Pacific ocean perch (Sebastes alutus) is a slow growing species of demersal rockfish, which inhabits the continental slope of the west coast of North America. This species represents a highly commercial fishery and an important part of the groundfish fishery of British Columbia. A variety of biological factors are known to influence the concentrations of trace metals in fish, including, age, body size and diet; all of which vary in this species. Little is known of the concentrations of total mercury and total arsenic in Sebastes alutus from British Columbia, a Canadian province where marine groundfish have previously been found with elevated concentrations of mercury. The spatial variability of trace elements across different fishing regions within British Columbia is also unknown. Substantial variability in concentrations of both mercury and arsenic has been reported in marine fish from around the globe. In the case of arsenic, associations between concentrations in muscle tissue and a variety of biological variables are not frequently reported. This contrasts with mercury, which is known to be intrinsically linked to the biology of fish. Consequently, biological variability in fish has the potential to confound studies of mercury and possibly arsenic in fish. This thesis examines the influence of biological variables and fishing region on total mercury and total arsenic in Sebastes alutus from British Columbia. It also assesses the concentrations found in muscle tissue from a food safety perspective. Samples were obtained from a commercial fish processing plant on Vancouver Island and had been caught by a commercial fishing vessel in Hecate Strait, Queen Charlotte Sound and the west coast of Vancouver Island. A multivariate outlier determination method was used to quantify the natural background variability across all three fishing regions. Significant differences in concentrations between regions were identified. This spatial variability of total arsenic did not appear to be related to age, body or body size. However, the spatial variability of mercury concentrations appear to be associated with the size and age of the fish sampled. The outlier determination procedure also identified the presence of elevated concentrations of both mercury and arsenic in specimens that were determined to be outliers. Outliers originated predominantly from the west coast of Vancouver Island and exceeded regulatory limits for both mercury and arsenic. In addition to the outliers, estimated quantities of MeHg frequently exceeded Provisional Tolerable Intakes for children and pregnant women. Generalized Additive Models were produced to examine the effect of age, body size (length and mass) and diet (δ13C and δ15N) on concentrations of total mercury and total arsenic in Sebastes alutus within each fishing region. These identified significant nonlinear, qualitative patterns between mercury and body size in two out of three fishing regions. A significant nonlinear effect of age on arsenic concentrations was found. Model results also suggest an effect on arsenic concentrations of organic carbon sources; i.e., fish with stronger links to continental slope or inshore food webs (with relatively enriched δ13C signatures) had greater arsenic concentrations. / Graduate

M.Tech. (Homoeopathy) / The ability to consume oxygen during exercise relies on the functionality of the cardiorespiratory system to deliver oxygen to the working muscles and therefore generate ATP or energy (Astrand et al., 2003). Performance enhancement drugs are becoming increasingly popular as athletes are under extreme pressure to enhance their performance (Shermer, 2008). The purpose of this study was to look for a safe alternative to increase oxygen consumption during exercise. The aim included determining whether the homeopathic remedy Arsenicum album 200CH had an effect on oxygen consumption during submaximal cycling. The study consisted of 32 healthy participants who were randomly divided into a control (placebo) or experimental (treatment) group. Two baseline tests were performed where no medication (remedy or placebo) was given two days apart and the average of the two were taken as the baseline average. After a further two days, the first medication test was conducted after participants were given the treatment 5 minutes prior to testing to ascertain the immediate effect of the medication. The last test was performed after one week of administering where the medication was given twice daily to distinguish what the prolonged effect of the medication was on oxygen consumption. The test consisted of a warm-up at 25-Watts for women and 50-Watts for men, the test included cycling at 3 minute increments where the wattage was increased every 3 minutes by 25-Watts until the participants reached their age-predicted maximum. When this maximum was reached, the wattage was decreased to the warm-up wattage and a cool-down commenced. Heart rate was recorded every minute and documented. The participant was also asked to rate their perceived rate of exertion at the end of every 3minute stage, as a subjective measurement. Although the time periods of administration yielded different results, both were statistically insignificant. The immediate administration showed a negative trend whereas the prolonged administration showed a positive trend in the treatment group after one week. Despite not showing statistical significance, it warrants additional research over a longer period of time.

M.Sc. / Millions of inhabitants worldwide are exposed to arsenic contaminated drinking water as a result of natural and man-made processes. Arsenic especially its inorganic forms, arsenic (III) and arsenic (V) have negative effects on human health especially in developing countries. Therefore fabricating low cost and efficient adsorbents for arsenic (III) removal is of great importance. The aim of this study is to use magnetite (Fe3O4) as filler, incorporated into a polymer blend forming composites as adsorbents for arsenic (III) removal. This work presents the fabrication, characterization and application of Fe3O4-EVA/PCL composites for arsenic (III) removal from water. Fe3O4/Ethylene-vinyl acetate copolymer (EVA)/polyaniline (PANI) and Fe3O4/Ethylene-vinyl acetate copolymer (EVA)/polycaprolactone (PCL) nanocomposites have been successfully synthesized by melt blending technique using a laboratory mixer (Thermo Scientific Haake Rheomex OS). The composites were characterized using scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques. Thermal analysis was done by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and mechanical properties using INSTRON 4443 mechanical Tester. Ability of [EVA (70%) PCL (15%) Fe3O4 (15%)] composites to adsorbed As(III) from water has been investigated through batch experiments. The maximum adsorption was 2.83 mg/g of As(III) ions at 26 ±1°C and pH 8.6. Adsorption data were fitted to Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The process fits well with the Langmuir isotherm. As(III) obeyed pseudo-second order kinetics. The nanocomposites investigated in this study showed good potential for As(III) removal from contaminated water may be due to the dispersion of the magnetite nanoparticles into the polymer blend composites which increases the surface area for the adsorption.

Master of Science / Department of Geology / Saugata Datta / Elevated levels of dissolved arsenic (As), iron (Fe) and manganese (Mn) are seen in the shallow, anoxic groundwaters of southeast Bangladesh on the Ganges- Brahmaputra- Meghna River delta. Over the past decade the mechanisms of As release have been widely debated. It is understood that As can sorb onto Fe-bearing minerals and can be subsequently released when reactions, such as microbially driven processes, occur. This study takes a multi disciplinary approach to understand the extent of the natural reactive barrier along the Meghna River and to evaluate the role of the natural reactive barrier in As sequestration and release in groundwater aquifers. River water and groundwater interactions occur in the hyporheic zone, which is defined as the transient subsurface region where river water and groundwater mix. The natural reactive barrier can develop within the hyporheic zone, where Fe-bearing minerals accumulate with a potential for As sorption, along with reworking and re-deposition of sediments along the riverbank. Shallow sediment cores, and groundwater and river water samples were collected from the east and west banks of the Meghna River in Jan. 2016. Groundwater and river water samples were tested for total dissolved Fe, Mn, and As concentrations; δ₂H, δ₁₈O isotopic ratios. Fluorescence spectroscopic characterization of groundwater organic matter provided insight into the hydro-geochemical reactions active in the groundwater and the hyporheic zone. Eight sediment cores of ~1.5 m depth were collected ~10 m away from the edge of the river. Vertical solid-phase concentration profiles of Fe, Mn, and As were measured by four different methods (hand-held XRF, and ICP-OES analysis of 3 digestions: aquaregia (HNO₃: HCl 1:3), 1.2 M HCl, and 1 M NaH₂PO₄ + 1 M L-ascorbic acid extractions). Enrichment of solid phase Fe, Mn, and As and the presence of possible Fe and Mn oxides in the sediments illustrate the existence of an natural reactive barrier at this reach of the Meghna. HCl extractions of sediment revealed solid-phase As accumulation along the west riverbank reaching concentrations of ~1500 mg/kg. Aqueous geochemical results showed the highest dissolved As concentrations in shallow wells (<30 m depth), where organic matter was fresh, humic-like, and aromatic. Humic-like dissolved organic matter present in the groundwater may enhance Fe oxide dissolution. Microbial reduction of organic matter prompts the reduction of Fe³⁺ to Fe²⁺, causing As to mobilize into groundwater. This study quantified the extent of As accumulation in the sediments along a 1 km stretch of the Meghna River. These findings contribute to the understanding of geochemical processes involved in As release into groundwaters from sediments within a fluvial deltaic environment.

Elevated levels of arsenic (As) in soils and water around the world are both a significant human health and environmental hazard. With increasing global water demands, there is a requirement to further the understanding of the biogeochemical cycling of As from soils and sediments. This thesis focussed on exploring the environmental controls on the occurrence and subsequent mobility of As in a range of natural environments. Arsenic was found to undergo mobilisation from both river sediments and upland peats under changing environmental conditions. The transport of As was found to be correlated with both iron (Fe) and organic carbon (OC), however temporal changes in both sediment/soil composition and movement of water through catchments have a important role in controlling the ultimate transport of As within the environment. A range of investigative methods were employed to study the occurrence and mobility of As within the river sediments of the Allier and Loire Rivers (France), including sequential extraction procedures and batch incubation studies. Arsenic was associated with the reducible phases of sediments, indicating the major role of Fe(oxy)hydroxides in the storage of As in river sediments. In addition to the presence of labile As, the rapid release of As was dependent on the initial sediment composition. Temporal changes in sediment composition may therefore play an important role in controlling the movement of As within fluvial systems. The combination of lead (Pb) and strontium (Sr) isotopic analysis with sequential extraction studies of sediments from the Loire and Allier Rivers was able to determine the relative dominance of granites and basalts within the sediments. This approach provided a first order study on which to better understand the mineral origins of the sediments. The analysis of multiple Pb isotopes was able to eliminate possible anthropogenic contribution to contamination within the sediments, confirming the importance of geogenic cycling of As within the rivers. Information on the origin of mineral formation was obtained through 87Sr/86Sr isotopic analysis, with the formation of Fe-minerals not occurring uniformly along the course of the rivers. While the Sr within the sediment phase targeting well-crystallised Fe(oxy)hydroxides was in equilibrium with the sampled river water, the formation of amorphous Fe minerals was likely occurring in waters upstream of the study sites, within the Massif Central. Total concentration profiles peat from two subcatchments within the Peak District (United Kingdom) provided evidence for both the retention and post depositional movement (PDM) of As within the solid phase, dependent on local conditions. For the first time, the partitioning of As was determined within ombrotrophic peat, and found to be in contrast to Pb, with oxidisible As (likely associated with organic matter) dominating, while Pb was found predominantly within the reducible sediment phase. High temporal resolution monitoring of the organic-rich streamwater draining the peat showed the transport of As was variable, with As found largely in the soluble form despite extensive peat erosion. The evidence for PDM, and the subsequent soluble transport of As demonstrated the importance of biogeochemical processes in releasing As from the solid phase. Once mobilised, both the ratio of Fe:OC and the form of Fe were found to be factors controlling transport of As, with the flushing of stored porewaters an important contribution to As transport from the peat. Despite OC-rich waters, the occurrence of high concentrations of Fe may dominate control of As within the aqueous phase. At relatively high (>0.2) Fe:OC ratios, the particle size distribution of As was closely correlated with that of >1um Fe, although the presence of dissolved and colloidal As was found even within these waters. Given the temporal variability of As transport within the streams, knowledge of the mixing order and ratio between Fe, OC, and As within natural waters may be required for prediction of the mobility and ultimate fate of As.

This paper provides a risk assessment of pertinent toxic contaminants in the tailings of the Iron King Mine using a model of aeolian transport fated in human alveolar lung. Here, we studied particulate matter of tailings that are 10 microns (𝜇𝑚) or less in diameter (𝑃𝑀₁₀) because these is most hazardous fraction. We used in-vitro bioaccessibility and in-vivo Microtox® data to determine the relationships between chronic inhalation of these tailings. Our data suggest that arsenic and zinc are the two principle drivers for toxicity of the Iron King Mine’s PM₁₀ tailings and that arsenic will solubilize in human alveolar biofluids at the expense of other noteworthy elemental contaminants in the tailings. The principle contaminant of concern for chronic exposure is arsenic, due to its increased bioaccessibility over time. Our data show that synthetic lung fluid (SLF) mitigates the toxic effects of arsenic, despite its increase in bioaccessibility over time. Therefore, we suggest a buffering mechanism of phosphate competition with arsenate to explain this mitigation of toxicity in SLF. We conclude that public health risk of chronic inhalation of IKM PM₁₀ tailings may be less severe than would otherwise be suggested by high concentrations of toxic contamination in the tailings impoundment.

Iron is ubiquitous in the environment, ranking fourth in abundance in the earth's crust. Iron is responsible for many environmental mechanisms including the distribution of plant nutrients and pollutants. Iron can exist in several minerals, including iron oxides. Arsenic is a naturally occurring metalloid which has been confirmed by the EPA as a carcinogen. Recently, an arsenic epidemic has unfurled in Bangladesh, poisoning an estimated 70 million people. Arsenic contamination does not exist only in the third world, but also in the United States, including Iowa. Due to the widespread distribution of arsenic and the potential for it to be leached into groundwater supplies, there has been a growing interest in establishing removal mechanisms. Atomic absorption (AA) spectroscopy and inductively coupled plasma optical emission spectrometry (ICP-OES) have been used. There has been a shift in arsenic analysis methods with the advent of more sensitive methods such as the inductively coupled plasma mass spectrometer (ICP-MS). The geology department recently acquired a Thermo Scientific XSERIES ICP-MS, so an arsenic analysis method was developed in preparation for the research conducted in this study. The ICP-MS, however, only measures total arsenic concentration. As this study focused on the oxidation state of arsenic, an alternative means for determining oxidation state was developed. As(V)-selective cartridges were used to adsorb arsenate, while letting arsenite run through. This method was checked for effectiveness and used to determine aqueous arsenic oxidation state. X-ray absorption spectroscopy (XAS) was used to determine the oxidation state of arsenic adsorbed onto the surface of iron oxide. Goethite (α-FeOOH) and magnetite (Fe3O4) are both known to strongly adsorb arsenic. In this work, the potential for As(III) oxidation and As(V) reduction by goethite was studied. As documented by Amstaetter et al., there was some evidence for adsorbed As(III) oxidation by an Fe(II)/goethite system. This study, however, also showed some evidence for oxidation of adsorbed arsenite in the presence of goethite alone. As(V) reduction by magnetite was also studied. Magnetite is capable of having different stoichiometries, or ratios of Fe(II) to Fe(III). Both an oxidized, x=0.27, and a near-stoichiometric, x=0.49, magnetite were studied for their ability to reduce arsenate. There was no evidence for As(V) reduction in the aqueous or adsorbed phase for either system.

No description available.

This thesis develops high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS) method used for the analysis of glutathione arsenic complexes in biological samples. The aim of the thesis was to verify the suitability of this methods and to perform pilot studies on analysis of the enzymatic methylation assay containing glutathione and urine. Inclusion of post-column hydride generation step resolves the problem of changing sensitivity of ICP-MS with gradient elution. Using the standards of glutathione complexes, it was verified that the HPLC-HG-ICP-MS method can provide both qualitative and quantitative analysis of these complexes. The limit of detection was found at 5 pg/ml. Analysis of the methylation assay of arsenic with glutathione showed that only DMAsGS complex occurs in the assay during methylation. It was verified that the presence of the enzyme is required for the complex formation. In the samples of urine from unexposed people analyzed by HPLC- HG-ICP-MS and hydride generation-cryotrapping-inductively coupled plasma mass spectrometry (HG-CT-ICP-MS), only the presence of free pentavalent arsenic species was found, whereas neither glutathione complexes nor trivalent species could be observed.

No description available.