority segments of society. The remediation of this social and environmental crisis will require a concerted effort from multiple segments of society. An important part of this remediation must be the enhanced inclusion of minority and marginalized populations in decision-making processes that are of direct consequence to their communities (e.g., decisions about the placement of industrial facilities in a community or the remediation of a superfund site). This dissertation presents research that addresses this goal (greater inclusion of previously neglected groups in environmental policy decision-making processes) through a tri-dimensional research framework: • The examination of these communities' perception of risk, • The development of a greater understanding of minority and marginalized populations' instinctive decision-making processes, • The testing and development of decision aids for these groups.

Committee: Virginie Bouchard (Advisor) Subjects: Environmental Sciences