Mercury Distribution in Medium-Size Rivers and Reservoirs of the São Paulo State (Southeast Brazil).

This article discusses mercury concentrations in water, sediment, bivalves, and fish samples in rivers and reservoirs of Brazil. According to the authors, many of the results can be considered as background concentrations for the area. In spite of high population and industrialization, the results showed that in the investigated areas there was no important source of mercury contamination However, they concluded that even at low total mercury concentrations in sediment and water, concentrations in fish can reach values that pose concerns for consumption, mainly in man-made reservoirs. Biomonitoring is important to detect biogeochemical conditions that lead to methyl mercury formation.