Geochemical Journal, Vol. 46 (No. 1), pp. 13-19, 2012
Jefferson Mortatti,1 Graziela Meneghel de Moraes1 and Jean-Luc Probst2
1Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, CEP 13416-970, Piracicaba, SP, Brazil
2INP, ENSAT, Ecolab, Av. Agrobiopole, BP 107, 31216 Castanet Tolosan, France
(Received March 31, 2011; Accepted September 22, 2011)
The distribution of heavy metals in recent sediments deposited along the Tietê River, a highly polluted river in southeast region of Brazil was studied. Around the metropolitan area of São Paulo city (25 million people), the pollution is related to municipal wastes and industrial effluents with reinforced downstream by agricultural activities. The observed increase of heavy metal concentrations is particularly important for Zn in the upper basin and Cu, Co and Cr at mouth. Geo-accumulation index calculation, related to the regional background, showed that the sediments along the basin are seriously polluted by heavy metals of anthropogenic origin, mainly Cu, Co, Cr and Zn. Calculated index suggests medium to very strongly pollution.
Key words: heavy metals, Tietê River, sediments, geo-accumulation index, pollution