Chemosphere 100 (2014) 71–76
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
The neurological effects of prenatal and postnatal mercury/methylmercury exposure on three-year-old children in Taiwan Hsing-Cheng Hsi a, Chuen-Bin Jiang b,c, Tzu-Hsuan Yang d, Ling-Chu Chien d,⇑ a
Graduate Institute of Environmental Engineering, National Taiwan University, Taiwan Department of Pediatrics, Taipei Mackay Memorial Hospital, Taipei, Taiwan c Mackay Junior College of Medicine, Nursing and Management, Taipei, Taiwan d School of Public Health, Taipei Medical University, Taiwan b
h i g h l i g h t s 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.
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Article history: Received 2 November 2013 Received in revised form 16 December 2013 Accepted 20 December 2013 Available online 23 January 2014 Keywords: Mercury Methylmercury Neurological effects Fish intake Children
a b s t r a c t 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 89.6 ng g 1. The methylmercury concentrations in hair, fingernail, and toenail samples were 1.96, 0.64, and 0.55 lg g 1, respectively. Seventy percent of children had hair methylmercury concentrations exceeding the U.S. environmental protection agency (EPA) reference of 1 lg g 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. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Children may be vulnerable to exposure to various environmental toxicants during the gestational, neonatal, infant, and toddler periods. According to biomonitoring data from the Centers for Disease Control (CDC) and other prevention biomonitoring studies in the Unites States, people are exposed to 27% metals (COEH, 2011). The American Academy of Pediatrics also recommends further awareness and monitoring of children and pregnant women to metal exposure (COEH, 2011).
⇑ Corresponding author. Address: School of Public Health, Taipei Medical University, 250, Wu-Hsing Street, Taipei 110, Taiwan. Tel.: +886 2 27361661x6516; fax: +886 2 27384831. E-mail address: [email protected] (L.-C. Chien). 0045-6535/$ - see front matter Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2013.12.068
Mercury (Hg), especially methylmercury (MeHg), is neurotoxic and causes neurodevelopmental disabilities such as language and learning/attention deficits, especially in the fetus (Freire et al., 2010). Previous research has indicated that prenatal and postnatal exposure to Hg, even to low-level Hg (e.g., children hair Hg concentrations
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
The neurological effects of prenatal and postnatal mercury/methylmercury exposure on three-year-old children in Taiwan Hsing-Cheng Hsi a, Chuen-Bin Jiang b,c, Tzu-Hsuan Yang d, Ling-Chu Chien d,⇑ a
Graduate Institute of Environmental Engineering, National Taiwan University, Taiwan Department of Pediatrics, Taipei Mackay Memorial Hospital, Taipei, Taiwan c Mackay Junior College of Medicine, Nursing and Management, Taipei, Taiwan d School of Public Health, Taipei Medical University, Taiwan b
h i g h l i g h t s 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.
a r t i c l e
i n f o
Article history: Received 2 November 2013 Received in revised form 16 December 2013 Accepted 20 December 2013 Available online 23 January 2014 Keywords: Mercury Methylmercury Neurological effects Fish intake Children
a b s t r a c t 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 89.6 ng g 1. The methylmercury concentrations in hair, fingernail, and toenail samples were 1.96, 0.64, and 0.55 lg g 1, respectively. Seventy percent of children had hair methylmercury concentrations exceeding the U.S. environmental protection agency (EPA) reference of 1 lg g 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. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Children may be vulnerable to exposure to various environmental toxicants during the gestational, neonatal, infant, and toddler periods. According to biomonitoring data from the Centers for Disease Control (CDC) and other prevention biomonitoring studies in the Unites States, people are exposed to 27% metals (COEH, 2011). The American Academy of Pediatrics also recommends further awareness and monitoring of children and pregnant women to metal exposure (COEH, 2011).
⇑ Corresponding author. Address: School of Public Health, Taipei Medical University, 250, Wu-Hsing Street, Taipei 110, Taiwan. Tel.: +886 2 27361661x6516; fax: +886 2 27384831. E-mail address: [email protected] (L.-C. Chien). 0045-6535/$ - see front matter Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2013.12.068
Mercury (Hg), especially methylmercury (MeHg), is neurotoxic and causes neurodevelopmental disabilities such as language and learning/attention deficits, especially in the fetus (Freire et al., 2010). Previous research has indicated that prenatal and postnatal exposure to Hg, even to low-level Hg (e.g., children hair Hg concentrations
