Submitted by Maike Costa (maiksebas@gmail.com) on 2017-02-09T11:58:42Z No. of bitstreams: 1 arquivo total.pdf: 1438788 bytes, checksum: 9590b3fb5151d31119e2920baea83d58 (MD5) / Made available in DSpace on 2017-02-09T11:58:42Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 1438788 bytes, checksum: 9590b3fb5151d31119e2920baea83d58 (MD5) Previous issue date: 2016-06-20 / Minimally ripened cheeses, a category that includes the coalho cheese, have physicochemical characteristics that facilitate the survival and growth of pathogenic bacteria associated with foodborne illness outbreaks. Use of mathematical models in the predictive microbiology allows to estimate the effect of biotic and abiotic conditions on microbial growth, and hence the possible risk associated with the presence and increase of the population of a specific pathogen in a particular food. Considering these aspects, the present study aimed to: (i) assess the coalho cheese as a potential substrate for the growth of the pathogenic bacteria Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. in function of temperature, pH and water activity (aw) found in commercial samples of this type of product; and (ii) performing primary modeling growth of different strains of E. coli in coalho cheese samples stored under low temperature. The estimates of the growth kinetics parameter (maximum growth rate - Grmax, log UFC/g/h) in function of the combination of the values (percentile 20, 50, 75 and 90) for temperature, pH and aw were generated by ComBase Predictor. The growth kinetics (Grmax) of E. coli strains in coalho cheese (10 °C) was assessed by using the primary model of Baranyi and Roberts (1994), available in spreadsheet DMFit 3.5 (ComBase). The largest Grmax values as a function of different combinations of temperature, pH and aw were observed for L. monocytogenes (Grmax 0.01 to 0.07 log CFU/g/h), Salmonella (Grmax 0.01 to 0.04 log CFU/g/h) and S. aureus (Grmax <0.01 to 0.05 log CFU/g/h). E. coli Grmax values varied from 0.01 to 0.03 log CFU/g/h. Overall, the Grmax values increased as the temperature increased in cheese samples, regardless of the aw and pH values. The estimated Grmax values for the E. coli strains when inoculated into coalho cheese ranged from 0.01 to 0.03 log CFU/g/h, respectively. High R2 values (≥ 0.97) were obtained to the growth curves of all E. coli strains tested. The estimates of the growth kinetics parameters in function of the values of temperature, aw and pH tested, as well as those observed in artificially contaminaed cheese samples showed that the coalho cheese is characterized as favorable substrate for the survival and growth of E. coli, L. monocytogenes, Salmonella spp. and S. aureus, which may pose a risk to consumers’ health if contaminated with these bacteria during production, transportation or marketing. / Os queijos de baixa maturação, categoria que inclui o queijo de coalho, possuem características físico-químicas que podem facilitar a sobrevivência e crescimento de bactérias patogênicas associadas a surtos de doenças transmitidas por alimentos. O emprego de modelos matemáticos na microbiologia preditiva permite estimar o efeito das condições bióticas e abióticas sobre o crescimento microbiano, e, consequentemente, o possível risco associado à presença e evolução da população de um patógeno em um alimento determinado. Considerando estes aspectos, o presente estudo teve como objetivos: (i) avaliar o queijo de coalho como substrato potencial para o crescimento das bactérias patogênicas Escherichia coli, Listeria monocytogenes, Staphylococcus aureus e Salmonella spp. em função de valores de temperatura, pH e atividade de água (aa) encontrados em amostras comerciais deste tipo de produto; e (ii) realizar modelagem primária do crescimento de diferentes cepas de E. coli em amostras de queijo de coalho armazenadas sob baixa temperatura. As estimativas dos parâmetros de cinética de crescimento (taxa máxima de crescimento – Grmax, log UFC/g/) em função da combinação dos valores (Percentil 20, 50, 75 e 90) de temperatura, pH e aa foram geradas pelo ComBase Predictor. A cinética de crescimento das cepas de E. coli em queijo de coalho (10 °C) foi avaliada por meio do Grmax utilizando o modelo primário de Baranyi e Roberts (1994), disponível na planilha do DMFit 3.5 (ComBase). Os maiores valores de Grmax em função das diferentes combinações de temperatura, pH e aa foram verificados para L. monocytogenes (Grmax 0,01 – 0,07 log UFC/g/h), Salmonella spp. (Grmax 0,01 – 0,04 log UFC/g/h) e S. aureus (Grmax 0,01 – 0,05 log UFC/g/h). Os valores de Grmax para E. coli variaram de 0,01 a 0,02 log UFC/g/h. De forma geral, os valores de Grmax aumentaram, proporcionalmente a temperatura nas amostras de queijo, a despeito dos valores de aa e pH. Os valores estimados de Grmax das cepas de E. coli quando inoculadas em queijo de coalho variaram de 0,01 a 0,03 log UFC/g/h. Foram obtidos elevados valores de R2 (≥ 0,97) para as curvas de crescimento de todas as cepas de E. coli testadas. As estimativas dos parâmetros de cinética de crescimento em função dos valores de temperatura, aa e pH testados, bem como àqueles verificados em amostras artificialmente contaminadas, mostram que o queijo de coalho se caracteriza como substrato favorável para a sobrevivência e crescimento de E. coli, L. monocytogenes, Salmonella spp. e S. aureus, podendo representar um risco a saúde aos consumidores caso seja contaminado com estas bactérias durante a sua produção, transporte ou comercialização.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-05T15:07:47Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 20160404 Tese final Duarte catalogada formato digital.pdf: 4026733 bytes, checksum: d6ac5259ffcea51116ee53e1ba8c164a (MD5) / Made available in DSpace on 2016-08-05T15:07:47Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 20160404 Tese final Duarte catalogada formato digital.pdf: 4026733 bytes, checksum: d6ac5259ffcea51116ee53e1ba8c164a (MD5) Previous issue date: 2016-03-18 / CNPq / The environment is a complex system where human, ecological environment (e.g., plants, animals, microbes), materials (eg, pollutants, medical), and meteorological/oceanographic conditions interact. The human impact has potential to cause significant damage to the ecological environment (e.g., potential oil spills on the coast cause risk to coastal ecosystems, tuna industrial fishing cause risk to sharks that are bycaught). Similarly, the human impact may turn against the human itself by favoring the growth of populations of unwanted species (e.g., poor sanitation favors the growth of microbial populations that cause risk of an excessive proportion of sick humans). Therefore, it has been demanded an efficient method of quantifying the risks in systems where plant, animals or microbes populations are involved in order to give support to risk management in environmental issues, fisheries management and public health. First, this paper proposes a methodology capable of quantifying ecological risks (i.e., likelihood of adverse effects on the ecosystem, in the long term, due to exposure to stressors such as chemical, fishing, etc.) or microbial risks (i.e., likelihood of adverse effects in humans, in the long term, due to exposure to microbial pathogens). It uses population modeling to simulate future changes in populations of ecologically important species (e.g., fish, corals, sharks), or undesirable (e.g., parasites), under conditional scenarios simulating the influence humans impacting and/or managing the risks. The risk is calculated in terms of probability of extinction or decline, explosion or growth of these populations over time. Second, the methodology is applied to four case studies in Brazil. Each of them have their specific conclusions, as follows. (1) Ecological Risk Assessment caused by potential maritime accidents in the transportation of oil to the port of Suape. Conclusion: low but significant ecological risk. (2) Ecological Risk Assessment caused by potential maritime accidents in the passage of oil tankers nearby Fernando de Noronha. Conclusion: negligible ecological risk, although a more detailed analysis is required due to limited data. (3) Microbial Risk Assessment to Porto de Galinhas community inherent to sanitation and medical treatment program. Conclusion: high microbial risk, the current sanitation level is not enough to contain the spread of schistosomiasis disease, and periodic treatment of patients is not efficient to reduce risks significantly. (4) Ecological Risk Assessment of tuna industrial fishing in Brazilian waters. Conclusion: industrial tuna fishing does not cause significant risks to the population of Mako sharks in the South Atlantic Ocean. In each case study, several conditional scenarios were simulated for the next 100 years, including adverse scenarios and scenarios with risk control measures. Thus, it was possible to quantify the added risk caused by each adverse condition as well as the reduced risk caused by each control measure. In this way, the manager has objective information to prioritize scenarios and evaluate the cost-effectiveness of control measures. The general conclusion of this work is that the proposed methodology has proven to be practicable, useful and efficient. / O meio-ambiente é um sistema complexo onde interagem humanos, meio ecológico (e.g., plantas, animais, micróbios), materiais (e.g., poluentes, medicinais) e condições meteorológicas/oceanográficas. O impacto humano tem potencial para causar danos significativos ao meio ecológico (e.g., potenciais vazamentos de petróleo na costa causam risco ao ecossistema costeiro, pesca industrial de atum causa risco aos tubarões que são pescados por acidente). Similarmente, o impacto humano pode se voltar contra o próprio humano ao favorecer o crescimento de populações de espécies indesejáveis (e.g., saneamento básico precário favorece o crescimento de populações de micróbios que causam risco de haver uma excessiva parcela de humanos doentes). Portanto, tem sido demandado um método eficiente de quantificar os riscos inerentes a sistemas onde populações de plantas, animais ou micróbios estejam envolvidas, de forma a dar suporte para o gerenciamento dos riscos em problemas de gestão ambiental, gestão pesqueira e saúde pública. Em primeiro lugar, este trabalho propõe uma metodologia capaz de quantificar riscos ecológicos (i.e., probabilidade de ocorrência de efeitos adversos no ecossistema, no longo prazo, devido à exposição a estressores como químicos, pesca, entre outros) ou microbianos (i.e., probabilidade de ocorrência de efeitos adversos em humanos, no longo prazo, devido à exposição a patógenos microbianos). Utilizase a modelagem populacional para simular futuras mudanças nas populações de espécies ecologicamente importantes (e.g., peixes, corais), ou indesejáveis (e.g., parasitas), quando condicionadas a cenários que simulam a influência do humano causando impacto e/ou gerindo os riscos. O risco é calculado em termos de probabilidade de extinção ou declínio, explosão ou crescimento, dessas populações ao longo do tempo. Em segundo lugar, aplica-se a metodologia para avaliar o risco inerente a quatro estudos de caso no Brasil. Cada um deles tem sua conclusão específica, como segue. (1) Análise de Risco Ecológico causado por potenciais acidentes marítimos no transporte de petróleo para o porto de Suape. Conclusão: baixo risco ecológico, porém significativo. (2) Análise de Risco Ecológico causado por potenciais acidentes marítimos na passagem de navios petroleiros ao largo de Fernando de Noronha. Conclusão: risco ecológico negligenciável, mas uma análise mais detalhada é necessária devido à escassez de dados. (3) Análise de Risco Microbiano à comunidade de Porto de Galinhas inerentes ao sistema de saneamento básico e programa de tratamento medicinal. Conclusão: alto risco microbiano, o nível de saneamento básico atual não é suficiente para conter a proliferação da doença esquistossomose, e o tratamento periódico de doentes não é eficiente para reduzir os riscos significativamente. (4) Análise de Risco Ecológico causado pela pesca industrial de atum em águas brasileiras. Conclusão: a pesca industrial de atuns não causa riscos significativos à população de tubarões Mako no oceano Atlântico Sul. Em cada estudo de caso, foram simulados diversos cenários condicionais para os próximos 100 anos, incluindo cenários adversos e cenários com medidas de controle dos riscos. Assim, foi possível quantificar a adição do risco causada por cada cenário adverso e a redução do risco causada por cada medida de controle. Desta forma, o gestor tem informação objetiva para priorizar cenários e avaliar o custo-benefício das medidas de controle. A principal conclusão deste trabalho é que a metodologia proposta provou-se ser praticável, útil e eficiente.

Sanitation, renewable energy, and food security are among the most pressing global development needs of the century, especially for small cities with rapid population growth. Currently, 53% of the world’s population either lacks access to improved sanitation or discharges fecal waste to the environment without treatment. Furthermore, 80% of food consumed in developing regions is produced by 500 million small farms, and while many of them are still rain-fed, irrigated agriculture is increasing. The post-2015 Sustainable Development Goals, recently adopted by the United Nations, include targets to address the water-energy-food nexus. Wastewater reuse in agriculture can be an important solution for these goals, if it is done safely. Globally, 18 – 20 million hectares of agricultural land are irrigated with wastewater, but much is untreated, unregulated, or unsanctioned, causing concerns and uncertainty about health risks. There is a need to better understand pathogen removal in natural and non-mechanized wastewater treatment systems, such as waste stabilization ponds (WSPs) and upflow anaerobic sludge blanket (UASB) reactors, which are commonly used in small cities and towns. Riverbank filtration (RBF) is also a natural technique used by farmers in developing countries to treat surface water polluted with untreated sewage, but pathogen removal in these systems has seldom been assessed in developing countries. The focus of this dissertation is on pathogen removal in natural and non-mechanized wastewater treatment and reuse systems, to evaluate the health implications of water reuse for irrigation, with the following three objectives: 1) assess the current understanding of virus removal in WSP systems through a systematic review of the literature; 2) measure the removal of viruses and their association with particles in systems with WSPs, UASB reactors, or both; and 3) assess the fate and transport of pathogens and fecal indicators in wastewater treatment systems with direct and indirect reuse for irrigation to estimate microbial risks. To advance the understanding of virus removal in WSP systems, a comprehensive analysis of virus removal reported in the literature from 71 different WSP systems revealed only a weak to moderate correlation of virus removal with theoretical hydraulic retention time (HRT). For each log10 reduction of viruses a geometric mean of 14.5 days of retention was required, but the 95th percentile of the data analyzed was 54 days. Also, whereas virus-particle association and subsequent sedimentation has been assumed to be an important removal mechanism for viruses in WSPs, the literature review revealed a lack of evidence to confirm the validity of this assumption. The association of human adenovirus (AdV) with wastewater particles was assessed in five full-scale wastewater treatment systems in Bolivia, Brazil, and the United States (two with only WSPs, two with a UASB reactor and WSPs, and one with only UASB reactors). A mesocosm study was also conducted with WSP water from one of the full-scale systems, and some samples were also analyzed for pepper mild mottle virus (PMMoV), F+ coliphage, culturable enterovirus (EV), norovirus (NoV), and rotavirus (RV). Results indicate that WSPs and UASB reactors affect virus-particle associations in different ways, which may differ for different viruses. In UASB reactor effluent, PMMoV was more associated with particles <180 >µm, showed no indication of settling in subsequent ponds, and appeared to degrade in pond sediments after 5 days. In contrast, AdV in UASB reactor effluent was associated with small and large particles, and in subsequent ponds, particle-associated AdV showed evidence of possible settling or more rapid decay at the water surface. AdV and culturable EV were also more volumetrically-concentrated in UASB reactor sludge than they were in untreated sewage, WSP water, UASB effluent, and WSP sediments, indicating that the reactors may cause these viruses to become entrapped and concentrated in granular sludge. Some viruses may be removed in the sludge, but others exit the reactors in solution and attached to particles. The resuspension of pellets from centrifuged UASB reactor sludge samples in an eluant buffer indicated reversible AdV association with granular sludge, but some associations with particles in solution may not be reversible. The fate and transport of pathogens and fecal indicators was assessed in Bolivia for two WSP systems with direct reuse for irrigation, and one on-farm RBF system used to treat surface water polluted by untreated sewage. In the WSP systems, despite HRTs of 10 days, pathogen and fecal indicator removal was generally ≤1-log10, possibly due to overloading and short-circuiting from sludge accumulation. The RBF system provided removals on the order of 2-log10 for protozoan parasites, 3-log10 or more for viruses, and 4-log10 or more for bacteria. The use of RBF also reduced cumulative estimated health burdens associated with irrigated lettuce. Irrigation of lettuce with untreated river water caused an estimated disease burden that represents 37% of the existing burden from acute diarrhea in Bolivia; when RBF was used, this decreased to only 1.1%, which is not epidemiologically-significant, and complies with the World Health Organization guidelines. Ratios of concentrations of microorganisms in irrigation water to their respective concentrations in soil or crops were calculated, to assess transfer from irrigation water to soil or crops. These ratios (with units mL g-1) were generally < 0.1 mL g-1 for coliphage, between 1 and 100 mL g-1 for Giardia and Cryptosporidium, and generally between 100 and 1,000 mL g-1 for helminth eggs. Higher ratios could indicate more efficient transfer from water to soil or crops, longer persistence in soil or on crops, or slower leaching away from soil or crops. The results from this research demonstrate that pathogen removal in full-scale natural wastewater treatment systems happens via complex mechanisms that vary with respect to pathogen type, treatment systems configuration, and other environmental and operational parameters. Future research and innovation efforts should focus on the use of a combination of natural and non-mechanized technologies, surface-flow systems (e.g., WSPs) and subsurface systems (e.g., RBF), applied at both semi-centralized (e.g., wastewater treatment plant) and decentralized levels (e.g., on farms), to evaluate how this affects the efficiency and resiliency of pathogen removal. Also, future research is needed to further elucidate reasons for the observed differences in virus-particle associations in natural wastewater treatment systems.

Dados mundiais apontam haver uma associação entre o aumento do comércio de vegetais minimamente processados prontos para o consumo (VPC) e o aumento da ocorrência de surtos de enfermidades transmitidas por alimentos. Durante o processamento industrial de VPC, a desinfecção é a principal etapa de inativação de micro-organismos patogênicos presentes, mas nessa etapa também pode ocorrer contaminação cruzada, com transferência de contaminantes de produtos contaminados para não-contaminados. Neste trabalho, foram coletadas informações sobre as práticas empregadas na etapa de desinfecção em dez importantes indústrias produtoras de VPC no Estado de São Paulo, avaliando-se, em seguida, a influência dessas práticas na qualidade microbiológica dos produtos e na inativação de Salmonella Typhimurium, bem como na ocorrência de contaminação cruzada por este patógeno. Um modelo de avaliação quantitativa de risco microbiológico foi elaborado para estimar o impacto da contaminação cruzada durante a etapa de desinfecção no risco de infecção por Salmonella devido ao consumo de VPC. Observou-se que, em todas as indústrias visitadas, a desinfecção dos vegetais era feita com produtos à base de cloro em concentrações de 50 a 240 mg/L, que resultava em redução de até 1,2 log na carga microbiana dos vegetais que entravam na linha de processamento. Ao avaliar a influência das características da água de processamento (pH, temperatura, concentração de matéria orgânica e concentração de dicloroisocianurato de sódio) e do tempo de contato entre a água clorada e os vegetais na redução de Salmonella, observou-se que a concentração do produto à base de cloro foi o parâmetro que apresentou maior influência (p<0.05). Concentrações de dicloroisocianurato de sódio acima de 10 mg/L foram necessárias para controle da contaminação cruzada durante a etapa de lavagem. O modelo de avaliação de risco construído indicou quantitativamente haver uma relação entre a concentração de dicloroisocianurato de sódio na água de desinfecção e o risco de ocorrência de surtos causados por Salmonella em VPC. Cenários simulando uso de dicloroisocianurato de sódio em concentrações abaixo de 5 mg/L indicaram que mais de 96% dos casos preditos de infecção por Salmonella poderiam ser atribuídos à ocorrência de contaminação cruzada, enquanto que em cenários com concentrações acima de 50 mg/L, casos de infecção devidos à contaminação cruzada não foram preditos. Estes resultados mostram que o controle da qualidade da água e o monitoramento da concentração de sanitizante na etapa de desinfecção são essenciais para evitar a ocorrência de contaminação cruzada e garantir a produção de VPC seguros para o consumo. / Surveillance data in several countries show an association between consumption of minimally processed ready-to-eat (RTE) vegetables and increased occurrence of foodborne diseases outbreaks. During RTE vegetables processing, washing-disinfection is the main step aiming to ensure inactivation of pathogenic microorganisms, but also is the step in which cross-contamination may occur, with transfer of contaminants from contaminated to non-contaminated products. In this study, we collected information on the practices employed during the washing-disinfection step in ten RTE vegetables processing plants located in the State of Sao Paulo, Brazil, and evaluated the influence of these washing practices on the microbial quality of the products and inactivation of Salmonella Typhimurium, as well as on the occurrence of cross-contamination by this pathogen. A quantitative microbial risk assessment model was built in order to estimate the impact of cross-contamination during the washing step on the risk of infection by Salmonella due to the consumption of RTE vegetables. In all visited processing plants, the disinfection step was done using chlorine-based products, in concentrations ranging from 50 to 240 mg/L, achieving a reduction of up to 1.2 log in the microbial load of vegetables entering the processing line. When the influence of washing water parameters (pH, temperature, organic load and sodium dichloroisocyanurate concentration) and time of contact between chlorinated water and vegetables on reduction of Salmonella were evaluated, sodium dichloroisocyanurate concentration influenced the most (p<0.05). Concentrations above 10 mg/L were necessary for avoiding cross-contamination during washing step. The risk assessment model indicated quantitatively a relationship between sodium dichloroisocyanurate concentration and the risk of illness caused by Salmonella in RTE vegetables. When simulation was done with less than 5 mg/L of sodium dichloroisocyanurate, most (>96%) of the illnesses arose from cross-contamination. However, when the concentration was 50 mg/L or higher, no illnesses arising from cross-contamination were predicted. These results show that controlling the quality of the water and monitoring the concentration of the sanitizer in the disinfection step are essential to avoid occurrence of cross contamination and ensure production of RTE vegetables that are safe for consumption.

Greywater is domestic household wastewater without inputfrom the toilet, i.e. wastewater from sinks, the shower,washing machine and dishwasher in a home. Source separation ofgreywater can be a strategy to enhance recirculation of plantnutrients and/or improve water use. The risk for transmissionof disease when reusing greywater is largely dependent on thecross-contamination by faeces. High levels of faecalindicators, mainly thermotolerant coliform bacteria, have beenreported in greywater, indicating substantial faecal pollution.However, growth of indicator bacteria within the system leadsto an overestimation of thefaecal input and thus the hygienerisk. The faecal input of the greywater in Vibyåsen,Sollentuna, North of Stockholm, was estimated to be 0.04 ±0.02 g faeces person-1 day-1 from the quantification of thefaecal sterol coprostanol, compared to 65 g, 5.2 g and 0.22 gp-1 d-1 using E. coli, enterococci and cholesterolrespectively. Prevalence of pathogens in the population and the faecalload based on coprostanol concentrations were used to form thebasis of a screening-level quantitative microbial riskassessment (QMRA) that was undertaken for rotavirus, Salmonellatyphimurium, Campylobacter jejuni, Giardia intestinalis andCryptosporidium parvum, looking at the treatment required to bebelow an acceptable level of risk (10-3) for reuse or dischargeof the greywater. The different exposure scenarios simulated–groundwater recharge, direct contact, irrigation andrecreational water–showed that a reduction of 0.7–3.7 log was needed for rotavirus, with the measured level offaecal load in Vibyåsen. The other pathogen of concern wasCampylobacter, where a 2.2 log reduction was needed forgroundwater recharge. The infectious dose of Salmonella is highand the excretion numbers of Giardia cysts and Cryptosporidiumoocysts low, resulting in no treatment requirements for theseorganisms under these circumstances. Pathogen input fromcontaminated food via the kitchen sink had a minor effect onthe microbiological quality of the greywater. Studies on virusoccurrence in greywater as well as validation of the faecalload of greywater at another site would give valuable input forfuture QMRAs. Greywater treatment efficiency studies, especially on virusremoval, are scarce and more investigations are warranted.Active sludge may not be a suitable technique for greywater dueto the low carbon content in this flow. Chemical precipitationhas the advantage of removing phosphorus as well as virusesefficiently and it is suggested as one possible method fortreating greywater. Otherwise the most common practice forgreywater treatment in Sweden is soil infiltration. However, itis suggested that the recommendations for wastewaterinfiltration also be observed for greywater, despite the lowfaecal load, due to the simulated results on virus reductionneeded. <b>Key words:</b>greywater, greywater reuse, greywatertreatment, microbial risk assessment, groundwater recharge,irrigation, recreational water, faecal contamination, indicatorbacteria, index organisms, faecal sterols, bacteriophages,enteric pathogens, rotavirus, Salmonella, Campylobacter,Giardia, Cryptosporidium, Legionella / NR 20140805

Unsafe sanitation systems poses a risk for pathogen transmission, wherefore it is important to both inactivate pathogens present in human excreta and conduct safe sanitation systems from use to end-use. The Peepoo toilet, using ammonia sanitisation, have been suggested as a low-cost sanitation solution and is implemented in schools in Kibera, an urban slum in Kenya. This master thesis aim to study the inactivation efficiency of ammonia sanitisation when treating human excreta with urea, and to quantify the risks of exposure to microbial hazards from the Peepoo sanitation system using faecal indicator bacteria. Excreta was collected from four schools in Kibera. After adding urea to mimic the inactivation of the Peepoo in the laboratory, the inactivation rate was correlated to temperature and free ammonia concentration for Campylobacter spp., Escherichia coli and Enterococcus spp.. Campylobacter spp. and E. coli both had a high inactivation rate even at low temperature and low addition of urea. Inactivation rate of Enterococcus spp. was lower and close to zero when 1.87 % urea was added for 15 °C. For Enterococcus spp. a lag-phase was observed, which was not affected by temperature but by concentration of free ammonia. For investigated bacteria, inactivation rate increased with increased temperature and free ammonia concentration. Along the Peepoo management chain, several hazardous events were identified such ascontamination during usage, handling and transportation. Sampling showed a higher contamination of Enterococcus spp. than of E. coli. Enterococcus spp. was used as a faecal indicator for Ascaris and E. coli was used as an indicator of E. coli O157:H7 in a quantitative microbial risk assessment (QMRA). Through the QMRA, the risk of infection of Ascaris and E. coli O157:H7 for one exposure event was simulated based on a Exponential and a Beta-Poisson dose-response model respectively. The risk of infection of Ascaris was around 12 % regardless of where exposure occurs, if Ascaris eggs were present. For risk for infection with E. coli O157, the simulated risks were below 10 % at almost all exposure points, with most of the high risk exposure points located in the schools. There are risks of pathogen transmission in the Peepoo management chain that should be further investigated. Ammonia sanitisation permits a high degree of microbial inactivation but to secure a safe end-product it is recommended to be kept in room temperature (24.05±0.62 °C) or higher.

O lançamento de esgotos domésticos in natura, efluentes das estações de tratamento de esgoto e escoamento superficial, são relatados como importantes causas de poluição das águas superficiais. Sabe-se que a alteração da qualidade das águas dos rios restringe seus múltiplos usos e contribui para o aumento de doenças de veiculação hídrica, em decorrência da exposição oral a bioagentes patogênicos. Neste contexto, o objetivo do presente estudo foi identificar e quantificar bioagentes presentes na água do rio Pardo, Brasil, e estimar o risco de infecção e de doença por Cryptosporidium spp. e Giardia spp. para a população, devido ao uso do rio como fonte de abastecimento público e recreação de contato primário, por meio da abordagem da Avaliação Quantitativa de Risco Microbiológico (AQRM). Durante os anos de 2015 e 2016, foram realizadas seis coletas de amostras da água do rio Pardo (período chuvoso e período seco) em seis pontos, totalizando 36 amostras. Foram realizadas análises de identificação e quantificação de E. coli, Salmonella Não Tifóide, Cryptosporidium spp. e Giardia spp. Para estimativa de risco de infecção e de doença por Cryptosporidium spp. e Giardia spp. (AQRM), foram considerados diferentes populações (crianças e adultos), volumes de água ingerido, concentração de (oo)cistos e duração e frequência da exposição, de acordo com o cenário estabelecido. Os valores médios para E. coli variaram de 6,57 x 101 UFC/100 mL a 6,07 x 103 UFC/100 mL, apresentando diferenças estatisticamente significantes (p < 0,05) entre os períodos chuvoso e seco. As densidades de Salmonella Não Tifóide foram baixas (<0,6473 a 1,55 NMP/100 mL), com frequência de 13,9% das amostras positivas, evidenciando a circulação desse patógeno no ambiente. A concentração de (oo)cistos de Cryptosporidium spp. e Giardia spp. variou de <0,1 a 0,4 oocistos/L e <0,1 a 4,4 cistos/L, respectivamente. Para abordagem da AQRM devido a ingestão da água do rio Pardo usada para abastecimento público, a probabilidade anual de infecção por Cryptosporidium spp. e Giardia spp. foi maior para adultos do que para crianças, sendo que na maioria dos pontos apresentou resultados superiores ao risco anual tolerável pela USEPA (1 x 10-4). No que diz respeito ao uso da água do rio Pardo para recreação de contato primário, a probabilidade diária e anual de infecção, bem como a probabilidade de doenças, foi maior para crianças, seguida de adultos/homens e adultos/mulheres. A probabilidade de criptosporidiose e giardíase esteve abaixo do limite tolerável pela USEPA (3,6 x 10-2), exceto no Ponto 4, em que a estimativa de risco de doença por Giardia spp. para crianças esteve acima deste valor. A presença de bioagentes em amostras de água do rio Pardo pode estar relacionada à poluição das águas por fontes pontuais e difusas. Esses achados refletem a importância de priorizar os recursos para implantação e complementação das Estações de Tratamento de Esgoto na UGRHI 4, a fim de prevenir as doenças de veiculação hídrica em populações que utilizam a água do rio Pardo para abastecimento público e recreação de contato primário / The discharge of domestic sewage, effluents of wastewater treatment plants and surface runoff, are reported as important causes of surface water pollution. It is known that the alteration of river water quality restricts its multiple uses and contributes to the increase of waterborne diseases, due to oral exposure to pathogenic bioagents. In this context, the aim of the present study was to identify and quantify bioagents present in Pardo river water, Brazil, and to estimate the risk of infection and disease by Cryptosporidium spp. and Giardia spp. for the population, due to the use of the river as source of public supply and primary contact recreation, through the approach of Quantitative Microbial Risk Assessment (QMRA). During the years of 2015 and 2016, six samples of water from the Pardo river (rainy and dry season) were collected at six points, totaling 36 samples. Identification and quantification analyzes of E. coli, Non-typhoid Salmonella, Cryptosporidium spp. and Giardia spp. To estimate the risk of infection and disease by Cryptosporidium spp. and Giardia spp. (QMRA), different populations (children and adults), volumes of ingested water, concentration of (oo) cysts, duration and frequency of exposure were considered according to the established scenario. Mean values for E. coli varied from 6.57 x 101 CFU / 100 mL to 6.07 x 103 CFU / 100 mL, showing statistically significant differences (p <0.05) between the rainy and dry season. Non-typhoid Salmonella densities were low (<0.6473 at 1.55 MPN / 100 mL), with a frequency of 13.9% of the positive samples, evidencing the circulation of this pathogen in the environment. Cryptosporidium spp. and Giardia spp. concentration ranged from <0.1 to 0.4 oocysts / L and <0.1 to 4.4 cysts / L, respectively. In order to approach the QMRA due to the ingestion of Pardo river water used for public supply, the probability of annual infection by Cryptosporidium spp. and Giardia spp. was higher for adults than for children, and in most points presented results higher than the risk tolerable by USEPA (1 x 10-4). Regarding the use of Pardo river water for primary contact recreation, the daily and annual probability of infection, as well as the probability of illness, was higher for children, followed by adults / men and adults / women. The probability of cryptosporidiosis and giardiasis was below the limit tolerable by USEPA (3.6 x 10-2), except in Point 4, where the estimated risk of disease by Giardia spp. for children was above this value. The presence of bioagents in Pardo river water may be related to water pollution by point and diffuse sources. These findings reflect the importance of prioritizing the resources for implementation and complementation of wastewater treatment plants at UGRHI 4, in order to prevent waterborne diseases in populations that use Pardo river water for public supply and primary contact recreation

Submitted by Verena Pereira (verenagoncalves@uefs.br) on 2018-07-16T21:36:33Z No. of bitstreams: 1 Disserta??o SILVA, 2018.pdf: 2779443 bytes, checksum: 40c836b0d66d471baa3bbcd33b9d4b10 (MD5) / Made available in DSpace on 2018-07-16T21:36:33Z (GMT). No. of bitstreams: 1 Disserta??o SILVA, 2018.pdf: 2779443 bytes, checksum: 40c836b0d66d471baa3bbcd33b9d4b10 (MD5) Previous issue date: 2018-03-01 / Treatment and reuse of gray water (GW) has been studied as an alternative for non-potable uses. The objective of this study was to evaluate the potential for reuse of treated gray water (TGW) in a high standard residence in Feira de Santana ? BA. The microbiological risk for TGW use was assessed via the methodology Quantitative Microbial Risk Assessment (QMRA); the potential for generating bad odors by means of pH, DO and ORP measurements; the color was measured directly; and the embodied energy using the methodology of Life Cicle Assessment LCA. The average microbiological risk of TWG was of the order of 10-5 DALY.pppa-1. The ACT also presented ow potential for generating bad odors. The measured color was on average 13.5HU, with a standard deviation of 10 uH. The system?s embodied energy found was 2.74 kWh/m? of TGW produced, lower than the local concessionaire numbers. The gray water (GW) is found to have great potential for less noble reuse purposes / O tratamento e o re?so de ?guas cinzas tem sido estudado como uma alternativa para usos n?o pot?veis. O objetivo deste trabalho foi avaliar o potencial de re?so de ?gua cinza tratada (ACT) em uma resid?ncia de alto padr?o em Feira de Santana ? BA. Analisou-se o risco microbiol?gico atrav?s da metodologia da Avalia??o Quantitativa de Risco Microbiol?gico (AQRM); o potencial de gera??o de maus odores por meio de pH, OD e ORP; a cor medida diretamente; e a energia incorporada usando a metodologia da An?lise do Ciclo de Vida (ACV). A m?dia do risco microbiol?gico da ACT foi da ordem de 10-5 DALY.pppa-1. A ACT tamb?m monstrou baixo potencial em gerar maus odores. A cor medida foi em m?dia 13,5 uH, com desvio padr?o de 10 uH. A intensidade energ?tica do sistema foi de 2,74 kWh/m? de ACT produzida, resultado inferior ao da concession?ria local. Conclui-se que a ?gua cinza (AC) possui grande potencial de re?so para fins menos nobres

The Water Framework Directive requires reduced environmental impacts from human activities and for the assessment of the non-market benefits of pollution remediation schemes. This policy shift has exacerbated the research problems surrounding the physical, social and economic consequences of the relationship between land use and water quality. This research seeks to quantify the major socio-economic and environmental benefits for people which may arise as riverine pollution is reduced. To achieve these aims this research integrates primary data analyses combining choice experiment techniques with geographical information system based analyses of secondary data concerning the spatial distributions of riverine pollution. Current knowledge on the microbial quality of river water, measured by faecal indicator organism (FIO) concentrations and assessed at catchment scale, is inadequate. This research develops generic regression models to predict base- and high-flow faecal coliform (FC) and enterococci (EN) concentrations, using land cover and population (human and livestock) variables. The resulting models are then used both to predict FIO concentrations in unmonitored watercourses and to evaluate the likely impacts of different land use scenarios, enabling insights into the optimal locations and cost-effective mix of implementation strategies. Valuation experiments frequently conflate respondents’ preferences for different aspects of water quality. This analysis uses stated preference techniques to disaggregate the values of recreation and ecological attributes of water quality, thereby allowing decision makers to better understand the consequences of adopting alternative investment strategies which favour either ecological, recreational or a mix of benefits. The results reveal heterogeneous preferences across society; specifically, latent class analysis identifies three distinct groups, holding significantly different preferences for water quality. From a methodological perspective this research greatly enhances the ongoing synthesis of geographic and economic social sciences and addresses important policy questions which are of interest to a variety of stakeholders, including government departments and the water industry.

Globally a major health concern according to the World health organization (WHO, 2011) is gastro-intestinal infections caused by fecally contaminated water. The access to drinking water has increased due to international efforts, however the long-term sustainability and safety of the water accessed have gained criticism, and many water sources have proven to be both contaminated (UN, 2016) and badly managed (WHO, 2016a).  This thesis aims to design a monitoring program for small-scale water treatment in order to make the water supply sustainable in terms of providing safe water in a long-term perspective. A case-study was conducted for three treatment systems under constructed in rural Ecuador. The monitoring program design was based on a literature review and conducting a quantitative microbial risk assessment (QMRA). QMRA is a tool for estimating microbial risks, by using quantitative data on microbial contamination and estimating health risks. Data for the QMRA was gathered from literature and in field, and the reference pathogens used in the QMRA were E.coli O157:H7, Rotavirus and Giardia. In order to estimate infection risk from drinking water consumption for the community a QMRA-model called MRA, developed by Abrahamsson et al. (2009) was used.  Observations of the catchment areas and measurement of water quality regarding aspects other than microbial contamination indicated that the main risk was microbial contamination from fecal contaminations in the catchment area. The results from the QMRA indicated that the treatment using chlorination reduces E.coli O157:H7 under the acceptable risk level of 1/1000 infections per person and year, while the systems using biosand filters (BSF) are more effective in reducing rotavirus and Giardia. If the BSF are combined with chlorination the annual probability of infection caused by consumption of the treated water per year and person was 0.42/1000 for E.coli O157:H7, 570/1000 for Rotavirus and 25/1000 for Giardia.  The resulting monitoring program was divided into two parts: one part aimed to prevent contamination and one part designed to measure pH, temperature, conductivity, turbidity on a weekly basis and microbial indicator tests using a presence/absence method monthly. Additional testing is to be done in case of events of such character that the water quality could be effected, for example an extreme weather event.  It was concluded that the designed monitoring program could help improve the water quality in a long-term perspective, but it is dependent on the possibilities to get the necessary support, especially in the implementation phase. Recommended further studies includes collection of more site-specific data to make the QMRA results more representative, and evaluation of the monitoring program design by implementing it and optimizing it in the communities. / Runt om i världen skapar en otillräcklig tillgång på rent vatten och sanitet mycket lidande. Enlig världshälsoorganisationen WHO (2011) är ett av de ledande världshälsoproblem mag- och tarminfektioner som orsakats av vattenburna fekala patogener. Trots att antalet människor med tillgång till en dricksvattenkälla har ökat till följd av internationella ansträngningar, är hållbarheten och säkerheten för vattenkvalitén problematisk. Många dricksvattenkällor har visat sig vara både förorenade (UN, 2016) och undermåligt skötta (WHO, 2016a). Målet med denna studie är att ta fram ett vattenkvalitetsövervakningsprogram för tre småskaliga vattenreningsverk, för att dessa ska producera säkert vatten i ett långsiktigt perspektiv.  En fallstudie utfördes i byar på landsbygden i Ecuador där systemen planerats. Metoden för att ta fram ett kvalitetsövervakningsprogram var litteraturstudie och mikrobiell riskanalys. Den mikrobiella riskanalysen genomfördes med en metod som kallas Kvantitativ Mikrobiell Risk Analys (QMRA). I QMRA kan hälsorisker från mikrobiell kontamination estimeras med kvantitativdata på mikrobiell förorening. Data för att genomföra QMRA samlades från litteraturen och fältbesök. För att estimera hälsorisker i byarna i fallstudien användes en QMRA-modell som heter MRA framtaget av Abrahamsson et.al. (2009).  Observationer i fält och data på ingående vatten tydde på att de största riskerna för vattenkvalitén var fekal kontamination från djur och människor. Resultaten från QMRA:n visade att reningsverket med klorering reducerade E.coli O157:H7 till en nivå under den accepterade risknivå, satt till 1/1000 infekterade per år och person. Reningsverken med biosandfilter (BSF) var mer effektiva i reduktionen av rotavirus och Giardia. Då klor kombinerades med BSF i modellen blev den årliga infektionsnivån per person 570/1000 för Rotavirus och 25/1000 för Giardia.  Vattenkvalitetsövervakningsprogrammet delades in två delar: en kontaminationsförebyggande och en för att mäta pH, temperatur, konduktivitet och turbiditet veckovis, samt mikrobiella indikatortest med en metod som noterar förekomst av bakteriekolonier (presence/absence metod) månadsvis. Extra tester ska även göras vid sådan händelse som kan komma att påverka vattenkvalitén avsevärt, exempelvis en kraftig storm.  Slutsatsen är att det framtagna vattenkvalitetsövervakningsprogrammet kan göra att vatten-källan blir mer säker och hållbar i ett långsiktigt perspektiv, men att framgången är beroende av att rätt hjälp finns tillhanda speciellt i implementeringsfasen. Fortsatta studier behövs för att göra resultaten från QMRA:n mer representativa, exempelvis genom att samla mer områdesspecifikdata. Vidare skulle det vara intressant att implementera kvalitetsövervakningsprogrammet för att utvärdera och optimera det.