Centre of Public Health Research, Av Catalunya 21, 46020, Valencia, Spain.
Sci Total Environ. 2011 May 1;409(11):2298-305. doi: 10.1016/j.scitotenv.2011.02.004. Epub 2011 Mar 12.
Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother-child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood).
A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blood by thermal decomposition, amalgation, and Atomic Absorption Spectrometry. Maternal sociodemographic, lifestyle and dietary factors were obtained by questionnaires during pregnancy. A multivariate logistic regression model was constructed. The dependent variable was a dichotomous lead level variable (detected vs no detected, i.e. ≥ vs < 2μg/dL).
A low percentage of cord blood samples with lead levels ≥ 2μg/dL were found (5.9%). Geometric mean and maximum were 1.06μg/dL and 19μg/dL, respectively. Smoking at the beginning of pregnancy, age, social class, weight gain during pregnancy, gravidity, and place of residence were the maternal factors associated with detectable cord blood lead levels. Mother's diet does not appear to be a determining factor of lead exposure. Nevertheless, daily intake of iron and zinc may act as a protective factor against having cord blood lead levels ≥ 2μg/dL.
In the different regions of Spain taking part in this study, lead levels to which newborns are exposed are low. Mobilization of lead from bones may be the main contributor to the cord blood levels.
铅是一种已知的神经毒物。胎儿和婴儿对铅暴露非常敏感，因为他们的血脑屏障尚未完全形成。因此，监测产前和婴儿早期的血铅水平非常重要。本研究旨在评估西班牙四个基于人群的母婴队列中胎儿期铅暴露及其与母体因素的关系。本研究是在 INMA 项目 INfancia y Medio Ambiente（环境与儿童）的框架内进行的。
共有 1462 名孕妇于 2004 年至 2008 年期间被招募。通过热分解、汞齐化和原子吸收光谱法分析脐带血中的铅。在怀孕期间通过问卷调查获得母体社会人口统计学、生活方式和饮食因素。构建了多变量逻辑回归模型。因变量为二分类铅水平变量（检出与未检出，即≥2μg/dL 与<2μg/dL）。
脐带血样本中铅水平≥2μg/dL 的检出率较低（5.9%）。几何平均值和最大值分别为 1.06μg/dL 和 19μg/dL。妊娠初期吸烟、年龄、社会阶层、孕期体重增加、孕次和居住地是与可检出脐带血铅水平相关的母体因素。母亲的饮食似乎不是铅暴露的决定因素。然而，铁和锌的每日摄入量可能是防止脐带血铅水平≥2μg/dL 的保护因素。
在参与本研究的西班牙不同地区，新生儿接触的铅水平较低。骨骼中铅的动员可能是脐带血水平的主要贡献者。
