Mercury in human and environmental samples from two lakes in Amapa, Brazilian Amazon

• Published in: Ambio 1999-06, Vol.28 (4), p.296-301
• Main Authors: Guimaraes, J.R.D, (Univ. Fed. do Rio de Janeiro (Brazil). Inst. de Biofiscia Carlos Chagas Filho)Fostier, A.H, Forti, M.C, Melfi, J.A, Kehrig, H, Mauro, J.B.N, Malm, O, Krug, J.F
• Format: Article
• Language: English
• Subjects: AMAZONIA; AMAZONIE; BIOAVAILABILITY; BIODISPONIBILIDAD; BIODISPONIBILITE; BRASIL; BRAZIL; BRESIL; CONTAMINANTES INDUSTRIALES; COURS D'EAU; CURSOS DE AGUA; Freshwater fishes; Gold mining; Hair; Human hair; INDUSTRIAL POLLUTANTS; LAC; LAGOS; Lake sediment cores; LAKES; MERCURE; MERCURIO; MERCURY; Methylation; POLLUANT INDUSTRIEL; Pollutant emissions; POLLUTION DE L'EAU; POLUCION DEL AGUA; RIVERS; Sediments; WATER POLLUTION; Watersheds
• ISSN: 0044-7447; 1654-7209

Total Hg was determined in sediment, piscivorous fish and human hair from two similar lake areas in Amapá State, Brazilian Amazon: Duas Bocas Lake (DBL), influenced by Hg releases from gold mining; and Pracuúba Lake (PL), a pristine site 15 km to the north. In DBL, Hg profiles in sediments clearly documented the evolution of Hg pollution, and Hg was significantly higher in fish and human hair than in PL.203Hg methylation rates in sediments and methylmercury proportions in fish suggest a high Hg bioavailability in both lakes. Average daily fish intake is approx. 200 g, and at DBL 95% of fish samples (N = 40) exceeded the 150 ng Hg g-1safety limit. Hg in human hair averaged 28 μg g-1(N = 15), i.e. a level at which neurotoxic effects have been found. However, Hg was also high in the pristine PL, where 67-100% (N = 34) of the fish had levels that exceeded the safety limit, and 87% of hair samples (N = 15) had above 10 ng Hg g-1. In both areas, children and pregnant women should be advised to consume nonpiscivorous and/or small fish species. Hg levels should also be investigated in other areas of the Amapá coastal plain.