低水平汞暴露对儿童智力发育影响的前瞻性研究

目的 评估胎儿期低水平汞暴露对学龄儿童智力发育的影响.方法 在2009年6月至2010年6月,对在苏州市吴江区第一人民医院住院的产妇进行健康问卷调查,采集脐血、胎发检测汞暴露水平.在2016年10月至2017年8月,对部分儿童进行随访,填写问卷,检测血汞、尿汞、发汞,并用Wechsler儿童智力量表修订版(WISC-R)对入组儿童进行智力测试.结果 研究期间共完成206例儿童的随访,其中男童102例,女童104例,平均年龄为89.6±3.5月龄.随访儿童的脐血汞几何均数为2.12μg/L,胎发汞为272.73μg/kg,7岁儿童随访时血汞几何均数为1.19μg/L,发汞为339.50μg/kg,尿汞为0.41μg/L.脐血汞水平与胎发汞和血汞水平均呈正相关(r值分别为0.470、0.175),胎发汞水平与血汞水平、尿汞水平及发汞水平均呈正相关(r值分别为0.364、0.248、0.242),血汞水平与尿汞水平、发汞水平均呈正相关(r值分别为0.366、0.536).学龄期血汞水平对男童语言智商及总智商呈负性影响(β值分别为-15.18、-17.66).结论 胎儿期汞暴露处于较低水平,胎儿期汞暴露对儿童智能发育无明显影响,而儿童期汞暴露对男童智能发育可能产生一定的负性影响,而对女童无显著影响.

Prospective study of influence of low level mercury exposure on intelligence of children

Objective To evaluate the influence of prenatal low level mercury exposure on intelligence of school-aged children. Methods Puerperants hospitalized in First People's Hospital of Wujiang District of Suzhou from June 2009 to June 2010 were investigated with health questionnaire,and cord blood and fetus hair was collected to test mercury exposure level.Some children were followed up from October 2016 to August 2017,and questionnaire were filled and mercury in blood,urine and hair of children was detected.The children's intelligence was tested with revised Wechsler intelligence scale for children(WISC-R).Results Follow-up of 206 children with average age of 89.6 ± 3.5months including102 boys and 104 girls was completed during the study. Geometric mean of cord blood mercury level was 2.12μg/L,and that of fetus hair mercury level was 272.73μg/kg in children who were followed up.Geometric mean of blood mercury level,hair mercury level and urinary mercury level in seven-year old children who were followed up was 1.19μg/L,339.50μg/kg and 0.41μg/L,respectively.Cord blood mercury level was positively correlated with fetus hair mercury level and blood mercury level(r value was 0.470 and 0.175,respectively).Fetus hair mercury level was positively correlated with blood mercury level,urinary mercury level and hair mercury level(r value was 0.364,0.248 and 0.242, respectively).Blood mercury level was positively correlated with urinary mercury level and hair mercury level(r value was 0.366 and 0.536,respectively).Blood mercury level had negative influence on total intelligence quotient in school age boys(β value was-15.18 and-17.66,respectively).Conclusion Prenatal mercury exposure is at low level.Prenatal mercury exposure has no obvious influence on intelligence development of children.Childhood mercury exposure has certain negative effect on intelligence development of boys but no obvious effect on intelligence development of girls.