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Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in marshy soils and sediments within Warri and its environs, NegeriaBayowa, Adejoke Victoria 11 1900 (has links)
Marshy soil and sediment samples were collected during dry and rainy seasons within Warri, and Agbarho, 20km away as control. Levels of 16 USEPA priority Polycyclic Aromatic Hydrocarbons PAHs were determined using GC-FID. Source prediction analysis was also done. The study was in Niger Delta region, Nigeria from January to March and June to August 2012 in dry and wet seasons. Benzo(a)pyrene had highest total concentration of 3.302mg/kg and mean value of 1.651mg/kg in dry season soil samples. However, sediment samples had highest levels for total concentration of PAHs of 19.362mg/kg and mean of 4.840mg/kg for both dry and rainy seasons within Warri. PAHs concentration was higher in dry than rainy seasons for soil and sediment samples. Source prediction analysis revealed that PAHs in sediments for dry season were pyrolytic while rainy seasons were petrogenic sources. For soils, the dry season was mixed sources while the rainy season was petrogenic. / Environmental Science / M. Sc. (Environmental Science)
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An assessment of heavy metal pollution near an old copper mine dump in Musina, South AfricaSingo, Ndinannyi Kenneth 24 October 2013 (has links)
Heavy metal pollution in water and soil is a serious concern to human health and the
associated environment. Some heavy metals have bio-importance but the bio-toxic effects of
many of them in human health are of great concern. Hence, there was a need for proper
understanding of the concentration levels of these heavy metals in ground water and soil
around the community residing in the vicinity of the defunct mine. Mining has become
prominent in this area because of the existence of copper lodes, veins and veinlets. It was
therefore necessary to assess these selected metals associated with copper mining as their
concentration has a tendency to affect the environment and human health. The objective of
this study was to establish the levels of lead (Pb)-zinc (Zn)-copper (Cu)-arsenic (As)-nickel
(Ni) metals in ground water and soil associated with an old copper mine in the vicinity of the
township and to compare them with the South African and international standards in order to
safeguard the health of the community using such water for drinking purpose.
Clean sampling plastic bottles were used to collect water from five water boreholes being
used at present. Water samples were filtered using membrane filtration set LCW (0.45 μm).
The samples were digested sequentially with different procedures for the total metal
concentration. Concentrations of four metals commonly associated with Cu mining were
examined at five different water boreholes which are used for drinking and industrial
purposes. Flame Atomic Absorption Spectrophotometer (Perkin Elmar S/n 000003F6067A,
Singapore) was used to analyze metals in water samples at Eskom Ga-Nala Laboratory: pH,
electrical conductivity and turbidity were analyzed using an auto titrator meter (AT-
500,Japan), conductivity meter (Cole-parmer® YO-19601-00) and turbidity meter (AL 250TIR,
Agua lytic, German) respectively.
Soil samples were collected from the selected areas where human health is of a serious
concern, and a hand held auger drill was used to recover samples, while shovels were used
to prepare the sampling area. The samples were sieved up to 63.0 μm particle size and
digested with aqua-regia. Flame Atomic Absorption Spectrophotometer (Model: AA400;
Year: 2008; Manufacturer: Perkin Elmer; Germany; Serial no: 201S6101210) was used at
the University of Venda Laboratory to analyze soil from the study area for possible heavy
metal contamination due to the defunct Cu mine in the area.
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The results showed variation of the investigated parameters in water samples as follows: pH,
6.0 to 7.51; EC, 70.0 to 96.40 μS/cm and turbidity, 1.05 to 4.56 NTU. The mean
concentration of the metals increased in the followed order: Pb<Cu<As<Ni. Ni is the most
abundant in the ground water determined with value of (6.49 μg/g). The observations have
confirmed that most ground water contains an appreciable quantity of Ni. The mean value of
As in water is (4.20 to 4.84 μg/g), Pb and Cu have (2.13 to 2.58 μg/g) and (1.52 to 2.52 μg/g)
respectively. For soil samples, the mean concentration of the metals increased in the
following order: Pb<Cu<Zn<As<Ni. Pb ranged from (0.023 to 0.036 μg/g) followed by Cu
(0.28 to 0.45 μg/g) then Zn (0.026 to 0.053 μg/g), the mean range of As in soil ranged from
(0.054 to 0.086 μg/g). However, some studies show much higher contamination of As from
the natural sources and Ni with (0.057 to 0.144 μg/g) lastly. Accumulation of heavy metals in
soil is of concern due to their toxic effects on human and animals.
The quality of ground water from the five boreholes studied was satisfactory with turbidity
(T), electrical conductivity (EC) and heavy metals (HM’s) below the WHO limit. The water
therefore may, according to the WHO Standards be safely used as a drinking water. The
concern lies on pH which was slightly (0.5) below the standard. There is a serious need to
monitor the ground water which is now used for drinking purposes.
This study revealed that heavy metal pollution in soil from the abandoned Cu mine in Musina
is a threat to the health of the community. Although pollution was between medium and low
in the contamination index, it is therefore important for the Musina Municipality or mine
owner of Musina (TVL) Development Co Ltd copper mine to advocate possible remedial
actions which will safeguard the environment and human health.
The tailing at Musina’s old Cu mine have high pH and they lack normal soil stabilization
processes, as a result the tailing does not develop a good plant cover. Pollution of the
ground water resources is also evident in the study area where there is seepage or ingress
of polluted water to the underground aquifers. Small-scale mining in Musina is causing
further degradation to the environment but it supports the South African Waste Hierarchy by
promoting the reuse and recycling of the tailing and mine dumps for the production of bricks.
Mine workers are exposed to the above mentioned toxic heavy metals daily. Medicine will
not help stop the poisoning. The only way to stop the metal poisoning is to stop being
exposed to the heavy metals. / Environmental Sciences / M. Sc. (Environmental Management)
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Trace organics pollution in the aquatic environmentWong, Wang-wah., 黃宏華. January 1993 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
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Toxicity assessment of engineered nanoparticles / Evaluation de la toxicité de nanoparticules de synthèsePu, Yubing 20 January 2017 (has links)
L'objectif de cette thèse est d'améliorer la compréhension de la toxicité de diverses nanoparticules de synthèse (ENPs) pour l'homme et l'écosystème. Les travaux réalisés s’appuient sur la combinaison de données toxicologiques et d’un modèle environnemental - le modèle USEtox. En tant qu'élément important de l'évaluation de l'impact du cycle de vie, le facteur de caractérisation (CF) a été utilisé, dans ce travail, comme indicateur de toxicité pour l'homme et l'écosystème. Pour avoir accès aux courbes dose-réponse et à différentes données toxicologiques, des expériences in vitro ont été réalisées en exposant des neutrophiles porcins fraîchement isolés à trois types de nanoparticules de synthèse. Les modifications morphologiques, les taux de mortalité et la chimioluminescence des neutrophiles ont été évaluées. De plus, pour estimer le temps de persistance des nanoparticules de synthèse dans l'écosystème eau douce, un modèle basé sur la science des colloïdes a été développé. Il prend en compte les comportements spécifiques des nanoparticules de synthèse et inclut des recommandations sur le choix des paramètres hydrologiques régionaux. Enfin, une enquête documentaire exhaustive a été réalisée pour recueillir les données écotoxicologiques de diverses nanoparticules de synthèse. Dans le cadre du modèle USEtox, le CF toxicologique non cancérogène pour cuivre NPs et les CF écotoxicologiques pour 14 ENPs sont recommandés. Ces valeurs des CF pourraient être utiles à l'avenir pour évaluer les impacts environnementaux des produits contenant des ENPs. / The objective of this thesis is to improve understandings of toxicity of various engineered nanoparticles (ENPs) to human and ecosystem. It is realized via coordinating toxicological data and a scientific consensus environmental model -- the USEtox model. As an important element in life cycle impact assessment, the characterization factor (CF) is employed as a toxicity indicator for human and ecosystem in this work. To obtain the firsthand dose-response phenomena and human toxicological data, in vitro experiments have been conducted by exposing freshly isolated porcine neutrophils to three kinds of ENPs (i.e. copper, nickel and aluminum oxide nanoparticles). The morphologies, mortality rates, and chemiluminescence, of neutrophils are observed or monitored. Additionally, to estimate the persistence time of ENPs in freshwater ecosystem, a fate model on the basis of colloid science is developed. It takes nano-specific behaviors of ENPs into account and includes recommendations of regionalized hydrological parameters. Finally, a comprehensive literature survey is accomplished to collect the ecotoxicological data of various ENPs. Under the framework of USEtox model, the non-carcinogenic human toxicological CFs for Copper NPs and the ecotoxicological CFs for 14 ENPs are recommended. These CF values could be useful in the future when evaluating the environmental impacts of products containing ENPs.
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Improvements in the dosimetric models of selected benthic organismsCaffrey, Emily Amanda 02 October 2012 (has links)
The International Commission on Radiological Protection (ICRP) has modeled twelve
reference animal and plant (RAP) species using simple geometric shapes in Monte���Carlo
(MCNP) based simulations. The focus has now shifted to creating voxel phantoms of
each RAP to advance the understanding of radiation interactions in nonhuman biota.
The work contained herein presents results for the voxel phantom of the Dungeness crab,
Metacarcinus magister, the Sand Dab, Limanda limanda, and the brown seaweed, Fucus
vesiculosus, and details a generalized framework for creating voxel phantoms of the other
RAPs. Absorbed fractions (AFs) for all identified organs were calculated at several
discrete initial energies: 0.01, 0.015, 0.02, 0.03, 0.05, 0.1, 0.2, 0.5, 1.0, 1.5, 2.0, and 4.0
MeV for photons and 0.1, 0.2, 0.4, 0.5, 0.7, 1.0, 1.5, 2.0 and 4.0 MeV for electrons. AFs
were then tabulated for each organ as a source and target at each energy listed above.
AFs whose error exceeded 5% are marked with an underline in the data tables; AFs
whose error was higher than 10% are shown in the tabulated data as a dashed line. The
AF���s were highly dependent on organ mass and geometry. For photons above 0.5 MeV
and electrons above 0.2-0.4 MeV a nontrivial amount of energy escapes the source organ. / Graduation date: 2013
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Site specific evaluation of urban brownfields contaminated with trace metalsMurray, Patricia, 1964- January 1999 (has links)
This thesis is part of a broader project that examines three different approaches to evaluating trace metal contamination in urban brownfields: the measure of total soil metals; calculating bioavailable metals; and the use of species as bioindicators of trace metals in soils. Chapter 1 discusses the problems inherent in each approach such as; inconsistent results due to differences in techniques, extrapolation from laboratory to field, and the influence of species differences and environmental conditions. Chapter 2 is a site description measuring biodiversity, community structure and activity of three urban brownfields. The site description was used to select organisms that were subsequently evaluated for their usefulness as bioindicators of trace metals (chapter 3). Of the three plant species used (dandelion, bladder campion, and chicory), dandelion has the possibility of being a suitable bioindicator of Cd, Ni, and Zn, while bladder campion may be suitable for evaluating Cd, Ni, Pb, and Zn.
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Quantification of the human health risks associated with kerosene use in the informal settlement of Cato Manor, Durban.Muller, Elizabeth Anne. January 2001 (has links)
The main objective of this study was to investigate the application of the United States Environmental Protection Agency (US EPA) human health risk assessment framework for quantifying the adverse human health effects of exposure to inhaled kerosene pollutants in the South African context. The study was based in the informal settlement of Cato Crest in Cato Manor, Durban. This dissertation includes a theoretical review of the environment/health Relationship, the US EPA health risk assessment approach, it's history, and the health effects of kerosene combustion products. Chapter three outlines the methodology for the study, detailing how time-activity pattern data and air quality results were collected from the community of Cato Crest. Chapter four presents the results of the health risk assessments conducted for nitrogen dioxide, benzene and toluene exposure - using both local and US EPA exposure values in the health risk assessments. A critical evaluation of the US EPA human health risk assessment framework in the South African context is provided in chapter five. The results of the study revealed that a 1-hour exposure to the nitrogen dioxide concentrations measured in Cato Crest would not present any adverse health effects. A 24-hour exposure to
NO2 using US EPA default exposure values provided a slight possibility of adverse health effects being experienced in sensitive individuals in some houses. 24-Hour exposure to NO2 using local exposure values could result in both sensitive individuals and even some healthy individuals experiencing adverse health effects in all houses. Potential adverse health effects include coughing, wheezing, chest tightness, broncho-constriction and increased airway resistance. Sensitive individuals include those with asthma or other respiratory diseases. Exposure to 24hour benzene concentrations (using US EPA default exposure values) is not likely to result in individuals experiencing adverse health effects. Exposure to the same benzene concentrations at
local exposure times will cause potential adverse health effects in sensitive individuals. Sensitive individuals are those with respiratory ailments and blood diseases or disorders. Exposure to monitored toluene concentrations over a 24-hour period (using both US EPA default exposure values and local exposure values) is unlikely to result in adverse health effects being experienced by any individuals. The US EPA human health risk assessment framework is seen as applicable to South Africa where developed areas are concerned (as these areas are quite similar to North American populations). In areas of South Africa that are considered less developed or undeveloped, local conditions need to be substituted into health risk assessments where
possible. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
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'Stink, maar uit die verkeerde rigting' : pollution, politics and petroleum refining in South Africa, 1948-1960.Sparks, Stephen. January 2004 (has links)
This dissertation analyses the history of the politics of pollution and petroleum refining in South Africa during the first decade of Apartheid, focusing on the country's first two oil refineries, both of which were built by multinational oil companies in Durban in the 1950s and 60s. It traces the origins of the development of environmental regulation in relation to oil refinery pollution. The dissertation outlines the development of a sense of disillusionment caused by the persistence of pollution problems associated with petroleum refining in the face of failed attempts at technological and expert interventions. The study identifies the existence of a civic culture amongst Bluff residents founded on ratepayer and landowner identities, through which they were able to exercise considerable purchase on the local State. Ultimately, the story of how two petroleum refineries ended up in the midst of residential communities in south Durban's represents a reiteration of the importance of race to the development of local urban landscapes during Apartheid. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2004
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Estudo de parâmetros relevantes da poluição da água por efluentes de lavanderia e tinturaria industriais em um rio não perene / Study of relevant parameters of water pollution by effluents from industrial laundry and dry cleaning in a river is not perennialRoberto César Mendes Marques dos Santos 10 June 2008 (has links)
O objetivo deste trabalho foi avaliar as condições para modelagem da poluição de um rio não perene por efluente de lavanderia e tinturaria industriais. Foram coletadas amostras do efluente tratado no município de Toritama, Pernambuco e do rio Capibaribe a montante e a jusante do lançamento desse efluente. Foram analisados: temperatura, pH, cor, turbidez, sólidos sedimentáveis, condutividade elétrica, nitrogênio (amônia, nitrito e nitrato), oxigênio dissolvido, demanda química de oxigênio, demanda bioquímica de oxigênio, contagem padrão de bactérias e coliformes totais e termotolerantes. Os resultados de temperatura, pH, cor, turbidez e sólidos sedimentáveis do efluente industrial não interferiram na qualidade da água do rio Capibaribe. A condutividade elétrica elevada devido ao excesso de sais existentes no efluente de lavanderia e tinturaria industriais foi um dos parâmetros responsável pelo desequilíbrio ecológico. A ausência de oxigênio dissolvido nesse efluente tratado foi um fator que desfavoreceu a autodepuração da água. O lançamento de matéria orgânica na água do rio Capibaribe, com baixa concentração de oxigênio dissolvido foi confirmado pelos valores elevados da demanda bioquímica de oxigênio. Os valores elevados de contaminação bacteriológica detectados também contribuíram para a poluição da água. A não perenidade do rio no período de estiagem e a dificuldade de determinar a vazão devido à existência de barragens no trecho analisado, foram fatores que dificultaram o desenvolvimento de uma metodologia para identificar o tipo de modelo matemático que deveria ser aplicado no referido estudo. A ocupação desordenada da região por Empresas desse segmento nas margens do Rio e a falta de saneamento básico nessa região foram os fatores que caracterizaram a poluição difusa. Então, a construção de um modelo para simular o impacto ambiental por efluente de lavanderia e tinturaria industriais foi inviável. As condições de investigação não ofereceram recursos mínimos necessários para a modelagem da água do rio Capibaribe em Toritama. Há necessidade de um levantamento de dados em pequenos trechos do Rio para que os resultados experimentais possam ser avaliados e interpretados, visando à elaboração de um modelo que possa auxiliar na gestão dos recursos hídricos da região / The objective of this study was to evaluate the conditions for modeling the pollution of a river by an effluent from laundry and dying industries. Samples were collected from this treated effluent in the city of Toritama, Pernambuco and in the Capibaribe river before and after the effluent launch. Temperature, pH, color, turbidity, sedimented solids, electrical conductivity, nitrogen (ammonium, nitrite and nitrate), dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, bacteria counting pattern and coliforms (total and thermotolerant) were analyzed. The results of temperature, pH, color, turbidity and sedimented solids from the industrial effluent did not interfere in the water quality of the Capibaribe river. The high electrical conductivity due to the excess of salts in this effluent was one of the parameters responsible for the ecological imbalance. The absence of dissolved oxygen in the treated effluent was one of the factors that did not help the selfdepuration of water. The launch of organic material in the Capibaribe river water with low concentrations of dissolved oxygen was confirmed by the high biochemical oxygen demand. The high bacteriological contamination detected also contribuited for the water pollution. The non sustainability of the river in the period of drought and the difficulty of determining the flow because of dams in the stretch examined, were determining factors that haltered the development of a methodology to identify the type of the mathematic model that should be applied in this study. The disorderly occupation of laundry and dying industries on the banks of the river and the lack of sanitation in the region were the factors that characterized the diffuse pollution. Thus, the construction of a model to simulate the environmental impact of the effluents from the laundry and dying industries was not feasible. The conditions for this investigation did not offer minimal resources needed for the modeling of the River in Toritama. There is a need for a survey of data in small portions of the Rio so that the experimental results can be evaluated and interpreted, targeting the development of a model that could assist in the management of water resources in the region
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Metal bioaccumulation, membrane integrity and chlorophyll content in the aquatic macrophyte ceratophyllum demersum from the Diep River, Western CapeErasmus, Deborah Vivian January 2012 (has links)
Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2012. / The Diep River is approximately 80 km in length and runs through agricultural land and
urban parts of greater Cape Town, South Africa before entering the Atlantic Ocean, via an
estuary. Generally, metal pollution in South African rivers is not well documented and
using plants to monitor metal bioaccumulation is even less documented. The aim of this
study was to investigate aluminium, iron, copper and zinc metal pollution in the Diep River
and bioaccumulation of these metals in the leaves and stems of the submerged
macrophyte Ceratophyllum demersum L. Furthermore, the effects of bioaccumulated
metals on membrane integrity and chlorophyll content of these plants were investigated.
Site 1 was situated in the upper reaches of the river adjacent to agricultural land, while site
2 was in an urban area, where industrial activities predominate. C. demersum (from an
uncontaminated source) were introduced into the river at the two sites and compared with
one another on a fortnightly basis over a 12 week period. Plants at site 2 were also
compared to existing plants that were naturally growing at the site. Comparisons were also
made between leaves and stems of the plants, to establish the organ of preference
regarding metal accumulation and storage. Samples were digested with nitric acid and an ICP-MS was used to analyse metal
concentrations in the water, sediment and plants. Chlorophyll extraction was done using
dimethyl sulphoxide (DMSO) and the absorbance values determined using a
spectrophotometer. Chlorophyll a, chlorophyll b and total chlorophyll contents were
recorded and compared. Cell membrane integrity was determined by leaving plants for 24
hours in deionised water and measuring electrical conductivity and solutes (sodium,
calcium, potassium and magnesium) before and after placement of the plants.
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