Evaluating total mercury and methylmercury biomagnification using stable isotopes of carbon and nitrogen in fish from the Madeira River basin, Brazilian Amazon.

The isotopic signatures of carbon in primary consumer fish species in the Madeira River basin (Western Amazon) follow a pattern, with basal species feeding mainly on C (e.g., vascular plants and phytoplankton).

Total mercury and methylmercury in river dolphins (Cetacea: Iniidae: Inia spp.) in the Madeira River Basin, Western Amazon.

In the Amazon, mercury (Hg) contamination comes from ASGM operations along with soil remobilization processes associated with deforestation. The objective of this study was to evaluate the exposure to methylmercury (MeHg) and total mercury (THg) in 88 samples of skin and blubber tissue obtained from live captured river dolphins (Inia boliviensis, Inia geoffrensis, and Inia spp.) in the Madeira River Basin.

Chromium distribution in an Amazonian river exposed to tannery effluent.

This study aims to evaluate the Cr concentrations in surface water, suspended particles, and bottom sediments exposed to tannery effluent releases in the Candeias River. Cr concentrations were compared in relation to environmental thresholds imposed by United States Environmental Protection Agency (USEPA) and the Brazilian Environmental Council (CONAMA), and the geoaccumulation index (Igeo) was calculated in bottom sediment. Samples were collected in flood and dry seasons.

Total and methyl-mercury in hair and milk of mothers living in the city of Porto Velho and in villages along the Rio Madeira, Amazon, Brazil.

High fish consumption and extended breastfeeding are hallmarks of traditional lifestyle in Western Amazonia. We studied sources of mercury exposure, fish-methylmercury (meHg) and dental-amalgam filling, in 75 urban and 82 rural lactating mothers. Total mercury was determined in all samples while meHg concentrations were determined in subsamples of milk (45) and hair (27) of urban mothers living in Porto Velho (PV) and in hair (46) and milk (37) of mothers living in traditional communities (TC) of the Rio Madeira.

Mercury and DDT exposure risk to fish-eating human populations in Amazon.

In order to investigate the potential risk of mercury and DDTs exposure to fish-eating human populations in Samuel Reservoir, not affected directly by gold-mining activities, the axial muscle of Cichla monoculus was analyzed. Twenty-nine and thirty adults individuals were collected respectively on February (rainy season) and August (dry season) 2007. The specimens were sacrificed by spinal section before sex identification, body weight and total length determination.