International Center for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
Int J Epidemiol. 2010 Oct;39(5):1206-16. doi: 10.1093/ije/dyp369. Epub 2010 Jan 19.
Exposure to arsenic through drinking water has been associated with impaired cognitive function in school-aged children in cross-sectional studies; however, there are few longitudinal studies and little information on effects of exposure in early life when the brain is generally most vulnerable.
A longitudinal cohort study beginning in early pregnancy was conducted in rural Bangladesh, where arsenic concentrations in well water vary considerably. We assessed the effects of pre- and postnatal arsenic exposure on development of 2112 children at 18 months of age with Bayley Scales of Infant Development-II (mental and psychomotor development indices), Wolke's Behavior Rating Scale and maternal report of language. We related the measures of child development to arsenic concentrations in maternal urine in gestational weeks 9 and 30 and child's urinary arsenic at 18 months of age. Details of socio-economic background, home stimulation and anthropometric measurements of mothers and children were also available.
Median maternal urinary arsenic concentration averaged over early and late gestation was 96 µg/l, whereas children's urine contained 35 µg/l of arsenic. There was no significant effect of any of the arsenic exposure measures on any of the child development measures after controlling for social and economic confounders, child's age and sex.
Contrary to expectations, we found no indications of adverse effects of pre- or postnatal arsenic exposure on child development at 18 months. It remains possible that duration of exposure is critical and that effects will become apparent later in childhood.
横断面研究表明，通过饮用水接触砷与学龄儿童认知功能受损有关；然而，纵向研究较少，关于生命早期（大脑通常最脆弱）暴露于砷的影响的信息也很少。
在孟加拉国农村地区开展了一项始于妊娠早期的纵向队列研究，那里井水的砷浓度差异很大。我们评估了产前和产后砷暴露对 2112 名 18 个月大的儿童发育的影响，使用贝利婴幼儿发展量表第二版（心理和精神运动发育指数）、沃尔克行为评定量表和母亲报告的语言进行评估。我们将儿童发育的衡量标准与母亲妊娠第 9 周和第 30 周的尿液中砷浓度以及儿童 18 个月时的尿液中砷浓度相关联。还提供了社会经济背景、家庭刺激以及母亲和儿童的人体测量学测量的详细信息。
妊娠早期和晚期中位数母亲尿液中砷浓度平均为 96µg/l，而儿童尿液中含有 35µg/l 的砷。在控制了社会经济混杂因素、儿童年龄和性别后，任何砷暴露指标都与儿童发育的任何指标均无显著相关性。
与预期相反，我们没有发现产前或产后砷暴露对 18 个月大儿童发育有不良影响的迹象。暴露持续时间可能是关键，并且在儿童后期可能会出现明显的影响。
