title: Neurodevelopment of Amazonian infants: antenatal and postnatal exposure to methyl- and ethylmercury.
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 (3.95 ± 1.8 ppm) were statistically (P = 0.0001) different from those of infants from Porto Velho (3.84 ± 5.5 ppm) and Bom Futuro (1.85 ± 0.9 ppm). Differences in vaccine coverage among these populations resulted in significantly higher (P = 0.0001) 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 r = -0.2300; P = 0.0376) correlation between HHg and GDS for infants from Porto Velho, but not for the rural infants from Bom Futuro (Spearman r = 0.1336; P = 0.0862) and Itapuã (Spearman r = 0.1666; P = 0.5182). Logistic regression applied to variables above or below the median GDS showed that EtHg exposure (estimated probability = -0.0157; P = 0.0070) and breastfeeding score (estimated probability = -0.0066; P = 0.0536) 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.
authors.affiliation: Department of Nutrition, University of Brasília, 70919-970 Brasília, DF, Brazil. dorea@rudah.com.br
authors.forename: José G
authors.initials: JG
authors.lastname: Dórea
authors.forename: Rejane C
authors.initials: RC
authors.lastname: Marques
authors.forename: Cintya
authors.initials: C
authors.lastname: Isejima
mesh_terms: D001938:Brazil; D001942:Breast Feeding; D002658:Developmental Disabilities / Q000139:chemically induced; D004032:Diet; D004034:Diet Surveys; D005035:Ethylmercury Compounds / Q000493:pharmacokinetics / Q000506:poisoning*; D005260:Female; D006197:Hair / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D018811:Maternal Exposure; D008628:Mercury / Q000032:analysis* / Q000493:pharmacokinetics; D008767:Methylmercury Compounds / Q000493:pharmacokinetics / Q000506:poisoning*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects; D012424:Rural Population; D012959:Socioeconomic Factors; D014505:Urban Population
chemical_list: D005035:Ethylmercury Compounds; D008767:Methylmercury Compounds; D008628:Mercury