Al-Saleh Iman, Shinwari Neptune, Nester Michael, Mashhour Abdullah, Moncari Lina, El Din Mohamed Gamal, Rabah Abdullah
Biological & Medical Research Department, King Faisal Specialist Hospital & Research Centre, 3354, Riyadh, Saudi Arabia.
J Trop Pediatr. 2008 Oct;54(5):300-7. doi: 10.1093/tropej/fmn019. Epub 2008 Mar 18.
Extensive data shows a direct link between low-level lead exposure during early development and deficits in neurobehavioral-cognitive performance evident late in childhood through adolescence. Our previous studies confirmed the transfer of lead from the mother to the fetus as well as the effect of low lead exposure on neuropsychological behavior in school children. Such results led us to design a longitudinal survey to evaluate the effect of prenatal and/or postnatal lead exposure on early cognitive development among selected group of children from birth to 2 years of age. During the first stage of this study (between March and July 2004), we measured lead levels in 653 umbilical cord blood samples taken from healthy Saudi mothers delivering at King Khalid Hospital, Al-Kharj. This gave a good opportunity to look at the prevalence of increased blood lead levels in umbilical cord blood and to identify risk factors for prenatal lead exposure. The mean cord lead levels were 2.21 +/- 1.691 microg/dl in the range of 0.284-17.276 microg/dl. Only 1.23% of the newborns had blood lead levels >10 microg/dl, the Center for Disease Control level of concern. To investigate risk factors affecting cord blood lead levels, only subjects with lead levels above the 75th percentile (2.475 microg/dl) were selected in the multiple regression models. We observed that cord blood lead levels were significantly influenced by maternal age, the location of residence and intake of prenatal supplements. Controlling for newborn's head circumferences confounders, it was found that cord blood lead levels were significantly and negatively associated with newborn's head circumference (beta = -0.158, p = 0.036). The negative association was seen between intake of prenatal supplements and cord blood lead levels emphasizing the role of prenatal supplementations during pregnancy. The significant reductions in newborns, head circumferences due to lead exposure may have serious implications for their future performance and achievement. This study reveals that even at low prenatal lead exposure, all possible measures to inspect lead sources in our environment and reduce lead exposure should be taken.
大量数据表明，在早期发育过程中低水平铅暴露与儿童晚期至青少年期明显的神经行为认知能力缺陷之间存在直接联系。我们之前的研究证实了铅从母亲转移至胎儿，以及低铅暴露对学龄儿童神经心理行为的影响。这些结果促使我们设计了一项纵向调查，以评估产前和/或产后铅暴露对选定的一组从出生到2岁儿童早期认知发育的影响。在本研究的第一阶段（2004年3月至7月），我们测量了从哈吉尔市哈立德国王医院分娩的健康沙特母亲采集的653份脐带血样本中的铅水平。这为观察脐带血中血铅水平升高的患病率以及确定产前铅暴露的风险因素提供了一个很好的机会。脐带血铅水平的平均值为2.21±1.691微克/分升，范围在0.284 - 17.276微克/分升之间。只有1.23%的新生儿血铅水平>10微克/分升，这是疾病控制中心关注的水平。为了调查影响脐带血铅水平的风险因素，在多元回归模型中仅选择铅水平高于第75百分位数（2.475微克/分升）的受试者。我们观察到脐带血铅水平受到母亲年龄、居住地点和产前补充剂摄入量的显著影响。在控制新生儿头围混杂因素后，发现脐带血铅水平与新生儿头围显著负相关（β = -0.158，p = 0.036）。产前补充剂摄入量与脐带血铅水平之间存在负相关，强调了孕期产前补充剂的作用。铅暴露导致新生儿头围显著减小可能对其未来的表现和成就产生严重影响。这项研究表明，即使产前铅暴露水平较低，也应采取一切可能的措施来检查我们环境中的铅源并减少铅暴露。
