International Center for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Int J Epidemiol. 2011 Dec;40(6):1593-604. doi: 10.1093/ije/dyr176.
Exposure to arsenic through drinking water has been associated with impaired cognitive function in school-aged children in a few cross-sectional studies; however, there is little information on critical windows of exposure.
We conducted a population-based longitudinal study in rural Bangladesh. We assessed the association of arsenic exposure, based on urinary arsenic (U-As; twice during pregnancy and twice in childhood), with the development of about 1700 children at 5 years of age using Wechsler Pre-school and Primary Scale of Intelligence [intelligence quotient (IQ)].
Median maternal U-As in pregnancy was 80 µg/l (10-90 percentiles: 25-400 µg/l). Children's urine contained 35 (12-155) µg/l and 51 (20-238) µg/l at 1.5 and 5 years, respectively. Using multivariable-adjusted regression analyses, controlling for all potential confounders and loss to follow-up, we found that verbal IQ (VIQ) and full scale IQ (FSIQ) were negatively associated with (log) U-As in girls. The associations were consistent, but somewhat stronger with concurrent arsenic exposure [VIQ: B = -2.4, 95% confidence interval (CI) = -3.8 to -1.1; FSIQ: B = -1.4, 95% CI = -2.7 to -0.1, n = 817), compared with that at 1.5 years (VIQ: B = -0.85, 95% CI = -2.1 to 0.4; FSIQ: B = -0.74, 95% CI = -1.9 to 0.4, n = 902), late gestation (VIQ: B = -1.52, 95% CI = -2.6 to -0.4; FSIQ: B = -1.35, 95% CI = -2.4 to -0.3, n = 874) and early gestation (VIQ: B = -1.23, 95% CI = -2.4 to -0.06; FSIQ: B = -0.92, 95% CI = -2.0 to -0.2, n = 833). In boys, U-As showed consistently low and non-significant associations with all IQ measures. An effect size calculation indicated that 100 µg/l U-As was associated with a decrement of 1-3 points in both VIQ and FSIQ in girls.
We found adverse effects of arsenic exposure on IQ in girls, but not boys, at 5 years of age.
一些横断面研究表明，儿童通过饮用水接触砷与认知功能受损有关；然而，关于关键暴露窗口期的信息却很少。
我们在孟加拉国农村进行了一项基于人群的纵向研究。我们评估了基于尿液砷（U-As；妊娠期间两次和儿童期两次）的暴露与约 1700 名 5 岁儿童的智力发展之间的关联，使用的是韦氏学前和小学智力量表[智商（IQ）]。
妊娠期间母亲 U-As 的中位数为 80μg/l（10-90 百分位数：25-400μg/l）。儿童在 1.5 岁和 5 岁时尿液中的含量分别为 35（12-155）μg/l 和 51（20-238）μg/l。通过多变量调整回归分析，控制所有潜在混杂因素和随访失访，我们发现女孩的言语智商（VIQ）和全量表智商（FSIQ）与（对数）U-As 呈负相关。这些关联是一致的，但与同期砷暴露相比，关联更为强烈[VIQ：B=-2.4，95%置信区间（CI）=-3.8 至-1.1；FSIQ：B=-1.4，95%CI=-2.7 至-0.1，n=817]，而与 1.5 岁时的暴露相比[VIQ：B=-0.85，95%CI=-2.1 至 0.4；FSIQ：B=-0.74，95%CI=-1.9 至 0.4，n=902]，晚孕期[VIQ：B=-1.52，95%CI=-2.6 至-0.4；FSIQ：B=-1.35，95%CI=-2.4 至-0.3，n=874]和早孕期[VIQ：B=-1.23，95%CI=-2.4 至-0.06；FSIQ：B=-0.92，95%CI=-2.0 至-0.2，n=833]。在男孩中，U-As 与所有 IQ 测量值均显示出一致的低且无统计学意义的关联。效应量计算表明，U-As 增加 100μg/l 与女孩的 VIQ 和 FSIQ 降低 1-3 分相关。
我们发现砷暴露对女孩的智商有不良影响，但对男孩没有影响，这种影响在 5 岁时出现。
