TY - JOUR

T1 - Impact of prenatal methylmercury exposure on neurobehavioral function at age 14 years

AU - Debes, Frodi

AU - Budtz-Jørgensen, Esben

AU - Weihe, Pal

AU - White, Roberta F.

AU - Grandjean, Philippe

PY - 2006/9

Y1 - 2006/9

N2 - A cohort of 1022 consecutive singleton births was generated during 1987-1988 in the Faroe Islands, where increased methylmercury exposure occurs from traditional seafood diets that include pilot whale meat. The prenatal exposure level was determined from mercury analyses of cord blood, cord tissue, and maternal hair. At age 14 years, 878 of 1010 living cohort members underwent detailed neurobehavioral examination. Eighteen participants with neurological disorders were excluded. Blood and hair samples obtained from the participants were analyzed for mercury. The neuropsychological test battery was designed based on the same criteria as applied at the examination at age 7 years. Multiple regression analysis was carried out and included adjustment for confounders. Indicators of prenatal methylmercury exposure were significantly associated with deficits in finger tapping speed, reaction time on a continued performance task, and cued naming. Postnatal methylmercury exposure had no discernible effect. These findings are similar to those obtained at age 7 years, and the relative contribution of mercury exposure to the predictive power of the multiple regression models was also similar. An analysis of the test score difference between results at 7 and 14 years suggested that mercury-associated deficits had not changed between the two examinations. In structural equation model analyses, the neuropsychological tests were separated into five groups; methylmercury exposure was significantly associated with deficits in motor, attention, and verbal tests. These findings are supported by independent assessment of neurophysiological outcomes. The effects on brain function associated with prenatal methylmercury exposure therefore appear to be multi-focal and permanent.

AB - A cohort of 1022 consecutive singleton births was generated during 1987-1988 in the Faroe Islands, where increased methylmercury exposure occurs from traditional seafood diets that include pilot whale meat. The prenatal exposure level was determined from mercury analyses of cord blood, cord tissue, and maternal hair. At age 14 years, 878 of 1010 living cohort members underwent detailed neurobehavioral examination. Eighteen participants with neurological disorders were excluded. Blood and hair samples obtained from the participants were analyzed for mercury. The neuropsychological test battery was designed based on the same criteria as applied at the examination at age 7 years. Multiple regression analysis was carried out and included adjustment for confounders. Indicators of prenatal methylmercury exposure were significantly associated with deficits in finger tapping speed, reaction time on a continued performance task, and cued naming. Postnatal methylmercury exposure had no discernible effect. These findings are similar to those obtained at age 7 years, and the relative contribution of mercury exposure to the predictive power of the multiple regression models was also similar. An analysis of the test score difference between results at 7 and 14 years suggested that mercury-associated deficits had not changed between the two examinations. In structural equation model analyses, the neuropsychological tests were separated into five groups; methylmercury exposure was significantly associated with deficits in motor, attention, and verbal tests. These findings are supported by independent assessment of neurophysiological outcomes. The effects on brain function associated with prenatal methylmercury exposure therefore appear to be multi-focal and permanent.

KW - Adolescent

KW - Food contamination

KW - Methylmercury compounds

KW - Neuropsychological tests

KW - Neurotoxicity syndromes

KW - Prenatal exposure delayed effects

UR - http://www.scopus.com/inward/record.url?scp=33750827079&partnerID=8YFLogxK

U2 - 10.1016/j.ntt.2006.02.005

DO - 10.1016/j.ntt.2006.02.005

M3 - Journal article

AN - SCOPUS:33750827079

VL - 28

SP - 536

EP - 547

JO - Neurotoxicology and Teratology

JF - Neurotoxicology and Teratology

SN - 0892-0362

IS - 5

ER -