ARSENIC CONCENTRATION IN SEDIMENTS NEAR A METALLURGICAL PLANT (SEPETIBA BAY, RIO-DE-JANEIRO, BRAZIL)

The Engenho Inlet, situated in Sepetiba Bay, has been undergoing transformations since the 1960's, due to the installation of a zinc metallurgical industry. In the chemical production process, arsenic is used to purify ore. Results show that most samples are above natural arsenic levels (10 mg kg-1), reaching 360 mg kg-1 near the effluent in the strongly bound fraction and 140 mg kg-1 in the weakly bound fraction at a depth of 28 cm. In the middle of the Inlet the values were 260 mg kg-1 and 80 mg kg-1 in the strongly and weakly bound fractions at a depth of 20 cm. These results indicate arsenic remobilization towards the Sepetiba Bay. The high availability of this metalloid in the ecosystem can damage the local biota and probably the local population as well.