The neurological effects of prenatal and postnatal mercury/methylmercury exposure on three-year-old children in Taiwan

• Published in: Chemosphere (Oxford) 2014-04, Vol.100, p.71-76
• Main Authors: Hsi, Hsing-Cheng, Jiang, Chuen-Bin, Yang, Tzu-Hsuan, Chien, Ling-Chu
• Format: Article
• Language: English
• Subjects: Adult; Air. Soil. Water. Waste. Feeding; Animals; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Child, Preschool; Children; Cognition - drug effects; Environment. Living conditions; Environmental Exposure - adverse effects; Female; Fish intake; Fishes; Humans; Infant; Male; Medical sciences; Mercury; Mercury - metabolism; Mercury - toxicity; Metals and various inorganic compounds; Methylmercury; Methylmercury Compounds - metabolism; Methylmercury Compounds - toxicity; Neurological effects; Neuropsychological Tests; Pregnancy; Prenatal Exposure Delayed Effects - metabolism; Prenatal Exposure Delayed Effects - physiopathology; Public health. Hygiene; Public health. Hygiene-occupational medicine; Taiwan; Toxicology; United States
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2013.12.068

•Hg/MeHg concentrations in meconium, hair, nail, and toenail were correlated.•Children with high hair MeHg and fish intake caused low expressive language score.•Postnatal Hg exposure had greater impacts than prenatal on children neurodevelopment. This study attempts to elucidate the relationship between neurological effects and mercury/methylmercury concentrations in various biomarkers, including meconium, hair, fingernail, and toenail. Eight-three mother–infant pairs were recruited between August 2008 and December 2009, and follow-up examinations on these children were completed after three years. The Bayley Scales of Infant and Toddler Development (Bayley-III) for evaluating the cognitive, language, and motor development of three-year-old children were calculated and validated. The geometric mean of the total mercury concentration in meconium was 89.6ngg−1. The methylmercury concentrations in hair, fingernail, and toenail samples were 1.96, 0.64, and 0.55μgg−1, respectively. Seventy percent of children had hair methylmercury concentrations exceeding the U.S. environmental protection agency (EPA) reference of 1μgg−1. A significantly positive correlation was obtained between methylmercury levels in hair, fingernail, and toenail. These methylmercury levels were also significantly positively correlated with the children’s fish intake and negatively correlated with a Bayley-III scale score of expressive language. The prenatal mercury exposure, however, did not show significant influence on neurological development. High fish consumption appears to be a critical risk factor for methylmercury levels in children and may cause a lower expressive language score.