mercury concentration was measured in the hair of people who live and work in centres were rocks and minerals are processed to recover gold by amalgamation with mercury. hair samples were analysed for total mercury (t-hg) by cvaas (cold vapour atomic absorption spectrometry) in males (n= 104) and females (n= 11) aged 2 - 68 years. t-hg ranged between 1.0 and 186.4 μg.g-1. the highest value was found was found in a 34 year woman, the other members of her family had between 5.0 and 83.0 μg.g-1. males had an arithmetic mean of 8.15 μg.g-1 (min = 1.0 μg.g-11. max = 83.95 μg.g-1), which is less than the value found for females of 33.6 ?g.g-1.(min = 1.0 μg.g-1. max = 186.4 μg.g-1). the 27 % of females hair samples exceeded the limit of 10 μg.g-1 that the world health organization consider as the non observed adverse effects levels (noael). for males this proportion was only 4 % with a noael of 50 μg.g-1. there was no statistical difference in t-hg between the first four age groups, but the group > 50 years showed the highest mean (7.5 μg.g-1) differing significantly from other age groups. it was also found that samples of the most consumed carnivorous fishes have hg levels above the value of 0.5 μg.g-1. in general, results showed the presence of hg in individuals with concentrations in hair similar to those reported for other mining areas in south america.