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Journal of Biomedicine and Biotechnology
Volume 2012 (2012), Article ID 132876, 9 pages
http://dx.doi.org/10.1155/2012/132876
Research Article

Neurodevelopment of Amazonian Infants: Antenatal and Postnatal Exposure to Methyl- and Ethylmercury

1Department of Nutrition, University of BrasΓ­lia, 70919-970 BrasΓ­lia, DF, Brazil
2Federal University of Rio de Janeiro, Campus MacaΓ©, 27971-550 Rio de Janeiro, RJ, Brazil
3Departament of Statistics, Federal University of SΓ£o Carlos, 13566-590 SΓ£o Carlos, SP, Brazil

Received 5 December 2011; Accepted 4 February 2012

Academic Editor: João B.T. Rocha

Copyright © 2012 José G. Dórea et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Neurodevelopment as Gesell development scores (GDSs) in relation to mercury exposure in infants (<6 months of age) of one urban center and two rural villages, respectively, of fisherman and cassiterite miners. Mean total hair-Hg (HHg) concentrations of infants from Itapuã ( 3 . 9 5 Β± 1 . 8  ppm) were statistically ( 𝑃 = 0 . 0 0 0 1 ) different from those of infants from Porto Velho ( 3 . 8 4 Β± 5 . 5  ppm) and Bom Futuro ( 1 . 8 5 Β± 0 . 9  ppm). Differences in vaccine coverage among these populations resulted in significantly higher ( 𝑃 = 0 . 0 0 0 1 ) mean ethylmercury (EtHg) exposure in urban infants (150 μg) than in infants from either village (41.67 μg, Itapuã; 42.39 μg, Bom Futuro). There was an inverse significant (Spearman π‘Ÿ = βˆ’ 0 . 2 3 0 0 ; 𝑃 = 0 . 0 3 7 6 ) correlation between HHg and GDS for infants from Porto Velho, but not for the rural infants from Bom Futuro (Spearman π‘Ÿ = 0 . 1 3 3 6 ; 𝑃 = 0 . 0 8 6 2 ) and Itapuã (Spearman π‘Ÿ = 0 . 1 6 6 6 ; 𝑃 = 0 . 5 1 8 2 ). Logistic regression applied to variables above or below the median GDS showed that EtHg exposure (estimated p r o b a b i l i t y = βˆ’ 0 . 0 1 5 7 ; 𝑃 = 0 . 0 0 7 0 ) and breastfeeding score (estimated p r o b a b i l i t y = βˆ’ 0 . 0 0 6 6 ; 𝑃 = 0 . 0 5 3 6 ) score were significantly associated with GDS. Conclusion. In nurslings whose mothers are exposed to different levels of fish-MeHg (HHg), a higher score of neurological development at six months was negatively associated with exposure to additional TCV-EtHg. Results should be interpreted with caution because of unaccounted variables.