Faculty of Health Sciences, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada.
Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati, OH, USA.
Environ Health. 2019 Jan 9;18(1):4. doi: 10.1186/s12940-018-0443-5.
Mercury is toxic to the developing brain, but the lowest concentration associated with the development of behavior problems is unclear. The purpose of this study was to examine the association between very low-level mercury exposure during fetal development and behavior problems in children.
We used data from 389 mothers and children in a prospective pregnancy and birth cohort study. We defined mean prenatal mercury concentration as the mean of total whole blood mercury concentrations in maternal samples collected at 16- and 26-weeks of gestation, delivery, and neonatal cord blood samples. We assessed parent-reported child behavior up to five times from two to 8 years of age using the Behavioral Assessment System for Children (BASC-2). At 8 years of age, we assessed self-reported child anxiety using the Spence Children's Anxiety Scale (SCAS). We used multiple linear mixed models and linear regression models to estimate the association between mean prenatal mercury concentrations and child behavior and anxiety, respectively.
The median prenatal total blood mercury concentrations was 0.67 μg/L. Overall, we did not find statistically significant associations between mean prenatal mercury concentrations and behavior problems scores, but a 2-fold increase in mercury concentrations at 16-weeks gestation was associated with 0.83 point (95% CI: 0.05, 1.62) higher BASC-2 anxiety scores. Maternal and cord blood mercury concentrations at delivery were associated with parent-reported anxiety at 8 years.
We found limited evidence of an association between very-low level prenatal mercury exposure and behaviors in children, with an exception of anxiety.
汞对发育中的大脑有毒，但与行为问题发展相关的最低浓度尚不清楚。本研究旨在探讨胎儿发育过程中极低水平汞暴露与儿童行为问题之间的关系。
我们使用了前瞻性妊娠和出生队列研究中的 389 名母亲和儿童的数据。我们将产前平均汞浓度定义为妊娠 16 至 26 周、分娩时和新生儿脐带血样本中母亲全血总汞浓度的平均值。我们在 2 至 8 岁时使用儿童行为评估系统（BASC-2）评估了父母报告的五次儿童行为。在 8 岁时，我们使用斯宾塞儿童焦虑量表（SCAS）评估了自我报告的儿童焦虑。我们使用多线性混合模型和线性回归模型分别估计了产前平均汞浓度与儿童行为和焦虑之间的关系。
中位数产前总血汞浓度为 0.67μg/L。总体而言，我们没有发现产前平均汞浓度与行为问题评分之间存在统计学显著关联，但妊娠 16 周时汞浓度增加两倍与 BASC-2 焦虑评分升高 0.83 分（95%CI：0.05，1.62）相关。分娩时的母亲和脐带血汞浓度与 8 岁时的父母报告的焦虑相关。
我们发现极低水平产前汞暴露与儿童行为之间存在有限的关联证据，除了焦虑之外。
