Water is a basic human need (Millennium Development Goal-Target 10) and a central element in all civilisations, yet microbial contamination of surface waters used for drinking, contact recreation, and shellfishery provides an effective vehicle for the spread of microbial waterborne diseases and outbreaks that can cause illness or death in humans. Microbial pathogens remain the most direct, real and pervasive risk to human health, especially in Less Economically Developed Countries. However, water quality managers are restricted in providing effective monitoring and management designs and strategies by the inability to identify routinely the source of microbial contamination. Microbial water quality of many surface waters is likely to deteriorate further as a result of climate change. This research used the River Ouse catchment (SE England) as a test-bed to investigate the application of simple and low-cost monitoring and approaches that can be applied in other river catchments, to monitor and manage microbial water quality during various meteorological conditions and seasons. This novel approach is the first time such methods have been combined in order to study a river catchment. As such, it represents a significant advancement in our understanding of complex environmental processes and ability to manage and mitigate adverse environmental impacts. Sixteen parameters were measured and analysed from 365 water samples collected approximately every fourteen days from fourteen discrete sampling sites. The chemophysical parameters were measured using recommended instruments and procedures whilst faecal indicator organisms (FlO) were enumerated using International Organisation for Standardisation (ISO) methods and procedures. In addition to ISO methods, the study trialled a newly developed low-cost phage-based method capable of identifying human faecal contamination in surface waters. The results showed that all sampling sites were microbially contaminated, and suggested that the main source. was non-human. Thermotolerant coliforms (TTC) and presumptive intestinal enteroCOCCI (ENT) levels tended to be 1.1-1.2 logs higher during rainstorm events. Spatio-temporal variations in microbial parameters were accounted for by three principal components (67.6%). Bacterial indicator decreased downstream while chemophysical parameters increased downstream. Models generated for TTC and ENT accounted for 63% and 65% variability in TTC and ENT levels respectively. Cluster Analysis of the fourteen sampling sites revealed six 'sentinel' sampling sites and this process is proposed as a means of rationalising river catchment monitoring. The correlation between TTC and phages of Bacteroides (GB-124) was very small (r=0.05) whilst those between turbidity, suspended solids, and bacterial indicators were significantly positively strong. Hence, turbidity could serve as a low-cost screening tool for microbial pollution. A capricious climate, animal and human interferences were likely faecal pollution sources. The findings offer low-cost screening approaches for river catchment management through the identification of 'when and where' pollution levels are most likely to represent a potential risk to public health under various meteorological conditions, and help those responsible for water quality monitoring to better target resources in future. These demonstrably effective approaches will contribute to future European collaborative work to improve waterborne FlO and pathogen prediction ('hotspots' of elevated waterborne disease risk during changing climate patterns), and future EU and WHO initiatives (such as Water Safety Plans) to improve environmental disease protection for all.

Made available in DSpace on 2015-03-26T13:47:22Z (GMT). No. of bitstreams: 1 texto completo.pdf: 761454 bytes, checksum: 12b991fd727e757f5f80c026d87d867c (MD5) Previous issue date: 2013-12-19 / The objective of this work is to characterize the microbiological quality of bottled natural mineral water sold in Viçosa - MG and understand users' perceptions related to this source of water supply for human consumption. To diagnose the quality of bottled water samples were collected from four brands of natural mineral water bottled in gallon 20 liters for microbiological evaluation. The quality of these waters was verified by bacteriological tests for Escherichia coli, total coliforms, Enterococci, Pseudomonas aeruginosa and values of color and turbidity. The profile of consumers of bottled water, the perception of water quality and factors that motivate the choice of this type of water were studied by means of interviews with application of qualitative method employing the strategy of content analysis. For the presence of total coliforms only brand D showed this bacterium, equivalent to a contamination of 25 % of the samples from this brand. There was no presence of E.coli in any brand analyzed. For enterococci, all the brands had at least once this bacteria, and the brand B showed contamination of 37.5 % of the studied samples. Presence of P.aeruginosa was observed in two marks (A and C) contaminated with 25% of the investigated samples for each brand. Regarding the qualitative study on consumer perception of bottled natural mineral water was observed that the question of why choice for consumption of bottled water is less related to the sense of health protection and more to the spread of a social practice, consolidated and legitimated in everyday life. / O objetivo deste trabalho foi caracterizar a qualidade microbiológica de águas minerais naturais envasadas comercializadas no município de Viçosa-MG e compreender as percepções dos usuários relacionadas a essa fonte de abastecimento de água para consumo humano. Para o diagnóstico da qualidade da água envasada foram coletadas amostras de quatro marcas de água mineral natural envasada em galão de 20 litros para avaliação microbiológica. A qualidade dessas águas foi verificada por meio de análises bacteriológicas para Escherichia coli, coliformes totais, Enterococos, Pseudomonas aeruginosa e valores de cor e turbidez. O perfil dos consumidores de água envasada, a percepção sobre qualidade da água e fatores que motivam a escolha desse tipo de água foram pesquisados por meio da realização de entrevistas, com aplicação do método qualitativo empregando a estratégia da análise de conteúdo. A presença de coliformes totais foi identificada somente na marca D, sendo que 25% das amostras tiveram resultado positivo. Não houve detecção de E. coli em qualquer das marcas analisadas. Para Enterococos, todas as marcas apresentaram pelo menos uma amostra positiva, sendo que a marca B apresentou contaminação em 37,5% das amostras pesquisadas. A presença de P. aeruginosa foi observada em duas marcas (A e C) com contaminação de 25% das amostras pesquisadas referente a cada marca. Em relação ao estudo qualitativo sobre a percepção dos consumidores de água mineral natural envasada foi possível perceber que a questão do motivo de escolha para o consumo da água envasada está relacionada menos ao sentido de proteção da saúde e mais à disseminação de uma prática social, consolidada e legitimada no cotidiano.