A nutritional dilemma: fish consumption, mercury exposure and growth of children in Amazonian Bolivia

Abstract

To study associations between nutritional status and mercury exposure among communities of the Beni River. Cross-sectional survey of mothers and their children from 15 riverside Amerindian communities in the Beni River valley (Amazonian Bolivia). Hair mercury content (H-Hg) served as a bioindicator of mercury exposure. A total of 556 people were measured. Anthropometric indices of nutrition were calculated after measurements of stature, weight, arm circumference and subcutaneous fat folds. Indicators of lifestyle were collected: subsistence activity, fish consumption and ethnicity. The median of H-Hg was equal to 4.0 μg/g (CI 95%: 3.6 ∼ 4.4). There existed a significant relationship between H-Hg and nutritional indices in 5- to 10-year-old children (F = 12.1; p < 0.0001) but not in other age groups. Fishing activity, fish consumption and ethnicity had an effect upon the variance of H-Hg. Positive relationships between nutritional status and H-Hg may be related to the high nutritional value of fish. Among women, the relationship between H-Hg and nutritional status was negative (F = 7.1; p < 0.001), but this disappeared when ethnicity and subsistence activity were taken into account. In these Amazonian communities, recommendations aimed at lowering fish consumption to prevent mercury exposure should be balanced against nutritional advantages conferred upon growing children.

Keywords:

• hair mercury content
• nutritional status
• growth
• fish consumption
• Amerindians

Acknowledgements

We warmly thank the riverside communities of the Beni River for their kind cooperation. We are indebted to the LCA team (Environmental Quality Laboratory, Institute of Ecology, Universidad Mayor de San Andrès, La Paz, Bolivia) namely Lucia Alanoca, Vania Garcia and Jaime Chincherros (director) for their help in the determination of hair mercury content. We also thank our colleagues of the SELADIS (Sonia Jimenez, Mariluz Soto, Susana Revollo and Sara Perez, directora) for their constant support and help during the surveys. This paper is a tribute to our colleague Marc Roulet († 2006) who inspired and coordinated the ATI research program. The research was sponsored by Research Unit 024, Epidemiology and Prevention, IRD, France; Action Thématique Interdépartementale (ATI); Usage des Sols et des Sédiments; and Impact Sanitaire, IRD, France.