In low-resource contexts, household-level point-of-use water treatment (POUWT) techniques are the final, and sometimes only, barrier against waterborne illnesses, and in these and other water-related applications, health risks can be quantified using one of two methods. Firstly, Escherichia coli (or other indicator organism) counts can be used to monitor water and determine adherence to a health-based limit (i.e. compliance monitoring). Secondly, E. coli can be used to conduct a quantitative microbial risk assessment (QMRA), indicating the level of protection conferred by a given POUWT device by spiking test water with E. coli to ascertain a reduction efficacy relative to that target organism, a process referred to as challenge testing, which is typically carried out in a laboratory context. Although both methods are well established, both have scope for improvement for effective field application in low-resource contexts. Regarding compliance monitoring, I assessed the performance of a new low-cost field kit for E. coli enumeration, which was designed by others. I also assessed the feasibility of re-using some disposable materials, in terms of sterility and mechanical wear. The use of the new low-cost field kit was successful during the fieldwork campaign; however, re-using disposable materials introduced a relatively high occurrence of false positive results during E. coli enumeration. Use of the new low-cost field kit can reduce financial barriers, thus enabling greater water quality testing coverage. Regarding challenge testing, the aim of this study was to adapt current protocols to assess the household performance (as opposed to laboratory performance) of POUWT techniques. I developed a conceptual framework to conduct Field Challenge Tests (FCT’s) on POUWT techniques, using a probiotic health supplement containing E. coli as the challenge organism. I successfully carried out a FCT in Malawi with limited resources, verifying FCT viability. Applications of such FCT’s include quality control practices for manufactured devices, guiding QMRA and recommendations by public health organizations regarding POU device selection, and assessing the impact of user training programmes regarding POUWT techniques. / Graduate

In the rural areas of Madagascar only 29% of the population has access to clean water and 10% has access to improved sanitation. It has been estimated that environmental risk factors, such as inadequate access to clean drinking water and proper sanitation, are responsible for 94% of the diarrheal disease burden. This study was focused on testing a point-of-use technology called the Tulip filter, which is a siphon ceramic candle filter impregnated with silver. The purpose is to assess its feasibility for implementation in rural regions of Madagascar through a laboratory study performed at the University of South Florida. The study tested the Tulip filters for turbidity, total coliform, and E. coli removal for various types of water. Each filter processed synthetic water classified as control (tap water, <1 >NTU), low turbidity (5-7 NTU), medium turbidity (25-35 NTU), or high turbidity (60-80 NTU). Approximately once every 100 L the filters processed pond water to test coliform removal. Furthermore, the pthesis size distribution was measured to analyze the effectiveness of filter to remove various pthesis sizes. Two of the seven Tulip filters tested had some quality control issues with the glue connecting the ceramic candle to the plastic cap and failed at 350 L. Of the functioning filters, the turbidity removal ranged from 93% to 98% with none of the 779 samples taken from 4 filters above the WHO recommended 5 NTU for drinking water. The log removal of total coliforms was about 3.90 to 4.16 and achieved an average of 1 CFU/100mL of E. coli in the filtered water. WHO guidelines consider water with 1-10 CFU/100 mL a "low risk" and all but one of the working filters had E. coli and total coliform concentrations within, or below, this range for all samples (n=20 for each filter). The filters also showed an average of 96% removal of pthesiss of all size ranging from 0.5 to 10 µm. This study finds that the Tulip filter is an appropriate of point-of-use technology that enables rural areas access to "low risk" water, at a low cost and with minimal maintenance. This study also reinforces the importance of adding silver or another biocide to ceramic filters because pthesiss of sizes up to 10 µm are able to pass through the filter. This is particularly a problem because pathogens can range from 0.01 µm to 100 µm.

Currently 884 million people worldwide are living without access to an improved source of drinking water (WHO/UNICEF, 2011). Piped-water on premises is the ultimate goal of World Health Organization (WHO) due to the ability to treat all of the water and distribute it safely in pressurized pipes. However, Household Water Treatment and Safe Storage (HWTS) is an option for improving the quality of drinking water where that infrastructure is not yet developed, especially where there is a risk of recontamination between point of collection and point of use (Clasen, 2006). This study analyzed one such HWTS, the ceramic pot water filter. The study compared the hydraulic properties of the FilterPure (FP) and Potters for Peace (PFP) ceramic pot filters through a thirteen-month field study in the Dominican Republic and laboratory studies at the University of South Florida. In the field study 55 filters were tested for first hour flow rate and hydraulic conductivity. Eight first hour flow rate tests were conducted in the field on one month intervals during months 7- 13. FP filters had an average first hour flow rate of 553 ml/hr and PFP Filters had a first hour flow rate of 395 ml/hr. No significant change in first hour flow rate was observed over time in FP filters. PFP experienced an average increase of 31 ml/hr per month during the seven-month testing period. Falling head tests were conducted on four filters in the laboratory and the flow rate was modeled to determine hydraulic conductivity. Hydraulic conductivity values for FP filters ranged from k = 0.0495 - 0.0831 cm/hr and for PFP filters ranged from k = 0.0136 - 0.0389 cm/hr. Eight out of 29 (26%) Potters for Peace filters in the field had first hour flow rates of less than 250 ml/hr by month nine of the study and had to be replaced and removed from the study. In total 24 of 55 (44%) filters (8 FP and 16 PFP) had to be removed from the study due to several reasons discussed in this thesis.

Gram-negative infection has been linked to hospital water although few studies have examined whether water systems are reservoirs of nosocomial pathogens. This study investigated longitudinal recovery of the opportunistic pathogens Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii from water outlets of a haematology unit and evaluated Point-Of-Use Filtration (POU-F) as a control measure. In a two-year double cross-over trial, water samples and swabs were taken weekly from 39 showers/taps on the unit. Four study phases alternated between non-filtered (Phases 1 &amp; 3), and filtered outlets (Phases 2 &amp; 4) using Pall AquasafeTM 14-day filters. In Phases 1 &amp; 3; 99% of 1396 samples yielded bacterial growth, with colonies generally too numerous to count. Target species were isolated from 22% of water samples (P. aeruginosa 14%; S. maltophilia 10%) and 10% of swabs. P. aeruginosa was particularly associated with handwash stations and S. maltophilia with showers. A. baumannii was not isolated. With POU-F; 22% of 1242 samples yielded bacterial growth (mean CFU/100ml ,4.6). S. maltophilia was isolated only once from water but never from outlet swabs. PCR typing identified clusters of isolates colonizing different outlets over time but no clear association between water and patient isolates was identified. The incidence of Gram negative infections remained low throughout the study. Without POU-F, water from taps/showers represented a source of bacteria including the target species. POU-F substantially reduced the frequency and number of target species from every outlet, and merits further investigation as an intervention to protect immunocompromised patients from opportunistic pathogens.

Submitted by Marcio Emanuel Paixão Santos (marcio.santos@ucsal.br) on 2018-06-21T17:02:54Z No. of bitstreams: 1 DISSERTACAOVICTORMAGALHAESDUARTE.pdf: 5911465 bytes, checksum: 6117af0ebbe7176d6a0b430080b16c8e (MD5) / Approved for entry into archive by Linda Bulhosa (linda.gomes@ucsal.br) on 2018-06-21T19:19:19Z (GMT) No. of bitstreams: 1 DISSERTACAOVICTORMAGALHAESDUARTE.pdf: 5911465 bytes, checksum: 6117af0ebbe7176d6a0b430080b16c8e (MD5) / Made available in DSpace on 2018-06-21T19:19:19Z (GMT). No. of bitstreams: 1 DISSERTACAOVICTORMAGALHAESDUARTE.pdf: 5911465 bytes, checksum: 6117af0ebbe7176d6a0b430080b16c8e (MD5) Previous issue date: 2010-03-31 / A pesquisa trata da qualidade da água potável consumida na cidade do Salvador, bem como apresenta as principais conseqüências para a saúde pela ingestão dos contaminantes que possam estar presentes na água potável e as medidas preventivas mais adequadas para removê-las. As contaminações que ocorrem nas fontes advêm do aumento da atividade industrial, do desenvolvimento de compostos agrícolas sintéticos, do despejo dos esgotos doméstico e industrial no meio ambiente sem o devido tratamento. A metodologia adotada incluiu análises da água potável consumida em Salvador, avaliação da legislação brasileira, sendo demonstrado que, mesmo quando são atendidos os parâmetros contidos na mesma, não pode ser garantida que a água potável não vá trazer sérios problemas para a saúde das pessoas a curto, médio e longo prazo. Os resultados demonstram que as pessoas avaliadas não possuem conhecimentos básicos necessários sobre os riscos dos contaminantes da água e o que fazer para minimizar as suas conseqüências. Mesmo sabendo que as concentrações dos contaminantes na água mudam muito de um dia para o outro, adotamos critérios científicos modernos ao serem avaliadas as análises de água fornecida pela empresa de saneamento da cidade, dos poços de água de uma empresa do Pólo Petroquímico de Camaçari e de amostras de água mineral encaminhadas a laboratórios especializados. Varias contaminantes da água foram mencionados e avaliados segundo critérios toxicológicos usando-se valores máximos fixados nas legislações do Brasil, Estados Unidos e Comunidade Européia (Organização Mundial de Saúde). Efeitos aditivos e sinergéticos dos contaminantes da água alem do fator denominado susceptibilidade individual foram citados como condições essenciais nas avaliações dos riscos reais das concentrações e das misturas dos contaminantes presentes na água potável consumida. Foram apresentadas técnicas de tratamento que possibilitam remover as impurezas orgânicas, inorgânicas, biológicas e radioativas da água potável, permitindo que as pessoas possam minimizar ao máximo os riscos de contaminação por via hídrica, conservando a saúde em elevados níveis. Foram ainda feitas sugestões que objetivam reduzir/eliminar as contaminações dos nossos mananciais de água potável, quer seja por ações federais, estaduais e municipais e da colaboração direta dos próprios cidadãos. Diante dos aspectos científicos abordados aqui, concluímos que tanto a água mineral quanto a água da rede de distribuída municipal não são isentas de riscos para consumo humano. / The research talks about the drinking water which is consumed in Salvador city and presents the main health consequences of the contaminants that can be found in the water and the prevention measurements more suitable to remove them. Contaminations which can be found in the water sources come from the growth industrial activities, synthetic agriculture compounds, domestic sewage and waste water that run-off without a proper treatment. The methodology used included drinking water analyzes consumed in Salvador city, an evaluation of Brazilian legislation, being demonstrated that, even when the legal parameters in the laws are fulfilled, it can not warranty that drinking this water will not produce serious health problems in the people in a short, medium and long period of time. The results show that people who were evaluated do not have enough basic knowledge about the risks of water contaminants and they do not know what to do to minimize their consequences. Even knowing that the concentration of the drinking water contaminants change a lot from one day to another, it was adopted modern scientific methodology when the water analyzes from the municipal water supply company were evaluated. The same methodology was adopted in the well water samples from a company in the Petrochemical Complex in Camaçari area and from mineral water samples which were sent to specialized laboratories. Many contaminants in the water were mentioned and evaluated under toxicological standards using maximum values established in the Brazilian, United States and European legislation (World Health Organization). Additive and synergetic effects of the drinking water contaminants besides the factor named individual susceptibility were cited as essential conditions in the real risk assessment of the contaminants concentration and mixtures of them present in the drinking water in study. It was presented point of use treatment techniques that make possible to remove organic, inorganic, biological and radioactive contaminants from drinking water. Doing that, people can minimize as much as possible the contamination risks from water sources, keeping the health in high levels. Yet it was done suggestions that aim to reduce or eliminate the contaminants of our drinking water sources, by federal, state and municipal actions and direct collaboration of the citizens themselves. In front of the scientific aspects mentioned here, we concluded that as much the mineral water as the municipal water from the distribution network are not free of risks to the human consumption.

Gram-negative infection has been linked to hospital water although few studies have examined whether water systems are reservoirs of nosocomial pathogens. This study investigated longitudinal recovery of the opportunistic pathogens Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii from water outlets of a haematology unit and evaluated Point-Of-Use Filtration (POU-F) as a control measure. In a two-year double cross-over trial, water samples and swabs were taken weekly from 39 showers/taps on the unit. Four study phases alternated between non-filtered (Phases 1 & 3), and filtered outlets (Phases 2 & 4) using Pall AquasafeTM 14-day filters. In Phases 1 & 3; 99% of 1396 samples yielded bacterial growth, with colonies generally too numerous to count. Target species were isolated from 22% of water samples (P. aeruginosa 14%; S. maltophilia 10%) and 10% of swabs. P. aeruginosa was particularly associated with handwash stations and S. maltophilia with showers. A. baumannii was not isolated. With POU-F; 22% of 1242 samples yielded bacterial growth (mean CFU/100ml ,4.6). S. maltophilia was isolated only once from water but never from outlet swabs. PCR typing identified clusters of isolates colonizing different outlets over time but no clear association between water and patient isolates was identified. The incidence of Gram negative infections remained low throughout the study. Without POU-F, water from taps/showers represented a source of bacteria including the target species. POU-F substantially reduced the frequency and number of target species from every outlet, and merits further investigation as an intervention to protect immunocompromised patients from opportunistic pathogens. / School of Life Sciences, University of Bradford and Pall Medical (Pall Europe Ltd)

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