Understanding the relationships between human health, water, sanitation, and environmental health is a requirement to understanding the challenges that face researchers when it comes to addressing global health relating to water and sanitation. Access to improved water and sanitation is not only a precondition to health, but to all aspects of daily living. Target 7.C of the Millennium Development Goals (MDGs) addresses worldwide disparities in access to improved water and sanitation by calling for the reduction in "half of the proportion of people without sustainable access to safe drinking water and sanitation by 2015". Over 90% of the population of Costa Rica has access to improved water and sanitation, thus exceeding the water and sanitation targets for the Millennium Development Goals (MDGs). Despite having access to water and sanitation, little is known whether communities are only interested in access or if quality and quantity of water and sanitation systems are as equally as important. Target 7.c of the MDGs does not include water quality in the definition of safe water. Furthermore, the use of the words "safe" and "improved" in the target are often interchanged and can be misleading, especially when considering the impact of water quality on population health. In Costa Rica, households in the Nandamojo watershed have access to improved water and sanitation; it is unclear whether the drinking water is potable with respect to Costa Rican and the World Health Organization (WHO) water quality standards. The impact of leaking septic systems on human and environmental health is also unknown. Illnesses associated with recreational water are an increasing public health problem, causing a great burden of disease in bathers every year. The global health impact of infectious diseases associated with recreational water exposure has been estimated at around three million disability-adjusted life years (DALYs) per year, resulting in an estimated economic loss of around twelve billion dollars per year. Fecal and chemical contamination of recreational water is a concern, especially in areas of non-point source pollution. Health-based water monitoring is often conducted in recreational waters as a tool for assessing risk. In Costa Rica, recreational water sampling is conducted at coastal beach areas only, neglecting other surface waters used by residents and tourists. Community perspectives regarding recreational water use and the associated risks are limited. Understanding these perspectives will enable public health professionals to better target community needs, such as education and to address the concerns of participating communities. This dissertation was divided into three chapters. The first chapter explored community perceptions on improved water and sanitation, the second chapter assessed community water systems and the risk of acute diarrheal disease, and the third chapter captured community perceptions on recreational water use and the risk of waterborne illness. Methodologies for water sampling and analyses were used to assess water quality, while household interviews and focus groups were conducted to capture qualitative data. Results from the first chapter showed participants had positive perceptions towards their improved water and sanitation systems. Household interviews revealed almost half of the respondents had concerns with water quality, while less than 25% did not think their septic tanks leaked or overflowed during rain events. Focus group discussions revealed common themes. Participants identified water quality, health, pipes, water scarcity, odors, insects, and overflow/infiltration of water and sanitation to be important issues. Participants revealed convenience, improved health and safety and the lack of odors to be themes directly related to customer satisfaction of improved water and sanitation. Results from the second study revealed 57% of household samples had total coliform bacteria above the Costa Rican standard for safe drinking water exceeding the single standard limit of zero, while 61% failed the World Health Organization standard for fecal coliforms exceeding the single standard limit of zero. AGII was identified in 41 of the 378 household residents (11%). The odds ratio for AGII among household residents with a water sample positive for total coliforms was 1.88 (0.81-3.17). Fecal coliforms were statistically significant for those with AGII (OR = 3.19, 1.43-7.12). Regression modeling analyses revealed individuals with AGII and household drinking water positive for fecal coliforms to be statistically significant (OR = 3.01, 1.33 - 6.84), while other covariates (total coliforms, gender, treated water, and families) also had odds ratios greater than one, but were not significant. Results from the third chapter indicated most respondents felt recreational water sources, such as streams and rivers were contaminated with human, animal, and chemical wastes. Focus group participants also stated they did not use inland waters for recreational purposes for these reasons. However, many did admit using marine water for recreational bathing and felt these areas were not contaminated. These beliefs did coincide with the water quality results from freshwater sources, but not marine sources. Fecal coliform contamination was widespread throughout the watershed in freshwater sources. Marine water samples failed the World Health Organization (WHO) and Costa Rican recreational water standards for fecal coliform and enterococci in 36% and 6% of the samples, respectively. The overall results of this dissertation suggest that the definitions of improved water and sanitation have to include, at a minimum, water quality, water quantity, proper construction and containment of storage tanks, and oversight and maintenance of these systems. Given the challenges facing communities in the Nandamojo watershed regarding water and sanitation, it is essential for scientists, researchers, policy makers, water committees, health providers, and community members to design and implement strategies in water resource management and proper waste management. Communities and water committees would also be best served if they worked with government agencies to conduct concurrent testing of both recreational water and drinking water, especially since both them target many of the same parameters.

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<p>This thesis aimed at studying mechanisms involved in control of tissue fluid homeostasis during inflammation.</p><p>The interstitial fluid pressure (P_IF) is of importance for control of tissue fluid balance. A lowering of P_IF <i>in vivo</i> will result in a transport of fluid from the circulation into the tissue, leading to edema. Loose connective tissues that surround blood vessels have an intrinsic ability to take up fluid and swell. The connective tissue cells exert a tension on the fibrous network of the tissues, thereby preventing the tissues from swelling. Under normal homeostasis, the interactions between the cells and the fibrous network are mediated by β1 integrins. Connective tissue cells are in this way actively controlling P_IF.</p><p>Here we show a previously unrecognized function for the integrin αVβ3, namely in the control of P_IF. During inflammation the β1 integrin function is disturbed and the connective tissue cells release their tension on the fibrous network resulting in a lowering of P_IF. Such a lowering can be restored by platelet-derived growth factor (PDGF) -BB. We demonstrated that PDGF-BB restored P_IF through a mechanism that was dependent on integrin αVβ3. This was shown by the inability of PDGF-BB to restore a lowered P_IF in the presence of anti-integrin β3 IgG or a peptide inhibitor of integrin αVβ3. PDGF-BB was in addition unable to normalize a lowered P_IF in β3 null mice. Furthermore, we demonstrated that extracellular proteins from <i>Streptococcus equi</i> modulated αVβ3-mediated collagen gel contraction. Because of the established concordance between collagen gel contraction <i>in vitro</i> and control of P_IF <i>in vivo</i>, a potential role for these proteins in control of tissue fluid homeostasis during inflammation could be assumed. Sepsis and septic shock are severe, and sometimes lethal, conditions. Knowledge of how bacterial components influence P_IF and the mechanisms for tissue fluid control during inflammatory reactions is likely to be of clinical importance in treating sepsis and septic shock.</p>

A total of 44 intermittent sand filter-septic systems, in five counties of Western Oregon, were sampled over a three-month period during the summer of 1995. The sand filter systems varied in age from 36 months up to 167 months (3 to 13.9 years). Liquid samples were taken from the septic tank and distribution box. In addition, soil samples were taken adjacent to the disposal trench and away from the disposal field area (control). All samples were analyzed for Total Kjeldahl Nitrogen (TKN) and nitrate and nitrite. Nitrite was not detected in any of the samples. The average removal of total nitrogen (TKN + nitrate) through the filter was found to be 43%. Nitrate was determined to be the dominant form of nitrogen in the sand filter effluent making up 94% of the total nitrogen. The age of the system was found not to be a predictor of the system's performance. Once the effluent entered the disposal field, little if any transformation of nitrogen occurred at an average depth of 30 inches (76.2 cm). / Graduation date: 1996

This thesis aimed at studying mechanisms involved in control of tissue fluid homeostasis during inflammation. The interstitial fluid pressure (PIF) is of importance for control of tissue fluid balance. A lowering of PIF in vivo will result in a transport of fluid from the circulation into the tissue, leading to edema. Loose connective tissues that surround blood vessels have an intrinsic ability to take up fluid and swell. The connective tissue cells exert a tension on the fibrous network of the tissues, thereby preventing the tissues from swelling. Under normal homeostasis, the interactions between the cells and the fibrous network are mediated by β1 integrins. Connective tissue cells are in this way actively controlling PIF. Here we show a previously unrecognized function for the integrin αVβ3, namely in the control of PIF. During inflammation the β1 integrin function is disturbed and the connective tissue cells release their tension on the fibrous network resulting in a lowering of PIF. Such a lowering can be restored by platelet-derived growth factor (PDGF) -BB. We demonstrated that PDGF-BB restored PIF through a mechanism that was dependent on integrin αVβ3. This was shown by the inability of PDGF-BB to restore a lowered PIF in the presence of anti-integrin β3 IgG or a peptide inhibitor of integrin αVβ3. PDGF-BB was in addition unable to normalize a lowered PIF in β3 null mice. Furthermore, we demonstrated that extracellular proteins from Streptococcus equi modulated αVβ3-mediated collagen gel contraction. Because of the established concordance between collagen gel contraction in vitro and control of PIF in vivo, a potential role for these proteins in control of tissue fluid homeostasis during inflammation could be assumed. Sepsis and septic shock are severe, and sometimes lethal, conditions. Knowledge of how bacterial components influence PIF and the mechanisms for tissue fluid control during inflammatory reactions is likely to be of clinical importance in treating sepsis and septic shock.

Severe sepsis and septic shock comprise a significant number of emergency department (ED) admissions annually. With the advent of early goal directed therapies, early identification and intervention have become paramount in this population. Few studies, however, have examined the role of serum lactate as a predictor of mortality or endpoint to resuscitation among this population. We aimed to show that improved lactate clearance is associated with decreased 28-day in-hospital mortality. We retrospectively examined data from the Yale Sepsis Registry for patients with severe sepsis or septic shock who had lactate levels that were measured initially in the ED and subsequently when the patient arrived on the floor. This study received institutional review board approval. Lactate clearance was calculated as a percentage, and comparison between patients who cleared lactate and those who did not were made for mortality data as well as baseline characteristics and interventions required between the two groups. 207 patients (110 male) with mean age and standard deviation (SD) of 63.17 ± 17.9 years were examined. 136 patients (65.7%) were diagnosed with severe sepsis and 71 patients (34.3%) had septic shock. Of those with identified sources of infection, pneumonia was the most common (54 patients, 26.1%). There were 171 patients in the clearance group and 36 patients in the non-clearance group, all of whom had a mean time of 9 hours 8 minutes ± 4 hours 6 minutes between lactate measurements. 28-day mortality rates were 15.2% (26 patients) in the lactate clearance group and 36.1% (13 patients) in the non-clearance group (p<0.01). Vasopressor support within 72 hours of admission was initiated among 61.1% (22 patients) in the non-clearance group compared with 36.8% (63 patients) in the clearance group (p<0.01). Mechanical ventilation was required for 36.3% (62 patients) in the clearance group and 66.7% (24 patients) in the non-clearance group (p=0.001). Rates of severe sepsis, mean number of SIRS and organ dysfunction criteria, and initial creatinine were similar between the two groups; however, only 86.1% (31 patients) in the non-clearance group received intravenous fluids in the ED compared with 98.8% (169 patients) in the clearance group (p=0.002). 33.3% (12 patients) in the non-clearance group had chronic obstructive pulmonary disease (COPD) compared with 15.2% (26 patients) in the clearance group (p<0.05). The mean Mortality in Emergency Department Sepsis (MEDS) scores were 8.78 ± 3.96 for the clearance group and 10.4 ± 4.48 for the non-clearance group (95% CI, -3.1 to -.14, p<0.05). These results show significantly higher mortality rates among patients who do not clear their lactate in the ED. Additionally, these patients require vasopressor support and mechanical ventilation more often. Lactate clearance was significantly associated with receipt of fluids and may also reflect lower MEDS score. Our findings suggest lactate clearance could be used as an endpoint for ED resuscitation and in stratifying mortality risk among patients with severe sepsis or septic shock. Future studies might seek to prospectively validate these findings and incorporate multivariate analysis to determine factors affecting lactate clearance.

A dual wavelength method was developed for the field detection of optical brighteners (OBs), fluorescent laundry additives used as indicators of anthropogenic wastes. The method was quantitative for OBs under variable levels of fluorescent colored dissolved organic matter (CDOM). Based on excitation at 300-400 nm and 440 and 550 nm emission, the method assumed a constant ratio of fluorescence due to CDOM alone, even if absolute amplitude varied. Concentrations of OBs were computed as the difference between the observed 440 nm emission and the expected CDOM fluorescence at 440 nm, as extrapolated from the 550 nm fluorescence and established CDOM fluorescence ratio. Real-time inner filter corrections were based on absorption modeled from 550 nm fluorescence and from exponential relationships at alternate wavelengths. The effects of temperature and dissolved oxygen on CDOM fluorescence and computed OB were quantified but were minimal because effects were comparable between the two fluorescence regions. Assumptions on the locally conservative behavior of CDOM were supported in field surveys of sewered and non-sewered areas. Varying water masses were detected, but OB quantities were detected that did not co-vary with fluorescence alone. Eleven geographic regions of peninsular Florida and sources of OBs were sampled to evaluate the method under a broader range of CDOM and to conduct an extensive detergent spike analysis. Fluorescence data were collected as EEMs and subjected to PARAFAC modeling, isolating eight spectral factors that could sufficiently describe all samples. There were no visible regions of the spectra that were unique to detergents or OBs, but a previously unreported peak in the UV (<230 / 284 ex / em) was tentatively identified as a detergent surfactant and should be pursued as a potential complementary indicator of anthropogenic wastes. Limits on EEM fluorescence measurements were identified: maximum linear range, maximum turbidity, and sensitivity to assumptions. A sub-sampling technique of EEM data approximated the filter fluorometer readings, was used to optimize the dual wavelength method, validated the method with spike recoveries, and presented alternative approaches.

Sludge accumulation, treatment and disposal can represent a high percentage of the operating cost for a wastewater system. This is especially important for small-scale and onsite wastewater treatment systems, where sludge removal can be one of the few operating costs of the system. In 2000, as a result of a large number of septic system failures, the community of Wardsville installed a Clearford Industries Inc. Small Bore Sewer™ (SBS™) system which included two-chamber 3600 L tanks located on the properties of individual homes. The tanks were collectively attached to a small bore piping system to deliver the effluent from the tanks to a small community wastewater treatment system. During the summer of 2007, a field study was initiated with a community survey, followed by a review of candidate sites, leading to the selection of 29 sites for site investigation and sampling. Sampling involved the collection of samples for sludge characterization along with the measurements of the height of solids (scum and sludge) within the tank. The data were analyzed to determine the factors having a statistically significant impact on solids accumulation rates within each of the two chambers of the tank. Household water usage was found to be the variable having the strongest association with sludge and scum accumulation, and models were estimated relating solids accumulation to water usage in order predict pump out frequency. A second field sampling program was conducted in Wardsville during April 2008, involving only the first chamber of 13 primary clarifier tanks. Overall contributions have been made in understanding and quantifying solids accumulation rates and sludge characterization in onsite primary clarifier tanks. As well, the information gained from the analysis of the data collected provides a meaningful insight into the factors influencing solids accumulation within individual residential primary clarifier tanks, and points to future research directions for understanding the factors influencing solids accumulation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-25 15:34:46.243

Sludge accumulation, treatment and disposal can represent a high percentage of the operating cost for a wastewater system. This is especially important for small-scale and onsite wastewater treatment systems, where sludge removal can be one of the few operating costs of the system. In 2000, as a result of a large number of septic system failures, the community of Wardsville installed a Clearford Industries Inc. Small Bore Sewer™ (SBS™) system which included two-chamber 3600 L tanks located on the properties of individual homes. The tanks were collectively attached to a small bore piping system to deliver the effluent from the tanks to a small community wastewater treatment system. During the summer of 2007, a field study was initiated with a community survey, followed by a review of candidate sites, leading to the selection of 29 sites for site investigation and sampling. Sampling involved the collection of samples for sludge characterization along with the measurements of the height of solids (scum and sludge) within the tank. The data were analyzed to determine the factors having a statistically significant impact on solids accumulation rates within each of the two chambers of the tank. Household water usage was found to be the variable having the strongest association with sludge and scum accumulation, and models were estimated relating solids accumulation to water usage in order predict pump out frequency. A second field sampling program was conducted in Wardsville during April 2008, involving only the first chamber of 13 primary clarifier tanks. Overall contributions have been made in understanding and quantifying solids accumulation rates and sludge characterization in onsite primary clarifier tanks. As well, the information gained from the analysis of the data collected provides a meaningful insight into the factors influencing solids accumulation within individual residential primary clarifier tanks, and points to future research directions for understanding the factors influencing solids accumulation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-25 15:34:46.243

Groundwater is an important resource that is relied on by approximately half of the world’s population for drinking water supply. Source water protection efforts rely on an understanding of flow and contaminant transport processes in aquifers. Bedrock aquifers are considered to be particularly vulnerable to contamination if the overburden cover is thin or inadequate. The objective of this study is to further the understanding of modeling, sampling, and the potential for anthropogenic contamination in fractured bedrock aquifers. Two numerical modeling studies were conducted to examine geochemical groundwater sampling using multi-level piezometers and the role of discretization in a discrete fracture radial transport scenario. Additionally, two field investigations were performed to study the variability of bacterial counts in pumped groundwater samples and the potential for anthropogenic contamination in a bedrock aquifer having variable overburden cover in a semi-urban setting. Results from the numerical modeling showed that choosing sand pack and screen materials similar in hydraulic conductivity to each other and the fractures intersecting the borehole can significantly reduce the required purge volume. Spatiotemporal discretization was found to be a crucial component of the numerical modeling of solute transport and verification of the solution domain using an analytical or semi-analytical solution is needed. Results from the field investigations showed fecal indicator bacterial concentrations typically decrease on the order of one to two orders of magnitude from the onset of pumping. A multi-sample approach that includes collection at early-time during the purging is recommended when sampling fecal indicator bacteria for the purpose of assessing drinking water quality. Surface contaminants in areas with thin or inadequate overburden cover can migrate quickly and deeply into the bedrock aquifer via complex fracture networks that act as preferential pathways. While the presence of fecal indicator bacteria in groundwater samples signifies a possible health risk through human consumption, it was the suite of pharmaceuticals and personal care products that allowed the identification of septic systems and agriculture as the dominant sources of contamination. Land-use planning and source water protection initiatives need to recognize the sensitivity of fractured bedrock aquifers to contamination. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2011-02-28 17:27:54.806