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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.
111

Samband mellan medelhavskost, fisk- och skaldjursintag samt tjock- och ändtarmscancer : En litteraturstudie

Saleh, Nadja, Jannebring, Frida January 2021 (has links)
Background: Colon- and rectalcancer is the third most common cancer form worldwide. Previous research shows that unhealthy eating habits has a connection as a causal factor for cancer and that it's possible to prevent a third of all cancer cases with a changed diet. Medeiterranian diet consist of a high intake of seafood and is believed to be a healthpromoting diet. It is also a lower prevalence of cancer among the mediterranian coast. A WHO-report shows that about 1,5 - 2 % of all cancer cases have a connection to environmental pollution and nowadays most waters contains environmental pollution. Aim: The aim of this study was to update the state of knowledge between the mediteranian diet, it's frequency of seafood intake and colon- and rectal cancer in adults.  Method: A literature review was used to answer the aim. The article search was made in PubMed where 12 articles were chosen and passed the quality review. Results: There was an ambiguously connection between mediterranean diet and the incidence of colon- and rectalcancer as research did not agree on whether there was a connection or not and the amount of studies used was limited. Some studies believe that there’s a significant connection while others believe that there isn’t any connection. The study partly confirms the connection between the intake of seafood and the prevalence of colon- and rectalcancer where they who ate according to the WHO-recommendations possibly had a smaller risk of developing colon- and rectalcancer compared to those who ate either more or less seafood than recommended.  Conclusion: More research is needed in the field to ensure possible connection. / Bakgrund: Tjock- och ändtarmscancer är den tredje vanligaste cancerformen världen över. Tidigare forskning visar att ohälsosamma matvanor har en koppling som orsak till cancer och att det genom att förbättra kostvanorna är det möjligt att förebygga en tredjedel av alla cancerfall. Medelhavskost med sitt höga intag av fisk- och skaldjur anses vara en hälsofrämjande kost och kring medelhavskusten är det en minskad förekomst av dödsfall orsakade av cancersjukdom. En rapport av WHO visar att ca 1,5–2 % av alla cancerfall har kopplingar till kemiska föroreningar och de flesta vatten innehåller numera kemiska föroreningar.  Syfte: Syftet med studien var att uppdatera kunskapsläget för samband mellan medelhavskost, dess intag av fisk- och skaldjur och tjock-och ändtarmscancer hos vuxna över 18 år. Metod: En litteraturstudie användes för att besvara syftet. Artikelsökningen skedde i PubMed där 12 artiklar valdes ut och klarade kvalitetsgranskningen.  Resultat: Ett tvetydigt samband fanns mellan medelhavskost och förekomsten av tjock- och ändtarmscancer då forskningen inte var överens om huruvida det finns ett samband eller inte samt att det var en begränsad andel studier. Vissa studier menar att det finns ett signifikant samband medan andra menar att det inte finns något samband.   Studien stärker till viss del sambandet mellan fisk- och skaldjurintag och förekomst av tjock- och ändtarmscancer där de som åt fisk enligt WHO´s nuvarande rekommendationer möjligen hade en minskad risk för tjock- och ändtarmscancer jämfört med de som åt antingen mer eller mindre. Slutsats: Mer forskning behövs inom området för att säkerställa eventuella samband.
112

Creative Solutions for Environmental Issues in Morocco and the Mediterranean Region

Johnson, Robert E. 02 November 2018 (has links)
No description available.
113

An assessment of the foliar heavy metal contamination in the Palabora Mining region

Kendall, Louise 07 February 2014 (has links)
This study was conducted in order to ascertain the levels of elemental concentrations in tree leaf and leaf litter samples collected in two areas at the Rio Tinto Palabora Mining Company. The elemental content in leaves from trees growing in the smelter plume deposition area and in the area around the main copper tailings was determined. The study will provide further insight into the extent of the contamination in these areas exhibiting high visible contamination and potentially high impacts. Sampling was carried out in November 2008, April 2011 and November 2011. A total of 135 leaf samples from three tree species (Lonchocarpus capassa, Colophospermum mopane and Euclea divinorum) were analysed, of which 74 samples were from the smelter plume deposition area, 51 samples were from the main copper tailings seepage area and 10 were leaf litter samples. Elemental concentrations in the leaves were measured and total percentages of C, H, N and S were determined. The highest concentrations of elements were found in the leaf litter samples from the smelter plume deposition area in 2008, with the average concentrations being: 1.57 ug/g of Ni, 9.44 ug/g of Bi, 16.3 ug/g of Pb, 110 ug/g of Mn, 122 ug/g of Ti, 483 ug/g of Al, 1463 ug/g of Cu, 2812 ug/g of S and 5611 ug/g of Fe. Element concentrations in trees varied with the tree species, higher levels were found in L. capassa and E. divinorum leaves than in C. mopane leaves. In the leaves analysed from the smelter plume deposition area the element concentrations decreased in the order S > Fe > Al > Cu > Mn > Ti > Pb > Ni > Bi. In the leaves from the Cu tailings seepage area the element concentrations decreased in the order S > Fe > Mn > Cu > Al > Ti > Ni > Bi > Pb. Significant differences were observed for the concentrations of certain metals and elements in the leaves between the three years (2008 to 2011) and between seasons (April to November). The concentrations generally decreased from 2008 to 2011and from April to November 2011. The findings from this study indicate that both of the high impact areas investigated are contaminated by the mining activities, with trees growing in the smelter plume deposition area showing higher contamination than trees in the Cu tailings seepage area. The leaves and leaf litter sampled in this study can be used as bioindicators of the contamination in this region.
114

Mopane worms (Imbrasia belina) as indicators of elemental concentrations in a trophic system

Pillay, Sumeshni 20 January 2016 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, South Africa, in fulfilment of the requirements for the degree of Master of Science. August 2015 / The impacts of mining on the environment continue to pose a risk in many regions. Palabora Mining Company (PMC) situated in Limpopo Province, South Africa is of environmental interest because of its shared border with South Africa’s Kruger National Park. PMC generates both gaseous (emitted from the reverberator (Rev; also known as a smokestack)) and solid (stored in the tailings storage facility (TSF)) waste products. To assess possible pollution to the environment from PMC’s activities, two study species were chosen, the Anomalous Emperor Moth (Imbrasia belina [Westwood 1849] (Lepidoptera: Saturniidae)) and its primary host the mopane tree (Colophospermum mopane [Kirk ex Benth.]). In addition to these two species being abundant on and around PMC, the mopane moth and all stages of its lifecycle are a source of food to many animals, and mopane caterpillars are a valuable source of food and income to many people in this region. Mopane caterpillars and mopane leaves were collected from on and around PMC at varying distances from the reverberator and TSF, as well as from several control sites. The elemental contents of these samples were analysed for 25 elements, focusing on copper, iron, aluminium, silicon, arsenic, zinc, nickel, lead, mercury, chromium and cadmium. In addition to these elemental analyses, the carbon and nitrogen isotopic compositions of these samples as well as caterpillar headwidth, body mass and mandible wear were also measured to assess the impacts of elemental concentrations on caterpillar growth. No mopane caterpillars were found at the two reverberator sites closest to the reverberator itself. Overall these two reverberator sites appear to be most contaminated, as concentrations of 14 of the 25 elements measured were highest in the mopane leaves from these two sites. The copper concentrations at these two sites, 42 ppm and 29 ppm respectively, were at levels that are considered toxic to plants. Assuming that 10 mopane caterpillars (each weighing 5g) are consumed a day, copper concentrations in the mopane caterpillar bodies across sites (between 8 ppm and 12 ppm) would equate to a maximum of 0.56 mg.day-1, which is less than the recommended maximum intake level of 10 mg.day-1 suggested for humans. As there was little difference between sites in terms of leaf carbon and nitrogen composition, elemental concentrations do not appear to be affecting the nutritional content of the leaves. This would suggest that caterpillar growth is not affected by elemental concentrations at sites where they can survive. Similarly, caterpillar headwidths did not vary greatly between sites for each instar, suggesting that elemental concentrations are not affecting mopane caterpillar growth. Headwidths and mandible wear were found to be useful tools to age mopane caterpillars within an instar, and can be used in future to ascertain if mopane caterpillars are bioaccumulating elements or eliminating excess elements when they moult.
115

MICROPLASTICS IN BIOTIC AND ENVIRONMENTAL SAMPLES TAKEN NEAR TWO MUNICIPAL WASTEWATER TREATMENTS PLANTS IN THE GRAND RIVER, ONTARIO

Weir, Ellie January 2021 (has links)
Microplastics are present in municipal wastewater treatment plant (WWTP) effluents; however, it is unclear whether these contaminants are ingested by biota living downstream of these outfalls. This study examined whether microplastic levels in caged biota, resident fish, and environmental samples were elevated near the Waterloo and Kitchener WWTP outfalls along the Grand River in the fall of 2019. Amphipods (Hyalella azteca), fluted-shell mussels (Lasmigona costata), and rainbow trout (Oncorhynchus mykiss) were caged at one upstream reference site and two impacted sites downstream of the Kitchener WWTP for 14 (amphipods and trout) or 28 (mussels) days. Rainbow darter (Etheostoma caeruleum) were collected using a backpack electrofisher from 10 sites up and downstream of both the Kitchener and Waterloo WWTPs, along with surface water and sediment samples. Whole body Hyalella, fish digestive tracts, and fluted-shell mussel tissues (hemolymph, digestive glands, and gills) were digested in 20% potassium hydroxide. Environmental samples were processed using filtration and density separation, then visual identification of microplastics was done. Elevated particle counts were found in rainbow trout digestive tracts at the Kitchener outfall site, compared to the upstream reference and downstream farfield sites. Additionally, particle concentrations in sediment were significantly higher at the Waterloo outfall, compared to all other sites (except for one upstream location). However, whole Hyalella, fluted-shell mussel tissues (hemolymph, digestive glands, and gills), digestive tracts of rainbow darter, and surface waters did not show elevated counts downstream of these discharges. Across all samples, fibers were the most common morphology, and blue and clear particles were prevalent in samples collected near WWTPs. Overall, these findings suggest that the Kitchener and Waterloo WWTPs could be important sources of particles to the Grand River, adding to our understanding of the fate of this contaminant in freshwater ecosystems. / Thesis / Master of Science (MSc)
116

Association Between Smoking Status and Homocysteine Levels and Possible Effect Modification by Cholesterol and Oestradiol

Omoike, Ogbebor Enaholo, Paul, Timir K., Ridner, Stanley L., Awasthi, Manul, Harirforoosh, Sam, Mamudu, Hadii M. 17 February 2020 (has links)
Introduction: This study aimed to examine the association of smoking status with homocysteine levels and to determine whether the association is modified by oestradiol or cholesterol. Methods: Data (N = 4580) were obtained from National Health and Nutrition Examination Survey 2003–2004 with analysis done in 2018 on adults aged ≥20 years. The outcome was homocysteine; smoking status was the exposure variable and categorized as current, former or never smoker. Generalized linear models were used to examine the associations between smoking status and homocysteine levels, while assessing the impact of oestradiol and cholesterol. Results: After adjusting for age, sex, ethnicity, education and income level, homocysteine levels did differ by smoking status ((current smokers versus never smokers: β: 0.18 CI: 0.00, 0.36), (former smokers: β: 0.10 CI: –0.09, 0.28)). The addition of oestradiol as an interaction term in adjusted models was associated with a 16.6% increase in homocysteine levels when compared to models without the interaction term. Oestradiol but not cholesterol did moderate the association between smoking status and homocysteine levels. Discussion and conclusions: Homocysteine levels did differ across smoking status after adjusting for confounders. Oestradiol did moderate the relationship between homocysteine and smoking status.
117

Urban snö och dess miljöeffekter : En enkätstudie om hur svenska kommuner förhåller sig till miljöskydd och nuvarande lagstiftning kopplade till kommunala snödeponier / Urban snow and it’s environmental effects; : a survey study on Swedish municipalities snow deposits and their application of environmental protection and current regulations

Crawford, Cecilia January 2023 (has links)
Snow handling practices are managed by Swedish municipalities, and urban snow is usually removed to be placed at a central or local snow deposit. Snow deriving from urban areas can contain environmental pollutants in various extents. Through atmospheric deposition, traffic emissions and road maintenance strategies, urban snow accumulates pollutants such as metals, organic and inorganic compounds, which in turn spread to receiving waters and soil through the meltwater. During wintertime, snow is ploughed and removed from highways and roads to insure safe conditions for drivers, cyclists, and pedestrians. This study has analyzed Swedish municipalities snow handling strategies regarding current environmental law and degree of environmental protection on land-based snow deposit sites. Through a semi-qualitative web survey sent to all 290 Swedish municipalities, respondents were asked questions regarding the organization’s snow handling strategies and environmentally protective actions within their snow deposits. The results of this study showed that the use of snow deposits varies in different regions, and that most snow deposits are not equipped with any technical infrastructure to mitigate eventual environmental effects on the local environment. Environmental management in the form of systematic sampling of snow, soil, groundwater and receiving waters are found to be rare, which sequentially makes it difficult for municipalities to investigate the possible local environmental effects caused by depositing snow. In conclusion, environmental investigation and protection at snow deposit sites can be crucial to hinder further local pollution in some areas, but is as of yet not constantly executed by current practices.
118

Natural disaster, catastrophe and environmental protection in Vietnam: Editorial / Thiên tai, thảm họa và bảo vệ môi trường tại Việt Nam

Chu, Thi Thu Ha 24 August 2017 (has links)
During development process, especially under the impact of climate change, natural disaster is one of the major challenges. In fact, the degree of devastation of natural disasters such as storms, floods and landslides are enormous, causing severe damage to people, property and environmental degradation. These natural disasters increasingly occurring more frequently in the last 20 years claimed the lives of many people. Unlike natural disasters, catastrophes are often related to human factors. Thus, the policy on response, treatment should also take into account the legal process in order to ensure that the principle of the polluter must bear responsibility after incidents and catastrophes. The catastrophe is a serious disruption of a community activity, causing loss of life, environment and material on a large scale. Normally catastrophe is beyond the capacity of affected communities to cope with, if only sources power of that community is used. The impact of economic - social development, climate change and natural disasters, environmental pollution situation, the capacity to respond to environmental incidents ... has been the pressure and challenge to Vietnam. / Trong quá trình phát triển, đặc biệt dưới tác động của biến đổi khí hậu, thiên tai là một trong những thách thức lớn. Trong thực tế, mức độ tàn phá của thiên tai như bão, lũ và sạt lở đất là rất lớn, gây thiệt hại nặng nề về người, tài sản và gây suy thoái môi trường. Những thảm họa do thiên tai gây ra đang ngày càng xảy ra thường xuyên hơn trong 20 năm qua, cướp đi sinh mạng của nhiều người. Khác với thiên tai, thảm họa môi trường thường liên quan đến yếu tố con người. Do đó, chính sách ứng phó, xử lý cũng cần tính đến các quá trình pháp lý nhằm đảm bảo nguyên tắc người gây ô nhiễm phải chịu trách nhiệm sau sự cố, thảm họa. Thảm họa là sự phá vỡ nghiêm trọng hoạt động của một cộng đồng, gây ra những tổn thất về người, môi trường, vật chất trên diện rộng. Thảm họa thường vượt quá khả năng đối phó của cộng đồng bị ảnh hưởng nếu chỉ sử dụng các nguồn lực của cộng đồng đó. Tác động của sự phát triển kinh tế - xã hội, biến đổi khí hậu và thiên tai, thực trạng ô nhiễm môi trường, năng lực ứng phó với sự cố môi trường… đã và đang là những áp lực và thách thức không nhỏ với Việt Nam.
119

THE EFFECT OF WASTEWATER EFFLUENT ON THE GUT CONTENT MICROBIOME OF RAINBOW DARTER (ETHEOSTOMA CAERULEUM)

Restivo, Victoria January 2020 (has links)
MSc Thesis - The effect of wastewater effluent on the gut microbiome of rainbow darter / The microbiome plays an important role in host physiology and can be influenced by species, diet, and environment. Municipal wastewater effluent contains a mixture of chemicals including antibiotics and antimicrobials that may affect the gut microbiome of fish living downstream of these discharges. Thus, this study examines the effect of wastewater treatment plant (WWTP) effluent on the gut microbiome of wild rainbow darter (Etheostoma cearuleum), and examines how the gut microbiome of wild fish changes in the lab. Fish were collected from sites upstream and downstream of 2 major WWTPs along the central Grand River and gut contents were aseptically sampled. After extracting gDNA, nested PCR of the V3-V4 region of the 16S rRNA gene, and Illumina sequencing were performed. The gut microbiome of exposed fish had increased bacterial diversity and was dominated by Proteobacteria, which has been linked to altered health outcomes in mammals. Next, rainbow darters were collected from a reference site on the Grand River. Fish were sampled in the field, after a 14 day lab acclimation, and after a 28 day exposure to environmental stressors (WWTP effluent or triclosan, an antimicrobial found in WWTP effluent). Surprisingly, there were no changes in the microbiome after exposure to environmental stressors. Major changes were observed between the field and laboratory fish suggesting that environment and diet are important factors influencing the gut microbiome. Changes in the gut microbiome continued up to 42 days in the lab, indicating longer acclimation periods may be needed. This study showed that effluents altered the gut microbiome of fish in the field, but not in the laboratory for unknown reasons. Laboratory studies indicated that transitioning to a new environment may require greater than 14 days before achieving a stable microbiome. / Thesis / Master of Science (MSc) / Wastewater is the largest source of pollution affecting Canada’s aquatic ecosystems; effluents contain antibiotics and antimicrobials that can affect fish and other aquatic life. The gut microbiome of fish is influenced by host species, its diet, and the environment, and thus contaminants released via wastewater effluents may alter the gut microbiome of fishes in receiving waters. This study found that the gut microbiota of rainbow darter fish exposed to wastewater effluents in the central Grand River (Waterloo/Kitchener, Ontario) were dominated by Proteobacteria and had increased diversity. Wild fish transitioned to the lab were dominated by Firmicutes and had decreased bacterial diversity in the gut compared to those in the wild. Altogether, these results suggest that wild fish exposed to wastewater effluents had altered gut microbiomes; transitions to new environments and laboratory acclimation periods are important considerations when studying the fish gut microbiome.
120

Capsella bursa-pastoris (L.) Medic. as a biomonitor of heavy metals

Aksoy, A., Hale, William H.G., Dixon, Jean M. January 1999 (has links)
No

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