Chevrier Cécile, Sullivan Kimberly, White Roberta F, Comtois Callie, Cordier Sylvaine, Grandjean Philippe
Inserm, U625, University of Rennes I, GERHM, IFR140, F-35000 Rennes, France.
Neurotoxicology. 2009 Jan;30(1):37-46. doi: 10.1016/j.neuro.2008.09.012. Epub 2008 Oct 17.
In order to better define the effects of methylmercury (MeHg) exposure on neurodevelopment, qualitative error types observed in the responses of exposed children to the Stanford-Binet Copying Test were categorized and quantified using raw data from two studies of 395 Amazonian children aged 7-12 years (from Brazil and French Guiana). These outcomes were related to hair-mercury concentration as the biomarker of MeHg exposure (range=0.5-63.8 microg/g). The combined analysis of data from two separate countries had two major goals: (1) to gain clues concerning the underlying neuropathological mechanisms of observed effects based on convergent evidence of MeHg-related qualitative outcomes in the two studies and (2) to explore possible cultural determinants of test response based on divergent outcomes in the two countries. Multiple linear and logistic regression analyses were performed with adjustment for confounders. In the combined data set, mercury exposure was negatively associated with scores on the drawing task: a score reduction of 1.2 (s.e., 0.3) points was observed in the children with a hair-mercury concentration above 10 microg/g compared to those with a hair level below 1 microg/g; this effect appeared to be stronger in the younger children. Risk of committing one or more errors of rotation, simplification or perseveration in the drawings increased with hair-mercury concentration in both cultural settings, providing convergent evidence of specific types of MeHg-related neurocognitive outcomes. However, relationships between mercury exposure and scores on the Block organization component of the test varied according to the study site, indicating that other factors must be considered in evaluating responses to the demands of this cognitive task.
为了更好地确定甲基汞（MeHg）暴露对神经发育的影响，利用来自两项针对395名7至12岁亚马逊儿童（来自巴西和法属圭亚那）的研究的原始数据，对暴露儿童在斯坦福-比奈临摹测验中的反应所观察到的定性错误类型进行了分类和量化。这些结果与作为甲基汞暴露生物标志物的头发汞浓度相关（范围为0.5 - 63.8微克/克）。对来自两个不同国家的数据进行综合分析有两个主要目标：（1）基于两项研究中与甲基汞相关的定性结果的趋同证据，获取有关观察到的影响的潜在神经病理机制的线索；（2）基于两个国家的不同结果，探索测试反应可能的文化决定因素。进行了多元线性和逻辑回归分析，并对混杂因素进行了调整。在综合数据集中，汞暴露与绘图任务的得分呈负相关：头发汞浓度高于10微克/克的儿童与头发汞水平低于1微克/克的儿童相比，得分降低了1.2（标准误，0.3）分；这种影响在年幼儿童中似乎更强。在两种文化背景下，绘图中出现一种或多种旋转、简化或持续错误的风险都随着头发汞浓度的增加而增加，这为特定类型的与甲基汞相关的神经认知结果提供了趋同证据。然而，汞暴露与测试的积木组织部分得分之间的关系因研究地点而异，这表明在评估对这项认知任务要求的反应时，必须考虑其他因素。
