Arsenic contamination and dispersion in the Engenho Inlet, Sepetiba Bay, SE, Brazil

Arsenic distribution and dispersion in sediments of the Engenho Inlet and t he Sepetiba Bay were investigated in order to evaluate the extent of the co ntamination caused by a metallurgical plant installed in the Sepetiba Bay w atershed. The ore used in the smelting process, the soil around the plant, and ore waste collected inside the plant were also analyzed for As. Very hi gh As concentrations in the strongly and weakly bound fractions (up to 63 0 00 and 52 700 mug g(-1), respectively) were found in the ore waste. The soi ls also contained high concentrations of both the strongly and weakly bound fractions (748 and 636 mug g(-1), repectively), although the ore itself co ntained lower levels of the two fractions (63 and 13 mug g(-1), respectivel y). The sediments of the Engenho Inlet had a high degree of contamination ( up to 347 mug g(-1)) decreasing toward Sepetiba Bay where the lowest concen trations were found (up to 50 mug g(-1)). Altough lower concentrations were found in the Sepetiba Bay sediments, they are 5 times higher than the worl d average. The results showed that there is an As transport from the Engenh o Inlet to the Sepetiba Bay. These results suggests that the bay's fish and mollusk stock my be contaminated. This contamination may adversely affect the health of the local population, whose main protein supply is seafood.