No description available.

Arsenic (As) contamination presents an ecosystem and human health risk at Giant Mine, a historic gold mine near Yellowknife, NWT currently undergoing the final stages of assessment for remediation. Arsenic concentration is elevated in sediments at Giant Mine due to contamination from several forms of mine waste including flotation tailings, roaster calcine and impoundment spills. The Giant Mine Remediation Project has stated aims to remediate the surface of the site, including Baker Creek which runs through the property, to a condition that is a productive environmental habitat and spawning ground. Environmental scanning electron microscope (ESEM) and synchrotron-based micro- X-ray Absorption Near Edge Spectroscopy (µXANES), micro-X-ray fluorescence (μXRF) and micro-X-ray diffraction (μXRD) techniques were employed to characterize the As-host phases and determine the solid-phase speciation of As in mine waste and sediments. Arsenopyrite, Fe-oxides, Fe-root plaque, and As_2 O_3 were the major phases identified. Sediment toxicity was measured using 10-day Chironomus dilutes and 21-day Pimephales promelas exposure tests. The toxicity tests found responses ranging of from 100% mortality at the most contaminated site to no statistical difference to the control groups in the least As contaminated site. Toxicity test chamber conditions were directly monitored with dialysis probes (mini-peepers) and Diffusive Gradients in Thin Films (DGTs). DGT and mini-peeper deployment in the test beakers allowed for direct correlation of their measurements to trace metal uptake and bioaccumulation during the toxicity tests. Linear regression and ANOVA statistics were used to correlate, when possible, As tissue concentrations in Chironomus dilutes and Pimephales promelas to DGT, mini-peeper and surface water concentration measurements. Statistical analysis was also conducted for Co, Cr, Cu, Ni, Pb, Zn, and Sb though these other metal/metalloids were not always suitable for analysis due to constraints caused by detection limits. It was found that DGT As was statistically correlated (r2=0.836 and p<0.0005) to uptake in Pimephales promelas but that total element concentrations were also statistically relevant and slightly better at predicting uptake (r2=0.873 and p<0.0005). Mini-peepers could not be analyzed statistically due to challenges in their use within some highly vegetated sediment samples. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-01 11:47:59.482

No description available.

In rural Bangladesh people drink water from an estimated 10-11 million tube wells, many with arsenic concentrations well above the national standard of 50µg/L. Characteristic skin lesions and more serious health effects are probable. The research reported here was designed to determine the relation between arsenic concentration and skin lesions on hands and feet controlling for education, use of tube well water, protein consumption and body mass index (BMI). The investigation included a well survey, a prevalence survey and a nested case-referent analysis. Studies were conducted in two villages (population 11670) in northern Bangladesh. In the well survey 1509 wells in use were identified and measurements of arsenic concentration made in 1422 (94%). Three estimates were made for each well, which yielded correlation among repeats = 0.93. The overall median was 47mg/L and the highest recorded 1760 mg/L. Paramedics examined soles and palms of 11087 individuals for skin lesions and identified 168 cases (1.5%). In the third phase, cases (over 16 years) were matched by age, gender and village to referents (target of 3) without skin lesions. Cases and referents were interviewed about protein in diet, use of well water, education and residential history. Conditional logistic regression was used to assess the effects of arsenic concentration, controlling for confounders. Subjects with lesions had a higher median concentration (250µg/L) than those without (47µg/L). Prevalence increased with both age and arsenic concentration, reaching 26.7% in those over 50 years of age and >500 µg/L. Of the 160 cases (≥16 years) 137 were interviewed, 127 with arsenic concentration measured in well water, together with their 504 referents. Cases were somewhat more likely to have lived in the villages throughout their lives and less likely to report using tube well water for cooking. The final model confirmed the high risk of lesions associated with arsenic concentrations. Using ≤50µg/L for comparison, an odds ratio of 15.2 (95%CI 7.2-32.2) was observed for those using tube wells with concentrations >500 µg/L, adjusting for use of tube well water in cooking and lifetime residence in the villages. The results from this research provide continuing support for the use of 50µg/L as a useful national standard. While the enforcement of this standard has immediate value, it cannot be considered final without comparable information on more serious health risks.

The poor in most developing countries are persistently marginalised in their living conditions, including their access to safe drinking water. The research objectives have been (1) to better understand why this state of affairs has endured despite decades of efforts and interventions, and (2) to propose more adequate alternatives. The central case study was concerned with drinking water in rural Bangladesh ?? a matter of grave urgency since the discovery of arsenic in the groundwater more than a decade ago. Millions of users are exposed to dangerous levels of contamination, and the implementation of solutions has been slow and inadequate. Little has been done so far to integrate the research on this complex humanitarian crisis. Many have argued that conventional views on development are ill-equipped to address the ??growing gap?? between rich and poor; the models often fail to interpret inequity beyond mere financial indicators. This thesis therefore puts forward a different analytical framework (based on the theoretical concepts of core-periphery and capital stock). This was designed to increase our understanding of marginalisation by taking into account unequal ownership of, entitlement to, and control over, ecological, technological, organisational and human assets. Through an action research methodology, this analytical framework was informed by a participatory programme that established safe drinking water supplies in several poor and arsenic-affected villages. The learning experience was then fed back into the programme. This pragmatic approach was also systemic, i.e., it emphasised the community level, which was framed within the context of external influences, various other programmes and national policies. This resulted in a clarification of the problem in terms of (1) lack of ownership of community land, resources, drinking water institutions and technical knowledge; (2) restricted access to (non-) governmental services and benefits from public or collective assets; and (3) exclusion from decision-making in new water sector developments. It was concluded that alternative strategies need to focus on vesting ownership, entitlement and control in marginalised communities. The steps to achieve this will have far-reaching ramifications for how organisations, policymakers and funding agencies perceive and plan development projects. The analytical and methodological approach of this thesis is relevant to other cases of marginalisation in different socio-economic contexts.

The poor in most developing countries are persistently marginalised in their living conditions, including their access to safe drinking water. The research objectives have been (1) to better understand why this state of affairs has endured despite decades of efforts and interventions, and (2) to propose more adequate alternatives. The central case study was concerned with drinking water in rural Bangladesh ?? a matter of grave urgency since the discovery of arsenic in the groundwater more than a decade ago. Millions of users are exposed to dangerous levels of contamination, and the implementation of solutions has been slow and inadequate. Little has been done so far to integrate the research on this complex humanitarian crisis. Many have argued that conventional views on development are ill-equipped to address the ??growing gap?? between rich and poor; the models often fail to interpret inequity beyond mere financial indicators. This thesis therefore puts forward a different analytical framework (based on the theoretical concepts of core-periphery and capital stock). This was designed to increase our understanding of marginalisation by taking into account unequal ownership of, entitlement to, and control over, ecological, technological, organisational and human assets. Through an action research methodology, this analytical framework was informed by a participatory programme that established safe drinking water supplies in several poor and arsenic-affected villages. The learning experience was then fed back into the programme. This pragmatic approach was also systemic, i.e., it emphasised the community level, which was framed within the context of external influences, various other programmes and national policies. This resulted in a clarification of the problem in terms of (1) lack of ownership of community land, resources, drinking water institutions and technical knowledge; (2) restricted access to (non-) governmental services and benefits from public or collective assets; and (3) exclusion from decision-making in new water sector developments. It was concluded that alternative strategies need to focus on vesting ownership, entitlement and control in marginalised communities. The steps to achieve this will have far-reaching ramifications for how organisations, policymakers and funding agencies perceive and plan development projects. The analytical and methodological approach of this thesis is relevant to other cases of marginalisation in different socio-economic contexts.

Thesis (M.S.)--University of Nevada, Reno, 2007. / "August 2007." Includes bibliographical references (leaves 65-66). Online version available on the World Wide Web.

Thesis (M.Sc.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 90-98.

Thesis (M.Sc. (Natural Resources Management))--Mahidol University, 2008.

Thesis (M.S.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 104-113).