Fishing activity, health characteristics and mercury exposure of Amerindian women living alongside the Beni River (Amazonian Bolivia)

Populations in Bolivian Amazonia are exposed to mercury contamination through fish ingestion. A group of 170 Amerindian women living along the banks of the Beni River were examined in order to detect any adverse effects on their health consistent with the toxic effects of mercury. The mercury content of the women's hair (H-Hg) was used as the bio-indicator of mercury exposure. The women answered a 24-h food recall questionnaire on the frequency of their fish consumption. They also underwent a clinical examination with their weight, stature, hemoglobin concentration in blood, and blood pressure being recorded. Significant relationships were found between fishing practices, the frequency of fish consumption and H-Hg levels with mercury contaminated women (H-Hg > 5 μg/g) being more likely to present neurological abnormalities (paresthesia, static and dynamic imbalance, poor motor coordination) than non-contaminated women. No relationship was found between blood pressure and mercury levels. Women with higher H-Hg reported more infant deaths than did women with lower levels. A logistic regression analysis which included socio-cultural traits, fish consumption habits and health characteristics was performed in order to determine the risks of contamination. Contaminated women were more likely to belong to those communities pursuing traditional fishing activities; moreover these women tended to be younger and frailer than other. They also exhibited mild neurological abnormalities and reported more infant deaths. These findings should stimulate local communities to take preventive actions directed towards the more “traditional” and vulnerable groups of population.