Prediction of water quality under the impacts of fine dust and sand storm events using an experimental model and multivariate regression analysis.

Many regions of the world, especially arid and semiarid areas, occasionally experience fine dust and sandstorms, known environmental problems that make normal life difficult. Since the intrusion of large amounts of dust into treatment plants may significantly change the water quality indices, the main goal of this study was to estimate these indices during the events, which can help decision-makers to improve water quality. To achieve relationships using nonlinear multivariate regression analysis, a long-term (three years: April 2017-February 2020) experimental study of water quality parameters including total dissolved solids (TDS), hydrogen content (pH), electrical conductivity (EC), chlorine (Cl), total hardness, sodium (Na), and magnesium (Mg) for water samples from wastewater treatment plants in Sistan region (Iran) was conducted where is one of the most popular regions in the world with high amount of annual fine dust level. Analysis of ANOVA showed that of all the independent parameters considered in this study, water quality parameters strongly correlated with monthly mean sand and dust storm index (SDSI), wind speed, temperature, and the number of monthly windy days. For the regression analysis, 25 months of data were used for the simulation process and 10 months for validation. The final results showed that the relationships obtained from the nonlinear multivariate regression analysis could predict the water quality indices very well (with R2 more than 0.75) except for Mg with R2 equal to 0.55. In addition, the maximum mean relative error belongs to Mg (10.8%) and then Na (9.9%) whereas the minimum mean relative error belongs to pH (2.6%) and then EC (2.9%).

Recent advances of sensing strategies for the detection of ß-glucuronidase activity.

ß-Glucuronidase (ß-GLU), a kind of hydrolase, is widely distributed in mammalian tissues, body fluids, and microbiota. Abnormal changes of ß-GLU activity are often correlated with the occurrence of diseases and deterioration of water quality. Therefore, detection of ß-GLU activity is of great significance in biomedicine and environmental health such as cancer diagnosis and water monitoring. However, the conventional ß-GLU activity assay suffers from the limitations of low sensitivity, poor accuracy, and complex procedure. With the development of analytical chemistry, many advances have been made in the detection of ß-GLU activity in recent years. The sensors for ß-GLU activity detection which have the advantages of rapid and reliable detection have been attracting increased attentions. In this paper, the principles, performances, and limitations of these ß-GLU sensors, including colorimetric sensing, fluorescent sensing, electrochemical sensing for the determination of ß-GLU activity, have been summarized and discussed. Moreover, the challenges and research trends of ß-GLU activity assay are proposed.

Physicochemical, microbiological quality, and risk assessment of water consumed by a quilombola community in midwestern Brazil.

The quality of the water consumed by a given community is related to its quality of life. In this sense, this study aimed to evaluate, from the perspective of health risk, the physical, chemical, and microbiological quality of drinking water, in a quilombola community, and the qualitative aspects intrinsic to its use and storage. For this, water samples, collected at the exits of the collective water supply system and from eight cisterns that store rainwater, used for human consumption, were analyzed. The samples were subjected to physical, chemical, and microbiological analysis, including adenovirus (HAdV) and enterovirus (EV). The probability of an individual acquiring infection through water consumption was determined by quantitative microbiological risk analysis using HAdV and Escherichia coli (EC) as reference pathogens. The results showed that the water in the deep tubular well had 270.8 mg/L of total hardness, leading to the rejection of its consumption by ingestion. Alternativity, the people in the community consume rainwater stored in cisterns. For this type of water, the presence of heterotrophic bacteria was found in 75%, total coliform was present in 100%, and Enterococci were detected in 25%. Furthermore, EC was present in 25%, EV in 50%, and HAdV in 100% of the samples. The probability of annual infection with HAdV and EC was, in the worst situation, 100% and 1.3%, respectively. Regarding the qualitative and quantitative aspects, there was a significant positive correlation between the absence of EC and the withdrawal of water from the cistern using a pump and the opposite when the withdrawal was carried out using a bucket or hose. Based on the results found, it is important to carry out actions aimed at improving water quality and, consequently, the quality of life of people living in the study community.

Are the existing guidelines sufficient for the assessment of bathing water quality? The example of Polish lakes.

The safety of beachgoers and swimmers is determined by the presence or absence of microbial contaminants and cyanobacterial toxins in the water. This study compared the assessment of bathing waters according to the Bathing Water Directive, which is based on the concentration of fecal contaminants, with some modifications, and a new method based on the concentration of chlorophyll-a, which corresponds to the World Health Organization (WHO) guidelines used for determining cyanobacterial density in the water posing threat to people health. The results obtained from the method based on chlorophyll-a concentration clearly showed that the number of bathing waters in Poland with sufficient and insufficient quality were higher in 2018 and 2019, compared to the method based on microbial contamination. The closing of bathing waters based only on the visual confirmation of cyanobacterial blooms might not be enough to prevent the threat to swimmers' health. The multivariate analyses applied in this study seem to confirm that chlorophyll-a concentration with associated cyanobacterial density might serve as an additional parameter for assessing the quality of bathing waters, and in the case of small water reservoirs, might indirectly inform about the conditions and changes in water ecosystems.

A critical review of water resources in Greece: The key role of agricultural adaptation to climate-water effects.

Τhe management and protection of a country's water resources is a matter of high priority, ensuring the development and socio-economic stability of a country. Unquestionably, Greece is a characteristic example of this, as water distribution is highly spatially and temporally unequally distributed, while irrigation and tourist consumers as well as the pollution load are expected to be increased in the near future. Water resources in Greece are particularly affected by climate extremes, with droughts, floods and soil erosion by water being the utmost consequences. Greece consumes the greatest amount of its available water resources in the agricultural sector. Also, there is much evidence of water shortage and bad/poor chemical status of some water bodies, mainly due to saltwater intrusion in coastal agricultural areas and intensively agricultural activities. Therefore, this review provides a literature update on the quantity and quality aspects of water resources in Greece for each water body, focusing on water relation effects (aridity/drought, floods and soil erosion by water). This paper, based on different sources of information and an extensive database of water related data, collects, evaluates and groups data from a quantity and quality point of view for all the different water bodies of Greece. Specific water districts such as the Aegean islands, the eastern part of Crete, Attica and Thessaly are expected to be the most affected by climate-water impacts with reduced crops yields, a greater risk of droughts and/or floods, a loss of agricultural land, declining water availability, and degraded water resources (surface and groundwater). Based on these findings, the proposed review highlights agricultural adaptation practices for increasing water use efficiency, ensuring the sustainability of water resources in Greece.

Situação sanitária e o uso da água do Igarapé Santa Cruz, município de Breves, Arquipélago de Marajó, Pará, Brasil / Sanitary situation and the use of the water of Santa Cruz Creek, municipality of Breves, Archipelago of Marajó, Pará, Brazil

RESUMO O estudo teve por objetivo verificar e avaliar a situação sanitária e o uso e qualidade das águas do Igarapé Santa Cruz, no município de Breves, Pará. Para obtenção dos dados, aplicou-se um questionário que abordou o uso das águas e as condições sanitárias dos moradores às margens do igarapé. Também foi realizada a coleta de água para as análises bacteriológica e dos parâmetros físico-químicos, em quatro pontos do igarapé, nos quais foram feitas duas medições para cada parâmetro a ser analisado, sendo uma na baixa-mar e outra na preamar, em agosto de 2017. Foi aplicado o teste de correlação de Pearson entre as variáveis físico-químicas e bacteriológicas, por meio do software Bioestat 5.3. Entre as 257 famílias entrevistadas, 175 (68,09%) utilizavam a água do igarapé para o uso doméstico, 106 (41,24%) afirmaram que a principal atividade de lazer das crianças é a recreação nas águas e 35 (13,62%) famílias despejam seus dejetos fecais direto no local. O valor médio de oxigênio dissolvido foi de 2 mg/L na maré baixa e de 4,1 mg/L na maré alta. Os valores médios do pH encontram-se entre 6,1 na baixa-mar e 7,0 na preamar. As médias de concentração de coliformes detectadas na baixa-mar foram de 101.809 NMP/100 mL para coliformes totais, 47.654 NMP/100 mL para coliformes termotolerantes e 24.970 NMP/100 mL para E. coli. Na preamar as médias foram de 49.639 NMP/ 100 mL para coliformes totais, 19.994 NMP/100 mL para coliformes termotolerantes e 4.462 NMP/100 mL para E. coli. Conclui-se que a população residente no Igarapé Santa Cruz vive em situação de vulnerabilidade e risco à saúde.

ABSTRACT The aim of this study was to verify and evaluate the sanitary situation and the use and quality of the waters of Santa Cruz creek, in the municipality of Breves, Pará. To obtain the data, a questionnaire was applied to the residents of the creeks waterfronts, which addressed the use of water and sanitary conditions. Water collection was also carried out for bacteriological physical-chemical parameters analysis, in four points of the creek, where two measurements were made for each parameter to be analyzed, one at low tide and one at high, in August 2017. The Pearson correlation test was applied between the physical-chemical and bacteriological variables, using the Bioestat 5.3 software. Among the 257 families interviewed, 175 (68.09%) used water from the stream for domestic use, 106 (41.24%) stated that the main leisure activity for children is recreation in the waters of the igarapé and 35 (13.62%) families dump their fecal waste directly into the stream. The mean dissolved oxygen value was 2 mg/L at low tide and 4.1 mg/L at high tide. The mean values for pH are between 6.1 at low tide and 7.0 at high tide. The mean coliform concentration detected at low tide was 101,809 NMP/100 mL for total coliforms, 47,654 NMP/100 mL for thermotolerant coliforms and 24,970 NMP/100 mL for E. coli. High tide the averages were 49,639 NMP/100 mL for total coliforms, 19,994 NMP/100 mL for thermotolerant coliforms and 4,462 NMP/100 mL for E. coli. It was concluded that the population residing near Santa Cruz creek lives in a situation of vulnerability and health risk.

The assessment of metal contamination in water and sediments of the lowland Ilova River (Croatia) impacted by anthropogenic activities.

The aim of the present study was to assess physico-chemical water parameters, granulometric sediment characteristics and concentrations of trace and macroelements in the water and sediments of the Ilova River. Samplings were conducted at three sampling sites (near villages Maslenjaca, Ilova and Trebez) along the Ilova River, differing in the source and intensity of the anthropogenic influence. This study indicated disturbed environmental conditions, most pronounced in the downstream part of the river (Trebez village) impacted by the activity of fertilizer factory. Water from the Ilova and Maslenjaca villages was of good quality, whereas COD, nitrates and phosphates exceeded the good quality levels in Trebez village. Trace and macroelement concentrations in water were mostly below thresholds set by environmental quality standards at all locations, but levels of Al, As, Cd and Ni were few times higher in Trebez village than at other locations. Metal contamination assessment of sediments (trace and macroelement concentrations, contamination and enrichment factor, pollution load index) confirmed deteriorated environmental quality in Trebez village. However, the overall assessment performed in this study revealed that anthropogenic impact was still not particularly strong in the Ilova River ecosystem. Nevertheless, the observed water and sediment characteristics serve as a warning and suggest that stricter protection measures should be initiated, including continuous monitoring and comprehensive quality assessment of the downstream part of the Ilova River, especially because it is a part of the protected area of the Lonjsko Polje Nature Park.

The production of on-line dialysis water for extracorporeal dialysis: proposals for an increased safety upgrade: a viewpoint.

INTRODUCTION: At the start of the 2000s, the progressive diffusion of high-flux extracorporeal dialysis and membranes saw an increased use of high infusion volumes injected into the patient's blood circuit following the advent of on-line water production plants. METHODOLOGY: Our 15-year experience with on-line extracorporeal methodologies using very high infusion volumes has led to the detection of errors and weaknesses, thus allowing us to correct and provide for the implementation of appropriate technology in dialysis water production plants with the aim of ensuring a higher chemical-physical, bacteriological and endotoxin quality. The initial procedures had already been outlined in the 2005 Italian Guidelines, although still today Health Technicians and Nephrologists operating in the field are unable to take on board specific integrations for on-line methods due to a lack of upgrading of documentation in both European and non-European Guidelines. RESULTS: After more than 17 years' experience, and in view of the technological implementations developed since 2005, we wish to put forward a series of suggestions in an attempt to improve the safety of on-line water, with uses ranging from drinking water, pre-treatment, osmosis, distribution circuit, hemodialysis monitors up to the most recent update of microbiological cultures. DISCUSSION: Additional, more stringent measures are required to prevent the occurrence of acute accidents during dialysis sessions and to reduce chronic inflammation-oxidation deriving from the use of not totally ultra-pure/sterile dialysis fluids. CONCLUSION: Our point of view based on our long-standing experience, the proposals made relate to procedures to be applied in technological maintenance, which the consultant nephrologist and other relevant personnel such as microbiologists, biologists, and technical operators should adhere to rigorously to ensure that the production of dialysis water on-line is viewed on a par with a pharmacological administration.

Modelação hidráulica e de qualidade da água dos sistemas de drenagem em meios urbanos / Hydraulic and water quality modelling of urban drainage systems

RESUMO: As inundações urbanas estão se tornando cada vez mais frequentes, de tal forma que a União Europeia publicou a Diretiva 2007/60/CE no sentido de mitigar as consequências relacionadas com este fenômeno e de impor limites à concentração de poluentes nas águas pluviais. O objetivo deste artigo foi apresentar uma modelação dos sistemas de drenagem em situação de inundações, baseada no software da United States Environmental Protection Agency (EPA), Storm Water Management Model (SWMM), em que o estudo de caso é analisar um sistema de drenagem urbana unitário, inserido na Zona Central de Coimbra, em Portugal. Recorrendo à metodologia Automatic Overland Flow Delineation (AOFD) para a geração de uma rede de drenagem superficial e implementando-a no SWMM, obteve-se um modelo de drenagem dual, que permite a análise do escoamento em situação de inundações, incluindo o controle de escoamento entre a superfície e a rede de coletores e a modelação da qualidade da água à superfície. Este modelo permite quantificar a carga poluente à superfície, relativamente ao parâmetro de sólidos suspensos totais, para um evento de precipitação extrema.

ABSTRACT: Urban floods are becoming more frequent. Thus, the European Union published the Directive 2007/60/CE to mitigate costs related with this phenomenon and to impose limits on the concentration of pollutants in pluvial water. The purpose of this study was to present the modelling of drainage systems in flood situations, based on the software of the United States Environmental Protection Agency (EPA), the Storm Water Management Model (SWMM), in which the study case is to analyze a unitary urban drainage system of Zona Central catchment in Coimbra, Portugal. By using the Automatic Overland Flow Delineation (AOFD) methodology for the generation of a superficial drainage network and implementing it in the SWMM, it was obtained a dual drainage model that allows the flow analysis in flood conditions, including flow control between the surface and collectors network and also modeling of water quality at the surface. This model allows quantifying the pollution load at the surface, relatively to the parameter of total suspended solids, for any extreme rainfall event.

¿Qué está pasando con el agua en el Valle de Aburrá (Medellín-Colombia)? / What is happening with the water in the el Aburra Valley?

El presente artículo, derivado de investigación, presenta un primer avance de algunas preguntas que han surgido respecto del abastecimiento sostenible y real de agua paraMedellín, su calidad y los negocios que circulan en torno a este preciado recurso, presenta este texto, algunos hallazgos que nos posibilitan generar algunas líneas de análisis, con elfin de aportar en el necesario debate público, al respecto.

This article, derived from a piece of research, presents a first advance of questions, which have arisen with respect to the real and sustainable supply of water for Medellin, its qualityand the businesses that circulate around this precious resource. This text presents some findings, which enable us to generate a number of lines of analysis, in order to contributein the necessary public debate, in this regard.

Field Application of the Micro Biological Survey Method for a Simple and Effective Assessment of the Microbiological Quality of Water Sources in Developing Countries.

According to the World Health Organization (WHO) guidelines, "safe drinking-water must not represent any significant risk to health over a lifetime of consumption, including different sensitivities that may occur between life stages". Traditional methods of water analysis are usually complex, time consuming and require an appropriately equipped laboratory, specialized personnel and expensive instrumentation. The aim of this work was to apply an alternative method, the Micro Biological Survey (MBS), to analyse for contaminants in drinking water. Preliminary experiments were carried out to demonstrate the linearity and accuracy of the MBS method and to verify the possibility of using the evaluation of total coliforms in 1 mL of water as a sufficient parameter to roughly though accurately determine water microbiological quality. The MBS method was then tested "on field" to assess the microbiological quality of water sources in the city of Douala (Cameroon, Central Africa). Analyses were performed on both dug and drilled wells in different periods of the year. Results confirm that the MBS method appears to be a valid and accurate method to evaluate the microbiological quality of many water sources and it can be of valuable aid in developing countries.

[Parmentier hygiene and public health]. / Parmentier, hygiène et santé publique.

The legend about Parmentier is quite reductive when it limits his activity to the promotion of potato. This military pharmacist intended mainly to make science serve human being, whatever could be his various activities. Actor of the foundation of food chemistry, reorganizer of military pharmacy, he has always been highly concerned with hygiene and public health. He then studied the quality of water, particularly in the case of river Seine, or the purity of air, especially in hospitals. The affair of Dunkerque exhumations or that of cesspools, or the utilisation of human excrements in agriculture were parts of the occurrences for which he had the opportunity to find a scientific approach allowing to solve the difficult questions that were asked to him, for the best benefit of public health. The exhaustive study he published in "Bulletin de pharmacie" for the conservation of meat shows that he did not ignore anything about freezing of food in order to preserve it. It is necessary not to forget the important role he played, as soon as he were informed of Jenner's discovery, for the diffusion of vaccination in France. It is simply astounding to observe how modern were the questions he solved and how intense was his spirit of dedication to the public good, when exerting his functions in "Comité de Salubrité de la Seine" or "Conseil de Santé des Armées", as well as outside these prestigious institutions.

Calidad bacteriológica del agua de consumo humano de la zona urbana y rural del municipio de Guatavita, Cundinamarca, Colombia / Bacteriological quality of the water for human consumption in urban and rural areas of the municipality of Guatavita, Cundinamarca, Colombia

Guatavita es un municipio ubicado en el Departamento de Cundinamarca, Colombia. Posee recursos hídricos como ríos, quebradas, lagunas y nacimientos, que representan un alto porcentaje del agua con que se abastece. El municipio tiene 16 acueductos en funcionamiento, pero solo el que abastece a la población de la zona urbana cuenta con un sistema de tratamiento de agua. En la zona rural existen 14 acueductos con un sistema básico de pretratamiento. Se analizó la calidad bacteriológica del agua de consumo humano de la zona urbana y rural (veredas Corales, Potrero Largo y Carbonera Alta), por medio de los indicadores de contaminación: coliformes totales y Escherichia coli, mediante la técnica de filtración por membrana. El agua de consumo humano de la zona urbana cumplió con los parámetros establecidos en la Resolución 2115 de 2007 del Ministerio de Protección Social, contrario a la zona rural, donde se encontraron recuentos de los indicadores de contaminación fecal, superiores a lo establecido. Por lo tanto, este recurso debe ser considerado como "agua natural", no apta para consumo humano, según el Decreto 1594 de 1984, por lo que debe ser destinada para potabilización bajo un tratamiento convencional.

Guatavita is a municipality in the department of Cundinamarca, Colombia. Guatavita has water resources such as rivers, streams, lakes and springs, which provide a large proportion of the water consumed by the population. Sixteen water supply systems are in operation, but only the one supplying the urban area is equipped with water treatment facilities. In the rural area there are 14 aqueducts with a basic pretreatment system. An analysis was made of the bacteriological quality of the water for human consumption in urban and rural areas (districts of Corales, Potrero Largo and Carbonera Alta) based on two contamination indicators: total coliforms and Escherichia coli, using membrane filtration technique. The water for human consumption in the urban area complied with the parameters contained in Resolution 2115/2007 of the Ministry of Social Protection. In the rural area, however, fecal contamination indicators were above the established limits. Therefore, this resource should be viewed as "natural water" not suitable for human consumption, according to Decree 1594/1984, and destined for potabilization by conventional treatment.

Protocolos para la contratación y puesta en marcha de plantas de tratamiento de agua para hemodiálisis / Protocols for engagement and starting of plants of water treatment for hemodialysis

INTRODUCCIÓN: Para lograr la mayor eficiencia y el mejor funcionamiento de las plantas de tratamiento de aguas para hemodiálisis se hace necesario analizar previamente el agua que va a ser suministrada para ese procedimiento, con el fin de que sean contratadas con un diseño idóneo de acuerdo con la calidad requerida, y posteriormente debe garantizarse que su puesta en marcha se realice sin afectaciones sanitarias que comprometan la seguridad de los pacientes. OBJETIVO: Elaborar protocolos para la contratación y puesta en marcha de nuevas plantas de tratamiento de aguas para hemodiálisis. MÉTODOS: Se realizó una revisión de la literatura internacional y nacional para la selección de procedimientos adecuados a las condiciones actuales del país y se utilizó la experiencia adquirida durante años en la evaluación de características de plantas de tratamiento de aguas. RESULTADOS: Se presentan las características de los protocolos elaborados y la aplicación de estos en ocho contrataciones de plantas de tratamiento y dos puestas en marcha. CONCLUSIONES: Los protocolos desarrollados permiten disponer por primera vez en el país de herramientas para uniformar las acciones que se deben ejecutar con el fin de garantizar la calidad del agua para la contratación y puesta en marcha de plantas de tratamiento de aguas de hemodiálisis, y contribuir a minimizar las complicaciones clínicas en los pacientes y a aumentar su calidad de vida(AU)

INTRODUCTION: To achieve the greater efficiency and the better functioning of plants for water treatment for hemodialysis, it is necessary to analyze previously the water to be supplied for this procedure to the end of be contracted with a suitable design according to the required quality and later it must to be guarantee that its starting be carried out without health affectations compromising the patient's safety. OBJECTIVE: To design protocols for hiring and starting of new plants for water treatment for hemodialysis. METHODS: A review of national and international literature for selection of procedures adapted to present conditions of our country and the experience acquired for years was used in the concepts assessment of plants of water treatment. RESULTS: The concepts of protocols designed are showed as well as its implementation in eight engagements of water treatment plants and two starting. CONCLUSIONS: The protocols developed allow the availability for the first time of tools to standardize the actions to be executed to guarantee the water quality for engagement and starting of plants of water treatment for hemodialysis ant to contribute to minimize the clinical complications in patients and to increase its quality of life(AU)

Protocolos para la contratación y puesta en marcha de plantas de tratamiento de agua para hemodiálisis / Protocols for engagement and starting of plants of water treatment for hemodialysis

INTRODUCCIÓN: Para lograr la mayor eficiencia y el mejor funcionamiento de las plantas de tratamiento de aguas para hemodiálisis se hace necesario analizar previamente el agua que va a ser suministrada para ese procedimiento, con el fin de que sean contratadas con un diseño idóneo de acuerdo con la calidad requerida, y posteriormente debe garantizarse que su puesta en marcha se realice sin afectaciones sanitarias que comprometan la seguridad de los pacientes. OBJETIVO: Elaborar protocolos para la contratación y puesta en marcha de nuevas plantas de tratamiento de aguas para hemodiálisis. MÉTODOS: Se realizó una revisión de la literatura internacional y nacional para la selección de procedimientos adecuados a las condiciones actuales del país y se utilizó la experiencia adquirida durante años en la evaluación de características de plantas de tratamiento de aguas. RESULTADOS: Se presentan las características de los protocolos elaborados y la aplicación de estos en ocho contrataciones de plantas de tratamiento y dos puestas en marcha. CONCLUSIONES: Los protocolos desarrollados permiten disponer por primera vez en el país de herramientas para uniformar las acciones que se deben ejecutar con el fin de garantizar la calidad del agua para la contratación y puesta en marcha de plantas de tratamiento de aguas de hemodiálisis, y contribuir a minimizar las complicaciones clínicas en los pacientes y a aumentar su calidad de vida.

INTRODUCTION: To achieve the greater efficiency and the better functioning of plants for water treatment for hemodialysis, it is necessary to analyze previously the water to be supplied for this procedure to the end of be contracted with a suitable design according to the required quality and later it must to be guarantee that its starting be carried out without health affectations compromising the patient's safety. OBJECTIVE: To design protocols for hiring and starting of new plants for water treatment for hemodialysis. METHODS: A review of national and international literature for selection of procedures adapted to present conditions of our country and the experience acquired for years was used in the concepts assessment of plants of water treatment. RESULTS: The concepts of protocols designed are showed as well as its implementation in eight engagements of water treatment plants and two starting. CONCLUSIONS: The protocols developed allow the availability for the first time of tools to standardize the actions to be executed to guarantee the water quality for engagement and starting of plants of water treatment for hemodialysis ant to contribute to minimize the clinical complications in patients and to increase its quality of life.

Prospecção de moluscos bivalves no estudo da poluição dos rios Cachoeira e Santana em Ilhéus, Bahia, Brasil / Bivalve molluscs prospection in pollution study from Cachoeira and Santana rivers in Ilheus, Bahia, Brazil

Um levantamento sobre o nível de poluição dos Rios Cachoeira e Santana (Ilhéus, Bahia, Brasil) foi realizado durante um trimestre, por meio da avaliação da qualidade microbiológica da água e de frutos do mar (Crassostrea rhizophorae – ostra-do-mangue e Tagelus plebeius - moapem) extraídos desses rios. Tradicionais indicadores de poluição como coliformes totais (Ct) e coliformes termotolerantes (CT), além de contagem padrão de microrganismos, com isolamento e identificação das enterobactérias, foram determinados nas amostras dos rios, os quais exibiram diferentes níveis de poluição fecal. Foram isolados 68 microrganismos, distribuídos em dez espécies, dentre elas, Salmonella typhi, Escherichia coli e Shigella sp., alertando para o risco do consumo in natura desses moluscos, mesmo quando em conformidade com a legislação estabelecida para CT. A prospecção de moluscos para o acompanhamento dos índices de poluição não se mostrou efetiva considerando a pesquisa de CT em ostras e moapens. Verificou-se também o maior grau de contaminação no Rio Cachoeira, o qual serve de base para distribuição de água na região e como fonte de subsistência, por meio da atividade extrativista, para a população ribeirinha.

A survey about the pollution level of the Cachoeira and Santana Rivers (Ilheus, Bahia, Brazil) was performed for a quarter, through the assessment of the microbiological quality of water and seafood (Crassostrea rhizophorae - oyster and Tagelus plebeius – razor clam) extracted from these rivers. Traditional indicators of pollution such as total coliforms (Ct) and thermtolerant coliforms (CT), and total count of micro-organisms, with isolation and identification of Enterobacteriaceae were determined in rivers samples, which exhibited different levels of faecal pollution. An amount of 68 micro-organisms was isolated, distributed in ten species, among them, Salmonella typhi, Escherichia coli and Shigella sp., warning about the risk of consuming these shellfish in nature, even when there is accordance with the laws established for CT. The bivalve prospection to monitor pollution levels was not effective considering CT detection in oysters and moapens. There was also the highest contamination degree in the Cachoeira River, which is used for water distribution in the region and as livelihood source through extractive activities for the riverside population.