Fish consumption by traditional subsistence villagers of the Rio Madeira (Amazon): impact on hair mercury.

BACKGROUND

Subsistence ribeirinhos of the Amazon Basin depend on fish for their principal source of protein, but fish availability changes with seasonal high and low waters.

AIM

To assess taxa and quantity of fish consumed and estimate attendant exposure to methyl-Hg in a traditional subsistence high fish-eating community of the Amazon Basin.

SUBJECTS AND METHODS

120 villagers in 18 households were followed for 6 months (August to February) for weighed portions of fish consumed.

RESULTS

Mean daily per capita fish consumption was high (406 g/day) with fish meals ranging from 4 to 14 times/week and an integrated yearly consumption of 148.2 kg/person. Median total-Hg concentrations in fish ranged from 0.011 to 0.409 ppm; six of the more consumed fish species comprised more than 50% of the fish consumed. The villagers mean hair-Hg concentration was high (17.4 +/- 11.5 microg/g), with both inter- and intra-household variation despite similar high fish consumption; only 7% showed hair-Hg concentrations < 5 microg/g, but 75% had hair-Hg levels above 10 microg/g. Maternal hair-Hg was significantly correlated with respective children's hair-Hg (Spearman r = 0.5390; p < 0.0001). The high daily fish intake of these villagers is predominantly of species with much lower Hg concentrations.

CONCLUSION

In Amazonian lifestyle of ribeirinho communities traditional fish consumption is high and depends on available species; fish is also the principal via of meHg exposure and attendant hair-Hg concentrations.