胎儿期低水平铅暴露对婴儿发育影响的前瞻性研究

Prenatal low level lead exposure and infant development in the first year: a prospective study in Shanghai, China

为了探讨胎儿期低水平铅暴露对婴儿出生以后发育的影响，于１９９３年８月～１１月间，在上海市杨浦区随机测定了３４８位产妇分娩时婴儿脐带血铅水平。将脐带血铅水平在第７０百分位以上及第３０百分位以下的婴儿分别作为高铅组及低铅组，进行３、６、１２月龄发育随访。结果发现，３月龄时高铅组Ｂａｙｌｅｙ婴儿发育量表的精神发育指数（ＭＤＩ）和心理运动发育指数（ＰＤＩ）均显著落后于低铅组儿童（Ｐ＜０．０１）。两组间ＭＤＩ的差别在６及１２月龄时持续存在（Ｐ＜０．０５），但两组ＰＤＩ间的差别在６及１２月龄随访时消失。相关回归及多元逐步回归分析表明，脐血铅水平与不同阶段ＭＤＩ之间均存在负相关关系，而两组间３月龄时ＰＤＩ的差别在排除掺杂因素作用后即不复存在。提示目前上海市区胎儿期铅暴露水平已足以对婴儿出生以后的神经发育产生不良影响。

The authors conducted this prospective study to assess the effects of prenatal low level lead exposure on infantile development of children in urban Shanghai. Totally 348 umbilical cord blood samples were collected and blood lead levels (CBPb) were determined. Based on their CBPb, the infants were classified into two exposure groups: 104 in a “low” lead group (CBPb<30th percentile, 0.357 mol/L), and 109 in a “high” lead group (CBPb>70th percentile, 0.516 mol/L). At 3,6 and 12 months, the Bayley scales of infant development were applied and capillary blood lead levels were measured. At all three ages, the mental development index scores were inversely correlated with the infants′CBPb. No statistically significant association between CBPb and the psychomotor development index scores was found at 6 and 12 months, even at 3 month the difference became not significant when adjused for confoundings. Postnatal lead levels were unrelated to concurrent developmental status. The authors conclude that prenatal low level lead exposure, which is relatively common in Shanghai, is associated with an adverse developmental impact on children during the first year of life.