Matching Items (202)
Description
In an industrialized world that relies heavily on low cost production and packaging produced without a viable end-of-life strategy, the accumulation of non-biodegradable plastics in the environment and particularly the oceans today is an urgent problem of global proportions. Plastics pose a significant threat to marine mammals due to mistaken ingestion as well as potential release of plasticizers and other chemicals. However, the interactions and consequences of ingestion of oceanic plastics by marine mammals have not been thoroughly studied. In this literature review, information regarding plastic ingestion by marine mammals was compiled to estimate the magnitude of adverse impacts and identify major knowledge gaps. Using comprehensive Boolean search terms in Web of Science of literature published between 1960 and 2020, it was determined that there were large discrepancies in the amount of research conducted among 10 different categories of marine mammals, with cetaceans being the primary focus group of most studies (70.3). In addition, different areas of the world, such as southern Africa, were found to have a disproportionately small number of studies on plastic impacts on marine mammalian life in their surrounding marine waters. Differences were found in the amount of plastics ingested by marine animals and a hypothesis of explaining these observations was formulated, attributing potential ingestion of plastic to the debris resembling different food sources in the mammals’ diets as well as different feeding mechanisms.
ContributorsFredette-Roman, Cassidy (Author) / Polidoro, Beth (Thesis director) / Rolsky, Charles (Committee member) / Halden, Rolf (Committee member) / School of Life Sciences (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
Historic mining of heavy metals (HMs) in Arizona has resulted in the creation of abandoned mine lands (AML), which can become sources of contamination and possible risks to human health. The goals of this work were to support the creation of databases useful for AML risk assessment, and to use Patagonia, Arizona as a case study to assess the relationship between water quality and proximity to AML sites. The of risk assessment database for AML contains risk calculation results from published national and international studies, with 4,667 data points from 75 unique papers. From the data visualization, 18 environmental contaminants, Cd, Co, Cr, Cu, F-, Fe, Hg, Mn, NH4+, Ni, Pb, Sb, Se, Tl, V, W, and Zn, had data points with non-carcinogenic health risks above commonly used health risk benchmarks. Comparatively, of the studies that computed a carcinogenic health risk, the seven contaminants evaluated (As, Cd, Cr, Cr(VI), Hg, Ni, Pb) all had data exceeding a 10-6 cancer risk (CR) reference value. In Patagonia, Pb, Cu, and Zn were measured at higher concentrations when closer to AML sites than at points downstream. These findings were corroborated by a comparison of contaminant concentrations across the watershed area, which additionally suggested a higher surface water solubility of HMs such as boron and barium.
ContributorsTerrones, Wesley (Author) / Hamilton, Kerry (Thesis director) / Halden, Rolf (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainable Engineering & Built Envirnmt (Contributor)
Created2024-05