Associations of prenatal and early childhood mercury exposure with autistic behaviors at 5 years of age: The Mothers and Children's Environmental Health (MOCEH) study

Jia Ryu, Eun Hee Ha, Boong Nyun Kim, Mina Ha, Yangho Kim, Hyesook Park, Yun-Chul Hong, Kyoung Nam Kim

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3 Citations (Scopus)

Abstract

Background Although mercury is an established neurotoxin, only few longitudinal studies have investigated the association between prenatal and early childhood mercury exposure and autistic behaviors. Methods We conducted a longitudinal cohort study using an ongoing prospective birth cohort initiated in 2006, wherein blood mercury levels were measured at early and late pregnancy; in cord blood; and at 2 and 3 years of age. We analyzed 458 mother-child pairs. Autistic behaviors were assessed using the Social Responsiveness Scale (SRS) at 5 years of age. Both continuous SRS T-scores and T-scores dichotomized by a score of ≥ 60 or < 60 were used as outcomes. Results The geometric mean of mercury concentrations in cord blood was 5.52 μg/L. In adjusted models, a doubling of blood mercury levels at late pregnancy (β = 1.84, 95% confidence interval [CI]: 0.39, 3.29), in cord blood (β = 2.24, 95% CI: 0.22, 4.27), and at 2 years (β = 2.12, 95% CI: 0.54, 3.70) and 3 years (β = 2.80, 95% CI: 0.89, 4.72) of age was positively associated with the SRS T-scores. When the SRS T-scores were dichotomized, we observed positive associations with mercury levels at late pregnancy (relative risk [RR] = 1.31, 95% CI: 1.08, 1.60) and in cord blood (RR = 1.28, 95% CI: 1.01, 1.63). Conclusion We found that blood mercury levels at late pregnancy and early childhood were associated with more autistic behaviors in children at 5 years of age. Further study on the long-term effects of mercury exposure is recommended.

Original languageEnglish
Pages (from-to)251-257
Number of pages7
JournalScience of the Total Environment
Volume605-606
DOIs
StatePublished - 15 Dec 2017

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Mercury
Blood
Health
confidence interval
blood
pregnancy
exposure
environmental health
mercury
Neurotoxins

Keywords

  • Autistic behavior
  • Birth cohort
  • Blood mercury
  • Early childhood exposure
  • Prenatal exposure

Cite this

@article{6bba8149b85f4707880973e6df1c4d74,
title = "Associations of prenatal and early childhood mercury exposure with autistic behaviors at 5 years of age: The Mothers and Children's Environmental Health (MOCEH) study",
abstract = "Background Although mercury is an established neurotoxin, only few longitudinal studies have investigated the association between prenatal and early childhood mercury exposure and autistic behaviors. Methods We conducted a longitudinal cohort study using an ongoing prospective birth cohort initiated in 2006, wherein blood mercury levels were measured at early and late pregnancy; in cord blood; and at 2 and 3 years of age. We analyzed 458 mother-child pairs. Autistic behaviors were assessed using the Social Responsiveness Scale (SRS) at 5 years of age. Both continuous SRS T-scores and T-scores dichotomized by a score of ≥ 60 or < 60 were used as outcomes. Results The geometric mean of mercury concentrations in cord blood was 5.52 μg/L. In adjusted models, a doubling of blood mercury levels at late pregnancy (β = 1.84, 95{\%} confidence interval [CI]: 0.39, 3.29), in cord blood (β = 2.24, 95{\%} CI: 0.22, 4.27), and at 2 years (β = 2.12, 95{\%} CI: 0.54, 3.70) and 3 years (β = 2.80, 95{\%} CI: 0.89, 4.72) of age was positively associated with the SRS T-scores. When the SRS T-scores were dichotomized, we observed positive associations with mercury levels at late pregnancy (relative risk [RR] = 1.31, 95{\%} CI: 1.08, 1.60) and in cord blood (RR = 1.28, 95{\%} CI: 1.01, 1.63). Conclusion We found that blood mercury levels at late pregnancy and early childhood were associated with more autistic behaviors in children at 5 years of age. Further study on the long-term effects of mercury exposure is recommended.",
keywords = "Autistic behavior, Birth cohort, Blood mercury, Early childhood exposure, Prenatal exposure",
author = "Jia Ryu and Ha, {Eun Hee} and Kim, {Boong Nyun} and Mina Ha and Yangho Kim and Hyesook Park and Yun-Chul Hong and Kim, {Kyoung Nam}",
year = "2017",
month = "12",
day = "15",
doi = "10.1016/j.scitotenv.2017.06.227",
language = "English",
volume = "605-606",
pages = "251--257",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier",

}

TY - JOUR

T1 - Associations of prenatal and early childhood mercury exposure with autistic behaviors at 5 years of age

T2 - The Mothers and Children's Environmental Health (MOCEH) study

AU - Ryu, Jia

AU - Ha, Eun Hee

AU - Kim, Boong Nyun

AU - Ha, Mina

AU - Kim, Yangho

AU - Park, Hyesook

AU - Hong, Yun-Chul

AU - Kim, Kyoung Nam

PY - 2017/12/15

Y1 - 2017/12/15

N2 - Background Although mercury is an established neurotoxin, only few longitudinal studies have investigated the association between prenatal and early childhood mercury exposure and autistic behaviors. Methods We conducted a longitudinal cohort study using an ongoing prospective birth cohort initiated in 2006, wherein blood mercury levels were measured at early and late pregnancy; in cord blood; and at 2 and 3 years of age. We analyzed 458 mother-child pairs. Autistic behaviors were assessed using the Social Responsiveness Scale (SRS) at 5 years of age. Both continuous SRS T-scores and T-scores dichotomized by a score of ≥ 60 or < 60 were used as outcomes. Results The geometric mean of mercury concentrations in cord blood was 5.52 μg/L. In adjusted models, a doubling of blood mercury levels at late pregnancy (β = 1.84, 95% confidence interval [CI]: 0.39, 3.29), in cord blood (β = 2.24, 95% CI: 0.22, 4.27), and at 2 years (β = 2.12, 95% CI: 0.54, 3.70) and 3 years (β = 2.80, 95% CI: 0.89, 4.72) of age was positively associated with the SRS T-scores. When the SRS T-scores were dichotomized, we observed positive associations with mercury levels at late pregnancy (relative risk [RR] = 1.31, 95% CI: 1.08, 1.60) and in cord blood (RR = 1.28, 95% CI: 1.01, 1.63). Conclusion We found that blood mercury levels at late pregnancy and early childhood were associated with more autistic behaviors in children at 5 years of age. Further study on the long-term effects of mercury exposure is recommended.

AB - Background Although mercury is an established neurotoxin, only few longitudinal studies have investigated the association between prenatal and early childhood mercury exposure and autistic behaviors. Methods We conducted a longitudinal cohort study using an ongoing prospective birth cohort initiated in 2006, wherein blood mercury levels were measured at early and late pregnancy; in cord blood; and at 2 and 3 years of age. We analyzed 458 mother-child pairs. Autistic behaviors were assessed using the Social Responsiveness Scale (SRS) at 5 years of age. Both continuous SRS T-scores and T-scores dichotomized by a score of ≥ 60 or < 60 were used as outcomes. Results The geometric mean of mercury concentrations in cord blood was 5.52 μg/L. In adjusted models, a doubling of blood mercury levels at late pregnancy (β = 1.84, 95% confidence interval [CI]: 0.39, 3.29), in cord blood (β = 2.24, 95% CI: 0.22, 4.27), and at 2 years (β = 2.12, 95% CI: 0.54, 3.70) and 3 years (β = 2.80, 95% CI: 0.89, 4.72) of age was positively associated with the SRS T-scores. When the SRS T-scores were dichotomized, we observed positive associations with mercury levels at late pregnancy (relative risk [RR] = 1.31, 95% CI: 1.08, 1.60) and in cord blood (RR = 1.28, 95% CI: 1.01, 1.63). Conclusion We found that blood mercury levels at late pregnancy and early childhood were associated with more autistic behaviors in children at 5 years of age. Further study on the long-term effects of mercury exposure is recommended.

KW - Autistic behavior

KW - Birth cohort

KW - Blood mercury

KW - Early childhood exposure

KW - Prenatal exposure

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U2 - 10.1016/j.scitotenv.2017.06.227

DO - 10.1016/j.scitotenv.2017.06.227

M3 - Article

C2 - 28667852

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VL - 605-606

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JO - Science of the Total Environment

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SN - 0048-9697

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