Risk factors for Cryptosporidium contamination in Minnesota public supply wells.

In a recent monitoring study of Minnesota's public supply wells, Cryptosporidium was commonly detected with 40% of the wells having at least one detection. Risk factors for Cryptosporidium occurrence in drinking water supply wells, beyond surface water influence, remain poorly understood. To address this gap, physical and chemical factors were assessed as potential predictors of Cryptosporidium occurrence in 135 public supply wells in Minnesota. Univariable analysis, regression techniques, and classification trees were used to analyze the data. Many variables were identified as significant risk factors in univariable analysis and several remained significant throughout the succeeding analysis techniques. These factors fell into general categories of well use and construction, aquifer characteristics, and connectedness to the land surface, well capture zones, and land use therein, existence of potential contaminant sources within 200-feet of the well, and variability in the chemical and isotopic parameters measured during the study. These risk categories, and the specific variables and threshold values we have identified, can help guide future research on factors influencing Cryptosporidium contamination of wells and can be used by environmental health programs to develop risk-based sampling plans and design interventions that reduce associated health risks.

Comparative assessment of water quality indices-a case study to evaluate water quality for drinking water supply and irrigation in Northern Mexico.

Water quality indices (WQIs) are numerical measures used by researchers and water managers to communicate water quality status to the public. This study analyzes the official databases from the CONAGUA monitoring network of the main tributary rivers in the middle basin of the San Pedro-Mezquital River in Durango, Mexico, for a 6-year period (2013-2018). We applied three WQIs to 432 data (18 sampling sites, four samples per year, 6 years): Canadian Council of Ministers of the Environment (CCME) WQI, National Sanitation Foundation (NSF) WQI, and Secretariat of Urban Development and Ecology (SEDUE) WQI. The Canadian index proved to be a flexible, appropriate, and rigorous methodology for assessing water quality based on its use. Results classify the water quality in the studied reservoirs as good, while river water was rated for public use, as marginal to very poor. No statistical significant differences in the quality of water between the rainy (June-October) and dry (November-May) seasons were found. However, tendency shows that in the rainy season the water quality was lower, mainly attributed to agricultural runoffs and bank erosion. The main contamination problem was the presence of fecal coliforms in high concentrations, which is associated to the high population density in the area, low sanitation efficiency, and multiple non-point discharges.

Statewide Quantitative Microbial Risk Assessment for Waterborne Viruses, Bacteria, and Protozoa in Public Water Supply Wells in Minnesota.

Infection risk from waterborne pathogens can be estimated via quantitative microbial risk assessment (QMRA) and forms an important consideration in the management of public groundwater systems. However, few groundwater QMRAs use site-specific hazard identification and exposure assessment, so prevailing risks in these systems remain poorly defined. We estimated the infection risk for 9 waterborne pathogens based on a 2-year pathogen occurrence study in which 964 water samples were collected from 145 public wells throughout Minnesota, USA. Annual risk across all nine pathogens combined was 3.3 × 10-1 (95% CI: 2.3 × 10-1 to 4.2 × 10-1), 3.9 × 10-2 (2.3 × 10-2 to 5.4 × 10-2), and 1.2 × 10-1 (2.6 × 10-2 to 2.7 × 10-1) infections person-1 year-1 for noncommunity, nondisinfecting community, and disinfecting community wells, respectively. Risk estimates exceeded the U.S. benchmark of 10-4 infections person-1 year-1 in 59% of well-years, indicating that the risk was widespread. While the annual risk for all pathogens combined was relatively high, the average daily doses for individual pathogens were low, indicating that significant risk results from sporadic pathogen exposure. Cryptosporidium dominated annual risk, so improved identification of wells susceptible to Cryptosporidium contamination may be important for risk mitigation.

Qualidade da água em um sistema de reservatórios em cascata - um estudo de caso no semiárido brasileiro / Water quality in a cascade reservoir system - a case study in the Brazilian semiarid region

RESUMO A escassez hídrica e o aumento da demanda de água para usos múltiplos incentivaram a construção de diversos reservatórios e sistemas de transferências hídricas entre bacias hidrográficas em diversas partes do mundo, principalmente em regiões áridas e semiáridas. Apesar de essas medidas mitigarem os aspectos quantitativos do abastecimento, a diminuição da qualidade da água disponível pode se tornar uma limitação importante. Este estudo teve por objetivo avaliar a qualidade da água no sistema de transferência que abastece a Região Metropolitana de Fortaleza, Ceará. Foram analisados 20 parâmetros de qualidade de água ao longo do sistema. Aplicou-se em seguida a análise de agrupamento utilizando a distância euclidiana associada ao método de ligação de Ward para agrupar os 13 pontos de coleta que foram estabelecidos conforme suas similaridades. A piora da qualidade da água ficou evidente ao longo do sistema, com o aumento da concentração de cianobactérias, pH, nitrogênio total, oxigênio dissolvido, turbidez e clorofila-a. Com relação às cianobactérias, duas espécies mostraram-se dominantes — Oscillatoria sp. e Microcystis sp. — e sete abundantes — Merismopedia sp., Cylindrospermopsis sp., Pseudanabaena sp., Anabaena sp., Aphanizomenon sp., Aphanocapsa sp. e Dolichospermum sp. A presença de cianobactérias potencialmente tóxicas e a piora da qualidade da água tornam a realização de monitoramentos frequentes e o desenvolvimento de sistemas de alerta essenciais para a adequada gestão dos recursos hídricos, tanto do ponto de vista ambiental quanto do de saúde pública.

ABSTRACT Water scarcity and increasing water demand for multiple uses encourage the construction of reservoirs and water transfer systems between watersheds in various parts of the world, especially in arid and semi-arid regions. Although these measures may mitigate the quantitative aspects of water supply, the quality decrease of the available water may become an important limitation. This study aimed to evaluate the water quality in the water transfer system that supplies the metropolitan region of Fortaleza, Ceará. Twenty water quality parameters were analyzed throughout the system followed by the application of the Euclidean distance and Ward's method to group the 13 sampling points according to their similarities. The worsening of the water quality was evident with increasing cyanobacterial concentration, pH, total nitrogen, dissolved oxygen, turbidity, and chlorophyll-a. Regarding cyanobacteria, two species were dominant: Oscillatoria sp. and Microcystis sp. while seven were abundant: Merismopedia sp., Cylindrospermopsis sp., Pseudanabaena sp., Anabaena sp., Aphanizomenon sp., Aphanocapsa sp. e Dolichospermum sp. The presence of potentially toxic cyanobacteria and the worsening of water quality make frequent monitoring and the development of alert systems essential for the management of water resources, both from an environmental and public health point of view.

Socioeconomic inequalities explain the association between source of drinking water and dental caries in primary dentition.

OBJECTIVE: To evaluate the association between source of drinking water and dental caries at age 5 and to test whether socioeconomic conditions act as confounding factors in such association. METHODS: The study was carried out in a sub-sample of the 2004 Pelotas Birth Cohort, which comprised the application of a questionnaire and clinical oral examination. The exposure was source of drinking water, collected through a question to the primary caregiver. The outcome was dental caries in primary dentition, measured through several standardized indicators of the decayed, missing and filled teeth index (dmft), assessing past and present dental caries. Socioeconomic indicators (family income and maternal education) were identified as potential confounding factors. After descriptive analysis, the association between source of water and measures of dental caries was assessed by Regression models. RESULTS: 1,084 children were evaluated and had complete information in all variables (83.2 % of the targeted sample). Dental caries experience was observed in 48.7 % of the children, with a mean of 1.9 decayed, missing or filled teeth. Most children consumed water from public water supply (76.0 %), and a socioeconomic pattern was observed, with children from lower income more likely to drink water from public supply. In crude analysis, children who consumed bottled water had a lower risk of decayed teeth, lower experience of dental caries and less severe disease. No associations were observed after adjustments for socioeconomic conditions. CONCLUSION: Underlying socioeconomic inequalities explained the association between prevalence and severity of dental caries in primary dentition and source of drinking water. CLINICAL SIGNIFICANCE: Drinking fluoridated tap water is as effective in dental caries prevention as bottled water with acceptable levels of fluoride, with the advantage of being accessible to all. Oral health prevention and treatment should be implemented as early in life as possible and should take into consideration the family's socioeconomic context.

Cyanobacterial biodiversity of semiarid public drinking water supply reservoirs assessed via next-generation DNA sequencing technology.

Next-generation DNA sequencing technology was applied to generate molecular data from semiarid reservoirs during well-defined seasons. Target sequences of 16S-23S rRNA ITS and cpcBA-IGS were used to reveal the taxonomic groups of cyanobacteria present in the samples, and genes coding for cyanotoxins such as microcystins (mcyE), saxitoxins (sxtA), and cylindrospermopsins (cyrJ) were investigated. The presence of saxitoxins in the environmental samples was evaluated using ELISA kit. Taxonomic analyses of high-throughput DNA sequencing data showed the dominance of the genus Microcystis in Mundaú reservoir. Furthermore, it was the most abundant genus in the dry season in Ingazeira reservoir. In the rainy season, 16S-23S rRNA ITS analysis revealed that Cylindrospermopsis raciborskii comprised 46.8% of the cyanobacterial community in Ingazeira reservoir, while the cpcBAIGS region revealed that C. raciborskii (31.8%) was the most abundant taxon followed by Sphaerospermopsis aphanizomenoides (17.3%) and Planktothrix zahidii (16.6%). Despite the presence of other potential toxin-producing genera, the detected sxtA gene belonged to C. raciborskii, while the mcyE gene belonged to Microcystis in both reservoirs. The detected mcyE gene had good correlation with MC content, while the amplification of the sxtA gene was related to the presence of STX. The cyrJ gene was not detected in these samples. Using DNA analyses, our results showed that the cyanobacterial composition of Mundaú reservoir was similar in successive dry seasons, and it varied between seasons in Ingazeira reservoir. In addition, our data suggest that some biases of analysis influenced the cyanobacterial communities seen in the NGS output of Ingazeira reservoir.

Epidemics caused by contamination of drinking water supplied by public water supply systems in terms of current legislation.

OBJECTIVES: This paper describes and comments on contemporary legislation concerning prevention of epidemics caused by contaminated drinking water from public water supplies in the Czech Republic. METHODS: Suggestions are made for removing existing legislative shortcomings, clarifying diction of existing laws and expanding sanctions and penalties for health injury caused by providers and operators of public drinking water. RESULTS: The author reflects on improving legislation concerning the compensation of victims of contaminated water with reference to the aftermath of a local epidemic in the Dejvice District of Prague. CONCLUSION: The issues raised should be addressed since better legislation can significantly contribute to the limitation of water-borne epidemics and their consequences.

La situación alimentaria de los desconectados de los servicios públicos domiciliarios en la parte alta de la comuna 3 de la ciudad de Medellín / The food situation of people without household utilities connection in the upper section of commune 3 in the city of Medellin / A situação alimentar dos desligados dos serviços públicos domiciliares na parte alta da comuna 3 da cidade de Medellín

Resumen Objetivo: Describir la situación alimentaria nutricional de los habitantes de las viviendas desconectadas de los servicios públicos domiciliarios de los barrios que conforman la franja alta de la comuna 3 de la ciudad de Medellín. Metodología: Se llevó a cabo un estudio descriptivo trasversal. Se tomó un tamaño de muestra de 220 hogares, por medio de un muestreo aleatorio simple. Se recogió información a través de un cuestionario estructurado y por el método de la Escala Latinoamericana y Caribeña de Seguridad Alimentaria (elcsa). Los análisis estadísticos fueron hechos en el software spss® versión 19. El análisis de la información se efectuó mediante análisis descriptivos y exploratorio de los datos. También se realizó un análisis de correspondencias múltiples, con el fin de establecer perfiles socioeconómicos y alimentarios de los hogares desconectados. Se estimó la asociación entre la desnutrición y variables socioeconómicas del hogar, con la prueba chi-cuadrado. Resultados: Existen dos formas de desconexión de los servicios públicos domiciliarios: una por prestación (falto de pago) y otra por acceso (viviendas en alto riesgo o por fuera del plan territorial de la ciudad). La distribución poblacional de los hogares es piramidal progresiva, donde se resaltan las familias nucleadas biparentales y la informalidad como la situación laboral de la cabeza de familia; la tenencia de la vivienda es propia y el nivel académico no sobrepasa la secundaria. Se asociaron las variables de desnutrición con las covariables de hacinamiento, nivel de ingreso y tipo de vivienda rancho. Se obtuvieron dos clasificaciones de los hogares, conformadas por hogares en inseguridad alimentaria y nutricional moderada a severa y hogares con inseguridad alimentaria leve. Conclusión: Los hogares desconectados de los servicios públicos domiciliarios de los barrios de la franja alta de la comuna 3 no cuentan ni con la capacidad económica ni con un entorno mínimo para mejorar sus condiciones de salud, lo cual constituye un riesgo alimentario permanente, especialmente para los menores de edad. La canasta básica de los hogares encuestados son alimentos que aportan, en su mayor proporción, carbohidratos y calorías; las frutas son consumidas en mínimas cantidades.

Abstract Objective: To describe the nutritional food situation of the inha bitants of households without household utilities connection in neighborhoods that form the upper section of commune 3 in the city of Medellin. Methodology: A descriptive cross-sectional study was conducted. Sample size was 220 households, using simple random sampling. Information was collected using a structured questionnaire and using the Latin American and Ca ribbean Food Security Scale-elcsa (in Spanish, Escala Latinoa mericana y Caribeña de Seguridad Alimentaria). A statistical analysis was conducted using spss® software Version 19. Infor mation analysis was conducted using descriptive an exploratory data analysis. Furthermore, a multiple correspondence analysis was conducted to establish social economic and food profiles of the households without utilities connection. The study estimated an association between malnutrition and household socioecono mic variables using a chi-square test. Results: We found that there are two ways of not being connected to household utili ties: one as a result of service disconnection (lack of payment) and the other because of access (high risk housing or outside the city's territorial plan). Household population distribution is pyramid-shaped and progressive, where the families are mainly represented by two-parent nuclear families where the head of the household has an informal labor situation; they have their own house and their schooling is no higher than Secondary School. Malnutrition variables were associated with covaria tes as overcrowding, income level and hut-type housing. Two household classifications were obtained which were households facing moderate to severe food and nutrition insecurity and ho mes facing slight food insecurity. Conclusion: Households that without utilities connection in the neighborhoods located in the upper sector of commune 3 do not have the economic capaci ty, and do not have a minimum setting to improve their health conditions, which creates a permanent food risk, particularly for underage children. The basic food basket of the participating households consists of food that mostly provides carbohydrates and calories; they eat fruit in minimum amounts.

Resumo Objetivo: Descrever a situação alimentar nutricional dos mora dores das Vivendas desligadas dos serviços públicos domicilia res dos bairros que compõem a faixa alta da comuna 3 da cidade de Medellín. Metodologia: O pessoal trabalhou neste estudo descritivo em linha viés. Pegamos um tamanho de amostra de 220, lares, e fomos utentes do método de amostragem aleatória simples. Coletando informações através da enquete estruturada e pelo método da escada latino-americana e caribenha da segu rança alimentar (elcsa). As análises estatísticas foram feitas no software spss® versão 19. As análises da exploração se fazem mediante analise descritiva e exploratória dos dados. Também se realizou uma análise de correspondência múltipla, com o in tuito se estabelecer perfis socioeconômicos e alimentares destes lares desligados. Se estimó la asociación entre la desnutrición y variables socioeconómicas del hogar, con la prueba chi-cuadra do. Resultados: Existem dois jeitos de desconexão dos serviços públicos domiciliários: uma por prestação (faltante de pagamen to) e outra por acessibilidade (moradias em alto risco ou por fora do planejamento territorial da cidade). A distribuição populacio nal destes lares é piramidal progressiva, onde se salientam as fa mílias nucleadas bi parentais e a informalidade como a situação laborista da testa da família; a tenência da moradia é própria e o nível académico não ultrapassa a secundaria. Se associaram as variáveis de desnutrição com as variáveis de superlotação, nível de renda e tipo de vivenda de favela. Se obtiveram duas classificações dos lares, conformadas por famílias duma inse guridade alimentaria e nutricional moderada indo pra severa e lares com inseguridade alimentaria leve. Conclusão: Os lares desconectados dos serviços públicos domiciliários dos bairros da faixa alta da comuna 3 não contam nem com a capacidade económica nem com um redor mínimo para melhorar as suas condições de saúde, o qual constitui um risco alimentar perma nente, especialmente para os menores de idade. A cesta básica dos lares perguntados é de alimentos que aportam, na sua maior proporção, carboidratos e calorias; as frutas são consumidas em mínimas quantidades.

Total coliform and E. coli in public water systems using undisinfected ground water in the United States.

Public water systems (PWSs) in the United States generate total coliform (TC) and Escherichia coli (EC) monitoring data, as required by the Total Coliform Rule (TCR). We analyzed data generated in 2011 by approximately 38,000 small (serving fewer than 4101 individuals) undisinfected public water systems (PWSs). We used statistical modeling to characterize a distribution of TC detection probabilities for each of nine groupings of PWSs based on system type (community, non-transient non-community, and transient non-community) and population served (less than 101, 101-1000 and 1001-4100 people). We found that among PWS types sampled in 2011, on average, undisinfected transient PWSs test positive for TC 4.3% of the time as compared with 3% for undisinfected non-transient PWSs and 2.5% for undisinfected community PWSs. Within each type of PWS, the smaller systems have higher median TC detection than the larger systems. All TC-positive samples were assayed for EC. Among TC-positive samples from small undisinfected PWSs, EC is detected in about 5% of samples, regardless of PWS type or size. We evaluated the upper tail of the TC detection probability distributions and found that significant percentages of some system types have high TC detection probabilities. For example, assuming the systems providing data are nationally-representative, then 5.0% of the ∼50,000 small undisinfected transient PWSs in the U.S. have TC detection probabilities of 20% or more. Communities with such high TC detection probabilities may have elevated risk of acute gastrointestinal (AGI) illness - perhaps as great or greater than the attributable risk to drinking water (6-22%) calculated for 14 Wisconsin community PWSs with much lower TC detection probabilities (about 2.3%, Borchardt et al., 2012).

Dinâmica de protozoários patogênicos e cianobactérias em um reservatório de abastecimento público de água no sudeste do Brasil / Dinamic of pathogenic protozoa and cyanobacteria in a reservoir used for water supply in southeastern Brazil

RESUMO O presente estudo foi baseado no monitoramento de um reservatório tropical (Vargem das Flores) utilizado para o abastecimento público de água de sete cidades da região metropolitana de Belo Horizonte, Minas Gerais. O reservatório foi monitorado durante quatro anos: período inicial (de 2004 a 2007) para células de cianobactérias e parâmetros físico-químicos e, subsequentemente (2007 e 2008), para oocistos de Cryptosporidium spp. e cistos de Giardia spp. em quatro estações de amostragem. Também foram avaliadas as concentrações de Escherichia coli de 2007 a 2008, o que permitiu a caracterização de cada ponto de amostragem de acordo com a legislação do Conselho Nacional do Meio Ambiente (CONAMA) nº 274/2000. Os resultados indicaram concentrações de (oo)cistos de Cryptosporidium spp. e Giardia spp. variando de 0 a 0,8 (oo)cistos.L-1, e as mais elevadas concentrações de células de cianobactérias, de 0,0 a 4,5 x 105 cels.mL-1, apontando assim para potencial risco à saúde humana caso a água do reservatório seja consumida sem tramento. As cianobactérias não foram encontradas durante a estação seca. O grupo retornou rapidamente após a desestratificação. A estação chuvosa foi caracterizada pela elevada ocorrência de cianobactérias com a predominância da espécie picoplanctônica (Aphanocapsa sp.), sobre Microcystis spp. previamente detectada, e apresentou as maiores variações de oxigênio dissolvido, turbidez, fósforo total, ortofosfato, amônia, nitrito e nitrato. A mudança observada no grupo das cianobactérias (Aphanocapsa spp. sobre Microcystis spp.) pode ser um indicativo das alterações das características da água. De acordo com as concentrações de E. coli , as estações foram classificadas como próprias para recreação de contato primário, de acordo com a Resolução CONAMA nº 274/2000.

ABSTRACT The current study monitored the water quality of a tropical reservoir (Vargem das Flores) used to supply potable water to seven cities in the metropolitan area of Belo Horizonte, Minas Gerais, southeast Brazil. The reservoir was monitored for four years: initially (from 2004 to 2007) for cyanobacterial cells and physicochemical parameters and, subsequently (in 2007 and 2008), for Cryptosporidium spp. oocysts and Giardia spp. cysts in four sampling stations. The concentrations of Escherichia coli were also measured in 2007 and 2008, wich allowed the characterization of each sampling point according to the National Environment Council (CONAMA) no. 274/2000. Results indicated concentrations of Cryptosporidium spp. and Giardia spp. (oo)cysts ranging from 0 to 0.8 (oo)cysts.L-1, and higher concentrations of cyanobacteria cells, from 0.0 to 4.5 x 105 cells.mL-1, thus indicating potential risks to human health, if the water from the reservoir is not properly treated before consumption. The group of cyanobacteria was not found during the dry season, returning soon after destratification. The rainy season was characterized by a higher ocurrence of cyanobacteria and predominance of picoplanktonic species (Aphanocapsa spp.), over the Microcystis spp. previously found and presented the highest variations in dissolved oxygen, turbidity, total phosphorous, orthophosphate, ammonia, nitrite and nitrate. The change observed within the group of cyanobacteria (Aphanocapsa spp. over Microcystis spp.) may be indicative of changing characteristics in the water source. All the sampling points were classified as adequate for primary contact recreation, given the E. coli concentrations, according to the CONAMA Resolution no. 274/2000.

Impact of Infrastructure on Mortality in Marginalised and Segregated Communities in the Slovak Republic.

AIM: Poverty and social exclusion is measured through different criteria and one of them is the health sector. The relationship between Roma population and the health sector is on the edge of researchers' interest in the Slovak Republic. The purpose of this paper is a quantification of the regional disparities in the development of mortality which is causally linked with selected infrastructural determinants - namely access to water and sewerage. These determinants differently participate in the structure of mortality in marginalised and segregated communities and they deepen regional disparities in health. METHODS: It is a spatial analysis of the districts of the Slovak Republic. The data from the Atlas of Roma communities in Slovakia 2013 is applied. Through the multiple linear regression model the relationship between mortality of the Roma population and water and sewerage availability in the Roma settlements is examined. Similarity between the districts is measured by the Euclidean metric system. RESULTS: The most appropriate district for representing the Slovak Republic average is the Dunajská Streda district in a field of arithmetic mean and the Velký Krtís district in a field of median value. The outermost district is represented by the Kosice-okolie district, conversely, the Trnava district is the closest to the rest of the Slovak Republic. The highest statistically significant impacts on mortality are explored in public water supply extension plan and public sewerage supply extension plan. It seems that water play a greater role in determining health of Roma population. The highest number of inhabitants with supplied public water and public sewerage is kept by the Kezmarok district, the Kosice district, and the Spisská Nová Ves district. CONCLUSIONS: Our results can be beneficial for health decision making, since in the Strategic Framework for Health of the Slovak Republic metrics for measuring and evaluating health aspects in Roma communities absent and that prevents them to be correlated with the planned interventions.

Social Perception of Public Water Supply Network and Groundwater Quality in an Urban Setting Facing Saltwater Intrusion and Water Shortages.

Perceptions developed by consumers regarding the quality of water reaching their household can affect the ultimate use of the water. This study identified key factors influencing consumers' perception of water quality in a highly urbanized coastal city, experiencing chronic water shortages, overexploitation of groundwater, and accelerated saltwater intrusion. Household surveys were administered to residents to capture views and perceptions of consumed water. Concomitantly, groundwater and tap water samples were collected and analyzed at each residence for comparison with perceptions. People's rating of groundwater quality was found to correlate to the measured water quality both in the dry and wet seasons. In contrast, perceptions regarding the water quality of the public water supply network did not show any correlation with the measured tap water quality indicators. Logistic regression models developed to predict perception based on salient variables indicated that age, apartment ownership, and levels of total dissolved solids play a significant role in shaping perceptions regarding groundwater quality. Perceptions concerning the water quality of the public water supply network appeared to be independent of the measured total dissolved solids levels at the tap but correlated to those measured in the wells. The study highlights misconceptions that can arise as a result of uncontrolled cross-connections of groundwater to the public supply network water and the development of misaligned perceptions based on prior consumption patterns, water shortages, and a rapidly salinizing groundwater aquifer.

Inequitable allocation of deep community wells for reducing arsenic exposure in Bangladesh.

Community wells that extend deeper than most private wells are crucial for reducing exposure to groundwater arsenic (As) in rural Bangladesh. This study evaluates the impact on access to safe drinking water of 915 such intermediate (90-150 m) and deep (>150 m) wells across a 180 km2 area where a total of 48,790 tubewells were tested with field kits in 2012-13. Half the shallow private wells meet the Bangladesh standard of 50 µg/L for As in drinking water, whereas 92% of the intermediate and deep wells meet the more restrictive World Health Organization guideline for As in drinking water of 10 µg/L. As a proxy for water access, distance calculations show that 29% of shallow wells with >50 µg/L As are located within walking distance (100 m) of at least one of the 915 intermediate or deep wells. Similar calculations for a hypothetical more even distribution of deep wells show that 74% of shallow wells with >50 µg/L As could have been located within 100 m of the same number deep wells. These observations and well-usage data suggest that community wells in Araihazar, and probably elsewhere in Bangladesh, were not optimally allocated by the government because of elite capture.

Quantifying and managing regional greenhouse gas emissions: waste sector of Daejeon, Korea.

A credible accounting of national and regional inventories for the greenhouse gas (GHG) reduction has emerged as one of the most significant current discussions. This article assessed the regional GHG emissions by three categories of the waste sector in Daejeon Metropolitan City (DMC), Korea, examined the potential for DMC to reduce GHG emission, and discussed the methodology modified from Intergovernmental Panel on Climate Change and Korea national guidelines. During the last five years, DMC's overall GHG emissions were 239 thousand tons CO2 eq./year from eleven public environmental infrastructure facilities, with a population of 1.52 million. Of the three categories, solid waste treatment/disposal contributes 68%, whilst wastewater treatment and others contribute 22% and 10% respectively. Among GHG unit emissions per ton of waste treatment, the biggest contributor was waste incineration of 694 kg CO2 eq./ton, followed by waste disposal of 483 kg CO2 eq./ton, biological treatment of solid waste of 209 kg CO2 eq./ton, wastewater treatment of 0.241 kg CO2 eq./m(3), and public water supplies of 0.067 kg CO2 eq./m(3). Furthermore, it is suggested that the potential in reducing GHG emissions from landfill process can be as high as 47.5% by increasing landfill gas recovery up to 50%. Therefore, it is apparent that reduction strategies for the main contributors of GHG emissions should take precedence over minor contributors and lead to the best practice for managing GHGs abatement.

Evolução e panorama atual da cobertura da fluoretação da água deabastecimento no Brasil, período de 2004 a 2013 / Evolution and current overview of the coverage of water fluoridation supply in Brazil, period 2004-2013

Introdução - A adição do íon fluoreto à água para consumo humano, objetivando a redução da incidência e prevalência da cárie dental, data de 1945. Esta ação de saúde pública foi reconhecida, em 1958, pela Organização Mundial de Saúde (OMS) e recomendada aos Estados-membros, durante a 22ª Assembléia Mundial de Saúde, em 1996. Após vários levantamentos epidemiológicos realizados respectivamente em 1986, 1996 e 2003, que confirmaram a precariedade da saúde bucal da população brasileira, em 2004, foi lançado o Programa Brasil Sorridente, tendo como um dos seus objetivos, com vistas à proteção à saúde,induzir provedores de serviços públicos de saneamento básico ao desenvolvimento de ações voltadas à fluoretação da água. Objetivo – Avaliar o Programa Brasil Sorridente no que se refere à fluoretação da água de abastecimento público, período 2004 a 2013. Material e Método – Estudo descritivo com utilização de dados secundários, tendo como unidade de análise os municípios brasileiros que distribuem água à população por meio de sistemas públicos de abastecimento. Realização de revisão bibliográfica baseada em recentes publicações sobre os benefícios, riscos e controvérsias relacionadas à adição de flúor à água para consumo humano...

Introduction – The addition of fluoride in water for human being consumption aiming the reduction of dental caries, it has been done since 1945. The measure of public health was recognized in 1958 by the World Health Organization (WHO) and recommended for all States Member at the 22ª World Health Assemble, in 1996. After epidemiologic studies performed between the decades 1986, 1996 and 2003 confirming the population´s bad oral health condition, in 2004, the Program Brasil Sorridente was relised, having as one of its objectives,with a view to protecting the health, induce sanitation providers to develop actions aimed to add fluoride to the drinking water. Objective – Avaluation of the Programa Brasil Sorridente in relation of water supply fluoridation, from 2004 to 2013. Material and Method – Adescriptive study, using secondary data, taking as the unit of analysis the brasilianmunicipalities that distributing water to the population through public water supply systems. Conducting literature review based on recent publications on the benefits, risks andcontroversies about the fluoride adding to driking water...