ANOMALOUS CONCENTRATIONS OF FLUORINE IN GROUNDWATERS

It is believed that concentrations up to 1.5 mg/L of fluorine in the waters are beneficial to human health in the prevention of dental caries in children. But higher values would be harmful and cause stains on teeth, dental fluorosis, and deformed bones. Through the literature review, it was noted t...

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Bibliographic Details
Authors: Silva, José Luiz Silvério da, Santiago, Mariana Ribeiro, Mancuso, Malva Andrea, Löbler, Carlos Alberto, Dressler, Valderi Luiz, Melo, Teresa Condesso de, Goffermann, Marcelo
Format: article
Status:Published version
Publication Date:2014
Country:Brasil
Institution:Universidade Federal de Santa Maria (UFSM)
Repository:Revista Ciência e Natura (Online)
Language:Portuguese
OAI Identifier:oai:ojs.pkp.sfu.ca:article/13457
Online Access:https://periodicos.ufsm.br/cienciaenatura/article/view/13457
Access Level:Open access
Keyword:Hypotheses. Review. GAS. Advances in knowledge.
Hipóteses
revisão
SAG
avanços no conhecimento.
Description
Summary:It is believed that concentrations up to 1.5 mg/L of fluorine in the waters are beneficial to human health in the prevention of dental caries in children. But higher values would be harmful and cause stains on teeth, dental fluorosis, and deformed bones. Through the literature review, it was noted that anomalous values of this element occur in crystalline, porous and karstic aquifers. The aim of this paper was to present an evolution of knowledge regarding fluoride anomalous concentrations, performing a case study on the Guarani Aquifer System/GAS. Locally the groundwater has high fluoride concentration in many Brazilian states above standards for human consumption. Many hypotheses were seeking to clarify the origin of these concentrations. However, there is still no consensus among researchers. There is a good relationship with sodic waters character, sulfated and/or chlorinated. Recent studies suggest an association with more saline, thermal waters in confined areas, associating the origin of fluoride to pre–SGA formations, carriers of salts and sulfated minerals. The most consensual hypothesis suggests the existence of mixtures with saline deep waters, indicating that there are areas where vertical flows predominate in relation to the horizontal at the GAS associated this natural process with the ion exchange capacity of the clay minerals.