Shen X M, Yan C H, Guo D, Wu S M, Li R Q, Huang H, Ao L M, Zhou J D, Hong Z Y, Xu J D, Jin X M, Tang J M
Research Center for Childhood Lead Poisoning Prevention, Shanghai Second Medical University, China.
Environ Res. 1998 Oct;79(1):1-8. doi: 10.1006/enrs.1998.3851.
We used a prospective study design to assess the effects of prenatal low-level lead exposure on the development of urban, inner-city children in Shanghai. Umbilical cord blood samples wee consecutively collected from 605 live newborns. Two hundred and fifty-seven samples were excluded from the study due to clotting. Lead levels were determined on 348 cord blood samples. The geometric mean was 9.2 micrograms/dl. Based on their cord blood lead levels, infants were classified into two exposure groups: 104 in a relatively low lead group (lead levels < or = 30 percentile), and 104 in a relatively high lead group (lead levels > or = 70 percentile). Seventy-five subjects failed to complete the study, and 133 babies were included in the final cohort: 69 babies in the high lead group and 64 in the low lead group. At 3, 6, and 12 months, the Bayley Scales of Infant Development were administered and capillary blood lead levels were measured. Detailed information was obtained on a wide range of variables relevant to infant development. At all three ages, the Mental Development index (MDI) scores, adjusted for confounders, were inversely related to the infants' cord blood lead levels. The difference of the mean adjusted MDI scores between low and high lead groups was 3.4 at 3 months, 6.3 at 6 months, and 5.2 at 12 months of age. These differences were statistically significant at all time points. No significant association between cord blood lead levels and the Psychomotor Development Index (PDI) scores was detected at all three visits after adjustment for confounders. Postnatal lead levels were unrelated to concurrent developmental status. We conclude that prenatal low-level lead exposure, which is relatively common in Shanghai, is associated with an adverse developmental impact on children through the first year of life.
我们采用前瞻性研究设计，以评估产前低水平铅暴露对上海市区内城儿童发育的影响。连续收集了605例活产新生儿的脐带血样本。由于凝血，257份样本被排除在研究之外。对348份脐带血样本进行了铅水平测定。几何平均值为9.2微克/分升。根据脐带血铅水平，婴儿被分为两个暴露组：104例属于相对低铅组（铅水平≤第30百分位数），104例属于相对高铅组（铅水平≥第70百分位数）。75名受试者未能完成研究，133名婴儿被纳入最终队列：高铅组69名婴儿，低铅组64名婴儿。在3个月、6个月和12个月时，进行贝利婴儿发育量表评估并测量毛细血管血铅水平。获取了与婴儿发育相关的广泛变量的详细信息。在所有三个年龄段，经混杂因素调整后的心理发展指数（MDI）得分与婴儿脐带血铅水平呈负相关。低铅组和高铅组调整后的平均MDI得分差异在3个月时为3.4，6个月时为6.3，12个月时为5.2。这些差异在所有时间点均具有统计学意义。在调整混杂因素后，在所有三次访视中均未检测到脐带血铅水平与心理运动发育指数（PDI）得分之间存在显著关联。产后铅水平与同时期发育状况无关。我们得出结论，在上海相对常见的产前低水平铅暴露与儿童出生后第一年的发育不良影响有关。
