Caracterização físico-química e quimiométrica da qualidade da água e sua correlação com doenças hídricas na zona urbana de Patos-PI

Abstract

Water quality intended for human consumption is a key aspect of public health, especially in semi-arid regions, where water supply relies mainly on surface reservoirs. In this context, this study aimed to evaluate the physicochemical quality of water distributed to the urban population of Patos do Piauí, Brazil, comparing it with water from the main supply source, the Poço do Marruá Reservoir, through physicochemical analyses, chemometric tools, and the interpretation of questionnaires applied to residents. Water samples were collected at 62 points within the urban area, in addition to samples from the reservoir, and analyzed for pH, turbidity, dissolved oxygen, total dissolved solids, hardness, total alkalinity, and chlorides. The data were organized in electronic spreadsheets, subjected to descriptive statistical analysis, and compared with the limits established by Brazilian environmental legislation. Principal Component Analysis (PCA) was applied for integrated data interpretation. The results indicated that, overall, the physicochemical parameters were within the limits established by CONAMA Resolution No. 357/2005, although localized variations were observed, associated with characteristics of the reservoir, the distribution system, and household water storage practices. PCA highlighted the influence of variables related to water mineralization on sample differentiation, as well as local variations between the studied neighborhoods, allowing an integrated understanding of the quality of water supplied to the urban population.