THRESHOLD FOR LEAD DAMAGE TO HEME-SYNTHESIS IN URBAN CHILDREN
THRESHOLD FOR LEAD DAMAGE TO HEME-SYNTHESIS IN URBAN CHILDREN
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DOI：
10.1073/pnas.79.10.3335
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发表时间：
1982-01-01
期刊：
影响因子：
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通讯作者：
DAVIDOW, B
中科院分区：
文献类型：
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作者：
PIOMELLI, S;SEAMAN, C;DAVIDOW, B
虽然铅没有生理功能，在偏远地区的人群血液中的含量可以忽略不计，但在工业化社会中观察到的通常血液铅水平（BPb）被认为是正常的。铅干扰许多生物化学系统，其中血红素生物合成途径，这是反映了一个指数增加红细胞原卟啉浓度（EP）作为BPb的增加。估计了城市儿童EP增加的阈值BPb。在所研究的2004名儿童中，BPb的范围为2-98 μ g/dl，其中1852名儿童的BPb ≤ 100 μ g/dl。30 μ g/dl，认为是正常值。初步分析表明，在达到阈值BPb（显然在12-20 μ g/dl之间）后，EP浓度出现指数增加。EP增加的阈值BPb的精确定义通过2种方法确定：分段线技术和概率单位分析。无论是分析整个群体还是仅分析具有正常BPb的样本子集（≤30 μ g/dl），两种方法都产生15-18 μ g/dl的阈值BPb（平均值，16.5）。血红素合成途径受到铅的影响，在城市儿童中普遍观察到的暴露水平，这是低于目前太容易接受为正常的限制。
Although Pb has no physiological function and is present in only negligible amounts in the blood of remote populations, it is accepted that the usual blood Pb level(s) (BPb) observed in industralized society as normal. Pb interferes with many biochemical systems, among them the heme biosynthetic pathway; this is reflected by an exponential increase in erythrocyte protoporphyrin concentration (EP) as BPb increases. The threshold BPb at which an increase of EP occurred in a population of urban children was estimated. In the 2004 children studied, BPb ranged from 2-98 .mu.g/dl, with 1852 having a BPb of .ltoreq. 30 .mu.g/dl, a value considered normal. Preliminary analysis suggested that an exponential increase in the concentration of EP occurred after a threshold BPb (apparently between 12-20 .mu.g/dl) was reached. Precise definition of the threshold BPb for an increase of EP was determined by 2 approaches: segmented line techniques and probit analysis. Whether the entire population was analyzed or only the subset of samples with normal BPb (.ltoreq. 30 .mu.g/dl), both methods yielded a threshold BPb of 15-18 .mu.g/dl (average value, 16.5). The heme synthetic pathway was affected by Pb at a level of exposure commonly observed in urban children, which was below the limit presently too easily accepted as normal.