In this study, the influences of the rainfall regimes and of the land use in the mobility of Zn, Cd, Ni, Cu, Mn and Fe in the surface sediment of the Contas River (Bahia State, Brazil) was evaluated with basis on the fractionation method that uses a three-step sequential extraction. The study was conducted in the middle of the Contas River, in an area that encompasses the urban perimeter and part of the rural zone of Jequié City that is influenced by agricultural, urban and industrial activities. The determinations of metals were conducted by flame atomic absorption spectrometry (FAAS). The result obtained from this study indicates that the concentrations of the metals in the soluble fractions of the sediments are directly associated with rainfall indices in the region. The study also indicated that the metals Zn, Cu, Cd and Ni exhibit higher concentrations in the sediments within the city.
toxic element; availability of metals; sediment samples; urban zone
