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.

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. (...)

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.