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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.
191

An integrated health, safety and environmental risk assessment model for the South African Global Systems Mobile Telecommunications (GSM) industry

Barnard, Frederick Jacobus 31 July 2005 (has links)
More than one billion people, almost one in six of the world's population, are now using GSM mobile phones. The situation in South Africa is no different from that in the rest of the world. The rise of mobile telephone usage in South Africa has been driven by a combination of factors such as demand, sector reform, the licensing of new competition, and the emergence of major strategic investors, such as Vodacom and MTN. It was estimated that by March 2005 there should be approximately 20 million cellular customers in South Africa. The growth in the South African cellular market is proportionate to the potential risks in an environment where organisations are continuously seeking ways of improving efficiency, cutting costs, and staying abreast of technological advances. Elements of risk control such as Safety, Health, and Environmental Management can no longer be left out of the equation while organisations in the GSM industry are considering increasing their networks to meet the demands of growth. Although risk assessments are not specifically defined in the Occupational Health and Safety Act (85 of 1993); Section 8 does, however, stipulate under the general duties of the employer that the employer must establish, as far as is reasonably practicable, which hazards to the health or safety of persons are attached to any work which is performed. This situation has changed with the promulgation of the Construction Regulations, GNR.1010 on 18 July 2003; which state that every contractor performing construction work shall, before the commencement of any construction work and during construction work, cause a risk assessment to be performed by a competent person appointed in writing, and that the risk assessment shall form part of the health and safety plan to be applied on the site. This requirement under the Construction Regulations will have a major impact on organisations in the GSM industry. Integrated Health, Safety and Environmental risk assessments have now become a prerequisite before considering any further expansion of the GSM network in South Africa. The relationship between the operational risk sub-disciplines of health, safety, and environmental management, as part of the risk-management function, has been established, and an operational risk-assessment model for the Global Systems Mobile Telecommunications industry in South Africa that measures occupational health, safety, and environmental management risks on an integrated basis has been developed. The risk assessment model for the South African GSM industry is based on assessing the frequency of an activity in relation to the impact on the organisation's business processes, incident/accident potential, financial impact, legal status, and the nature of ecological impact. / Business Management / D. Com. (Business Management)
192

An ecological assessment of the Holsloot River, Western Cape, South Africa

Le Roux, Anso 25 July 2013 (has links)
Human related activities have influenced the rivers of the southern Western Cape since as early as the 1700’s. As there is no detailed information available on ecological status of the Holsloot River, a tributary of the Breede River, this study aimed to gain insight into the effect of impacts associated with human activities on the habitat integrity of this river. The study intended to understand how seasonal changes, catchment characteristics and events are reflected in the ecological status of habitats along the river by applying bio-monitoring and river health measurements at selected sites in the upper, middle and lower reaches of the Holsloot River and compare the results to that of an undisturbed reference site. Results obtained in this study are compared with data gathered in 2008/2009 to determine if the ecological status of the river had changed in the period between the two sampling times. The study included assessment of the ecological status of the river based on standard bio-monitoring protocol (SASS5, IHI, IHAS and VEGRAI) as well as in situ water quality analysis (pH, dissolved oxygen, electrical conductivity and total dissolved solids). The construction of the instream Stettynskloof Dam changed the configuration of the riparian zone and river channel in the upper catchment area. Agricultural- and other human related activities, with consequent water abstraction, non-point-source pollution, loss of riparian vegetation, as well as dense stands of alien invader plants influence flow patterns and affects river ecology, especially in the dry summer months. Providing sufficient stream flow and adequate water levels, human related activities can create a larger variety of habitat types available that can support larger biodiversity and higher productivity. The level of inundation and stream flow, influenced by water abstraction as well as irrigation return-flow from extensive drainage systems especially in the dry months, contribute to the loss of biodiversity in the middle and lower reaches of the river. Where the upper reaches of the river are largely natural with few modifications, the habitat integrity deteriorates in the middle reaches so much so that ecosystem functioning are collectively impaired in lower reaches due to human related impacts. Sensitive macro-invertebrates found at lower seriously impacted parts of the river however, were in all probability washed down from lower impacted upstream habitats and may expectedly be able to again occupy habitats downstream if water quality and habitat availability improves. / Environmental Sciences / M. Sc. (Environmental Science)
193

Investigation of the relationship between genetic and environmental risk factors associated with obesity and insulin resistance in South African patients with non-alcoholic fatty liver disease(NAFLD)

Pretorius, Jakobus 12 1900 (has links)
Thesis (MSCMedSc)--Stellenbosch University, 2012. / Includes bibliography / ENGLISH ABSTRACT: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world. The disease spectrum of NAFLD extends from steatosis (types 1,2) to non-alcoholic steatohepatitis (NASH) with inflammation (types 3,4). The aims of the study were 1) to analytically validate high-throughput real time polymerase chain reaction (RT-PCR) assays for three selected single nucleotide polymorphisms (SNPs), FTO rs9939609 (intron 1 T>A), TNF-α rs1800629 (-308 G>A) and PPARγ rs1801282 (Pro12Ala, 34 C>G), and 2) to perform genotype-phenotype association studies in relation to biochemical abnormalities, disease severity and age of onset. A total of 119 patients with fatty liver identified on ultrasound, including 88 histologically confirmed NAFLD patients, and 166 control individuals were genotyped for the three selected SNPs. RT-PCR validated against direct sequencing as the gold standard was used for detection of genetic variation. All three SNPs were in Hardy Weinberg equilibrium in the study population, except for a deviation in genotype distribution detected for PPARγ rs1801282 in the NAFLD patient subgroup (p<0.001). After adjustment for age and gender, the risk-associated FTO rs9939609 A-allele was detected at a significantly higher frequency in the Caucasian compared with Coloured patients (p=0.005). The opposite was detected for the risk-associated TNF-α rs1800629 A-allele, which occurred at a significantly higher frequency in the Coloured compared with Caucasian NAFLD patients (p=0.034). The onset of fatty liver disease symptoms was on average 5 years younger in the presence of each risk-associated TNF-α rs1800629 A-allele (p=0.028). When considered in the context of an inferred genotype risk score ranging from 0-6, disease onset occurred on average 3 years earlier (p=0.008) in the presence of each risk-associated FTO A-allele, TNF-α A-allele or PPARγ C-allele. After adjustment for age, gender and race, no differences in genotype distribution or allele frequencies were observed between histologically confirmed NAFLD (types 1,2) and NASH (types 3,4) patients, while the minor allele frequency for the TNF-α rs1800629 was significantly higher in the total NAFLD (types 1-4) (p=0.047) as well as NASH subgroup (NAFLD types 3,4) (p=0.030) compared with obese patients without a histologically confirmed NAFLD diagnosis. A significant correlation was furthermore observed between the number of TNF-α rs1800629 A-alleles and increasing CRP levels (p=0.029), with a favourable reduced effect in the presence of low- to moderate alcohol intake. The average waist circumference of physically active NAFLD patients was 12% lower than in physically inactive patients (p=0.004). In view of the results presented in this study, the inclusion of the selected SNPs, and in particular the pro-inflammatory TNF-α rs1800629 polymorphism, may be considered as part of a comprehensive cardiovascular risk evaluation of NAFLD patients. Ultimately, early detection of patients with fatty liver disease symptoms and effective intervention based on the underlying disease mechanism may prevent progression from NAFLD to NASH, shown to be an independent risk factor for cardiovascular diseases. / AFRIKAANSE OPSOMMING: Nie-alkoholiese lewervervetting (NALV) is die mees algemene kroniese lewersiekte in die wêreld. Die siektespektrum van NALV strek van steatose (vervette lewer tipes 1,2) tot steatohepatitis met inflammasie (NASH tipes 3,4). Die doel van die studie was 1) om analities die hoë omset polimerase kettingreaksie (RT-PKR) metode te valideer vir die geselekteerde enkel nukleotied polimorfismes (ENPs) FTO rs9939609 (intron 1 T>A), TNF-α rs1800629 (-308 G>A) en PPARγ rs1801282 (Pro12Ala, 34 C>G), en 2) om genotipe-fenotipe assosiasie studies uit te voer ten opsigte van relevante biochemiese abnormaliteite, graad van die siekte en aanvangsouderdom. ’n Totaal van 119 pasiënte met vervette lewers is geïdentifiseer met behulp van ultraklank, insluited 88 histologies-bevestigde NALV pasiënte, en 166 kontrole individue. Hierdie pasiënte is gegenotipeer vir die 3 geselekteerde ENP’s. RT-PKR gevalideer met direkte DNA volgorde bepaling as die goue standaard, is gebruik vir opsporing van genetiese variasie. Al die ENP’s was in Hardy Weinberg ekwilibrium in die studie populasie, behalwe vir ’n afwyking in genotipe verspreiding waargeneem vir PPARγ in die NALV subgroep (p<0.001). Nadat aanpassings gemaak is vir ouderdom en geslag, is die risiko-geassosieerde FTO rs9939609 A-alleel waargeneem teen ’n betekenisvol hoër frekwensie in die Kaukasiese pasiënte in vergelyking met Kleurling pasiënte (p=0.005). Die teenoorgestelde is waargeneem vir die risiko-geassosieerde TNF-α rs1800629 A-alleel wat voorgekom het teen ’n betekenisvol hoër frekwensie in die Kleurling NALV pasiënte, in vergelyking met Kaukasiese NALV pasiënte (p=0.034). Die aanvang van NALV was gemiddeld 5 jaar vroeër in die teenwoordigheid van elke risiko-geassosieerde TNF-α rs1800629 A-alleel (p=0.028). Met inagneming van ’n genotipe risiko telling tussen 0–6, het aanvang van siekte gemiddeld 3 jaar vroeër voorgekom (p=0.008) in die teenwoordigheid van elke toenemende risiko-geassosieerde FTO A-alleel, TNF-α A-alleel en PPARγ C-alleel. Nadat aanpassings gemaak is vir ouderdom, geslag en ras, is geen verskille waargeneem in genotipe verspreiding of alleel frekwensies tussen histologies bevestigde NALV (tipes 1,2) en NASH (tipes 3,4) pasiënte nie, terwyl die minor alleel telling vir die TNF-α rs1800629 betekenisvol hoër was in die totale NALV (tipes 1–4) (p=0.047) asook die NASH subgroep (NALV tipes 3,4) (p=0.03) in vergelyking met vetsugtige pasiënte sonder ’n histologies bevestigde diagnose. ‘n Statisties beteknisvolle korrelasie is verder waargeneem tussen die aantal TNF-α rs1800629 A-allele en toenemende CRP vlakke (p=0.029), met n gunstige verlaagde effek in die teenwoordigheid van lae alcohol gebruik. Die gemiddelde middellyf-omtrek van fisies aktiewe NALV pasiënte was 12% minder as fisies onaktiewe pasiente (p=0.004). Na aanleiding van die resultate van hierdie studie behoort insluiting van geselekteerde ENP’s, en in besonder die pro-inflammatoriese TNF-α rs1800629 polimorfisme, as deel van ’n omvattende kardiovaskulere risiko evaluasie oorweeg te word. Aan die einde van die dag mag vroeë identifikasie van NALV pasiente en effektieve intervensie gebasseer op die onderliggende siekte meganisme, vordering tot NASH verhoed wat getoon is om ’n onafhanklike risiko faktor vir kardiovaskulêre siekte te wees. / Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Pathology
194

環境風險、環境運動與媒體:以台灣焚化爐政策爭議的媒體再現為例

林怡瑩 Unknown Date (has links)
本研究認為要了解台灣新聞媒體在「焚化風險/污染議題」上的表現,必須將其置放在台灣焚化政策爭議的整個歷史脈絡中來作探討,才能跨越「從媒體文本看世界」的侷限,了解國家、社會運動、媒體在「焚化政策爭議」中的互動關係。 研究方法方面,本研究以文獻分析法分析國家推動焚化爐的制度設計與「風險管理」的配套措施則,以參與觀察法、深度訪談與歷史文獻分析民間反焚化爐運動發的發展,並試圖辨識國家與社會運動各提出了哪些詮釋架構。在媒體文本方面,採用框架分析法。 本研究發現,從民國73年《都市垃圾處理方案》開始,「焚化」一直被定為主要垃圾處理政策;國家一方面以各種優惠、補貼、保障利潤的長期合約等機制扶植/圖利國內廠商;另一方面以「中央給錢、地方找地」的權責劃分原則搭配回饋金、公權力、民有民營模式三個機制來排除居民的反對與抗爭。 國家在推動焚化爐的過程中,鼓吹焚化有「減量化、安定化、衛生/無害化、資源回收、占地小、台灣垃圾適於焚化、焚化是先進國家主要垃圾處理方法」等優點,根本未提及戴奧辛及其他污染。待環保團體提出質疑,國家才透過新聞媒體來安撫社會大眾,提出「積極改善」、「配套措施」與「安全保證」,把問題導向「如何補救」而非「是否還要繼續接受污染」。在空氣污染防制方面,大型爐的戴奧辛排放標準遲至民國86年才訂出,小型爐管制最遲至92年才生效。鼓勵民間投資灰渣再利用的政策更是大大增加這些毒物流散到環境中的機率,而且因為我們看不見、不知道,所以毫無警覺。 早期的反焚化爐運動分成兩股力量,草根組織在社區抵擋焚化爐進入,專業環保團體則多次在媒體上揭露「焚化風險/污染」。民國88年起,開始有環保團體引介國外的反焚化論述給社區草根組織;在環保團體與地方組織緊密互動、串聯的過程中,發展出反焚化論述的「在地版本」,更快速壯大運動的影響力,迫使國家重新檢討焚化政策。在反美濃焚化爐的個案中,人們更見識到,在中央/地方政府施政作為與焚化技術雙雙失去正當性之後,焚化利益的政經共生體如何操弄法律、科學/技術與官僚體系特性來抗拒反對與改變。 在焚化風險的決策點上,中時、聯合兩大報並未提供警訊,主動揭露焚化爐可能帶來的風險/污染,也沒有自我批判或學習的能力,在下一次報導時提出警告。 在環保團體揭露焚化風險/污染時,兩報傾向用「兩面並陳、各說各話」的「衝突對立框架」來處理,但聯合報傾向凸顯兩造說法的兩極化、沒有交集,中時則是「形式對立、內容不強調對立」。不過,在揭露之後,民間團體還是很難得到媒體近用,但國家卻能輕鬆得到媒體進用,以科學研究的內部不確定性和外部權威、「安全保證」等機制,將議題引導至「風險管理」的詮釋框架,解除焚化政策的正當性危機。 在「反對焚化污染/風險運動」的媒體再現中,美濃反焚化爐運動完全被擠壓在地方版,只有官員圖利廠商被偵辦的新聞才上得了全國版,但此類「司法新聞」無法呈現中央/地方政府互踢皮球、集體卸責等整套「風險政治」的運作過程,不利於各地受害者的交流、串聯,亦不利社會輿論壓力的形成。 在討論垃圾問題的社論中,兩報均接受焚化是國家「既定政策」的事實,以「肯定並催促興建」、「視為既定事實」、「討論如何排除焚化爐興建困難的問題」、「信任科學/技術」等框架來支持「焚化爐是最佳方案」。「減量回收」政策從頭到尾都被套上個人實踐的道德化框架,削弱其可獨當一面,取代焚化爐的正當性,亦排除了國家在減量回收政策上的責任。 兩報探討垃圾與焚化爐問題的社論絕大多數是應垃圾大戰而寫,只有一篇聯合報社論以焚化爐風險為主題。兩報對於焚化爐爭議大致上有固定的框架,中國時報很一貫地抱持「焚化是不得不然的選擇」,所以要作好管制/公關工作的詮釋框架,聯合報則是一直強調源頭管制(減量)的重要性,只可惜該報的言論並不認為源頭管制可以完全取代焚化,故在立場上是採取「嚴格管制焚化爐,加上個人要作好源頭減量才是戴奧辛的治本之道」。不過,這種一致性僅限於全國版,地方版無法歸納出類似規則。
195

Les caractéristiques environnementales du risque d’exposition aux arbovirus au Québec

Rocheleau, Jean-Philippe 09 1900 (has links)
Les arboviroses représentent un fardeau sanitaire considérable et croissant à l’échelle mondiale. La complexité des facteurs biotiques et abiotiques qui interviennent dans la transmission de ces arbovirus pose un défi de taille aux scientifiques qui tentent de comprendre, de modéliser ou d’anticiper leur transmission ainsi qu’aux intervenants de santé publique qui ont la responsabilité de surveiller, d’évaluer et gérer le risque que posent les arbovirus pour la santé des populations. Cette étude visait à estimer et caractériser le risque d’exposition à plusieurs arbovirus suspectés d’être actifs et émergents au Québec mais dont la distribution avait peu ou n’avait pas été étudiée au Québec : le virus du Nil occidental (VNO), le virus de l’encéphalite équine de l’est (VEEE) et deux virus du sérogroupe de la Californie (VSGC), le virus de Jamestown Canyon (VJC) et le virus du lièvre d’Amérique (VLA). Basée notamment sur l’hypothèse selon laquelle les animaux d’espèces différentes qui partagent un environnement commun partagent également un risque environnemental commun, cette étude visait également à évaluer si les populations d’animaux de compagnie pouvaient aider à estimer et caractériser le risque d’infection arbovirale chez l’humain. L’échantillonnage sérologique de populations humaines, canines et équines du sud-ouest du Québec a permis d’évaluer et de comparer la séroprévalence aux arbovirus étudiés chez chacune de ces trois espèces. Les estimations de séroprévalence ont révélé un niveau d’activité arbovirale significative pour chacun des arbovirus. Des différences ont été remarquées quant au pourcentage de sujets séropositifs chez chacune des espèces. Les facteurs environnementaux ayant une influence sur le risque d’infection par le VEEE ont été modélisés à partir de données sérologiques et cliniques chez les chevaux. Les milieux humides boisés ont été identifiés comme les principaux environnements à risque pour le VEEE au Québec alors que les zones agricoles ont été identifiées comme des environnements protecteurs. Les facteurs environnementaux ayant un impact sur le risque d’infection par le VNO ont été modélisés à partir des données sérologiques chez le chien et des données cliniques agrégées chez l’humain. Cette modélisation a suggéré un risque singulièrement plus élevé en zone agricole chez le chien et un risque plus faible en zone forestière chez l’humain, des facteurs rarement identifiés dans la littérature Nord-Américaine. Les facteurs environnementaux et individuels ayant un impact sur le risque d’infection par les VSGC chez l’humain et le chien ont par la suite été modélisés à partir des données sérologiques chez ces deux espèces. D’après nos modèles, le risque d’infection par ces virus serait supérieur en zone forestière et le degré d’exposition aux piqures de moustiques serait un facteur déterminant du risque d’infection chez les deux espèces. Cette étude a permis de bonifier de façon substantielle le portrait de l’activité arbovirale au Québec. Elle a permis de caractériser la distribution du risque et a fourni des données probantes pouvant soutenir la recherche ainsi que la planification des interventions en santé publique. La méthodologie utilisée dans le cadre de cette étude supporte la pertinence de l’approche « One Health » pour l’étude des maladies vectorielles émergentes. / Arboviral infections represent a considerable and growing health burden globally. The complexity of biotic and abiotic factors involved in the transmission of these arboviruses pose a challenge to scientists trying to understand, model or anticipate arboviral transmission as well as to public health authorities who have the responsibility to monitor, assess and manage the public health risk posed by arboviruses. This study aimed at estimating and characterizing the risk of exposure to several arboviruses suspected of being active and emerging in Québec but whose distribution had not been studied thoroughly in Québec: West Nile virus (WNV), eastern equine encephalitis virus (EEEV) and two viruses of the California serogroup (CSG), Jamestown Canyon virus (JCV) and Snowshoe hare virus (SHV). Based on the assumption that animals of different species sharing a common environment also share similar environmental risk, this study also aimed to assess whether some populations of domestic animals could help to estimate and characterize the risk of arboviral infection in humans. Serological sampling of human, canine and equine populations from southwestern Québec was used to evaluate and compare the seroprevalence to the selected arboviruses in each of these three species. Seroprevalence estimates showed a significant level of arboviral activity for all arboviruses. Differences were noted in the percentage of seropositive individuals in each species. Environmental factors that influence the risk of infection by EEEV were modeled based on serological and clinical data in horses. Wooded wetlands were identified as the main risk environments for EEEV in Québec while agricultural areas were identified as protective environments. Environmental factors affecting the risk of WNV infection were modeled based on serological data in dogs and aggregated clinical data in humans. These models suggested a higher risk in agricultural areas in dogs and a lower risk in forest areas in humans, two factors rarely identified in the North American literature. Environmental and individual factors affecting the risk of infection by CSGV in humans and dogs have subsequently been modeled based on serological data in these two species. According to our models, the risk of infection with these viruses would be higher in forested areas and the degree of exposure to mosquito bites would be a risk factor for infection in both species. This study substantially enhanced the comprehension of arboviral activity in Québec. It allowed for characterizing the distribution of risk and provided evidence that may support research and planning of public health interventions. The methodology used in this study supports the relevance of the "One Health" approach for the study of emerging vector-borne diseases.
196

Avaliação do risco ambiental de sedimentos contaminados com triclosan, ibuprofeno e 17&alpha;-etinilestradiol empregando invertebrados marinhos bentônicos / Environmental risk assessment of sediments contaminated with triclosan, ibuprofeno and 17&alpha;-ethynylestradiol employing benthic marine invertebrates

Pusceddu, Fabio Hermes 16 August 2016 (has links)
Os protocolos de Avaliação de Risco Ambiental (ERA) de Fármacos e Produtos de Cuidados Pessoais (FPCP) recomendam o uso de ensaios ecotoxicológicos tradicionais (por exemplo algas, bactérias, invertebrados, peixes) e a avaliação de efeitos em um único nível de organização biológica para a determinação dos efeitos potenciais dos FPCP à biota. Considerando que efeitos em nível de sub-indivíduo pode afetar igualmente a aptidão ecológica de organismos marinhos, e que os mesmos estão cronicamente expostos aos FPCP, o objetivo do presente estudo foi avaliar o risco ambiental de triclosan (TCS), ibuprofeno (IBU) e 17&alpha;-etinilestradiol (EE2) em sedimentos marinhos utilizando respostas de efeitos sub-individuais e populacionais. Por meio do HPLC-ESI-MS/MS, as concentrações ambientais de TCS e IBU foram quantificadas em sedimentos marinhos coletados no entorno do emissário submarino de esgoto de Santos (Baía de Santos, São Paulo - Brasil) com 15,14 e 49,0 ng.g-1, respectivamente, enquanto o EE2 não foi detectado (<33 ng.g-1). Uma bateria de ensaios de toxicidade crônica (desenvolvimento embriolarval) com ouriços-do-mar (Lytechinus variegatus) e bivalves (Perna perna) foi realizada (efeito a nível de indivíduo) após exposição a sedimentos contaminados com os FPCP. Além disso, foram analisados alguns biomarcadores de Fase I (etoxiresorufina O-deetilase EROD e dibenzilfluoresceína DBF), de Fase II (glutationa S-transferase GST) do metabolismo, do sistema antioxidante (glutationa peroxidase GPx), de neurotoxicidade (colinesterase ChE), de estresse oxidativo (peroxidação lipídica LPO e danos em DNA) e de citotoxicidade que foram selecionados para avaliação das respostas a nível de sub-indivíduo em mexilhões Mytella charruana. Todos os compostos analisados apresentaram efeitos sobre o desenvolvimento embriolarval de L. variegatus e P. perna em concentrações ambientalmente relevantes. Em nível de sub-indivíuo foi possível observar que o TCS causou efeitos cito-genotóxicos (diminuição da estabilidade da membrana lisossomal, peroxidação lipídica e danos em DNA) e neurotóxicos. O IBU causou efeitos citotóxicos e neurotóxicos, enquanto o EE2 apresentou efeitos citotóxicos e danos em DNA. Nesse sentido, mesmo em baixas concentrações os FPCP são potencialmente capazes de alterar os mecanismos de manutenção da homeostase. Os dados químicos e ecotoxicológicos foram integrados e os quocientes de risco estimados para TCS, IBU e EE2 apresentaram valores superiores a 1,0, indicando alto risco ambiental destes compostos em sedimentos marinhos. Estes são os primeiros dados de avaliação de risco ambiental de FPCP em sedimentos de uma zona costeira brasileira. Os resultados sugerem que a ERA de fármacos e produtos de cuidados pessoais deve contemplar, além dos ensaios de toxicidade tradicionais o uso de biomarcadores como indicadores dos primeiros sinais de efeitos e, assim, estabelecer uma avaliação de risco mais efetiva que assegure a proteção e funcionamento dos ecossistemas aquáticos. / The guidelines for the Environmental Risk Assessment (ERA) of pharmaceuticals and personal care products (PPCPs) usually recommend the use of standard ecotoxicity assays (e.g. algae, bacteria, invertebrate, fish) and the assessment of endpoints at individual level for the evaluation of potential effects of PPCPs on biota. Considering that effects at sub-individual level can also affect the ecological fitness of marine organisms, and that marine organisms are chronically exposed to PPCPs, the aim of the current study was to evaluate the environmental risk of triclosan (TCS), ibuprofen (IBU) and 17&alpha;-ethynylestradiol (EE2) in marine sediments using sub-individual and population endpoints. Using LC-ESI-MS/MS, the environmental levels of TCS and IBU were quantified in marine sediments from the vicinities of the Santos submarine sewage outfall (Bay of Santos, São Paulo, Brazil) at 15.14 and 49.0 ng g-1, respectively, while EE2 was not detected (<33ng g-1). A battery (n=3) of chronic bioassays (embryo-larval development) with a sea urchin (Lytechinus variegatus) and a bivalve (Perna perna) were performed at populational level after exposure to spiked sediment. Phases I (ethoxyresorufin O-deethylase EROD and dibenzylfluorescein dealkylase DBF) and II (glutathione S-transferase GST) of the metabolism, antioxidant system (glutathione peroxidase GPX), neurotoxicity (cholinesterase ChE), oxidative effects (lipid peroxidation LPO and DNA damage strand breaks) and cytotoxicity were selected to evaluate the sublethal responses in the bivalve Mytella charruana. These compounds showed developmental effects on L. variegatus and P. perna at environmentally relevant concentrations. At sub-individual level TCS induced cyto-genotoxic (reduction on stability of lysosome membrane, lipid peroxidation and DNA damage) and neurotoxic effects. IBU caused cyto and neurotoxic effect, while EE2 caused cytotoxic and DNA damage. Chemical and ecotoxicological data were integrated and the quotient risk estimated for TCS, IBU and EE2 showed values higher than 1.0, indicating high environmental risks of these compounds in sediments. These are the first data of risk assessment of pharmaceuticals and personal care products in sediments of a Brazilian coastal zone. The results suggests that the ERA of pharmaceuticals and personal care products must include, in addition to the standard toxicity tests, the use of biomarkers as indicators of the early warning signs and thus provide a more effective risk assessment to security the protection and functioning of aquatic ecosystems.
197

Biomarqueurs d'exposition aux composés organochlorés et risque de cancer du sein : analyse de l'étude cas-témoins en population générale CECILE basée sur l'utilisation de modèles pharmacocinétiques / Biomarkers of exposure to organochlorine compounds and breast cancer risk : analysis of the CECILE study, a population-based case-control study in France, based on pharmacokinetic models to assess exposure during critical exposure windows

Bachelet, Delphine 23 January 2012 (has links)
Le cancer du sein est le plus fréquent des cancers de la femme. Son incidence n’est expliquée que partiellement par les facteurs de risque bien établis comme les facteurs reproductifs, hormonaux ou génétiques. Plusieurs éléments suggèrent l’existence de facteurs de risque environnementaux, tels que les polluants organochlorés persistants connus comme perturbateurs endocriniens. Les objectifs de ce travail sont : d’étudier les niveaux d’exposition, et leurs déterminants, au DDE (principal métabolite de l’insecticide DDT) et aux polychlorobiphényles (PCB) ; d’estimer par une modélisation pharmacocinétique à base physiologique (PBPK) les niveaux d’exposition au PCB-153 à la période péri-pubertaire qui constitue une fenêtre de susceptibilité accrue de la glande mammaire aux agents environnementaux ; d’étudier le rôle du DDE et du PCB-153 dans le risque de cancer du sein, à la fois à partir de prélèvements sanguins actuels et, pour le PCB-153, à partir de niveaux estimés à la période péri-pubertaire.Ce travail a été effectué à partir de l’étude CECILE, étude cas-témoins en population générale incluant 1055 témoins et 1080 cas de cancer du sein diagnostiqués de février 2005 à mars 2008 dans les départements d’Ille-et-Vilaine et de Côte d’Or chez lesquels un prélèvement sanguin a permis d’effectuer des dosages de p,p’-DDE et de PCB-153. La modélisation PBPK mise en place en coopération avec une équipe de toxicologues canadiens a permis de simuler des profils toxicocinétiques vie entière de PCB-153 et d’estimer les niveaux d’exposition au cours de la puberté. Cette modélisation est basée sur les niveaux mesurés au moment de l’enquête, les facteurs individuels de variation (poids, taille, grossesses, allaitement) connus d’après le questionnaire et la courbe de contamination environnementale au cours du temps.Les niveaux de contamination biologique observés sont plus faibles que ceux rapportés précédemment dans les populations occidentales. Nous montrons également que les principaux facteurs prédictifs des niveaux sériques de p,p’-DDE et de PCB-153 chez les femmes incluent l’âge, les habitudes alimentaires, le poids et ses variations au cours du temps, les grossesses et l’allaitement, et le lieu de résidence. Nous n’observons pas d’association entre les niveaux de p,p’-DDE et le risque de cancer du sein, mais une association inverse apparaît pour les cancers du sein de type négatifs pour les récepteurs hormonaux. Nous observons également une association inverse avec les niveaux de PCB-153 chez les femmes de 50 ans et plus. L’association inverse est renforcée lorsque les niveaux sont estimés pour la période péri-pubertaire à l’aide des modèles PBPK chez les femmes de la génération 1951-1960, correspondant à la cohorte de naissance des femmes de plus de 50 ans ayant connu les expositions aux PCB les plus élevées durant leur puberté.Plusieurs mécanismes biologiques pourraient expliquer l’association inverse observée entre le cancer du sein et l’exposition aux PCB. Ces résultats doivent être confirmés par des études tenant compte des fenêtres de susceptibilité de la glande mammaire et constituent une piste intéressante à approfondir. / Breast cancer is the most frequent cancer in women. Its incidence is only partially explained by well-established risk factors as reproductive, hormonal or genetic factors. It has been suggested that endocrine disrupting chemicals such as persistent organochlorine pollutants also play a role in breast cancer. The objectives of this study were: to assess exposure levels to DDE (main metabolite of DDT) and to polychlorobiphenyls (PCBs), and to explore their determinants; to estimate PCB-153 levels during the puberty using physiologically-based pharmacokinetic (PBPK) models, as this period of life constitutes a critical exposure window with increased susceptibility to carcinogens; to study the associations between breast cancer risk and separately DDE, PCB-153 measured at the time of diagnosis, and PCB-153 levels estimated during puberty.The analyses were based on data from the CECILE study, a population-based case-control study including 1055 controls and 1080 breast cancer cases who gave a blood specimen. The cases were diagnosed from February 2005 to March 2008 in two French administrative areas (Ille-et-Vilaine and Côte d’Or). p,p’-DDE and PCB-153 serum levels were measured. PBPK modeling allowed simulating PCB-153 lifetime toxicokinetic profiles and estimating exposure levels during puberty. These PBPK models were based on blood measurements at the time of recruitment in the study, on individual characteristics elicited from the questionnaire (weight, height, pregnancies, breastfeeding) and on the curve of environmental contamination by PCBs estimated since the 1930’s. The levels of biological contamination were lower than those previouly reported in Western populations in earlier periods. The main predictive factors of p,p’-DDE and PCB-153 serum levels included age; dietary habits; weight and its variations; pregnancies and breastfeeding; and residence area. We did not observed any association between p,p’-DDE levels and the risk of breast cancer, but an inverse association was observed for estrogen receptor-negative breast cancers. We also observed an inverse association of breast cancer with PCB-153 among women above 50 years. This inverse association was reinforced when considering PCB-153 levels estimated during peripubertal period from PBPK models, particularly among women born in 1951-1960, a birth cohort with peak exposure to PCB-153 during puberty. Biological mechanisms explaining the observed inverse association between breast cancer and PCB exposure are considered. These findings should be confirmed by further studies.
198

The implications of wicked problems for the legitimacy of European environmental policy development : the case of environmental risks from the pharmaceutical endocrine disrupter, 17α-ethinyl oestradiol, under the European Water Framework Directive

Gardner Le Gars, Joanne Claire January 2018 (has links)
The issue of environmental risks from the pharmaceutical endocrine disrupter 17 alpha-ethinyl oestradiol (EE2), which is an active ingredient in the contraceptive pill, confronts government responsibilities for citizens' health with potential environmental risks from its presence in aquatic ecosystems. Further to a risk appraisal process conducted under the Water Framework Directive (WFD) between 2006 and 2012, the European Commission recommended the imposition of an environmental quality standard for EE2. In 2013, this recommendation was rejected by politicians. The outcome was both contested and commended. The UK Government was particularly vehement in its opposition and claimed that the risk assessment process for EE2 was not robust. The UK Government also insisted that it had swayed opinion of other EU Member States to convince them that action for EE2 was not proportionate given the extremely elevated costs of risk control options. At the present time, environmental policy for EE2 and other endocrine disrupters remains resolutely ineffective. Despite three distinct policy interventions recommending precautionary action for EE2 during the past twenty years, emissions of this potent, oestrogenic endocrine disrupter continue unabated. This thesis explains why European politicians rejected the European Commission’s risk governance recommendations for EE2 in 2013 under the Water Framework Directive. This comprises its principal empirical contribution. A novel analytical framework which draws on insights from the policy sciences, risk governance and wicked problems literature is developed. This framework is employed to determine whether the policy outcome for EE2, and the decision-making processes that preceded it, were legitimate. The research findings in this respect advance understanding of the implications of specific properties of wicked problems, of which it is argued, EE2 is an example, for the legitimacy of decision-making processes during the risk appraisal and political phases of policy development in Europe. This comprises the principle theoretical contribution of the thesis. Recommendations to promote more effective and legitimate policy development for wicked problems in similar multi-level governance contexts are also made.
199

Decision-making for acceptable risk in contaminated site problems in British Columbia

Thomas, Deanna 11 1900 (has links)
Contaminated sites are a common problem across municipalities in the Greater Vancouver Regional District. These problems are complicated and multi-dimensional, and raise fundamental concerns about the risks to human and environmental health. This thesis shows however, that there are no easy answers to how much risk is "acceptable", and no one right way to decide. How the acceptable risk problem is structured is important, because fact and value issues, a source of controversy and dispute, are variously interpreted depending on how the problem is cast. The literature generically categorizes acceptable risk as either a technical, social or decision problem, and each of these have implications for the types of decision-making approaches and solutions that are considered appropriate in resolving acceptable risk. This thesis investigated how acceptable risk in contaminated site problems is handled in British Columbia by reviewing the provincial decision-making framework, and by surveying municipalities in the Greater Vancouver Regional District for their views on contaminated site problems and acceptable risk decision-making. The underlying goal of the thesis is to question the use of the current approach, the Pacific Place site criteria, as a model for acceptable risk decision-making in the province, and to explore the implications for urban communities. The Ministry of Environment is the central authority for contaminated sites in British Columbia and has generally taken a scientific and technical approach to the problem. Although the municipal survey suggests that the Pacific Place site criteria has a broad base of support in the GVRD, the technical emphasis has implications for urban communities. The approach is expert-oriented and largely excludes local and public involvement in the acceptable risk debate. The major concern is that important social value issues have been neglected, relative to the engineering and technical aspects of the problem. The research also finds however, that the majority of individuals in the municipal survey are willing to explore other methods of determining acceptable risk, and support in principle, local government and public involvement in deciding what these methods should be. This thesis suggests that British Columbia can benefit from a more comprehensive view of acceptable risk in contaminated site problems. Resource limitations at the provincial and local level, and the high stakes in contaminated site problems for urban communities point to the growing importance of incorporating a broad range of value issues and understanding the trade-offs in acceptable risk decisions. The Ministry of Environment can improve the current decision-making approach by: incorporating structured value assessments that elicit stakeholder values and address trade-offs; involving a wider range of stakeholders in standard setting and risk assessment, including the forthcoming review of the Pacific Place site criteria; creating forums to explore other decision-making approaches; and by encouraging private sector involvement in risk assessment and risk management. The province can also encourage and support community-based institutional networks, both at the municipal and regional level.
200

Farming in the Langkloof : coping with and adapting to environmental shock and social stress

De Kock, Carinus 04 1900 (has links)
Thesis (MA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: During the period 2006-2012, the Langkloof area, situated in the Eden District Municipality, suffered severely from environmental shocks and social stress including drought, flooding, hail, wildfire, heatwaves and reduced labour demand. These events negatively impacted many farmers and their livelihoods. In response to these external shocks and stressors, large-, medium- and small-scale farmers adopted numerous coping and adaptive strategies. This study performed a comprehensive livelihoods analysis of large-, medium- and small-scale farmers in the Langkloof area, using the widely recognized sustainable livelihoods framework developed by the United Kingdom’s Department for International Development, with a particular focus on coping and adaptive strategies against severe environmental shock and social stress. Variables used in the analysis were the vulnerability context in which farmers pursue a livelihood; livelihood assets (social, human, financial, natural and physical); the policies, institutions and processes in the external environment that influence the degree of ownership and access to assets; livelihood strategies pursued; and the various livelihood outcomes ultimately produced. The analysis of coping and adaptive strategies employed by farmers during these periods formed an integral part of this study. Sixteen livelihood asset indicators were identified to determine the total assets (human, social, physical, financial and natural) of the farmers. After scaling the indicators, a Principal Component Analysis (PCA) was used to assign weights to each indicator and to subsequently calculate the total assets of each household. Regarding the coping and adaptive strategies employed by farmers against environmental shock and social stress, the average number of strategies was calculated for each household. Spearman’s rank correlations were calculated for total assets achieved (capacity) and the number of strategies employed against environmental shock and social stress. / AFRIKAANSE OPSOMMING: Die Langkloofgedied, geleë in die Eden Distriksmunisipalitiet, is gedurende die tydperk 2006-2012 geweldig geteister deur omgewings- en sosiale gebeure, wat droogte, vloede, hael, veldbrande, hittegolwe en ʼn gevolglike verlaagde arbeidsaanvraag sluit. Hierdie rampe het verreikende nadelige gevolge op boere se lewensbestaan gehad. Terwyl hulle lewensbestaan tot die uiterste uitgedaag is, is verskeie hanterings- en aanpassingstrategieë teen omgewingskok en sosiale stres geïmplementeer. Met die gebruik van die Verenigde Koninkryk se Departement van Internasionale Ontwikkeling se volhoubare lewensbestaansraamwerk is ʼn gedetailleerde en alomvattende analise van groot, medium- en kleinskaalboere in die Langkloof se lewensbestaan gedoen, met ʼn sterk skem op hul hanterings- en aanpassingstrategieë teen omgewingskok en sosiale stress. Die analise veranderlikes het die kwesbaarsheidskonteks waarin boere hul lewensbestaan aanpak; hul verskeie bates (menslik, sosiaal, finansieel, fisies en natuurlik); die beleide, instansies en prosesse in die eksterne omgewing wat toegang tot en eienaarskap van bates reguleer; hul lewensbestaanstrategieë; en die lewensbestaansuitkomste wat bereik word, behels. Die analise van die boere se hanterings- en aanpassingstrategieë geïmplementeer teen omgewingskok en sosiale stres gedurende hierdie tydperk was ʼn integrale rol van hierdie studie. Sestien aanwysers is geïdentifiseer om die totale lewensbestaansbates (menslik, sosiaal, fisies, finansieel en natuurlik) van die boere te bepaal. Nadat die aanwysers geskaal is, is ‘n Hoofkomponentanalise (PCA) uitgevoer om gewigte aan elke aanwyser toe te ken vir die berekening van totale bates van huishoudings. Die hanterings- en aanpassingstrategieë ingestel deur boere teen omgewingskok en sosiale stres, is die gemiddelde aantal strategieë per huishouding. Spearman se rangorde korrelasies is bereken vir die totale bates (kapasiteit) en die getal strategieë geïmplementeer teen omgewingskok en sosiale stres.

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