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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 45 for “"Lead concentrations"”.
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Cadmium and lead concentrations in livers and kidneys of cattle slaughtered at Grootfontein abattoir in Namibia
… was to determine the levels of cadmium (Cd) and lead (Pb) in livers and kidneys of cattle slaughtered at Grootfontein abattoir in Namibia. The study design was based on the epidemiological principles to detect a single animal whose kidneys or liver contained Cd or Pb residues. The Grootfontein …
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Redox Reactions Influencing Lead Concentrations in Drinking Water: Formation and Dissolution of Lead(IV) Oxide and Impact of Galvanic Corrosion
<p>Two approaches have been used to mitigate lead release to drinking water are optimizing water chemistry to form stable lead corrosion products and replacing lead service lines with lead-free materials. The present study investigated the effects of water chemistry on the formation and dissolution …
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Evaluation of erythrocyte amino levulinic acid dehydratase as an indicator of chronic lead exposure in wild populations of rainbow trout
… acid dehydratase (ALA-D) and liver and bone lead concentrations were measured in 141 wild rainbow trout from two highway-influenced and two pristine streams. A significant relationship between ALA-D activity and liver lead concentrations among streams (r = 0.157) was observed. However, this …
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Determining the concentration and source of lead in chocolate using lead isotopes
… the world were analyzed to determine their lead concentrations and the isotopic composition of the lead. The lead isotope ratios were compared with published data from aerosols and volcanic rocks nearest to the cocoa growing regions. Samples from different countries and manufacturers were …
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Effects of installing point-of-use filters intended for lead removal on drinking water quality
… the aging drinking water distribution system can lead to elevated concentrations of toxic metals and harmful microorganisms that pose a risk to human health. Premise plumbing systems can be sites of elevated lead concentrations from lead service lines and are favorable environments for …
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Phytoremediation of Metal Contamination Using Salix (Willows)
… to plants, animals, and humans. Cadmium (Cd) and lead (Pb) are metal contaminants often found in AMD. In my mine outwash water samples, cadmium and lead concentrations were 19 and 160 times greater than concentrations in control waterways, and 300 and 40 times greater than EPA Aquatic Life Use …
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A GEOCHEMICAL MODEL FOR PREDICTING CORROSION- SCALE DISSOLUTION AND PHASE TRANSFORMATIONS IN DRINKING WATER DISTRIBUTION SYSTEMS
… geochemical model has been developed to predict lead dissolution and solid phase transformations in water distribution systems for varying water chemistry conditions and corrosion scale compositions. The equilibrium model is developed in PhreeqC.v.2.16.03 with reactions and thermodynamic …
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The city blues of an iridescent canary: physiological, behavioral, and developmental impacts of lead (Pb) on songbirds along an urban-to-rural gradient
… materials—including heavy metals like lead— persist within the environment for prolonged periods of time and present a widespread problem for all who live near contaminated areas. Despite the phase-out of lead usage, it continues to threaten the health of all organisms but especially …
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Characterizing Waterborne Lead in Private Water Systems
Lead is a common additive in plumbing components despite its known adverse health effects. Recent research has attributed cases of elevated blood lead levels in children and even fetal death with the consumption of drinking water containing high levels of lead. Although the federal Environmental …
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The effect of soil parameters on the bioavailability and retention of lead in rats
… (lime and phosphate) to the retention of lead in soil fed to rats. This study also related the amount of lead that can be extracted from in situ contaminated soils from a secondary smelter site to both soil properties and to the tissue lead concentrations in rats. In a six week feeding …
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Dissolution, Formation, and Transformation of the Lead Corrosion Product PbO<sub>2</sub>: Rates and Mechanisms of Reactions that Control Lead Release in Drinking Water Distribution Systems
As one of the major lead corrosion products in lead service lines, lead(IV) oxide: PbO<sub>2</sub>) can react with water through reductive dissolution, resulting in elevated lead concentrations in tap water. Limited data are available on the rates and mechanisms of PbO<sub>2</sub> dissolution. …
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Sources of variability in trace metal bioaccumulation by fish
… Peak Creek, Virginia. Whole-body and tissue concentrations of cadmium, lead, and zinc were determined by atomic absorption spectrophotometry. Variations in metal concentrations within each species were related to duration of exposure (age). Whole-body metal concentrations showed consistent …
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Heavy metal concentrations, aging techniques and population characteristics of mink in Virginia: with a review of the literature on delayed implantation in the mink
Lead, cadmium, zinc and copper concentrations were determined in bone, kidney and liver samples of mink (Mustela vison) trapped during 1981-83 in Virginia. Ages were determined to obtain population information. The literature on delayed implantation in mink was reviewed. Lead and cadmium …
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Understanding Practical Limitations of Lead Certified Point of Use (POU) Filters
… or bottled water. POU filters certified for lead removal have recently been distributed by the hundreds of thousands in communities amid water lead crises, as a temporary solution to protect consumers from elevated water lead levels. This thesis rigorously examines the efficacy of POU lead …
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Influence of Water Chemistry Parameters on the Dissolution Rate of the Lead (II) Carbonate Hydrocerussite
… has focused on the kinetic dissolution of the lead (II) carbonate hydrocerussite (Pb3(CO3)2(OH)2) under four pH conditions (7.5, 8, 9, 10), three dissolved inorganic concentrations (DIC; 10, 20, 50 mg C/L), and three initial hydrocerussite concentrations (10, 20, 50 mg/L) in batch experiments. …
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Role of Water Chemistry in Lead Release during Drinking Water Supply and Augmentation
<p>Lead is a toxic heavy metal and legacy contaminant in drinking water that can be released from lead service lines and lead-containing premise plumbing. Lead concentrations in water are sensitive to changes in water chemistry. The extent of lead release is often driven by the solubility of the …
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The occurrence and toxicology of heavy metals in Chesapeake Bay waterfowl
… and to determine effects of chronic cadmium and lead ingestion on energy metabolism in waterfowl. Concentrations of cadmium, lead, copper, and zinc were measured in 774 livers, 266 kidneys, and 271 ulnar bones from 15 species of ducks obtained from the Chesapeake Bay region. Liver and kidney …
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Effects of low level lead and cadmium on reproduction in Peromyscus leucopus and a study of lead concentration in small mammals from old orchards
Lead and cadmium frequently occur together as contaminants in polluted environments such as roadsides, urban areas, mines, and smelters. Few studies have been conducted to examine the possible interactive effects these metals may have on reproduction of wild species. The first part of this study …
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Metals Distribution in Roadside Soils and Himalayan Blackberries in Victoria, BC, Canada
… across Greater Victoria, BC. Arsenic (As) and lead (Pb) concentrations in soil samples in some areas exceeded BC Contaminated Sites Regulation soil standards, indicating contamination hotspots linked to high traffic. Arsenic and lead concentrations in the berries from high-traffic areas were …
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