Rio Grande University, ¹Hydrochemistry Laboratory, ²Geological Laboratory, CP 474, Rio Grande, RS, 96201-900, Brazil

^*Corresponding author: Tel. +55 53 233 6516; Fax: +55 53 233 6606. E-mail address:dqmhidro@super.furg.br

Abstract

  In order to compare their usefulness, various approaches were used for the assessment of the natural background of metals in sediments of the Southern end of Patos Lagoon, Brazil. Lithium and aluminum were chosen as the most appropriate normalizers for the sampling sites because iron demonstrated elevated values, particularly in the harbor. A strong correlation of Li with Al was observed, which confirmed the presence of pegmatite in the studied area which is rich in Li minerals. Using Li as a normalizer and applying an enrichment factor, cadmium presented elevated results, mainly in the harbor, probably due to 25 years of activity of a fertilizer complex, which uses raw material enriched with Cd up to 100 times the region's natural background.