Life Sciences Commons^™

Biochar Applications To The Remediation Of Lead And Polychlorinated Biphenyl Contaminated Water, Victory Itua Igberase

Theses and Dissertations

This study investigated the performance of biochar materials as adsorbents to remove Pb and polychlorinated biphenyl (PCB) in aqueous solutions. Batch adsorption and column experiment packed with biochar and geomaterials (pumice) in 1:1 volume ratio was evaluated to address the efficacy of biochar in removing Pb while only batch adsorption was employed for PCB removal with biochar materials. Overall, PT biochars performed the best (42–53 mg g−1) followed by BE biochars (10–32 mg g−1) and AB biochars (17–27 mg g−1) while high temperature biochars were favored in terms of maximum Pb adsorption capacity. Column Pb breakthrough showed similar results, with …

The Determination Of Lead In Blood By Electrothermal Atomization Atomic Absorption Spectrometry : Method Improvements And Clinical Fitness For Purpose For Detecting Elevated Blood Lead Levels, Emily Jean Pacer

Legacy Theses & Dissertations (2009 - 2024)

Lead (Pb) is ubiquitous in the environment and exposure can have adverse health effects even at low concentrations, particularly in young children. Blood lead levels (BLLs) are the best indicator of recent Pb exposure. Based upon data from the NHANES, the Centers for Disease Control and Prevention’s (CDC) blood Pb (BPb) reference value, defined as the 97.5th percentile of children 1-5 years old, was lowered from 10 μg/dL to 5 μg/dL in 2012. According to more recent NHANES data, the 97.5th percentile has decreased to 3.5 μg/dL. If the CDC recommends a further lowering of the BPb reference value, many …

Chemically Induced Phytoextraction Of Lead (Pb) Contaminated Soil By Switchgrass (Panicum Virgatum L.), Austin Gilly

Master of Science in Integrative Biology Theses

Soils contaminated with lead (Pb) from human activities including industrial byproducts create an environmental and human health risk. Phytoextraction through chemical acquisition of Pb in soils offer a potentially cost effective and ecologically driven approach to remediation. Switchgrass (Panicum virgatum L.) is known to have a tolerance for a wide range of heavy metals including Pb. Switchgrass is also able to grow in a wide range of climates. Soil chemistry manipulation, using chelates and plant growth promoters could provide an effective field method for phytoremediation using switchgrass. In this study chemically enhanced phytoextraction using the soil-fungicide Infuse (active ingredient …

Quantifying The Variability In Heavy Metal Concentrations In Produce Grown In Metals-Rich Soil, Harris Lowell Byers

Theses and Dissertations

Childhood Pb exposure is associated with a multitude of poor health outcomes. In food-insecure areas, growing fresh produce in residential backyard gardens is one option for parents; however, commonly grown crops are known to accumulate Pb in consumable tissues when grown in metals-rich soils. A variety of produce representing a continuum of consumable tissues were grown in soils collected from two residential vegetable gardens, a former metal foundry, and commercial topsoil purchased from a local hardware store. The concentrations of heavy metals in crop tissues were measured with custom wavelength dispersive X-ray Fluorescence (WD-XRF) spectroscopy and portable energy dispersive X-ray …

Accumulation And Spatial Distribution Of Lead And Other Trace Elements In Keratinized Tissues : Investigations Based On Analytical Atomic Spectrometry, Mina W. Tehrani

Legacy Theses & Dissertations (2009 - 2024)

Human biomonitoring for toxic metals such as lead (Pb) provides information about absorbed dose from all exposure routes, and is critical for identifying exposed individuals and assessing health risks. Blood Pb and bone Pb are the primary validated biomarkers for assessing short-term and historical Pb exposures, respectively, while non-traditional matrices, including keratinized tissues, can provide complementary exposure information. Hard keratinized tissues – including hair, nails, hooves, and horns – grow incrementally, potentially preserving chemical exposure histories over a span of days to years. Analytical limitations and poor interlaboratory reproducibility, however, have led to debate around the use of human nails …

Lead, Copper, And Iron In University Tap Water, Alison Mclendon

Honors Theses

This study observed concentrations of lead, copper, and iron in university tap water over an eight-week span during and between the summer and fall semesters. First draw and 30s flush samples were taken after overnight stagnation from the Honor House, College Hall, J. B. George Building, and International Center bathrooms and analyzed with an inductively-coupled plasma mass spectrometer (ICPMS). There was no obvious correlation between time in the semester and metal concentrations. Relative iron levels rose and fell at the same time in all buildings, but there was little correlation between buildings for lead and copper concentrations. The Honor House …

Evaluation Of Childhood Exposure To Lead In Community Water Systems In Maine, Nicholas Flavin

Muskie School Capstones and Dissertations

The concentration of lead in Maine’s public drinking water was evaluated from 4,700 first-draw water samples collected from 358 Maine Community Water systems. Samples collected from 2012-2015 were obtained by request from the Maine Center for Disease Control and Prevention’s (MeCDC)’s Drinking Water Program.

Exposure and physiological uptake of lead can be mathematically modelled or predicted based on the amount of lead in “background” sources of contaminated media such as soil, dust, water, air or dietary items; the better the characterization of lead in these media, the better the exposure predictions. To assess childhood lead exposure, EPA recommends using the …

X-Ray Fluorescence For Quantification Of Lead And Strontium In Vivo, Aaron James Specht

Open Access Dissertations

Lead (Pb) is a toxicant well known for its effects on almost every organ system in the body. Pb use in industry has declined since removal of Pb from gasoline, but many developing countries still have significant use of Pb. Exposure to Pb has been linked with diseases causing neurodegeneration and thus have lasting effects long after the initial exposure. Another metal, strontium (Sr), has been linked with bone disease in particular situations and shown to have uses in treating osteoporosis as a supplement. However, there are no studies of the effects of Sr using a meaningful biomarker. The most …

Consequences Of Developmental Lead (Pb2+) Exposure On Reproductive Strategies In Drosophila, Elizabeth Kathleen Peterson

Legacy Theses & Dissertations (2009 - 2024)

Anthropogenic lead (Pb) pollution is ubiquitous in the environment and a risk factor for both human and wildlife health. Pb exposure has the potential to alter reproductive strategies with respect to mate choice and reproductive output. This could be especially deleterious if these changes disrupt adaptive behavioral and reproductive life history strategies. Therefore, the overall aim of this body of work was to examine the consequences of developmental Pb exposure on reproductive strategies, using Drosophila melanogaster as a model system. In all experiments, D. melanogaster were reared from egg stage to adulthood in either control or leaded medium and were …

An Investigation Of The Uptake, Distribution, And Accumulation Of Lead And Other Trace Elements In Caprine Brain Tissues Using Analytical Atomic Spectrometry, Amy Joanna Steuerwald

Legacy Theses & Dissertations (2009 - 2024)

Exposure to toxic elements and dysregulation of essential elements have been implicated in neurodegenerative disorders. Despite the importance of trace elements in neurological function, little is known regarding their uptake and distribution within brain tissues. Even less is known regarding the impact of toxic metal exposure (i.e., Pb) on endogenous metals within the brain.

The Association Of Lead With Cataracts And Vision-Related Problems In Perimenopausal Women, Imogene Drakes

Walden Dissertations and Doctoral Studies

Around the world, women are subject to an earlier incidence of cataracts, have a higher risk for cataracts, and also have a higher risk for other vision-related problems than men. Previous research has indicated an association between endogenous lead stored in long bones and cataracts in men over 60 years of age; however, a similar study in women did not reveal an association. This case control study was conducted to investigate whether perimenopausal mobilization of endogenous lead serves as a possible causative factor for women's generalized vision issues and cataract incidence in particular. Secondary data were gathered from 1,416 women …

My Experience Exploring The Effects Of Lead (Pb +2) Toxicity In Drosophila Melanogaster Using Sociability Interaction Testing And Microarrays At The University Of Puerto Rico-Rio Piedras In San Juan, Puerto Rico, Charlton Diaz

Honors Theses

Lead is an environmental contaminant widely dispersed throughout the world. Exposure to lead causes neurological damage in humans and may be linked to neurodevelopmental pathologies such as attention deficit hyperactivity disorder, antisocial behavior, and autistic spectrum disorders (ASD). Drosophila melanogaster (fruit flies) have been used to understand the behavioral, synaptic, and molecular changes that occur after developmental exposure to lead and to study ASD-associated pathology. Flies were exposed through the mother and until eclosion to either a lead-laced medium or a control corn-based medium and were isolated until the beginning for the behavioral studies. Sociability testing was done using a …