Chemical and microbiological analysis of public school water in Uberaba Municipality

Abstract

This study evaluated the quality of water consumed by schoolchildren in the city of Uberaba, relying upon chemical analyzes to determine the levels of free-residual chlorine and levels of chromium, copper, manganese, lead and cadmium. Microbiological analysis was also performed in order to determine total coliforms and Escherichia coli, using the values established by Ordinance n0. 2914 of 2011 of the Ministry of Health as parameters for safe drinking water. Water samples were analyzed from the drinking fountains and kitchen faucets of eight public schools that serve children aged 0-5 years. Sampling was conducted quarterly from December 2011 to September 2012, resulting in four collections. The results revealed the presence of Escherichia coli and total coliforms above the valued permitted by legislation in more than 50% of the samples. It was also observed that concentrations of free-residual chlorine were below the minimum value required by law in nearly half of the samples analyzed. In relation to the concentration of metals, some samples had water contents of copper, cadmium, chromium, manganese and lead above the permissible levels. Statistical tests revealed that when analyzing the period of sampling, only the values for the concentrations of free-residual chlorine, chromium and lead showed no significant difference (p> 0.05). The results show the need for corrective actions at the water supply point for the school population, in addition to monitoring and controlling the quality of water for human consumption.