Metal and trace element assessments of bottom sediments from medium Tietê River basin, Sao Paulo State, Brazil: part II.

Concentration of metals in 15 bottom sediment samples from Tietê River, a significantly polluted river, were assessed. Total and partial trace element concentrations were determined, and As, Cd, Cr, Cu, Ni and Zn were found above local reference values. These metals were also higher than the threshold effect level (TEL) in some sampling points and Zn was higher than probable effect level (PEL) oriented values in almost all sampling points. The most polluted points were identified from Tietê to Barra Bonita Counties. Regarding sediment quality, this river is still polluted and precautions to minimize environmental problems caused by toxic metals to biota and to human health are necessary. [ABSTRACT FROM AUTHOR]