Evaluation of Ir, Ru, and W as permanent modifiers for the simultaneous determination of As, Bi, Pb, Sb, and Se in natural water by electrothermal atomic absorption spectrometry

Iridium-, Ru-, and W-coated platforms were prepared by thermal treatment of the transversely heated graphite atomizer and investigated for the simultaneous determination of As, Bi, Pb, Sb, and Se in tap water by electrothermal atomic absorption spectrometry. The maximum pyrolysis temperature for As and Bi increased in a modifier sequence W < Ru < Ir. For Pb, Sb, and Se, this sequence was W < Ru, It. Calculated characteristic masses in the presence of It, Ru, and W were 35, 33, and 35 pg for As; 63, 51, and 52 pg for Bi; 50, 32, and 34 pg for Pb; 40, 35, and 31 pg for Sb; and 39, 39, and 93 pg for Se, respectively. Ruthenium was elected as the optimum modifier.Repeatability of the measurements was typically < 6%. Recoveries of As, Bi, Pb, Sb, and Se added to tap water samples varied from 79 to 109%. Accuracy was also checked by analysis of five certified reference materials (CRMs) from the National Institute of Standards and Technology (NIST1640 - Trace Elements in Natural Water; NIST 1643d Trace Elements in Water) and High Purity Standards (Trace Metals in Drinking Water Standards, lots #812708, #591107, and #710710). A paired t-test showed that the results for the CRMs were in agreement at the 95% confidence level with the certified values. The graphite tube lifetime was about 650 firings. multi-element determination is particularly challenging due to the necessity of carefully optimizing compromise conditions.Based on the considerations listed above, the aim of this paper was to evaluate the behavior of Ir, Ru, and W as permanent modifiers for the simultaneous determination of As, Bi, Pb, Sb, and Se. The performance of the proposed procedure was also verified after the ETAAS analysis of tap waters and reference materials.

Effect of rinsing with water immediately after APF gel application on enamel demineralization in situ

This double-blind crossover in situ study evaluated the effect of rinsing with water immediately after the application of acidulated phosphate fluoride (APF) on enamel demineralization. APF application was followed by: no rinsing or consuming of liquids or solids for the next 30 min; immediately washing with water jet or drinking of a glass of water. All treatments showed a statistically significant decrease in enamel mineral loss compared to the control (p < 0.05), but the differences among treatments were not significant (p > 0.05). The data suggest that the recommendation of asking patients to refrain from drinking water following professional APF application does not seem to have an influence on the anticaries effect of fluoride. Copyright (C) 2005 S. Karger AG, Basel.

Impact of an environmentally realistic intake of water contaminants and superoxide formation on tissues of rats

Water contaminants have a high potential risk for the health of populations and for this reason their toxic effects urgently should be established. The present study was carried out to determine whether an environmentally realistic intake of water contaminants can induce tissue lesions, and to clarify the contribution of superoxide radical (O-2(.-)) formation to this effect. Male Wistar rats were given drinking water from the Tiett River (group A) and from the Capivara River (group B). The increased creatinine, glucose, alanine transaminase and amylase levels in serum reflected the toxic effects of river-water contaminants to renal, pancreatic and hepatic tissues of rats. As changes in lipoperoxide were observed in rats after river-water intake while superoxide dismutase activities decreased in these animals, it is assumed that the superoxide anion elicits lipoperoxide formation and induces tissue damage. There is evidence that oxygen tension reflects water pollution, since river-water with a-low oxygen tension induced more elevated toxicity in rat tissues. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

TOXIC EFFECTS OF WATER EUTROPHICATION ON PANCREATIC, HEPATIC AND OSTEOGENIC TISSUES OF RATS

Pollution, industrial solvents, concentrations of metals and other environmental agents are widely related to biochemicals values which are used in disease diagnosis of environmental toxicity. A rat bioassay validated for the identification of toxic effects of eutrophication revealed increased serum activities of amylase, alanine transaminase (BLT) and alkaline phosphatase (ALP) in rats that received algae, filtered water and nickel or cadmium from drinking water. Serum Cu-Zn superoxide dismutase activity decreased from its basal level of 40.8 +/- 2.3 to 26.4 U/mg protein, at 7 days of algae and at 48 hr of nickel and cadmium water ingestion. The observation that lipoperoxide concentration was not altered in rats treated with filtered water, while amylase, ALT and ALP were increased in these rats and in those treated with nickel or cadmium, indicated that pancreatic, hepatic and osteogenic lesions by eutrophication were not related to superoxide radicals, and might be due to a novel toxic environmental agent found in filtered and non-filtered algae water.

Performance of constructed wetland system for public water supply

The project is being conducted in the town of Analândia, São Paulo, Brazil. The constructed wetlands system for water supply consists of a channel with floating aquatic macrophytes, HDS system (Water Decontamination with Soil - Patent PI 850.3030), chlorinating system, filtering system and distribution. The project objectives include investigating the process variables to further optimize design and operation factors, evaluating the relation of nutrients and plants development, biomass production, shoot development, nutrient cycling and total and fecal coliforms removal, comparing the treatment efficiency among the seasons of the year; and moreover to compare the average values obtained between February and June 1998 (Salati et al., 1998) with the average obtained for the same parameters between March and June 2000. Studies have been developed in order to verify during one year the drinking quality of the water for the following parameters: turbidity, color, pH, dissolved oxygen, total of dissolved solids, COD, chloride, among others, according to the Ministry of Health's Regulation 36. This system of water supply projected to treat 15 L s-1 has been in continuous operation for 2 years, it was implemented with support of the National Environment Fund (FNMA), administered by the Center of Environmental Studies (CEA-UNESP), while the technical supervision and design were performed by the Institute of Applied Ecology. The actual research project is being supported by FAPESP.

Geo(anthropo)genic factors affecting the radioactivity in groundwaters from Guarani aquifer, Brazil

This investigation was carried out within the Paraná sedimentary basin, involved the sampling of 77 pumped tubular wells, and was realized with the puipose of evaluating the radioactivity in the Brazilian part of Guarani (Botucatu-Pirambóia, Tacuarembó, Misiones) aquifer. The radioactivity due to nuclides belonging to uranium and thorium series decay was investigated in terms of the uranium isotopes 234U and 238U, radon (222Rn), and the radium isotopes 226Ra and 228Ra. The obtained results were compared with the maximum permissible concentration limits in drinking water defined by the Brazilian national standard, as well with the guidelines for drinking water quality established by the World Health Organization. The importance of water-rock/soil interactions was considered in order to explain most of the obtained data.

Faecal contamination (viral and bacteria) detection in groundwater used for drinking purposes in São Paulo, Brazil

This project has been developed to evaluate the possible relationship between the cesspit (pit latrine) in as far as it degrades the quality of underground water. Its importance is due to the fact that in the rural communities in the State of São Paulo (Brazil) this type of cesspit is very common as a means of sewage disposal and these communities use underground water for their supply of drinking water. Rural properties distributed over the rural area in the municipality of São José do Rio Preto were selected. A preliminary study was then set up to determine the social situation and health of the households as well as qualitative evaluations on the type of water supply and sewage disposal of these communities. Campaigns of water sampling then followed and laboratory analyses of water taken from wells were carried out. Parameters were set up to evaluate the potability according to Brazilian legislation (2004) paying attention to microbiologic (coliforms, Crytosporidium sp., and adenovirus). The analyses showed evidence of possible interaction between the wells and the sewage effluents and drainage in these communities. A PCR reaction to detect adenovirus showed a presence in 53.3% of the samples. The tests for the detection of Cryotosporidium sp all showed a negative result.

El derecho humano al agua y al saneamiento frente a los Objetivos de Desarrollo del Milenio (ODM)

Prólogo de Alicia Bárcena

Best practices in regulating State-owned and municipal water utilities

Includes bibliography

Network for Cooperation in Integrated Water Resource Management for Sustainable Development in Latin America and the Caribbean No. 42

Editorial remarks.-- Open discussion: Conceptual change in regulation in a model of public service provision ; Policies and institutional frameworks for drinking water supply and sanitation ; Strategies for low-carbon development in megacities in Latin America ; Adapting to climate change in water management in the irrigation sector.-- Meetings: Towards a vision on natural resource governance for equality ; Water resources faced with uncertainty and the risk of climate change ; Regulation challenges in the water sector.-- News of the Network: Lessons to be drawn from the interprovincial Colorado River flow distribution agreement ; Rural drinking water programme in Chile ; Ecuador’s Act on Water Resources and Water Use and Exploitation.-- Internet and WWW News

An assessment of the economic and social impacts of climate change on the health sector in the Caribbean

Climate change affects the fundamental bases of good human health, which are clean air, safe drinking water, sufficient food, and secure shelter. Climate change is known to impact health through three climate dimensions: extreme heat, natural disasters, and infections and diseases. The temporal and spatial climatic changes that will affect the biology and ecology of vectors and intermediate hosts are likely to increase the risks of disease transmission. The greatest effect of climate change on disease transmission is likely to be observed at the extremes of the range of temperatures at which transmission typically occurs. Caribbean countries are marked by unique geographical and geological features. When combined with their physical, infrastructural development, these features make them relatively more prone to negative impacts from changes in climatic conditions. The increased variability of climate associated with slow-moving tropical depressions has implications for water quality through flooding as well as hurricanes. Caribbean countries often have problems with water and sanitation. These problems are exacerbated whenever there is excess rainfall, or no rainfall. The current report aims to prepare the Caribbean to respond better to the anticipated impact of climate change on the health sector, while fostering a subregional Caribbean approach to reducing carbon emissions by 2050. It provides a major advance on the analytical and contextual issues surrounding the impact of climate change on health in the Caribbean by focusing on the vector-borne and waterborne diseases that are anticipated to be impacted directly by climate change. The ultimate goal is to quantify both the direct and indirect costs associated with each disease, and to present adaptation strategies that can address these health concerns effectively to benefit the populations of the Caribbean.

Network for Cooperation in Integrated Water Resource Management for Sustainable Development in Latin America and the Caribbean No. 43

Editorial remarks.-- Open discussion: Energy efficiency and economic regulation in water supply and sewerage services ; Policies and institutional frameworks for drinking water supply and sanitation.-- News of the network: The goal of food self-sufficiency of the countries of the cooperation council for de Arab States of the Gulf ; Narrowing the gaps in drinking water and sanitation: an opportunity for users ; Water Users'Organizations Act of Peru ; Commission for the Integrated management of the Tárcoles River Basin, Costa Rica ; Water and sanitation Management Unit in Panama.-- Courses: Course "Strategic aspects of irrigation".-- Internet and WWW news

Network for Cooperation in Integrated Water Resource Management for Sustainable Development in Latin America and the Caribbean No. 38

Editorial remarks.-- Open discussion: Using performance indicators to monitor drinking water supply and sewerage services ; Implications of biofuel development for water management and use.-- News of the Network: Reflections of URSEA in Uruguay, 10 years after its creation ; National Environmental Sanitation Strategy of El Salvador.-- Meetings: Workshop on Transboundary Water Cooperation (Buenos Aires, Argentina) ; Importance of the value of water: lessons and challenges (Lima, Peru).-- Internet and WWW News

Network for Cooperation in Integrated Water Resource Management for Sustainable Development in Latin America and the Caribbean No. 40

Editorial remarks.-- Open discussion: Regulation under the public model of service provision ; Regulatory progress and challenges in Argentina ; Twenty years of SUNASS: development, experience, lessons learned and challenges ; Possible conflict between efficiency and sustainability ; Best practices in regulating State-owned and municipal water utilities.-- News of the Network: Water use charge in the Province of Buenos Aires ; National Drinking Water and Sanitation Sector Policy of Guatemala ; Sanitation Services Modernization Law of Peru ; Internet and WWW News

Assessment of surface water in two Amazonian rivers impacted by industrial wastewater, Barcarena City, Pará State (Brazil)

No ano de 2007, águas superficiais foram coletadas a partir de 21 pontos de amostragem na cidade de Barcarena, Região Norte, Brasil: um ponto de amostragem localizado em um pequeno córrego que recebe descarga de resíduos a partir da indústria de beneficiamento do caulim e deságua no Rio Curuperê, três pontos de amostragens localizados próximos de fontes que emergem na margem esquerda e deságuam no Rio Curuperê, nove pontos de amostragem no Rio Curuperê, que deságua no Rio Dendê, e oito no Rio Dendê, afluente da margem esquerda do Rio Pará. Para todas as amostras de água foram quantificadas 14 variáveis físico-químicas e níveis de 12 metais. Os resultados nos pontos próximos das fontes do Rio Curuperê apresentaram perfil físico-químico e níveis de metais típicos para águas superficiais e esses valores foram utilizados como referência para comparar e identificar possíveis alterações nas características químicas para os demais pontos de amostragem. Quando os resultados das fontes do rio Curuperê foram comparados com os resultados do ponto próximo a descarga de resíduos industriais foram observadas fortes alterações nos valores de 6 variáveis físico-químicas (pH, condutividade elétrica (EC), total de sólidos suspensos (TDS), nitrogênio amoniacal (N-NH4), sulfato (SO4) e salinidade) e aumento em magnitude dos níveis de quatro metais (Al, Fe, Mn e Zn), caracterizando que esses resíduos eram descarregados no ambiente sem tratamentos adequados. Os resultados nos demais pontos de amostragem demonstraram que estas condições anômalas também foram encontradas ao longo dos Rios Curuperê e Dendê, principalmente durante a maré baixa. A partir desta caracterização química das águas foram identificadas condições prejudiciais aos ecossistemas aquáticos e potencial risco à saúde da população local que usa os rios para consumo, recreação e transporte.