Gulson B L, Cameron M A, Smith A J, Mizon K J, Korsch M J, Vimpani G, McMichael A J, Pisaniello D, Jameson C W, Mahaffey K R
Graduate of School of the Environment, Macquire University, Sydney, New South Wales, Australia.
Environ Res. 1998 Aug;78(2):152-60. doi: 10.1006/enrs.1997.3810.
To determine the potential for using instead of blood as an indicator of lead exposure, especially in infants, lead concentrations and high-precision lead isotopic measurements have been compared in venous blood and "spot" urine (n > 260 from 182 different subjects) collected within the same 24-h period. Physiological conditions for the children and most of the adults were considered to be in a steady-state between body stores and lead in the environment. In the case of some adults, conditions were initially not steady-state because exposure conditions changed (for example, subjects moved to a country with lead of different isotopic composition.) There was a high correlation (r2 = ) between the blood and urine measurements of the isotope ratios but about 10% of measurements were outliers--the blood and urine measurements were further apart than was consistent with the measurement error that was generally obtained. The discrepancy was usually found to be associated with the urine measurement and was attributed to contamination during sampling. Weekly urine and monthly blood monitoring of an adult male over a 24-month period showed and excellent correlations, although the standard deviations were about an order of magnitude higher than the precision measured for replicate analyses of a single blood or urine sample. "Spot" urine analyses for two male subjects gave excellent agreement with 24-h urine samples. Standard deviations of the spot analyses were of similar order to those in the 24-month monitored subject. In cases where female adults from Eastern Europe migrated to Australia, there was generally a more rapid exchange of skeletal lead with Australian environmental lead in urine compared with blood. These data do not support a differential partitioning of endogenous lead into the plasma. At this stage, isotopic measurements of urine can be used as a proxy for isotopic measurements in blood. However, lead concentrations in blood and in urine are only weakly related. Concentrations of lead in urine cannot serve to predict concentrations of lead in blood, particularly at the lower range of exposures, for example, at blood concentrations less than 10 microgram/d1.
为了确定使用尿液而非血液作为铅暴露指标的可能性，尤其是在婴儿中，我们比较了在同一24小时内采集的静脉血和“即时”尿液（来自182名不同受试者，n>260）中的铅浓度和高精度铅同位素测量值。儿童和大多数成年人的生理状况被认为处于身体储存与环境中铅之间的稳态。在一些成年人中，由于暴露条件发生变化（例如，受试者迁移到一个铅同位素组成不同的国家），初始条件并非稳态。同位素比率的血液和尿液测量值之间存在高度相关性（r2 = ），但约10%的测量值为异常值——血液和尿液测量值之间的差异比通常获得的测量误差所预期的更大。这种差异通常与尿液测量有关，归因于采样过程中的污染。对一名成年男性进行的为期24个月的每周尿液和每月血液监测显示出极佳的相关性，尽管标准差比单次血液或尿液样本重复分析所测得的精密度高约一个数量级。对两名男性受试者的“即时”尿液分析与24小时尿液样本结果高度一致。即时分析的标准差与24个月监测受试者的标准差处于相似水平。在东欧成年女性移民到澳大利亚的情况下，与血液相比，尿液中骨骼铅与澳大利亚环境铅的交换通常更快。这些数据不支持内源性铅在血浆中的差异分配。在现阶段，尿液的同位素测量可作为血液同位素测量的替代方法。然而，血液和尿液中的铅浓度仅存在微弱关联。尿液中的铅浓度无法用于预测血液中的铅浓度，尤其是在较低暴露水平时，例如血液浓度低于10微克/分升时。
