Association between prenatal exposure to methylmercury and developmental outcomes in Seychellois children: Effect modification by social and environmental factors

Davidson, PW; Myers, GJ; Shamlaye, C; Cox, C; Gao, P; Axtell, C; Morris, D; Sloane-Reeves, J; Cernichiari, E; Choi, A; Palumbo, D; Clarkson, TW

HERO ID

2304986

Reference Type

Journal Article

Year

1999

Language

English

PMID

10591519

HERO ID 2304986
In Press No
Year 1999
Title Association between prenatal exposure to methylmercury and developmental outcomes in Seychellois children: Effect modification by social and environmental factors
Authors Davidson, PW; Myers, GJ; Shamlaye, C; Cox, C; Gao, P; Axtell, C; Morris, D; Sloane-Reeves, J; Cernichiari, E; Choi, A; Palumbo, D; Clarkson, TW
Journal NeuroToxicology
Volume 20
Issue 5
Page Numbers 833-841
Abstract The Seychelles Child Development Study (SCDS) is testing the hypothesis that prenatal exposure to low doses of MeHg from maternal consumption of fish is associated with the child's developmental outcomes. No deleterious relationships between exposure to MeHg and cognitive functions have been identified in the primary analysis of the main cohort through 66 months of age. We performed secondary analyses to determine if effect modification (EM) from social and environmental factors was affecting associations between MeHg and outcomes. Methods: MeHg exposure was determined by analysis of maternal hair growing during pregnancy. Children in our Main Study cohort were evaluated at 6.5 months (N = 740) for visual recognition memory and visual attention using the Fagan Infantest, at 19 months (N = 738) and 29 months (N = 736) with the Bayley Scales of Infant Development (BSID). Interactions between MeHg and Caregiver Intelligence, Family Income and Home Environment were examined by multiple regression analysis. Results: The median prenatal MeHg exposure was 5.9 ppm (Range 0.5 - 26.7 ppm). No EM occurred for preferential looking or visual attention at 6.5 months, for the BSID Psychomotor Scale at either 19 or 29 months, or for activity level at 29 months as measured by the BSID infant Behavior Record. Interactions between MeHg level and both caregiver intelligence and family income were statistically significant for the BSID Mental Scale at 19 months but not at 29 months. These showed enhancement of MDI scores with increasing maternal MeHg in higher caregiver IQ groups at several levels of family income. Conclusions: In Seychellois children, consistent major EM by social or environmental factors were not. identified. The small EM by caregiver intelligence and social factors at 19 months is consistent with the enhanced performance we reported when this cohort was examined at 66 months.
Pmid 10591519
Wosid WOS:000083920200017
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword methylmercury; developmental neurotoxicity; effect modification; social and environmental factors