Avaliação de perigos e categorização do grau de risco microbiológico em um sistema de tratamento e distribuição de água localizado em um município do interior de Minas Gerais, Brasil

• Ano de defesa: 2018
• Autor(a) principal: Marcelo Barbosa Motta
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ICB - DEPARTAMENTO DE MICROBIOLOGIA; Programa de Pós-Graduação em Microbiologia; UFMG
• Palavras-chave em Português: Análise da Água; Qualidade da água; Vigilância em saúde; Microbiologia; Vigilância em Saúde Pública; Qualidade da Água
• Link de acesso: http://hdl.handle.net/1843/42370; https://orcid.org/0000-0002-1454-2383

Consumption of non-potable water is a relevant public health problem due to the possibility of transporting numerous chemical and microbiological contaminants, posing a greater danger to the health of children under five years of age, an age group more susceptible to diseases. In 2005, the Brazilian Ministry of Health created the National Program of Surveillance in Environmental Health related to the Quality of Water for Human Consumption (VIGIAGUA), with the primary purpose of managing risks related to water supply to human populations in Brazilian territory. However, VIGIAGUA does not have a methodology capable of characterizing or managing risks, but some researchers have presented proposals for characterization of the hazard, considered as the first stage of risk management. In order to contribute to a hazard assessment and categorization of risks associated with water supply, this study created a work model to transform raw data of the basic parameters analyzed by the surveillance system, required by Administrative Rule 2.914/ 2011, in conceptual data related to low, medium and high risk levels. The data used in the application of the model were obtained through the analyzes of water quality surveillance conducted by the Regional Health Management of Itabira, in a municipality of the State of Minas Gerais with less than 10 thousand inhabitants, whose history of water contamination is alarming. Twelve samples/month were collected between May 2017 and April 2018, totaling 144 (108 treated water and 36 untreated). The results of the treated water analysis were classified according to the presence of hazards and categorized into risk levels. Statistical analyzes were performed using chi-square and Wilcoxon-Mann-Whitney tests. The results showed 83.3% contamination by total coliforms at the treatment withdrawal and 91.6% in the distribution system. The Escherichia coli contamination was 16.7% in the treatment withdrawal samples and 45.2% in the distribution system. All samples presented values of free residual chlorine well below the legal parameter. Most average turbidity values were satisfactory, however, 25% of the individual results found at the treatment withdrawal and two samples in the distribution system presented values above that recommended. The analysis of untreated water samples was carried out with the purpose of knowing the contamination pattern of the raw water of the region, resulting in 100% contamination by total coliforms and 97.2% contamination by E. coli. The results reflect the inability of the supply system analyzed to contain the presence of bacteria and suggest the presence of failures in the treatment and distribution of water of this city, and it was categorized as "high risk".