出生前后铅暴露对儿童智力的影响

The Effects of Prenatal and Postnatal Lead Exposure on Children Intelligence

[目的]研究出生前后不同时期儿童铅暴露及其父母基线血铅、母亲孕中期血铅等对儿童智力的影响。 [方法]采用前瞻性研究方法,从1996年开始在铅污染较严重的安徽省池州市贵池区进行了为期9年的流行病学调查。对新婚夫妇进行追踪观察至分娩,期间对夫妇进行基线调查,孕前观察,孕期随访,分娩情况记录,并定期观察随访其子代发育情况。共采集到210对夫妇基线血样,93份孕中血样,98份脐带血样。分别于2001年和2004年2次系统地对他们的子代进行体格检查和问卷调查,用中国-韦氏儿童智力量表(C-WYCSI)对儿童进行智力测试(2004年),并采集幼儿指血165份、儿童指血161份。采用PE-AA800原子吸收光谱仪进行血铅水平检测。[结果]①母亲基线血铅、父亲基线血铅、儿童血铅、婴幼儿血铅、脐带血铅和孕中血铅几何均数超过0．48 μmol/L(100μg/L)的样本所占比率分别为 32．38％、38．09％、45．30％、43．03％、10．20％和9．68％．②高血铅组儿童的动物下蛋、视觉分析、操作智商和总智商的得分显著低于正常血铅组儿童得分(P<0．05)。③儿童图片概括得分与其幼儿时期血铅水平(b=-0．187,P<0．05)、母亲基线血铅水平(6=-0．147,P<0．05)呈负相关;儿童领悟项目得分与父亲基线血铅水平呈负相关(6=-0．172,P<0．05);而儿童动物下蛋、视觉分析、操作智商得分均与儿童当前血铅水平呈负相关(P<0．05)。[结论]儿童出生前后不同时期铅暴露水平,特别是当前血铅水平对儿童智力有一定的不良影响,并以影响操作智商为主。

[ Objective ] To study the effects of prenatal and postnatal lead exposure （ father BBLL and mother BBLL, MPBLL, UCBLL, IBLL, CBLL ） on children intelligence. [ Methods ] A nine-year study was condusted in a place of severe environmental lead pollution, Guichi district of Chizhou city in Anhui province, China, from1996. Prospective cohort study was followed-up among 210 newly-wedded with the intention to pregnancy and living around a lead and zinc smelt factory from Dec. 1996 till Dec.1998 with observation of their offspring. We investigated 161 children with questionnaire and tested their intelligence quotient with C-WYCSI in Aug, 2004. Meanwhile, we measured the levels of lead in 210 couples baseline blood （ father BBLL and mother BBLL ）, mid-pregnancy blood （ MPBLL ） in 93 cases, umbilical cord blood （ UCBLL ） in 98 cases, blood of infants（ IBLL ）in 165 cases, blood of 161 children（ CBLL ）by PE-AA800 Atomic Absorption Spectrophotometer. [ Results ] ① The proportion that blood lead geometric mean of mother BBLL, father BBLL, children BLL, infants BLL, UCBLL and MPBLL were higher than 0.48 μmol/L（ 100μg/L ） were 32.38%, 38.09%, 45.30%, 43.03%, 10.20%, 9.68% respectively. ②The scores of animal eggs test, visual analysis, performance IQ and total IQ ill the HBL（ high blood lead level ）group were significantly higher than those in NBL（ normal blood lead level ） group. ③The single correlative and the multiple stepwise regression analysis showed that the score of picture generalization was negatively correlated significantly with infant BLL （ b=-O.187, P 〈 0.05 ） and mother BBLL （ b=-0.147, P 〈 0.05 ）; another significant negative association was found between the score of apperception and FBLL （ b=0.172, P 〈 0.05 ）. Furthermore, the scores of animal eggs test, visual analysis and performance intelligence quotient （ PIQ ）were positively correlated significantly with CBLL, respectively. [ Conclusion ] Adverse effects on intelligence quotient, especially on the PIQ, are found in children exposed to lead during prenatal and postnatal periods. And among the above six blood lead levels, CBLL plays the main role.