Iron deficiency associated with higher blood lead in children living in contaminated environments
Iron deficiency associated with higher blood lead in children living in contaminated environments
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DOI：
10.2307/3454964
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发表时间：
2001-10-01
影响因子：
10.4
通讯作者：
Goldman, LR
中科院分区：
文献类型：
--
作者：
Bradman, A;Eskenazi, B;Goldman, LR
缺铁会增加儿童铅暴露的证据主要基于动物数据和有限的人类研究，其中一些证据是相互矛盾的。没有关于儿童铁状况和血铅水平的研究说明环境铅污染，因此，他们的暴露源。因此，没有研究直接确定缺铁是否会改变环境铅和血铅的关系。在这项研究中，我们比较了生活在低、中、高污染环境中的缺铁和铁充足儿童的血铅水平。从319名1-5岁的儿童中收集了油漆、土壤、灰尘和血液中的铅、住房年龄和铁状况的测量结果。我们开发了两个铅暴露因子来总结相关的暴露变量：因子1总结了所有的环境措施，因子2加权为房屋灰尘的铅负荷。几何平均血铅水平为4.9 mug/dL; 14%超过10 mug/dL。许多儿童缺铁（24%铁蛋白< 12 ng/dL）。17%的土壤铅含量超过500 mug/g，23%和63%的室内和室外涂料样品超过5,000 mug/g。缺铁儿童血铅水平的未校正几何平均值高出1 mug/dL;排除亚洲人后，该差异更大（1.8 mug/dL）。非亚裔儿童的血铅水平在每三分位数的暴露量中均高于缺铁儿童，这是由因子1和因子2估计的。通过多变量回归调整潜在混杂因素后，缺铁儿童血铅水平升高持续存在;缺铁和铁充足儿童血铅水平的最大差异约为3 mug/dL，是生活在污染最严重环境中的儿童。亚裔儿童铁营养状况与血铅水平之间存在矛盾关系，值得进一步研究。改善铁的状况，沿着减少暴露，可能有助于降低大多数儿童的血铅水平，特别是那些生活在污染最严重的环境中的儿童。
The evidence that iron deficiency increases lead child exposure is based primarily on animal data and limited human studies, and some of this evidence is contradictory. No studies of iron status and blood lead levels in children have accounted for environmental lead contamination and, therefore, the source of their exposure. Thus, no studies have directly determined whether iron deficiency modifies the relationship of environmental lead and blood lead. In this study, we compared blood lead levels of iron-deficient and iron-replete children living in low, medium, or highly contaminated environments. Measurements of lead in paint, soil, dust, and blood, age of housing, and iron status were collected from 319 children ages 1-5. We developed two lead exposure factors to summarize the correlated exposure variables: Factor 1 summarized all environmental measures, and Factor 2 was weighted for lead loading of house dust. The geometric mean blood lead level was 4.9 mug/dL; 14% exceeded 10 mug/dL. Many of the children were iron deficient (24% with ferritin < 12 ng/dL). Seventeen percent of soil leads exceeded 500 mug/g, and 23% and 63% of interior and exterior paint samples exceeded 5,000 mug/g. The unadjusted geometric mean blood lead level for iron-deficient children was higher by 1 mug/dL; this difference was greater (1.8 mug/dL) after excluding Asians. Blood lead levels were higher for iron-deficient children for each tertile of exposure as estimated by Factors 1 and 2 for non-Asian children. Elevated blood lead among iron-deficient children persisted after adjusting for potential confounders by multivariate regression; the largest difference in blood lead levels between iron-deficient and -replete children, approximately 3 mug/dL, was among those living in the most contaminated environments. Asian children had a paradoxical association of sufficient iron status and higher blood lead level, which warrants further investigation. Improving iron status, along with reducing exposures, may help reduce blood lead levels among most children, especially those living in the most contaminated environments.