Influência do pH na formação de subprodutos orgânicos halogenados na oxidação com cloro da água superficial para consumo humano do rio Pardo, RP, Brasil / Influence of pH on the formation of halogenated organic by-products in the pre-oxidation step with chlorine in the treatment of surface water for human consumption

A busca por fontes alternativas de recursos hídricos é indispensável tornando a captação de água superficial uma opção viável para complementar o abastecimento público, porém, suas características exigem tratamento adequado para o consumo. O contato do cloro com a matéria orgânica (MO) presente em águas pode resultar na formação de diversas substâncias carcinogênicas, como os trialometanos (THM). A ausência de estudos sobre a característica predominante da matéria orgânica precursora no rio Pardo deixa uma preocupação quanto à tecnologia a ser empregada no tratamento da água, que deverá ser de ciclo completo com uma etapa complementar de pré-oxidação com cloro seguida de adsorção em carvão ativado pulverizado para garantir a remoção de microcontaminantes. O estudo foi conduzido no rio Pardo, inserido na Unidade de Gerenciamento de Recursos Hídricos (UGRHI-4), Ribeirão Preto, estado de São Paulo. A quantificação dos SOH foi realizada no cromatógrafo a gás modelo CG 2010 Marca Shimadzu com detector de captura de elétrons e a aquisição de dados foi obtida por um microcomputador com software para cromatografia CG Real Times Analysis. De modo geral, os parâmetros analisados para o rio Pardo demonstraram que o manancial se encontra dentro dos parâmetros da CONAMA n° 357 (2005) e CONAMA n° 430 (2011) considerados ideais para um rio de classe 2. Os parâmetros analisados neste trabalho podem contribuir com conhecimento para dar subsídio para seleção da tecnologia de tratamento de água do rio Pardo, sendo ela de ciclo completo devido a sua alternância na turbidez ao longo do ano. Dentre os SOH investigados pelo trabalho, foram encontrados apenas cinco (5), sendo esses o Clorofórmio, Dicloroacetonitrila, Bromodiclorometano, Cloro Hidrato e Tricloropropanona. O Clorofórmio e Cloro Hidrato tiveram suas maiores concentrações de 76 µg·L-1 e 68 µg·L-1, respectivamente. De forma geral, os compostos quantificados se encontram abaixo dos preconizado pela Portaria GM/MS nº 888 de 2021. Ao comparar os diferentes pH é possível observar uma tendência de aumento na formação de Trialometanos conforme o aumento no valor de pH. Entretanto, devido a faixa de pH empregada ter sido restrita entre 6,0 e 9,0 a análise estatística não nos permite afirmar que há uma associação direta entre o pH e a formação de SOH

The search for alternative sources of water resources is indispensable, making the capture of surface water a viable option to complement the public supply, however, its characteristics require adequate treatment for consumption. The contact of chlorine with organic matter (OM) present in water can result in the formation of several carcinogenic substances, such as trihalomethanes (THM). The absence of studies on the predominant characteristic of the precursor organic matter in the Pardo River leaves a concern about the technology to be used in the water treatment, which should be a complete cycle with a complementary step of pre-oxidation with chlorine followed by adsorption on charcoal activated powder to ensure the removal of microcontaminants. The study was conducted on the Pardo River, located at the Water Resources Management Unit (UGRHI-4), Ribeirão Preto, state of São Paulo. The quantification of SOH was performed in a gas chromatograph model CG 2010 Shimadzu brand with electron capture detector and the data acquisition was obtained by a microcomputer with software for chromatography CG Real Times Analysis. In general, the parameters analyzed for the Pardo River showed that the source is within the parameters of CONAMA No. 357 (2005) and CONAMA No. 430 (2011) considered ideal for a class 2 river. The parameters analyzed in this work can contribute with knowledge to subsidize the selection of water treatment technology for the Pardo River, which is a complete cycle due to its alternation in turbidity throughout the year. Among the SOH investigated by the work, only five (5) were found, these being Chloroform, Dichloroacetonitrile, Bromodichloromethane, Chlorohydrate and Trichloropropanone. Chloroform and Chlorine Hydrate had their highest concentrations of 76 µg·L-1 and 68 µg·L-1, respectively. In general, the quantified compounds are below those recommended by Ordinance GM/MS nº 888 of 2021. When comparing the different pHs, it is possible to observe a tendency towards an increase in the formation of Trihalomethanes as the pH value increases. However, because the pH range used was restricted to between 6.0 and 9.0, the statistical analysis does not allow us to state that there is a direct association between pH and the formation of SOH

Correlação entre Trihalometanos e o Desenvolvimento do Câncer de Bexiga / Correlation between Trihalomethanes and the Development of Bladder Cancer / Correlación entre Trihalometanos y el Desarrollo del Cáncer de Vejiga

Introdução: Os trihalometanos (THM) constituem um grupo de subprodutos gerados pela desinfecção da água por meio da cloração. Desde a primeira vez em que foram reportados, em 1974, são alvos de estudos que buscam estabelecer uma relação positiva entre a exposição dos humanos a esses compostos e o desenvolvimento de câncer. Objetivo: Revisão da literatura científica disponível sobre a presença de THM na água e sua relação com o desenvolvimento do câncer de bexiga. Método: Levantamento bibliográfico da revisão feito nas bases de dados ScienceDirect e PubMeb. Os descritores utilizados foram ''trihalomethane'', ''disinfection by-products'' e ''bladder cancer'' dos Descritores em Ciências da Saúde (DeCS) da Biblioteca Virtual em Saúde. Os artigos selecionados foram publicados nos últimos cinco anos. Resultados: A amostra final desta revisão foi constituída por 31 artigos, sendo a maioria deles publicados em jornais e revistas sobre meio ambiente. Analisaram-se estudos descritivos, metanálises e outros estudos individuais com delineamento experimental, encontrando uma associação positiva, mas controversa, entre os THM e o câncer, associada a diferentes mecanismos. A relação mais consistente tem sido entre a exposição crônica e o câncer de bexiga. Conclusão: Os estudos reconhecem que existem riscos significativos à saúde relacionados aos THM, no entanto, evidências que esclareçam os mecanismos de ação e o papel que outros fatores de risco possuem, juntamente com os THM, ainda permanecem incertas. Palavras-chave: Trihalometanos; Subprodutos da Desinfecção; Neoplasias da Bexiga Urinária

Introduction: The trihalomethanes (THM) are one of the by-products created from the chlorination process, the most applied technique for water disinfection. Since the first time they were reported in 1974, studies attempted to find a positive correlation between human's exposure to THM and cancer. Objective: Review the available scientific literature reported about the presence of THM in drinking water's treatment and its relation with the carcinogenic process of bladder cancer. Method: The present study consists of an integrative literature review. The articles were searched in the ScienceDirect and PubMed databases utilizing the following keywords obtained from the Subject Descriptors in Health Science (Virtual Health Library): "trihalomethanes", "disinfection by-products" and "bladder cancer". Results: In total, 31 articles were selected for this review, most of them published in environmental or toxicological journals. The authors analyzed descriptive studies, meta-analysis and other experimental studies, finding a positive, but controversial relationship between the t THM exposures, specifically the chronic, and the carcinogenic process associated with many pathological mechanisms. Conclusion: The studies recognized the potential risk of the THM exposure in humans, however, more evidence is needed for a better understanding of THM's toxicological aspects and the influence of other health risk factors in the carcinogenicity process

Introducción: Los trihalometanos (THM) constituyen un grupo de subproductos generado por la desinfección del agua mediante cloración. Desde la primera notificación en 1974, son objeto de estudios que buscan establecer una relación positiva entre la exposición humana a estos compuestos y el desarrollo de cáncer. Objetivo: Revisión de la literatura científica disponible sobre la presencia de THM en la agua y su relación con el desarrollo del cáncer de vejiga. Método: El estudio bibliográfico de la revisión se realizó em las bases de datos ScienceDirect y PubMeb. Los descriptores utilizados fueron ''trihalomethane'', ''disinfection byproducts'' e ''bladder cancer'' ­ de Descriptores de Ciencias de la Salud (DeCS) de la Biblioteca Virtual en Salud. Los artículos seleccionados han sido publicados en los últimos 5 años. Resultados: La muestra final de esta revisión consistió en 31 artículos, la mayoría publicados en periódicos y revistas ambientales. Se analizaron estudios descriptivos, metaanálisis y otros estudios individuales con diseño experimental, encontrando una asociación positiva, pero controvertida, entre los THM y el cáncer asociado con diferentes mecanismos. La relación más consistente ha sido entre la exposición crónica y el cáncer de vejiga. Conclusión: Los estudios reconocen que existen riesgos significativos para la salud relacionados con los THM, sin embargo, las pruebas que aclaran los mecanismos de acción y el papel que otros factores de riesgo tienen, junto con los THM, siguen siendo inciertos

Monitoramento das concentrações de trihalometanos na água potável / Monitoring the trihalomethanes concentrations in drinking water

The reduction of the incidence of water-borne diseases is achieved with the diffusion of the useof chlorination techniques. However, in spite of the benefits of this disinfection method,the reactions of chlorine with the natural organic matter occurring in the water induce theproduction of disinfection by products such as trihalomethanes. These products have already beenassociated with the incidence of some cancers types. Considering that in the Brazilian legislation,it is not mandatory measuring and controlling the occurrence of trihalomethanes at the exitand during the water distribution to the consumer. This study aimed at analyzing the relationshipbetween chlorination and its by products. Thus, this project evaluated the concentrations oftrihalomethanes in water collected at different points of supply in the municipality of Colombo,Paraná, Brazil, during the period from November 2015 to February 2016. Chromatographicmethods were employed, besides the spreadsheets provided by the Health Surveillance ofColombo for comparison. The found values were tabulated and they were compared with thelimits established by the Brazilian Ministry of Health- Ordinance No 05/2017. The results confirmedthat the values of those provided by the concessionaire responsible for the city water treatmentand supply, and being within the standards determined by the legislation.

A redução da incidência de doenças transmitidas pela água foi alcançada com a difusão douso de técnicas de cloração. Apesar dos benefícios desse método de desinfecção, as reações decloro com a matéria orgânica natural presente na água levam à formação de subprodutos dedesinfecção como trihalometanos. Esses produtos já foram associados à incidência de algunstipos de câncer em animais, e muitas vezes podem ser detectados em água tratada e fornecidapara o consumo. Pela legislação brasileira não é obrigatório efetuar o monitoramento detrihalometanos após o tratamento e distribuição de água. Frente a este problema, este estudoteve como objetivo avaliar as concentrações de trihalometanos em água coletada em diferentespontos de abastecimento no município de Colombo, PR, Brasil, durante o período de novembrode 2015 a fevereiro de 2016. Utilizou-se método cromatográfico para as análises, além deplanilhas fornecidas pela Vigilância Sanitária de Colombo. Todos os valores foram comparadoscom os limites estabelecidos na Portaria de Consolidação Nº 05/2017 do Ministério da Saúde.Os resultados confirmaram que os valores de trihalometanos fornecidos pela concessionária,responsável pelo tratamento e fornecimento de água na cidade, atendem aos parâmetros legais.

Monitoring the trihalomethanes concentrations in drinking water / Monitoramento das concentrações de trihalometanos na água potável

The reduction of the incidence of water-borne diseases is achieved with the diffusion of the use of chlorination techniques. However, in spite of the benefits of this disinfection method, the reactions of chlorine with the natural organic matter occurring in the water induce the production of disinfection by products such as trihalomethanes. These products have already been associated with the incidence of some cancers types. Considering that in the Brazilian legislation, it is not mandatory measuring and controlling the occurrence of trihalomethanes at the exit and during the water distribution to the consumer. This study aimed at analyzing the relationship between chlorination and its by products. Thus, this project evaluated the concentrations of trihalomethanes in water collected at different points of supply in the municipality of Colombo, Paraná, Brazil, during the period from November 2015 to February 2016. Chromatographic methods were employed, besides the spreadsheets provided by the Health Surveillance of Colombo for comparison. The found values were tabulated and they were compared with the limits established by the Brazilian Ministry of Health- Ordinance No 05/2017. The results confirmed that the values of those provided by the concessionaire responsible for the city water treatment and supply, and being within the standards determined by the legislation.

A redução da incidência de doenças transmitidas pela água foi alcançada com a difusão do uso de técnicas de cloração. Apesar dos benefícios desse método de desinfecção, as reações de cloro com a matéria orgânica natural presente na água levam à formação de subprodutos de desinfecção como trihalometanos. Esses produtos já foram associados à incidência de alguns tipos de câncer em animais, e muitas vezes podem ser detectados em água tratada e fornecida para o consumo. Pela legislação brasileira não é obrigatório efetuar o monitoramento de trihalometanos após o tratamento e distribuição de água. Frente a este problema, este estudo teve como objetivo avaliar as concentrações de trihalometanos em água coletada em diferentes pontos de abastecimento no município de Colombo, PR, Brasil, durante o período de novembro de 2015 a fevereiro de 2016. Utilizou-se método cromatográfico para as análises, além de planilhas fornecidas pela Vigilância Sanitária de Colombo. Todos os valores foram comparados com os limites estabelecidos na Portaria de Consolidação Nº 05/2017 do Ministério da Saúde. Os resultados confirmaram que os valores de trihalometanos fornecidos pela concessionária, responsável pelo tratamento e fornecimento de água na cidade, atendem aos parâmetros legais.

Drinking and recreational water-related diseases: a bibliometric analysis (1980–2015)

BACKGROUND: Water – related diseases are worldwide health concern. Microbial contamination and contaminant products in water are a source of disease outbreaks and development of cumulative toxic effects. Ensuring safe water is one of the goals to be achieved at the global level. The aim of this study was to assess publications on drinking and recreational water from a health point of view to understand current problems and future research trends in this field. METHODS: Scopus, the largest scientific electronic database, was used to retrieve related articles and present the results as bibliometric tables and maps. Search query was modified manually using related terms to maximize accuracy. RESULTS: A total of 2267 publications were retrieved with an average of 16.82 citations per article. The h-index of retrieved articles was 88. Visual mapping showed that E. coli, diarrhea, cryptosporidiosis, fluoride, arsenic, cancer, chlorine, trihalomethane, and H. pylori were most frequently encountered terms in title and abstract of retrieved articles. The number of articles on water microbiology was a significant (P < 0.01) predictor of worldwide productivity of water – related disease publications. Journal of Water and Health ranked first in number of publications with 136 (6.00 %) articles. The United States of America ranked first in productivity with a total of 623 (27.48 %) articles. Germany (15.44 %), India (16.00 %) and China (20.66 %) had the least international collaboration in water-related disease research. Environmental Protection Agency and Centers for Disease Prevention and Control were among top ten productive institutions. In the top ten cited articles, there were three articles about arsenic, one about aluminum, one about trihalomethane, one about nitrate, one about toxoplasmosis, one about gastroenteritis, and the remaining two articles were general ones. CONCLUSIONS: There was a linear increase in the number of publications on water – related diseases in the last decade. Arsenic, in drinking water is a serious concern. Cryptosporidiosis and other infectious gastroenteritis remain a major health risk of exposure to contaminated water. Increased number of publications from Asian countries was not associated with a high percentage of international collaboration.

Avaliação da exposição e o risco associado com compostos trihalometanos na água potável / Exposure assessment and the risk associated with trihalomethanes compounds in drinking water

Objetivo: Medir as concentrações de Trihalometanos (THM) na rede de distribuição de água potável da Baixada de Jacarepaguá, Rio de Janeiro-RJ, Brasil, e seus riscos associados. Métodos: Duzentas casas foram visitadas e coletaram-se amostras de água das torneiras do consumidores. Estimativas de riscos baseadas em exposições foram projetadas, empregando abordagens determinísticas e probabilísticas. Resultados: Os THMs (dibromoclorometano, bromofórmio, clorofórmio e bromodiclorometano) variaram de 3,08 ?g/l a 129,31 ?g/l Riscos não cancerígenos induzidos por ingestão de THMs foram abaixo do nível tolerável (10-6). Conclusão: Os dados obtidos nesta pesquisa demonstram que a exposição aos contaminantes da água potável e os riscos associados foram superiores ao nível aceitável.

Objective: To measure the concentrations of trihalomethanes (THMs) in marshland of Jacarepaguá drinking water, Rio de Janeiro-RJ, Brazil, and their associated risks. Methods: Two hundred houses were visited and samples were collected from consumer taps water. Risks estimates based on exposures were projected by employing deterministic and probabilistic approaches. Results: The THMs (dibromochloromethane, bromoform, chloroform, and bromodichloromethane) ranged from 3.08 ?g/l to 129.31 ?g/l. Non-carcinogenic risks induced by ingestion of THMs were below the tolerable level (10-6). Conclusion: Data obtained in this research demonstrate that exposure to drinking water contaminants and associated risks were higher than the acceptable level.

Presença de trialometanos na água e efeitos adversos na gravidez / Trihalomethanes in drinking water and adverse effects on pregnancy

Este trabalho constituiu um estudo do tipo transversal, que objetivou avaliar a possível associação entre a exposição a trialometanos presentes na rede pública de abastecimento de água da região metropolitana de São Paulo e a ocorrência de desfechos adversos na gravidez. Para a realização deste estudo, foram selecionados 19 municípios da região metropolitana de São Paulo que eram abastecidos por apenas uma estação de tratamento de água, no período de 1998 a 2002. Partiu-se da verificação dos níveis de trialometanos na água de abastecimento e da análise da prevalência de baixo peso ao nascer, prematuridade, anomalias congênitas, defeitos no tubo neural e no sistema nervoso central, nos recém-nascidos dos municípios estudados, para se analisar a associação entre a exposição a trialometanos e a ocorrência de desfechos adversos na gravidez. A população estudada consistiu em todas as mulheres grávidas e seus filhos recém-nascidos, residentes nos municípios selecionados durante o período de estudo, que tiveram suas declarações de nascido vivo registradas no Sistema de Informações sobre Nascidos Vivos (SINASC). Os níveis de trialometanos foram tratados como categorias. A análise descritiva foi seguida pela análise univariada, e esta pela análise multivariada. Para expressar as possíveis associações dos desfechos pesquisados com os trialometanos foi utilizado o teste qui-quadrado, seguido da estimativa das razões de chance (odds ratio - OR) com intervalos de 95 por cento de confiança. O controle das variáveis de confusão se deu através da análise de regressão logística múltipla não condicional, seguindo os procedimentos de Hosmer e Lemeshow (2000). As variáveis que apresentaram nível de significância estatística (p < 0,2) na análise univariada foram inseridas no modelo múltiplo...

This paper describes a cross-sectional study that aimed to evaluate the possible association between exposure to trihalomethanes present in public water supplies in the metropolitan region of São Paulo and the occurrence of adverse outcomes in pregnancy. In order to perform the research, 19 municipalities located in the metropolitan area of São Paulo that were supplied by only one water treatment plant, from 1998 to 2002, were selected. The starting point was the verification of trihalomethane levels in public water supplies and the analysis of the prevalence of low birth weight, preterm delivery, congenital anomalies, neural tube and nervous system defects in newborns of the municipalities that were involved in the study, in order to analyze the association between exposure to trihalomethanes and the occurrence of adverse outcomes in pregnancy. The population that was studied consisted of all pregnant women and their newborn children who were living in the selected municipalities during the research period, and had their birth certificates registered in the Information System on Live Births (SINASC). The levels of trihalomethanes were treated as categories. The descriptive analysis was followed by a univariate analysis and then by a multivariate analysis. To express the possible associations of the research outcomes with trihalomethanes, the chi-square test was used followed by the estimation of odds-ratio with a 95% confidence interval. Confounding variables were controlled through the analysis of unconditional multiple logistic regression, following the procedures of Hosmer and Lemeshow (2000). The variables that showed statistical significance (p < 0.2) in univariate analysis were entered into the multivariate mode. The results pointed out an association between possible risk of prematurity and malformation related to trihalomethanes, raising the need for in-depth studies, due to the implications of that fact in public health...

Formation and changes of regulated trihalomethanes and haloacetic acids in raw water of Yangtze River, Huangpu River and different treatment processes and pipelines network / 中华预防医学杂志

<p><b>OBJECTIVES</b>To investigate the pollutant levels of regulated disinfection by-products trihalomethanes (THMs) and haloacetic acids (HAAs) in raw water from the Huangpu River, the Yangtze River and different treatment processes and finished water, and to explore the changes tendency in transmission and distribution pipeline network.</p><p><b>METHODS</b>A total of 65 ml water samples with two replicates were collected from different raw water, corresponding treatment processes, finished water and six national surveillance points in main network of transmission and distribution, water source for A water plant and B, C water plant was the Huangpu River and the Yangtze River, respectively. Regulated THMs and HAAs above water samples were detected by gas chromatography.</p><p><b>RESULTS</b>The total trihalomethanes (THM(4)) concentration in different treatment processes of A water plant was ND-9.64 µg/L, dichlorobromomethane was the highest (6.43 µg/L). The THM(4) concentration in B and C water plant was ND to 38.06 µg/L, dibromochloromethane (12.24 µg/L) and bromoform (14.07 µg/L) were the highest in the B and the C water plant respectively. In addition to trichloroacetic acid in A water plant from the raw water, the other HAAs came from different treatment processes. The total haloacetic acids (HAA(6)) concentration of different treated processes in A water plant was 3.21 - 22.97 µg/L, mobromoacetic acid (10.40 µg/L) was the highest. Dibromoacetic acid was the highest both in B (8.25 µg/L) and C (8.84 µg/L) water plant, HAA(6) concentration was ND to 27.18 µg/L. The highest and the lowest concentration of THM(4) were found from the main distribution network of C and A water plant respectively, but the concentration of HAA(6) in the main water pipes network of A water plant was the highest, and the lowest in C water plant. The THMs concentration was 21.11 - 31.18 µg/L in C water plant and 6.72 - 8.51 µg/L in A water plant. The concentration of HAA(6) was 25.02 - 37.31 µg/L in A water plant and 18.69 - 23.32 µg/L in C water plant. The highest concentrations of brominated disinfection by-products in B and C water plant were 54.57 µg/L and 45.38 µg/L respectively, those were higher than A water plant (18.98 µg/L), and higher than the chlorinated disinfection by-products in B and C water plants (30.23 µg/L and 30.60 µg/L).</p><p><b>CONCLUSIONS</b>The THM(4) concentrations of finished water treated from Huangpu River was lower than finished water from the Yangtze River, while the HAAs concentrations in finish water from Huangpu River was higher than the two water plants of Yangtze River. The fluctuations of THMs and HAAs concentration in distribution network were low during transmission and distribution process.</p>

Measurement of chloroform in swimming pools' waters and swimmers' blood

A new microextraction method named dispersive liquid-liquid microextraction [DLLME] for determination of chloroform in pool water and blood of swimmers after swimming is described. This method was performed based on coupling dispersive liquid-liquid microextraction [DLLME] with gas chromatography-mass spectrometry [GC-MS]. Methanol and trichloroethylenes were used as the disperser solvent and the extraction solvents, respectively. The volumes of these solvents were optimized for pool water by central composite design. The study involved three indoor swimming pools and nine swimmers. Chloroform concentration of pool water was 118-135 micro g L[-1] and of blood ranged from 1.26 to 1.66 micro g L[-1]. Indoor swimming pools are closed environments presenting detectable levels of trihalomethanes [THMs]. Chloroform [CHCl3] is the most represented THMs. Therefore, the presence of CHCl3 may be considered representative of the THMs. The new method DLLME was applied for determination of CHCl3 in pool water and blood of swimmers after swimming inside the indoor swimming pool. The method was optimized by experimental design. Chloroform concentrations in the specified pool waters were 135, 124, 118 micro g L[-1]

Controle e vigilância de trihalometanos em água de abastecimento humano: o caso do desastre ambiental dos Rios Pomba e Paraíba do Sul / Control and monitoring of trihalomethanes in water supplies for human use: the case of environmental disaster of the Rios Pomba and Paraíba do Sul

(...) Este estudo avaliou a importância do monitoramento da qualidade da água de abastecimento humano para a saúde pública, ressaltando-se os aspectos toxicológicos das substâncias com potencial carcinogênico – os trihalometanos (THMs) – subprodutos do processo de desinfecção e contextualizando a região fluminense atingida pelo acidente ambiental em 2003 na Indústria Cataguases de papel Ltda. em Minas Gerais. (...)

Controle e vigilância de trihalomethanos em água de abastecimento humano: o caso do desastre ambiental dos rios Pomba e Paraíba do Sul / Trihalomethanos control and surveillance of drinking water: the case of environmental disaster of the Rivers Pomba and Paraiba do Sul

A vigilância da qualidade da água para consumo humano consiste no conjunto deações adotadas continuamente pelas autoridades de saúde pública para garantir que a água consumida pela população atenda ao padrão e normas estabelecidas na legislação e para avaliar os riscos que a água consumida representa à saúde humana. Este estudo avaliou a importância do monitoramento da qualidade da água de abastecimento humano para a saúde pública, ressaltando-se os aspectos toxicológicos das substâncias com potencial carcinogênico – os trihalometanos (THM’s) - subprodutos do processo de desinfecção e contextualizando a região fluminense atingida pelo acidente ambiental ocorrido em 2003 na Indústria Cataguases de Papel Ltda, em Minas Gerais. Trata-se de um estudo exploratório descritivo onde foram utilizados dados secundários oriundos de documentos oficiais da Secretaria de Estado de Saúde e Defesa Civil do Estado do Rio de Janeiro. Foi analisada a atuação do Setor de Saúde e Meio Ambiente do Centro de Vigilância Sanitária da Secretaria de Estado de Saúde do Rio de Janeiro nas inspeções às Estações de Tratamento de Água, no período de 2002 a 2006 e as ações desenvolvidas pelo Programa de Vigilância da Qualidade da Água para Consumo Humano no Estado do Rio de Janeiro (VIGIÁGUA-RJ), de 2001 a 2007. Avaliaram-se os resultados referentes ao controle de qualidade de água para o parâmetro Trihalometanos Totais (TTHM’s) dos sistemas de abastecimento atingidos pelo acidente, onde um dos quais apresentou a concentração máxima de 311,7 milgrama/L. Dentre os resultados de THM’s, quando especificados individualmente para os tipos principais (clorofórmio, bromodiclorometano, dibromoclorometano e bromofórmio), foipossível constatar que a concentração do clorofórmio é sempre maior quandocomparada aos demais. Face aos resultados de concentração dos THM’s e do seu potencial carcinogênico as autoridades de saúde e a comunidade científica devem acompanhar os casos de intoxicação crônica (neoplasias e câncer) das populações atingidas pelo desastre ambiental, assim como no restante da população exposta através da água de abastecimento.

[Study of natural organic matter characteristics and fractions in surface water resources of Tehran]

Natural organic matters [NOMs] are abundant in natural water resources and in many ways may affect the unit processes in water treatment. Although NOMs are considered harmless but they have been recognized as disinfection by-products [DBPs] precursors during the chlorination process. Formation of DBPs highly depends on the composition and concentration of NOMs. The objective of this study was to determine natural organic matter and its fractions concentrations in the surface water sources of Tehran. Water sampling was conducted monthly between May to July in three rivers of Lar, Jajrood and Karaj, as the main drinking water supplying sources in Tehran. Quantitative parameters of pH, EC, UV254 and DOC were studied based on standard methods. The XAD-7 resin method was used for fractionation of NOMs. Results showed that NOM concentrations in Lar, Jajrood and Karaj rivers were 8.53, 12.9 and 11.3 mg/L, respectively. The HPO [hydrophobic] fraction was predominant compared to the HPI [hydrophilic] fraction in water samples. The mean of total percent of HPO and HPI fractions were about 57% and 43%, respectively. Since the hydrophobic NOM fraction exhibits higher trihalomethane formation potential [THMFP] than hydrophilic part, Tehran water chlorination exhibits higher THMFP than haloacetic acid formation potential [HAAFP]. The information obtained from this study may be further employed in the design of the control techniques and management strategies for the water treatment plant, especially for DBPs reduction

A comparative study of the treatment techniques for controlling THM-precursors in raw and drinking water.

Silica gel adsorption, strong base anion exchange IRA 400-OH form resin were evaluated for the treatment of trihalomethane precursors present in raw and drinking water. A powdered silica gel having 60 to 120 mesh size and a previously dried IRA 400-OH form resin having 20-50 mesh size have been applied to artificial water samples and a specific analytical approach was used for selective removal of humic acid present in the water. This study aims to evaluate the role of contact time, pH, adsorption dose, concentration of humic acid (H.A.), flow rate on the reduction of THM-precursors as a result of adsorption of H.A. while passing raw water through silica gel and IRA 400 OH form resin column. Freundlich adsorption isotherm constants K for silica gel and IRA 400-OH form resin were determined as 1.13 x 10(-3) and 4.2 x 10(-3) mg/g respectively and l/n were found to be 0.9927 and 1.069 respectively.

Chlorinated drinking water, cancers and adverse health outcomes in Gangtok, Sikkim, India.

Long-term impacts of drinking chlorinated water on the incidence of cancers and other adverse health outcomes were assessed in a population-based cross-sectional study. The study was conducted by comparing a group exposed to chlorinated drinking water for more than thirty years with control groups with less or no exposure to chlorine. A house-to-house survey was completed to gather information on residential history, age, education, income, source and extent of treatment of water and health characteristics. All residents below thirty years of age were excluded from the database used for analyses to ensure that the groups were comparable. Fourteen cancer cases were found in the long-term exposed groups of 1085 persons and 9 cancer cases in the two control populations of 725 persons. The odds ratio for cancers (OR) was 1.05 (95% CI = 0.43-2.65) and is not statistically significant. Odds ratios for gastrointestinal disorders, kidney problems and skin infections were statistically significant ranging from 2.06 (95% CI = 1.01-4.17) to 2.2 (95% CI = 1.45-3.33). These OR values indicate that there is no significant association between the incidence of cancer and exposure to chlorinated water while chlorinating drinking water significantly reduced the incidence of non-carcinogenic adverse health effects like gastrointestinal diseases, skin infections, and kidney diseases.

Control of bromate and THM precursors using ozonation combined system / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system.</p><p><b>METHODS</b>The appropriate ozone dosage was determined, and then the changes of TOC, UV254 and THM formation potential (THMFP) in the combined system were evaluated.</p><p><b>RESULTS</b>One mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water. The pre-ozonation increased THMFP, but the conventional treatment system could effectively reduce the odor. The bio-ceramic filter could partly reduce CHCl3FP, but sometimes might increase CHCl2BrFP and CHClBr2FP. The biological activated carbon (BAC) filter could effectively reduce CHCl3FP and CHCl2BrFP, but increase CHClBr2FP. Compared with other filters, the fresh activated carbon (FAC) filter performed better in reducing THMFP and even reduced CHClBr2FP.</p><p><b>CONCLUSION</b>The combined system can effectively reduce taste, odor, CHCl3FP, and CHCl2BrFP and also bring bromate under control.</p>

Presença de trialometanos na água e efeitos adversos na gravidez / Presence of trihalometanes in drinking water and adverse effects during pregnancy

O presente trabalho constitui um estudo ecológico do tipo transversal que tem como principal objetivo avaliar a possível associação entre a exposição a trialometanos presentes na rede pública de abastecimento de água da região metropolitana de São Paulo e a ocorrência de desfechos adversos na gravidez. Para realização deste estudo, foram selecionados 19 municípios da região metropolitana de São Paulo que são abastecidos por apenas uma ETA, no período de 1998 a 2002. A população estudada consistiu em todas as mulheres grávidas e seus filhos recém-nascidos, residentes nos municípios selecionados. Os resultados obtidos apontaram para uma associação e um possível risco de malformação e prematuridade relacionadas a trialometanos oque suscita análises mais profundas dadas as implicações diretas e indiretas de tal fato sobre a saúde pública e levanta uma relevante discussão sobre os efeitos benéficos da cloração...

The present work constitutes a transversal ecological study that aims to evaluate the possible association between the exposure to trihalomethanes that are present in public water supplies of Sao Paulo’s metropolitan area and the adverse pregnancy outcomes. In order to perform the present study, it was selected 19 municipalities situated in the metropolitan area of São Paulo that are sourced by water from just one water treatment unit, from 1998 to 2002. The studied population consisted of all pregnant women and their newborn that were residents in the selected municipalities. The obtained results pointed out an association and possible risk of preterm delivery and congenial anomalies related to trihalomethanes, what leads to the necessity of deeper studies, taking into account the direct and indirect implication of that fact in public health. The results arise an important issue related to the relevant benefits of chlorination...

Extraction and ozonation of organic pollutants in drinking waters

The continuous liquid-liquid. CLLE. and solid-phase. SPE. extraction techniques were used to study a problem of international relevance. The work was incident on the evaluation of the efficiency and optimization of extracting techniques, CLLE. SPE and CLLE+SPE, towards chlorinated pesticides and phenolic compounds from the Giza treatment plant station [Egypt], where the degree of pollution of such substances in drinking waters must be reduced. The total recoveries, using SPE ranged between 0.74 - 0.87, whereas, the values were much less using the other two methods [0.158 - 0.196]; indicating the preferrability of the SPE technique. Analytical results were obtained through the various chromatographic techniques, liquid or gas, with adequately chosen detectors. A simple mathematical algorithm has been empirically developed allowing the assessment and comparison of the efficiencies of the three extracting procedures. Futher treatment with ozone resulted in the oxidation and elimination of organic pollutants, with consequent improvement of water quality [total pesticide content 0.332-0.19 micro gL[-1]]. A useful ozone treatment unit, capable of dealing with the ozonation of contaminants in tap water, was built

Waste water disinfection during SARS epidemic for microbiological and toxicological control / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To evaluate the disinfection of wastewater in China.</p><p><b>METHODS</b>During the SARS epidemic occurred in Beijing, a study of different disinfection methods used in the main local wastewater plants including means of chlorine, chlorine dioxide, ozone, and ultraviolet was carried out in our laboratory. The residual coliform, bacteria and trihalomethanes, haloacetic acids were determined after disinfection.</p><p><b>RESULTS</b>Chlorine had fairly better efficiency on microorganism inactivation than chlorine dioxide with the same dosage. Formation of THMs and HAAs does not exceed the drinking water standard. UV irradiation had good efficiency on microorganism inactivation and good future of application in China. Organic material and ammonia nitrogen was found to be significant on inactivation and DBPs formation.</p><p><b>CONCLUSION</b>Chlorine disinfection seems to be the best available technology for coliform and bacteria inactivation. And it is of fairly low toxicological hazard due to the transformation of monochloramine.</p>

Removal of chloroform [CHCL3] from Tehran drinking water by GAC and air stripping columns

The harmful substances, defined as trihalomethanes [THMs], were found to be formed during the disinfection of drinking water when chlorine was used as the disinfectant. In this research, the effectiveness of granular activated carbon [GAC] and air stripping [AS] packed column for the removal of chloroform [CHCL3] [as THMs basic indicator compound in many resources] in range of 50 to 300 micro g/L, from drinking water was studied. Pilots of GAC and air stripping columns were designed and set up. The study was carried out for the two cases of deionized and chlorinated Tehran tap water. Also the effects of flow rate, chloroform and TDS concentrations were considered in both treatment systems. Gas chromatography [GC] with electron capture detector [ECD] was used for determination of chloroform concentration in inlet and outlet samples. The obtained data were analyzed by SPSS and non-parametric KruskaI-Wallis method. Results showed a positive correlation between the flow rate and chloroform concentration, and removal efficiencies. The average of variations of removal efficiencies for AS and GAC columns with deionized water samples were, 89.9%, 71.2% and for chlorinated Tehran tap water were 91.2% and 76.4%, respectively. The removal of feed residual chlorine in these columns with 0.5, 0.8 ppm was 100%, respectively and re-chlorination for finishing water was recommended. Results showed AS to be considered more effective in chloroform removal for conventional water treatment plants as a finishing process

Comparison of Nanofiltration and GAC Adsorption Processes for Chloroform Removal from Drinking Water

In this research, the Chloroform [CHCl3] removal effectiveness of two water treatment systems including membrane technology and granular activated carbon [GAC] adsorption were studied. Two bench-scales were designed and set up: 1] Nanofiltration [NF] spiral-wound modules and 2] GAC adsorption column. Chloroform was considered as trihalomethanes [THMs] basic indicator compound. The inlet and outlet CHCl3 concentrations were detected by gas chromatography [GC] with electron capture detector [ECD]. The study was carried out for the two cases of spiked deionized water with CHCl3 and chlorinated Tehran tap water. Flow rate, CHCl3 and total dissolved solids [TDS] concentrations were considered in both treatment systems and the transmembrane pressures for membrane pilot, as the basic variables affecting removal efficiencies. Results showed that CHCl3 rejection coefficients for NF 300 Da, NF 600 Da and GAC Column, with various operation conditions had a range of 55.2% to 87.8%, 78% to 85% and 41.4% to 74.1%, respectively. It was found that removal efficiencies for NF 600 Da were lower than those of NF 300 Da and GAC column. The obtained data were analyzed by SPSS and non-parametric Kruskal-Wallis method. Results showed a positive correlation between the flow rate, CHCl3 concentration and chloroform rejection coefficients and the TDS concentration had no significant effect on chloroform removal efficiencies