Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, 18071 Granada, Spain.
J Epidemiol Community Health. 2010 Mar;64(3):223-8. doi: 10.1136/jech.2008.084574. Epub 2009 Aug 13.
Air pollution from traffic has been associated with cardiorespiratory diseases in children and adults, but there is little information on its potential neurotoxic effects. This study aimed to investigate the association between exposure to nitrogen dioxide (NO(2)), as a marker of traffic-related air pollution, and cognitive development in children.
A population-based birth cohort from southern Spain was followed from the age of 4 years for 1 year. Complete data for analyses were gathered on 210 children living in urban and rural areas. NO(2) exposure was predicted by means of land use regression models. A standardised version of the McCarthy Scales of Children's Abilities (MSCA) was used to assess children's motor and cognitive abilities. Multivariate analyses were performed to evaluate the relation between exposure to NO(2) and MSCA outcomes, adjusting for potential confounders.
A negative effect of NO(2) was found across all MSCA subscales, despite low predicted NO(2) exposure levels (5-36 microg/m(3)). Children exposed to higher NO(2) (>24.75 microg/m(3)) showed a decrease of 4.19 points in the general cognitive score and decreases of 6.71, 7.37 and 8.61 points in quantitative, working memory and gross motor areas, respectively. However, except for gross motor function, associations were not statistically significant.
Although results were not statistically significant, the associations found between exposure to NO(2) and cognitive functions suggest that traffic-related air pollution may have an adverse effect on neurodevelopment, especially early in life, even at low exposure levels.
交通产生的空气污染已被证实与儿童和成人的心肺疾病有关，但关于其潜在神经毒性影响的信息却很少。本研究旨在调查儿童暴露于二氧化氮（NO2）（交通相关空气污染的标志物）与认知发育之间的关系。
该研究是基于西班牙南部的一个人群出生队列，从 4 岁开始随访 1 年。共对居住在城市和农村地区的 210 名儿童进行了完整数据分析。通过基于土地利用的回归模型来预测 NO2 的暴露情况。采用 McCarthy 儿童能力量表（MSCA）的标准版本来评估儿童的运动和认知能力。采用多元分析来评估 NO2 暴露与 MSCA 结果之间的关系，同时调整了潜在的混杂因素。
尽管预测的 NO2 暴露水平较低（5-36μg/m3），但在所有 MSCA 子量表中均发现了 NO2 的负面效应。暴露于较高 NO2（>24.75μg/m3）的儿童在总认知评分中下降了 4.19 分，在定量、工作记忆和粗大运动区域中分别下降了 6.71、7.37 和 8.61 分。但是，除了粗大运动功能外，这些关联均无统计学意义。
尽管结果没有统计学意义，但 NO2 暴露与认知功能之间的关联表明，交通相关空气污染可能对神经发育产生不利影响，尤其是在生命早期，即使在低暴露水平下也是如此。
