894 resultados para environmental risk


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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa Para a obtenção do Grau de Mestre em Energia e Bioenergia

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Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.

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Existing research identifies preschoolers with communication delays as a population at risk for the development of behavioural concerns. This risk increases when additional environmental factors such as parental stress and family conflict are also present. Research has also shown that behavioural concerns can be stable over time when they develop early. However, early intervention has been shown to be effective in addressing these concerns. The effectiveness of early intervention in addressing both child and family outcomes increases when interventions are delivered in a family-centred approach. This research project made use of data related to child behaviour and parenting, gathered through the Family Resource Project which explored the parenting experiences and resource access and allocation decisions of families who have preschool children with and without communication delays. Cluster analysis was used to explore whether there were identifiable clusters of children and families within each sample. Interview data fi"om each identified family cluster was then explored further, to identify how parents described their child's behaviour and their experience of parenting. Results show that, within this sample, parents of preschoolers with communication delays described their child's behaviour and their experience of parenting differently than did parents of children without communication delays. Results also showed that within this sample parents experiencing parental stress and/or family conflict described their child's behaviour and their experience of parenting differently than did parents from other clusters. Results suggest support for early intervention and the use of family-centred intervention, particularly for families of children with communication delays.

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This paper examines the factors associated with Canadian firms voluntarily disclosing climate change information through the Carbon Disclosure Project. Five hypotheses are presented to explain the factors influencing management's decision to disclose this information. These hypotheses include a response to shareholder activism, domestic institutional investor shareholder activism, signalling, litigation risk, and low cost publicity. Both binary logistic regressions as well as a cross-sectional analysis of the equity market's response to the environmental disclosures being made were used to test these hypotheses. Support was found for shareholder activism, low cost publicity, and litigation risk. However, the equity market's response was not found to be statistically significant.

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Résumé La prédominance de l'obésité qui touche les enfants et les adultes a augmenté dans le monde entier ces dernières décennies. Les différentes études épidémiologiques ont prouvé que l'obésité est devenue une préoccupation profonde de santé aux États-Unis et au Canada. Il a été montré que l'obésité a beaucoup d’effets sur la santé ainsi il serait important de trouver différentes causes pour le gain de poids. Il est clair que l'obésité soit la condition de multiples facteurs et implique des éléments génétiques et environnementaux. Nous nous concentrons sur les facteurs diététiques et particulièrement le fructose où sa consommation a parallèlement augmenté avec l'augmentation du taux d'obésité. La forme principale du fructose est le sirop de maïs à haute teneur en fructose (HFCS) qui est employé en tant qu'édulcorant primordial dans la plupart des boissons et nourritures en Amérique du Nord. Il a été suggéré que la prise du fructose serait probablement un facteur qui contribue à l’augmentation de la prédominance de l'obésité. L'objectif de cette étude était d'évaluer s'il y a un rapport entre la consommation du fructose et le risque d'obésité. Nous avons travaillé sur deux bases de données des nations Cree et Inuit. Nous avons eu un groupe de 522 adultes Cree, (263 femmes et 259 hommes) dans deux groupes d'âge : les personnes entre 20 et 40 ans, et les personnes de 40 à 60 ans. Nous les avons classés par catégorie en quatre groupes d'indice de masse corporelle (IMC). L'outil de collecte de données était un rappel de 24 heures. En revanche, pour la base de données d'Inuit nous avons eu 550 adultes (301 femmes et 249 hommes) dans deux groupes d'âge semblables à ceux du Cree et avec 3 catégories d’indice de masse corporelle. Les données dans la base d'Inuit ont été recueillies au moyen de deux rappels de 24 heures. Nous avons extrait la quantité de fructose par 100 grammes de nourriture consommés par ces deux populations et nous avons créé des données de composition en nourriture pour les deux. Nous avons pu également déterminer les sources principales du fructose pour ces populations. Aucun rapport entre la consommation du fructose et l’augmentation de l’indice de masse corporelle parmi les adultes de Cree et d'Inuit n’a été détecté. Nous avons considéré l’apport énergétique comme facteur confondant potentiel et après ajustement, nous avons constaté que l'indice de masse corporelle a été associé à l’apport énergétique total et non pas à la consommation du fructose. Puisque dans les études qui ont trouvé une association entre la consommation de fructose et l’obésité, le niveau de la consommation de fructose était supérieure à 50 grammes par jour et comme dans cette étude ce niveau était inférieur à cette limite (entre 20.6 et 45.4 g/jour), nous proposons que des effets negatifs du fructose sur la masse corporelle pourraient être testés dans des populations à plus haute consommation. Les essais cliniques randomisés et éventuelles études cohortes avec différents niveaux de consommation de fructose suivis à long terme pourraient aussi être utiles. Mots clés : fructose, sirop de maïs à haute teneur en fructose (HFCS), obésité et poids excessif

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La maladie de Crohn (MC) pédiatrique a des conséquences majeures sur la qualité de vie des patients atteints (troubles de croissance, absentéisme scolaire, etc). L’étiologie de la MC est inconnue. La théorie de l’hygiène (TH) stipule que les conditions de vie sanitaires des pays industrialisés préviennent l’exposition antigénique et empêchent le développement de la tolérance immunitaire chez les enfants. Ceci mènerait à une réaction excessive du système immunitaire lors d’expositions subséquentes et engendrerait le développement de maladies inflammatoires chroniques telles la MC. Objectif: Analyser l’association entre la fréquence, la temporalité et le type d’infections infantiles (indicateurs d’environnements pourvus d’antigènes) et le risque de MC pédiatrique. Une étude cas-témoin fût réalisée, les cas de MC provenant d’un centre hospitalier tertiaire montréalais. Les témoins, provenant des registres de la Régie d’assurance maladie du Québec (RAMQ), furent appariés aux cas selon leur âge, sexe et lieu de résidence. L’exposition aux infections fût déterminée grâce aux codes de diagnostic ICD-9 inscrits dans la base de données de la RAMQ. Un modèle de régression logistique conditionnelle fût construit afin d’analyser l’association entre infections et MC. Des ratios de cotes (RC) et intervalles de confiance à 95% (IC 95%) furent calculés. Résultats: 409 cas et 1621 témoins furent recrutés. Les résultats de l’analyse suggèrent un effet protecteur des infections infantiles sur le risque de MC (RC: 0,67 [IC: 0,48-0,93], p=0,018), plus particulièrement au cours des 5 premières années de vie (RC: 0.74 [IC: 0,57-0,96], p=0,025). Les infections rénales et urinaires, ainsi que les infections des voies orales et du système nerveux central (virale), semblent particulièrement associées à l’effet protecteur. Les résultats de l’étude appuient la théorie de l’hygiène: l’exposition aux infections infantiles pourrait réduire le risque de MC pédiatrique.

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Microcosm studies were performed to evaluate the survival of Escherichia coli, Salmonella paratyphi and Vibrio parahaemolyticus in water and sediment collected from the freshwater region of Vembanad Lake (9 35◦N 76 25◦E) along the south west coast of India. All three test microorganisms showed significantly (p < 0.01) higher survival in sediment compared to overlying water. The survival in different sediment types with different particle size and organic carbon content revealed that sediment with small particle size and high organic carbon content could enhance their extended survival (p < 0.05). The results indicate that sediments of the Lake could act as a reservoir of pathogenic bacteria and exhibit a potential health hazard from possible resuspension and subsequent ingestion during recreational activities. Therefore, the assessment of bacterial concentration in freshwater Lake sediments used for contact and non contact recreation has of considerable significance for the proper assessment of microbial pollution of the overlying water, and for the management and protection of related health risk at specific recreational sites. Besides, assessment of the bacterial concentration in sediments can be used as a relatively stable indicator of long term mean bacterial concentration in the water column above

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Water quality of rooftop-collected rainwater is an issue of increased interest particularly in developing countries where the collected water is used as a source of drinking water. Bacteriological and chemical parameters of 25 samples of rooftop-harvested rainwater stored in ferrocement tanks were analyzed in the study described in this article. Except for the pH and lower dissolved oxygen levels, all other physicochemical parameters were within World Health Organization guidelines. Bacteriological results revealed that the rooftop-harvested rainwater stored in tanks does not often meet the bacteriological quality standards prescribed for drinking water. Fifty percent of samples of harvested rainwater for rural and urban community use and 20% of the samples for individual household use showed the presence of E. coli. Fecal coliform/fecal streptococci ratios revealed nonhuman animal sources of fecal pollution. Risk assessment of bacterial isolates from the harvested rainwater showed high resistance to ampicillin, erythromycin, penicillin, and vancomycin. Multiple antibiotic resistance (MAR) indexing of the isolates and elucidation of the resistance patterns revealed that 73% of the isolates exhibited MAR

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In the present study diversity of E. coli in the water samples of Cochin estuary were studied for a period of 3 years ranging from January 2010- December 2012. The stations were selected based on the closeness to satellite townships and waste input. Two of the stations (Chitoor and Thevara) were fixed upstream, two in the central part of the estuary namely Bolgatty and Off Marine Science Jetty, and one at the Barmouth. Diversity was assessed in terms of serotypes, phylogenetic groups and genotypes. Two groups of seafood samples such as fish and shellfish collected from the Cochin estuary were used for isolation of E. coli. One hundred clinical E. coli isolates were collected from one public health centre, one hospital and five medical labs in and around Cochin City, Kerala. From our results it was clear that pathogen cycling is occurring through food, water and clinical sources. Pathogen cycling through food is very common and fish and shellfish that harbour these strains might pose potential health risk to consumer. Estuarine environment is a melting pot for various kinds of wastes, both organic and inorganic. Mixing up of waste water from various sources such as domestic, industries, hospitals and sewage released into these water bodies resulting in the co-existence of E. coli from various sources thus offering a conducive environment for horizontal gene transfer. Opportunistic pathogens might acquire genes for drug resistance and virulence turning them to potential pathogens. Prevalence of ExPEC in the Cochin estuary, pose threat to people who use this water for fishing and recreation. Food chain also plays an important role in the transit of virulence genes from the environments to the human. Antibiotic resistant E. coli are widespread in estuarine water, seafood and clinical samples, for reasons well known such as indiscriminate use of antibiotics in animal production systems, aquaculture and human medicine. Since the waste water from these sources entering the estuary provides selection pressure to drug resistant mutants in the environment. It is high time that the authorities concerned should put systems in place for monitoring and enforcement to curb such activities. Microbial contamination can limit people’s enjoyment of coastal waters for contact recreation or shellfish-gathering. E. coli can make people sick if they are present in high levels in water used for contact recreation or shellfish gathering. When feeding, shellfish can filter large volumes of seawater, so any microorganisms present in the water become accumulated and concentrated in the shellfish flesh. If E. coli contaminated shellfish are consumed the impact to human health includes gastroenteritis, urinary tract infections (UTIs), and bacteraemia. In conclusion, the high prevalence of various pathogenic serotypes and phylogenetic groups, multidrug-resistance, and virulence factor genes detected among E. coli isolates from stations close to Cochin city is a matter of concern, since there is a large reservoir of antibiotic resistance genes and virulence traits within the community, and that the resistance genes and plasmid-encoded genes for virulence were easily transferable to other strains. Given the severity of the clinical manifestations of the disease in humans and the inability and/or the potential risks of antibiotic administration for treatment, it appears that the most direct and effective measure towards prevention of STEC and ExPEC infections in humans and ensuring public health may be considered as a priority.

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Worldwide water managers are increasingly challenged to allocate sufficient and affordable water supplies to different water use sectors without further degrading river ecosystems and their valuable services to mankind. Since 1950 human population almost tripled, water abstractions increased by a factor of four, and the number of large dam constructions is about eight times higher today. From a hydrological perspective, the alteration of river flows (temporally and spatially) is one of the main consequences of global change and further impairments can be expected given growing population pressure and projected climate change. Implications have been addressed in numerous hydrological studies, but with a clear focus on human water demands. Ecological water requirements have often been neglected or addressed in a very simplistic manner, particularly from the large-scale perspective. With his PhD thesis, Christof Schneider took up the challenge to assess direct (dam operation and water abstraction) and indirect (climate change) impacts of human activities on river flow regimes and evaluate the consequences for river ecosystems by using a modeling approach. The global hydrology model WaterGAP3 (developed at CESR) was applied and further developed within this thesis to carry out several model experiments and assess anthropogenic river flow regime modifications and their effects on river ecosystems. To address the complexity of ecological water requirements the assessment is based on three main ideas: (i) the natural flow paradigm, (ii) the perception that different flows have different ecological functions, and (iii) the flood pulse concept. The thesis shows that WaterGAP3 performs well in representing ecologically relevant flow characteristics on a daily time step, and therefore justifies its application within this research field. For the first time a methodology was established to estimate bankfull flow on a 5 by 5 arc minute grid cell raster globally, which is a key parameter in eFlow assessments as it marks the point where rivers hydraulically connect to adjacent floodplains. Management of dams and water consumption pose a risk to floodplains and riparian wetlands as flood volumes are significantly reduced. The thesis highlights that almost one-third of 93 selected Ramsar sites are seriously affected by modified inundation patterns today, and in the future, inundation patterns are very likely to be further impaired as a result of new major dam initiatives and climate change. Global warming has been identified as a major threat to river flow regimes as rising temperatures, declining snow cover, changing precipitation patterns and increasing climate variability are expected to seriously modify river flow regimes in the future. Flow regimes in all climate zones will be affected, in particular the polar zone (Northern Scandinavia) with higher river flows during the year and higher flood peaks in spring. On the other side, river flows in the Mediterranean are likely to be even more intermittent in the future because of strong reductions in mean summer precipitation as well as a decrease in winter precipitation, leading to an increasing number of zero flow events creating isolated pools along the river and transitions from lotic to lentic waters. As a result, strong impacts on river ecosystem integrity can be expected. Already today, large amounts of water are withdrawn in this region for agricultural irrigation and climate change is likely to exacerbate the current situation of water shortages.

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Background: Genetic and epigenetic factors interacting with the environment over time are the main causes of complex diseases such as autoimmune diseases (ADs). Among the environmental factors are organic solvents (OSs), which are chemical compounds used routinely in commercial industries. Since controversy exists over whether ADs are caused by OSs, a systematic review and meta-analysis were performed to assess the association between OSs and ADs. Methods and Findings: The systematic search was done in the PubMed, SCOPUS, SciELO and LILACS databases up to February 2012. Any type of study that used accepted classification criteria for ADs and had information about exposure to OSs was selected. Out of a total of 103 articles retrieved, 33 were finally included in the meta-analysis. The final odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by the random effect model. A sensitivity analysis confirmed results were not sensitive to restrictions on the data included. Publication bias was trivial. Exposure to OSs was associated to systemic sclerosis, primary systemic vasculitis and multiple sclerosis individually and also to all the ADs evaluated and taken together as a single trait (OR: 1.54; 95% CI: 1.25-1.92; p-value, 0.001). Conclusion: Exposure to OSs is a risk factor for developing ADs. As a corollary, individuals with non-modifiable risk factors (i.e., familial autoimmunity or carrying genetic factors) should avoid any exposure to OSs in order to avoid increasing their risk of ADs.

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The Sustainably Managing Environmental Health Risk in Ecuador project was launched in 2004 as a partnership linking a large Canadian university with leading Cuban and Mexican institutes to strengthen the capacities of four Ecuadorian universities for leading community-based learning and research in areas as diverse as pesticide poisoning, dengue control, water and sanitation, and disaster preparedness. By 2009, train-the-trainer project initiation involved 27 participatory action research Master’s theses in 15 communities where 1200 community learners participated in the implementation of associated interventions. This led to establishment of innovative Ecuadorian-led master’s and doctoral programs, and a Population Health Observatory on Collective Health, Environment and Society for the Andean region based at the Universidad Andina Simon Bolivar. Building on this network, numerous initiatives were begun, such as an internationally funded research project to strengthen dengue control in the coastal community of Machala, and establishment of a local community eco-health centre focusing on determinants of health near Cuenca. Alliances of academic and non-academic partners from the South and North provide a promising orientation for learning together about ways of addressing negative trends of development. Assessing the impacts and sustainability of such processes, however, requires longer term monitoring of results and related challenges.

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A wide variety of exposure models are currently employed for health risk assessments. Individual models have been developed to meet the chemical exposure assessment needs of Government, industry and academia. These existing exposure models can be broadly categorised according to the following types of exposure source: environmental, dietary, consumer product, occupational, and aggregate and cumulative. Aggregate exposure models consider multiple exposure pathways, while cumulative models consider multiple chemicals. In this paper each of these basic types of exposure model are briefly described, along with any inherent strengths or weaknesses, with the UK as a case study. Examples are given of specific exposure models that are currently used, or that have the potential for future use, and key differences in modelling approaches adopted are discussed. The use of exposure models is currently fragmentary in nature. Specific organisations with exposure assessment responsibilities tend to use a limited range of models. The modelling techniques adopted in current exposure models have evolved along distinct lines for the various types of source. In fact different organisations may be using different models for very similar exposure assessment situations. This lack of consistency between exposure modelling practices can make understanding the exposure assessment process more complex, can lead to inconsistency between organisations in how critical modelling issues are addressed (e.g. variability and uncertainty), and has the potential to communicate mixed messages to the general public. Further work should be conducted to integrate the various approaches and models, where possible and regulatory remits allow, to get a coherent and consistent exposure modelling process. We recommend the development of an overall framework for exposure and risk assessment with common approaches and methodology, a screening tool for exposure assessment, collection of better input data, probabilistic modelling, validation of model input and output and a closer working relationship between scientists and policy makers and staff from different Government departments. A much increased effort is required is required in the UK to address these issues. The result will be a more robust, transparent, valid and more comparable exposure and risk assessment process. (C) 2006 Elsevier Ltd. All rights reserved.