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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Review of the health risks associated with nitrogen dioxide and sulfur dioxide in indoor air

Brauer, Michael, Henderson, Sarah, Kirkham, Tracy, Lee, Kit Shan, Rich, Kira, Teschke, Kay 01 December 2002 (has links)
This review provides a review of scientific literature on the health effects of nitrous oxide and sulfur dioxide that will be used as a background document by Health Canada in its process of reviewing the Exposure Guidelines for Residential Indoor Air Quality. Please note that some tables are included in the full report; others are available as separate files.
32

Air emissions from the Chevron North Burnaby refinery: human health impact assessment

Kennedy, Susan M., Copes, Ray, Henderson, Sarah, Na, Sonia, MacKay, Colin 06 July 2002 (has links)
A risk assessment of the health impact of refinery emissions on the residents of the local community.
33

Development and Evaluation of a Novel Phytotoxicity Assay for the Aquatic Environment

Bengtson Nash, S Unknown Date (has links)
No description available.
34

Urban planning for environmental health: past and present.

Nevins, Frederick, January 1965 (has links)
Thesis--University of Pittsburgh. / Vita. Includes bibliographical references.
35

Urban planning for environmental health: past and present.

Nevins, Frederick, January 1965 (has links)
Thesis--University of Pittsburgh. / Vita. Includes bibliographical references.
36

Role of Diet and Xenobiotics in the Progression of Nonalcoholic Fatty Liver Disease

Li, Xilin 20 July 2018 (has links)
<p> Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease. The spectrum of NAFLD ranges from simple steatosis, to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and potentially hepatocellular carcinoma. Dietary factors and chemical exposure have been associated with the disease progression. In addition, the presence of NAFLD changes the metabolism of drugs and chemicals, which may in turn increase the susceptibility of the liver to xenobiotic induced toxicity. To examine the potential interplay of chemicals on diet-induced NAFLD, three studies were conducted in this dissertation project. In the first study, a mouse model was established that recapitulated the spectrum of liver damages seen in human NAFLD. Using a high fat diet (HFD), steatosis, NASH, progressive fibrosis, and liver tumor formation were produced in mice. Modulations of nuclear receptors involved in metabolism of endogenous and xenobiotic compounds were characterized at various stages of NAFLD. Using this mouse model, a second study examined if perfluorooctanoate (PFOA), a ubiquitous environmental contaminant, modulated the progression of NASH. The results showed PFOA induced hepatic DNA synthesis and liver inflammation were exacerbated in the mice fed with HFD. In contrast, PFOA decreased the severity of hepatic steatosis and fibrosis induced by HFD. To further investigate the mechanisms underlying these observed effects, a third study was performed that analyzed the hepatic transcriptome in liver samples taken from studies 1 and 2. The results of the third study demonstrated that cytokine and chemokine-related genes played important role in the development of both inflammation and fibrosis in NAFLD. Comparing PFOA to vehicle controls in HFD fed mice, PFOA disrupted the lipid homeostasis to favor clearance in the fatty liver, as most of the genes were enriched in the fatty acid oxidation pathways. In summary, this project established and a mouse model of HFD induced NAFLD and characterized the interplay of diet and chemicals in the disease progression. The results from this dissertation also indicated that patients with NAFLD may respond differently compared with healthy individuals. The potential susceptibility of this population to chemically induced hepatotoxicity needs to be carefully considered when assessing risk.</p><p>
37

Meat Consumption, Moral Foundations and Ecological Behaviors Among College Students

January 2013 (has links)
abstract: In recent years, overall consumption of meat products has been decreasing, and at the same time vegetarianism is on the rise. A variety of factors are likely driving changes in consumers' attitudes towards, and consumption of, meat products. Although concern regarding animal welfare may contribute to these trends, growing consumer interest in the roles that production and processing of meat play in terms of environmental degradation could also impact individuals' decisions about the inclusion of meat in their diets. Because these factors could be related to moral attitudes as well, the purpose of this study was to explore the relations among meat consumption, general environmental attitudes, and moral `foundations' of decision-making, including concern about minimizing `harm' and maximizing `care,' as well as issues of `purity' and `sanctity.' A survey was conducted among current college students using the New Ecological Paradigm scale and the Moral Foundations Questionnaire to assess environmental and moral attitudes. A food frequency questionnaire was used to assess meat consumption. Multiple linear regression analyses explored the relations of environmental and moral attitudes with meat consumption, controlling for potential confounding variables. The results showed no significant correlations among meat consumption, environmental attitudes or moral foundations of harm/care and purity/sanctity. / Dissertation/Thesis / M.S. Nutrition 2013
38

Biotransport of organic contaminants and mercury to a coastal food web in the Canadian High Arctic

Choy, Emily Sarah January 2009 (has links)
Seabird-derived nutrients enhance plant abundance in coastal ecosystems, increasing rates of primary productivity, and indirectly increasing consumer populations. However, at Cape Vera, concentrations of contaminants in the sediment of ponds below nesting colonies of northern fulmars (Fulmarus glacialis) are 10 to 60 times higher than in reference ponds (Blais et al. 2005). This pattern suggests that the colony concentrates hexachlorobenzene (HCB), total mercury (THg), and dichlorodiphenyltrichloroethane (DDT) through guano to pond sediments (Blais et al. 2005). It remains unclear whether the effects of these contaminants are localized to the ponds or whether they enter the food chain. This study was designed to determine whether organochlorines and mercury were transferred from a seabird colony to coastal food webs. Contaminant concentrations were measured in primary producers and animals. Nitrogen stable isotopes were used to detect seabird influence. Concentrations of SigmaPCB and SigmaDDT in organisms were high relative to other Arctic areas; however, THg concentrations were similar. Snow buntings (Plectrophenax nivalis ) had SigmaPCB (mean: 168 ng/g ww) and SigmaDDT (mean: 106 ng/g ww) concentrations that surpassed environmental guidelines for protecting wildlife. Biovector transport may be a source of contaminants to certain organisms at Cape Vera.
39

Benthic flux of mercury between sediments and the overlying water in the St Lawrence River near Cornwall, Ontario

Fathi, Mahsa January 2009 (has links)
Sediments, located near Cornwall have been historically contaminated with Hg and other metals by local industries. Cornwall was designated an area of concern by the International Joint Commission (IJC) in 1985. The concentrations of mercury in these sediments exceeded the sediment quality guideline (SQG), of 170 ng g-1 set by Environment Canada for the protection of aquatic biota. To identify the role of these contaminated sediments on mercury dynamics in the river, I measured concentrations of total mercury (THg) and methyl mercury (MeHg) in both the porewater and solid phase of sediment cores and in the overlying water to determine whether sediments are a net source or sink for Hg. A comparison of porewater profiles in June, July and August of 2007 revealed little seasonal variation in MeHg concentrations. I also compared THg and MeHg vertical profiles in sediments with complimentary redox-dependent variables, including sulfate, sulfide, and Fe2+ distributions which showed that zones of active sulfate reduction and Fe reduction have little effect on the distribution of dissolved MeHg in the sediments. THg in sediment cores was related to the sediment accumulation rates by 210Pb radiochronology which showed the history of industrial Hg emissions to the river. MeHg contributed 4% to 100% of the THg in the porewater samples, whereas in the solid phase it contributed less than 1% of the THg. There was little to no diffusion of THg and MeHg from sediments to the overlying water. I have concluded that sediments are a major sink for THg and MeHg to the St. Lawrence River near Cornwall.
40

Environmental Thyroid Endocrine Disruption in Shiner Perch (Cymatogaster aggregata)| An Analysis of Thyroid Glandular Function

Lee, Evan B. 03 November 2017 (has links)
<p> Industrialized and developed urban centers surround the aquatic ecosystem of San Francisco Bay, and are historic and current sources of anthropogenic contaminants to which resident wildlife is exposed and impacted. An indigenous fish species, the shiner perch (Cymatogaster aggregata), was demonstrated to exhibit significant reductions in plasma tetraiodothyronine (T4) concentrations when sampled from highly industrial Oakland Inner Harbor (OAK) as compared with less impacted locations like Redwood City (RED). This study combined histomorphological evaluation of thyroid follicular tissues and characterization of plasma thyroid hormones, T4 and triiodothyronine (T3). Fish from OAK, but not RED, exhibited reduced plasma T4, T3, and total thyroid hormones, changes that were significantly correlated with thyroid glandular changes including reduced follicular colloid sizes. The findings indicate environmental disruption of thyroid hormone biosynthesis and possible thyroid gland compensatory responses (to low thyroid hormone levels) given the reduced colloid volumes.</p><p>

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