Human hair mercury levels in Tucuruí area, State of Pará, Brazil.

The environmental mercury contamination at the Tucuruí water reservoir was studied by measuring the amount of mercury in human hair samples collected from fishermen and their families. Samples were also collected from the Parakanã Indian reservation in the vicinity to give information about the background levels in the area. The mercury concentrations in hair samples ranged from 0.9 to 240 mg/kg. The mean value in the main reservoir was 65 mg/kg. Seven values exceeded 100 mg/kg and 31 values exceeded 50 mg/kg. The hair Hg concentrations amongst the fishermen in Tucuruí reservoir are high enough to cause health effects. The fetal exposure is especially alarming. Changes in gold mining practises and in the human diet are recommended.