Geochemistry of mercury in sediments of a sub-tropical coastal lagoon, Sepetiba Bay, Southeastern Brazil

Abstract

Sheltered coastal areas have been acting as final receptors of industrial and urban effluents in most developing countries. The capacity of such water bodies to act as sinks of pollutants, in particular, of heavy metals, is related to the anaerobic conditions generally found in their bottom sediments. However, this capacity is mostly unknown and remobilization processes may eventually release deposited heavy metals to the water column (Nixon, 1980; Rasmussen, 1994; Barcellos et al., 1997). Therefore, knowing the total concentration of heavy metals in coastal sediments is not sufficient to determined the potential contamination of a given area. Rather, the potential availability of heavy metals in such environments is dependent on the strength of the binding with sedimentary phases.