Eficácia das medidas domiciliares de desinfecção da água para consumo humano: enfoque para o contexto de Santarém, Pará, Brasil / Efficacy of household methods for disinfecting water for human consumption: focus on the context of Santarém, state of Pará, Brazil / Efectividad de las medidas domiciliarias para desinfectar el agua para consumo humano: desde el contexto de Santarém, estado de Pará, Brasil

Na região Amazônica, cidades como Santarém, no Estado do Pará, Brasil, ainda carecem de Estações de Tratamento de Água para atender toda a população. Nesses locais, medidas domiciliares de desinfecção da água são importantes para preservar a potabilidade e evitar efeitos indesejáveis na saúde. Este estudo avaliou experimentalmente o efeito das medidas domiciliares na eliminação de Escherichia coli em amostras de água. As técnicas avaliadas para esse trabalho foram: (i) hipoclorito de sódio 2,5%; (ii) fervura; (iii) filtro de cerâmica; e (iv) exposição solar. Foram testadas amostras, combinando-se diferentes concentrações de E. coli (entre 3 e 100 unidades formadoras de colônias/100mL). Os resultados mostraram que as medidas domiciliares de desinfecção foram eficazes na eliminação da E. coli, com exceção do filtro de cerâmica, cujas amostras de água, mesmo após a filtragem, apresentaram-se positivas para o crescimento da bactéria. Considerando que a distribuição da água tratada não chega à maior parte da população que reside em Santarém e em áreas periurbanas, como em comunidades quilombolas e ribeirinhas, o uso das medidas como hipoclorito de sódio 2,5%, fervura e exposição solar poderão favorecer a promoção da saúde e diminuir a ocorrência de surtos de doenças diarreicas veiculadas pela água.

In the Amazon region, cities such as Santarém, in the state of Pará, Brazil, still lack Water Treatment Stations to serve the entire population. In these places, household methods of water disinfection are important to preserve potability and avoid undesirable health effects. Our study experimentally evaluated the effect of household methods for eliminating Escherichia coli in water samples. The techniques evaluated for this study were: (i) sodium hypochlorite 2.5%; (ii) boiling; (iii) ceramic filter, and (iv) sun exposure. Samples were tested, combining different concentrations of E. coli (from 3 to 100 colony forming units/100mL). The results showed that household disinfection methods were effective in eliminating E. coli; except for the ceramic filter, the water of which was still positive for their growth, even after filtration. Considering that the distribution of treated water does not reach most of the population living in Santarém and in peri-urban areas, such as the quilombola and riverside communities, the use of such methods as sodium hypochlorite 2.5%, boiling, and sun exposure may favor health promotion and reduce the occurrence of outbreaks of dysentery transmitted by water.

En la región Amazónica, las ciudades como Santarém, en el estado de Pará, Brasil, todavía carecen de Estaciones de Tratamiento de Agua para atender a toda la población. En estos lugares, las medidas de desinfección domiciliaria del agua son importantes para preservar la potabilidad y evitar efectos indeseables en la salud. Este estudio evaluó el efecto de medidas domiciliarias en la eliminación de Escherichia coli en muestras de agua. Las técnicas evaluadas en este trabajo fueron: (i) hipoclorito de sodio al 2,5%; (ii) hervir el agua; (iii) filtro cerámico y (iv) exposición al sol. Se probaron muestras combinando diferentes concentraciones de E. coli (entre 3 y 100 unidades formadoras de colonias/100mL). Los resultados mostraron que las medidas de desinfección domiciliaria fueron efectivas en la eliminación de E. coli, con excepción del filtro cerámico que presentó un resultado positivo para su crecimiento en las muestras de agua, aún después de filtrada. Considerando que la distribución de agua tratada no llega a la mayoría de la población residente en Santarém y en áreas periurbanas como comunidades quilombolas y ribereñas, el uso de técnicas como el hipoclorito de sodio al 2,5%; hervir el agua o exponerla al sol pueden favorecer una promoción de la salud y reducir el surgimiento de brotes de enfermedades diarreicas transmitidas por el agua.

Disinfection effect and its influencing factors of rural drinking water in Zhejiang Province / 预防医学

Objective@#To learn the disinfection effect and its influencing factors of drinking water in rural areas of Zhejiang Province,so as to provide scientific basis for the control of microbial pollution in drinking water and prevention of waterborne diseases. @*Methods@#A total of 5 299 samples from 879 rural water plants Zhejiang Province were collected by stratified sampling method in 2017. The disinfection effect of water samples was assessed quality according to GB 5749-2006 Hygienic Standards for Drinking Water. Logistic regression models were used to analyze the influencing factors for disinfection effect of rural drinking water. @*Results@#There were 540 rural water plants in Zhejiang Province adopting routine process for water purification,accounting for 61.43%;771 ones using surface water,accounting for 87.72%. About 4 458 samples（84.13%）were disinfected and the qualified rate was 86.05%,22.32% of which were disinfected by chlorine dioxide and the qualified rate was 100.00%. The results of multivariate logistic regression analysis showed that scale of water plant,disinfectant residue,use frequency of disinfection equipment,disinfection,season and source water turbidity were the influencing factors for the disinfection effect of rural drinking water（P<0.05）;disinfection,disinfectant residue,use frequency of disinfection equipment and source water turbidity were the influencing factors for the disinfection effect of finished water（P<0.05）;disinfection,disinfectant residue,use frequency of disinfection equipment,source water turbidity and scale of water plant were the influencing factors for the disinfection effect of tap water（P<0.05）;disinfectant residue,use frequency of disinfection equipment,source water turbidity and scale of water plant were the influencing factors forthe disinfection effect of surface water（P<0.05）;disinfectant residue,use frequency of disinfection equipment,source water turbidity and pH were the influencing factors for the disinfection effect of groundwater（P<0.05）.@*Conclusion@#The disinfection effect of drinking water in rural areas of Zhejiang Province is associated with source water quality,scale of plants,water purification technique and so on. The disinfection process should be improved,the management of water plants should be strengthened to reduce the risk of microbial contamination.

Desinfecção do sistema de água de equipamentos odontológicos com clorexidina / Disinfection of dental unit waterline with chlorexidine

Introdução: A água utilizada em procedimentos odontológicos pode apresentar- se contaminada, sendo fonte de infecção para profissionais e pacientes. Objetivo: Comparar a efetividade da clorexidina 0,1% e do hipoclorito de sódio 1% na desinfecção do sistema de água de equipamentos odontológicos. Método: Três equipamentos odontológicos sofreram desinfecção com clorexidina; e três, com hipoclorito de sódio mediante acionamento da seringa tríplice durante dois minutos. Amostras de água coletadas antes, após a desinfecção e no final do dia foram analisadas microbiologicamente. Amostras do filtro de abastecimento também foram analisadas. Resultados: As amostras coletadas antes da desinfecção mostraram altos níveis de contaminação (>500 UFC/ml). Após emprego dos desinfetantes, estas apresentaram-se nos padrões recomendados pela American Dental Association – ADA (<200 UFC/ml). A água do filtro de abastecimento também estava dentro dos limites estabelecidos pela ADA. Conclusão: Clorexidina 0,1% mostrou-se tão efetiva quanto hipoclorito de sódio 1% na desinfecção do sistema de água de equipamentos odontológicos.

Introduction: The water used in dental procedures may be contaminated and source of infection for patients and dental staff. Objective: The aim of this study was to compare the effectiveness chlorhexidine 0.1% and sodium hypochlorite 1% in the disinfection of dental unit waterline. Method: Three dental units were disinfection with chlorhexidine and three with sodium hypochlorite by flushing the triple syringe for two minutes. Water samples collected before and after disinfection and in the end of the day were analyzed microbiologically. Samples of the supply filter were also analyzed. Results: Samples collected before disinfection showed high levels of contamination (> 500 CFU / ml). After use of disinfectants, the samples were within the recommended standards by the American Dental Association – ADA (< 200 CFU / ml). The water supply filter was also within the limits established by the ADA. Conclusion: Chlorhexidine 0.1% was effective as sodium hypochlorite 1 % for the disinfection of dental unit waterlines.

Avaliação da eficácia da clorexidina na desinfecção do sistema de água odontológica / Chlorhexidine efficacies evaluation on disinfection of dental unit waterline

Introdução: A água utilizada nos procedimentos odontológicos apresenta-se contaminada e pode causar infecção cruzada. Objetivos: Neste estudo, investigou-se a qualidade da água de equipos odontológicos e a ação de diferentes concentrações de clorexidina na redução da contaminação. Métodos: Os parâmetros de contaminação utilizados foram o da American Dental Association e do Ministério da Saúde. Realizou-se análise bacteriológica em amostras de água de 17 seringas tríplices para verificar a qualidade microbiológica da água tratada ou não com clorexidina in vitro. Testaram-se concentrações de clorexidina 0,4%; 0,2%; 0,1%. Utilizou-se clinicamente clorexidina 0,1% na desinfecção do sistema de água por um minuto em 13 equipos e realizou-se nova análise bacteriológica da água. Resultados: Todos os grupos-controles apresentaram níveis elevados de contaminação, 100% dos grupos tratados in vitro com clorexidina e dos equipos que sofreram desinfecção com clorexidina 0,1% apresentaram-se descontaminados. Conclusão: Clorexidina 0,1% foi efetiva na redução da contaminação da água odontológica.

Introduction: The water used in dental procedures is contaminated and can cause crossed infection. Objective: This study investigates the quality of water on dental units and the action of different concentrations of chlorhexidine in the reduction of this contamination. Method: The contamination parameters used were the American Dental Association and the Brazilian Health State Department. It was executed a bacteriological analysis of water samples from 17 air-water syringes to verify the microbiological quality of water treated or not with chlorhexidine in vitro. It was examined concentrations of 0.4%; 0.2%; 0.1%. One percent chlorhexidine was used, clinically, in disinfection of dental unit waterline for one minute in 13 dental units and a new bacteriological analysis of water was made. Results: All control groups showed high levels of contamination, 100% of groups with chlorhexidine in vitro and all dental units who suffered disinfection with 0.1% chlorhexidine were free of contamination. Conclusion: One percent chlorhexidine was effective in reducing contamination of the dental water.

Priliminary Study on Chlorite Pollution of Drinking Water Disinfected by Chlorine Dioxide / 环境与健康杂志

[Objective] To explore the status of chlorite pollution in drinking water due to chlorine dioxide , aswell as its causes and counter measures. [Methods]A water plant collecting surface water as raw water slightly pol-luted by organic compounds and B water plant collecting ground water without organic compounds pollution wereselected as observed objectives. Chlorine dioxide generators were used in both of A and B water plants, their rawmaterials was chlorite for A plant and chlorate for B plant. The levels of chlorite in treated water from these twowater plants were determined by amperometric titration. [Results]The levels of chlorite in treated water of A waterplant ranged 0.530～0.760 mg/L, 2.6～3.8 times of the standard value, with a over standard rate of 100％, thelevels of B water plant range 0.257～0.733 mg/L, 1.3～3.7 times of the standard value, with a over standard rateof 83.3％. [Conclusion] The treated water of A and B water plants presented higher pollution by chlorite, the by-product of chlorine dioxide disinfection.

Application of Photocatalysis in Drinking Water Disinfection / 环境与健康杂志

This article presents the feasibility on application of TiO 2 photocatalysis in drinking water disinfection involving the removal of organic contaminants, inactivation of bacteria and virus. However, the efficacies of TiO 2 photocatalyst in killing of recalcitrant pathogenic protozoans such as Giardia lambia and Cyptosporidium or persistent algae need frurther investigation, and the photocatalytic approach lacks any residual disinfection capacity.

DEVELOPMENT OF 86-1 TYPE RESIN FOR DRINKING WATER DISINFECTION AND ITS EFFICACY / 第二军医大学学报

The 86-I type resin for drinking water disinfection is a disinfectant resin of anion complex type of polyhalogeated compound.IBr2-anion complex salt was originally Synthesized and was a brown red and transparent liquid.It was passed through the resin column for exchange and rinsed with water until there was no I-and Br-in the rinsing water.This resin may be produced with simple equipment and low cost, and its quality is stable.Water quality disinfected by this resin is good and safe for drinking.Coli group and f2 phage could be removed by 99.9999-100% in the laboratory, and water from various water sources, disinfected with a total count of bacteria being less than 100/ml, and coli group, less than 3/L.The results suggest that the water quality disinfected by this resin is in accordance with the standard for quality of drinking water in our country.