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：
10.1289/ehp.011091079
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发表时间：
2001-10
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;Sutton P;Athanasoulis M;Goldman LR
缺铁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。没有关于儿童铁状态和血铅水平的研究说明环境铅污染，因此，他们的接触来源。因此，尚无研究直接确定缺铁是否会改变环境铅与血铅的关系。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儿童和缺铁儿童的血铅水平。测量了319名1-5岁儿童的油漆、土壤、灰尘和血液中的铅、住房年龄和铁含量。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加权了室内灰尘的铅负荷。几何平均血铅水平为4.9微克/分升；14%超过10微克/分升。许多儿童缺铁（24%铁蛋白< 12 ng/dL）。17%的土壤铅含量超过500微克/克，23%和63%的室内和室外油漆样品超过5000微克/克。缺铁儿童未经校正的几何平均血铅水平高出1微克/分升；排除亚洲人后，这一差异更大（1.8微克/分升）。根据因子1和因子2对非亚洲儿童的估计，缺铁儿童的血铅水平每升高1个单位。多因素回归校正潜在混杂因素后，缺铁儿童血铅升高现象持续存在；在那些生活在污染最严重环境中的儿童中，缺铁儿童和缺铁儿童的血铅水平差异最大，约为3微克/分升。亚洲儿童铁含量高与血铅含量高之间存在矛盾关系，值得进一步研究。改善铁状态，同时减少接触，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 microg/dL; 14% exceeded 10 microg/dL. Many of the children were iron deficient (24% with ferritin < 12 ng/dL). Seventeen percent of soil leads exceeded 500 microg/g, and 23% and 63% of interior and exterior paint samples exceeded 5,000 microg/g. The unadjusted geometric mean blood lead level for iron-deficient children was higher by 1 microg/dL; this difference was greater (1.8 microg/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 microg/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.