Impact of organic mercury exposure and home delivery on neurodevelopment of Amazonian children.
In the transitioning Amazon, we addressed birth environment (home vs hospital) and associated perinatal organic-Hg exposures: methylmercury (MeHg) from maternal fish consumption and ethylmercury (EtHg) from pediatric Thimerosal-containing vaccines (TCVs) taken systematically during hospital delivery. We studied 365 children in relation to linear growth at 60 months and neurodevelopment (milestone achievements, Bayley Scale of Infant Development/BSID at 24 months, and Stanford-Binet intelligence tests at 60 months). Mothers delivered in hospitals vs those gave birth at home had significantly (p<0.0001) lower hair-Hg (HHg) concentrations (12.2 vs 23.9μg/g respectively) and shorter length of breastfeeding (8.5 vs 9.7 months respectively). Home-born children had significantly (p<0.0001) higher HHg (7.1μg/g) than hospital-born children (4.6μg/g). Hospital-born children also had significantly earlier (p<0.0001) hepatitis B vaccine than home-born children (1.5 vs 24.1days respectively) and higher (p<0.0001) exposures to total TCV-EtHg (75.8 vs 49.3μg respectively). Neither anthropometric indices nor neurodevelopment (except for fluid reasoning) were directly affected by birth environment. The percentage of hospital-born children with BSID (MDI or PDI) scores <80 was not significantly different from those born at home. In spite of the differences in HHg and EtHg levels between hospital-born and home-born children, no impact on neurodevelopment was observed.
Universidade Federal do Rio de Janeiro, Rio de Janeiro, CEP 27930-560 RJ, Brazil. Electronic address: rejanecmarques@globo.com.
Rejane C
RC
Marques
Universidade de Brasília, Brasília, 70919-970 DF, Brazil. Electronic address: bernardi.jve@gmail.com.
José V E
JV
Bernardi
Fundação Universidade Federal de Rondônia, Department of Nursing, Porto Velho, RO, Brazil. Electronic address: monicapl@bol.com.br.
Mônica P L
MP
Cunha
Universidade de Brasília, Brasília, 70919-970 DF, Brazil. Electronic address: jg.dorea@gmail.com.
José G
JG
Dórea
D000818:Animals; D001938:Brazil; D001942:Breast Feeding; D002657:Child Development; D002675:Child, Preschool; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006197:Hair / Q000737:chemistry; D006700:Home Childbirth; D006760:Hospitalization; D006801:Humans; D007361:Intelligence Tests; D018811:Maternal Exposure; D008628:Mercury / Q000032:analysis; D008767:Methylmercury Compounds / Q000032:analysis*; D011247:Pregnancy
D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D008628:Mercury
Cesarean delivery; Ethylmercury; Methylmercury; Thimerosal; Vaccines