Hammond P B, Bornschein R L, Succop P
Environ Res. 1985 Oct;38(1):187-96. doi: 10.1016/0013-9351(85)90083-0.
Dose-effect and dose-response relationships were analyzed for blood lead concentration (PbB) vs blood protoporphyrin concentration using multiple data points from 165 children, ages 3-36 months. Protoporphyrin concentrations were measured using a front-face fluorometer designed to measure zinc protoporphyrin (ZPP) and an extraction method designed to measure total protoporphyrin as the free base (FEP). Estimations were made of the threshold for PbB effects on FEP and ZPP, as well as the slopes of the PbB-FEP and PbB-ZPP interactions. There was essentially no difference in thresholds estimated using ZPP vs FEP as the effect parameter. There was no apparent effect of age on threshold. However, the slope for PbB vs ZPP was less steep than the slope for PbB vs FEP. Moreover, the average ratio FEP:ZPP was markedly elevated at 3 months (1.84:1) and decreased slowly, attaining unity at 33 months. The possible reasons for this discrepancy are discussed, as well as the implications for interpretation of lead screening program data.
利用165名3至36个月大儿童的多个数据点，分析了血铅浓度（PbB）与血原卟啉浓度之间的剂量效应和剂量反应关系。原卟啉浓度采用旨在测量锌原卟啉（ZPP）的前表面荧光计和旨在测量作为游离碱的总原卟啉（FEP）的提取方法进行测量。对PbB对FEP和ZPP的影响阈值以及PbB-FEP和PbB-ZPP相互作用的斜率进行了估计。以ZPP和FEP作为效应参数估计的阈值基本没有差异。年龄对阈值没有明显影响。然而，PbB与ZPP的斜率比PbB与FEP的斜率平缓。此外，FEP:ZPP的平均比值在3个月时显著升高（1.84:1），并缓慢下降，在33个月时达到1。讨论了这种差异的可能原因以及对铅筛查项目数据解释的影响。
