• José Luiz Silvério da Silva Universidade Federal de Santa Maria, Santa Maria, RS
  • Mariana Ribeiro Santiago Universidade Federal do Rio Grande do Sul, Porto Alegre, RS
  • Malva Andrea Mancuso Universidade Federal de Santa Maria, Frederico Westhphale, RS
  • Carlos Alberto Löbler Universidade Federal de Santa Maria, Santa Maria, RS
  • Valderi Luiz Dressler Universidade Federal de Santa Maria, Santa Maria, RS
  • Teresa Condesso de Melo Universidade de Lisboa, Lisboa
  • Marcelo Goffermann Serviço Geológico do Brasil, Porto Alegre, RS



Hypotheses. Review. GAS. Advances in knowledge.


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.


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How to Cite

Silva, J. L. S. da, Santiago, M. R., Mancuso, M. A., Löbler, C. A., Dressler, V. L., Melo, T. C. de, & Goffermann, M. (2014). ANOMALOUS CONCENTRATIONS OF FLUORINE IN GROUNDWATERS. Ciência E Natura, 36(2), 745–768.

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