Concentrações de flúor no Sistema Aquífero Serra Geral (SASG) na região metropolitana de Londrina e possíveis riscos à saúde humana

Abstract

Mostly groundwater has excellent chemical quality for human consumption, however, the presence of certain natural elements in excessive concentrations can lead to serious diseases. In this sense, fluoride belongs to the halogen group of the periodic table and is widely distributed in the environment in the form of fluorides. Because the effectiveness of this element in the prevention of dental caries is proven, it is necessary that the supply systems for the population carry out their addition in the waters of distribution for consumption. However, some areas naturally present anomalous fluoride concentrations, with values higher than the maximum allowed by current legislation. Ordinance No. 635/Bsb of December 1975 of the Ministry of Health, delimits the maximum values for human consumption according to the maximum daily temperature, ranging from 0.8 to 1.7 mg/L. On the other hand, The Consolidation Ordinance No. 5 of September 28, 2017, stipulates a maximum allow value of 1.5 mg/L. Geochemical diseases that can occur due to excessive fluoride intake are dental and skeletal fluorosis, in addition to other morbidities such as bone neoplasia. In the Metropolitan Region of Londrina (RML), water collection of the Serra Geral Aquifer System (SASG) predominates in some municipalities. In order to know the hydrochemical pattern related to ionic compounds dissolved in SASG waters in The RML, information was collected from two databases, from the Groundwater Information System (SIAGAS) and The Water and Earth Institute (IAT). From the information collected, the ionic balance was performed, allowing the elaboration of the Stiff and Piper diagrams, obtaining the hydrochemical classification of the water, such as Calcium Bicarbonates, Mixed Bicarbonates and Sodium Bicarbonates. The spatialization of the tubular wells was performed, as well as the spatialization of fluoride concentrations in wells and municipalities, spatially correlating with other constituents in the water, such as the average electrical conductivity, the pH and the sum of cations and anions. Many areas of hydrochemical anomaly were observed, prevailing in the east and northwest regions. Among the municipalities analyzed, Prado Ferreira presented the highest rate of cases of bone neoplasia, of 2.12% and Sertanópolis had the highest rate, with 0.49, in the category of tooth disorders and support structures. According to data from DATASUS, the municipality of Prado Ferreira presented the highest rate of cases of bone neoplasia and the municipality of Sertanópolis with tooth disorders and support structures.