title: Mercury in the environment and riverside population in the Madeira River Basin, Amazon, Brazil.
abstract: This work presents quality control results on the mercury concentrations in different environmental (river sediments, forest soils, river suspended matter and fish) and human samples from the lower Madeira River, Amazon sampled between 2001 and 2003, about 15-20 years after the nearly cessation of gold mining activities in the region, which reached its peak in the late 1980s. The study aimed to compare mercury concentrations in these environmental samples with those reported by other authors during the gold rush of the Madeira River Basin. Today, in the Madeira River the releases of mercury register a sudden reduction due the gold price fall in the international trade. However, about 100 t of Hg were released to the atmosphere and to aquatic systems in the region during the gold rush. The present survey shows that notwithstanding the reduction of Hg emissions to the Madeira River Basin from gold mining proper, concentrations in fish and humans are similar to those measured during the gold rush. Reduction in Hg concentrations is restricted to areas close to old point sources and only for abiotic compartments (air and sediments). Remobilization of Hg from bottom sediments plus re-emission from soils due to land use changes are probably responsible for keeping high Hg concentrations in biological samples.
authors.affiliation: Laboratório de Biogeoquímica Ambiental, Núcleos de Saúde and Ciência e Tecnologia, Universidade Federal de Rondônia, Rodovia BR-364 Km 9,5 Sentido Acre, 78900-500, Porto Velho, RO, Brazil. wanderbastos@brturbo.com.br
authors.forename: Wanderley Rodrigues
authors.initials: WR
authors.lastname: Bastos
authors.forename: João Paulo Oliveira
authors.initials: JP
authors.lastname: Gomes
authors.forename: Ronaldo Cavalcante
authors.initials: RC
authors.lastname: Oliveira
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Almeida
authors.forename: Elisabete Lourdes
authors.initials: EL
authors.lastname: Nascimento
authors.forename: José Vicente Elias
authors.initials: JV
authors.lastname: Bernardi
authors.forename: Luiz Drude
authors.initials: LD
authors.lastname: de Lacerda
authors.forename: Ene Glória
authors.initials: EG
authors.lastname: da Silveira
authors.forename: Wolfgang Christian
authors.initials: WC
authors.lastname: Pfeiffer
mesh_terms: D000818:Animals; D001938:Brazil; D004784:Environmental Monitoring; D005399:Fishes; D005506:Food Contamination; D019015:Geologic Sediments / Q000032:analysis; D006197:Hair / Q000737:chemistry; D006801:Humans; D008628:Mercury / Q000032:analysis*; D045483:Rivers; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008628:Mercury