SEASONAL VARIATION IN THE CONCENTRATION OF Cd, Zn AND Pb IN SUPERFICIAL SEDIMENTS OF CONCEPCION BAY, CHILE

Abstract

In thisstudy variations of total metal concentrations(Cd, Zn and Pb) were determined in superficial sediments and bottom waters, during both upwelling and estuarine circulation periods at Concepción Bay, Chile. The anodic stripping voltammetry was used in the determinations of metal contents in waters, and fíame atomic absorption techniques in sediments. In all periods, the concentration in both matrices showed the sequence Zn > Pb > Cd, but the total concentrations íor the three metáis, in sediments and water, were greater in the upwelling period than in the estuarine circulation period. The calculated modification factors (ratio between metal concentration in upwelling period to metal concentration in estuarine circulation period) showed the greatest variation for Cd in both periods.