Alessio L, Castoldi M R, Odone P, Franchini I
Br J Ind Med. 1981 Aug;38(3):262-7. doi: 10.1136/oem.38.3.262.
The behaviour of blood lead (PbB) and of some indicators of effect (erythrocyte protoporphyrin IX (EP), delta-aminolaevulinic acid dehydratase activity of erythrocytes (ALAD), and urinary delta-aminolaevulinic acid (ALAU)) were studied in subjects who had ceased working with inorganic lead for at least one year. Relations between these indices and chelatable lead (PbU-EDTA (lead in urine after injection of CaNa2 EDTA 1 g intravenously)), a test that is used to evaluate the lead deposits in the body, were also analysed. As a comparison, a group of subjects currently exposed was studied. In the workers with past exposure the PbB values were significantly lower, at the same PbU-EDTA levels, than those found in subjects at work. The relation between EP and PbU-EDTA shows that, corresponding levels of chelatable lead, the values of the erythrocyte metabolite are identical in the two groups. Considering the EP-PbB relation, however, at the same PbB levels the protoporphyrin values appear distinctly more altered in the subjects with past exposure. Similar results were obtained from a study of the relations between ALAD and PbU-EDTA and between ALAD and PbB. The relation between ALAU and PbU-EDTA, however, shows that, at the same PbU-EDTA levels the urinary metabolic in past-exposed subjects is distinctly lower than in subjects at work, while the relation between ALAU and PbB shows that, for similar blood lead values, the ALAU levels are identical. On the basis of the results obtained it is concluded that in subjects with past exposure, EP and ALAD can be used in establishing the persistence and extent of an "active deposit" of lead in the organism, while PbB is of very limited use.
对已停止接触无机铅至少一年的受试者的血铅（PbB）及某些效应指标（红细胞原卟啉IX（EP）、红细胞δ-氨基乙酰丙酸脱水酶活性（ALAD）和尿δ-氨基乙酰丙酸（ALAU））的行为进行了研究。还分析了这些指标与可螯合铅（PbU-EDTA，静脉注射1g CaNa2 EDTA后尿中的铅）之间的关系，该检测用于评估体内铅沉积情况。作为对照，对一组当前仍在接触铅的受试者进行了研究。在既往接触过铅的工人中，在相同的PbU-EDTA水平下，其PbB值显著低于仍在工作的受试者。EP与PbU-EDTA之间的关系表明，在可螯合铅水平相当的情况下，两组的红细胞代谢物值相同。然而，考虑到EP与PbB的关系，在相同的PbB水平下，既往接触过铅的受试者中原卟啉值的改变明显更大。对ALAD与PbU-EDTA以及ALAD与PbB之间关系的研究也得到了类似结果。然而，ALAU与PbU-EDTA之间的关系表明，在相同的PbU-EDTA水平下，既往接触过铅的受试者的尿代谢物明显低于仍在工作的受试者，而ALAU与PbB之间的关系表明，对于相似的血铅值，ALAU水平相同。根据所得结果得出结论，在既往接触过铅的受试者中，EP和ALAD可用于确定机体中铅“活性沉积”的持续存在及程度，而PbB的用途非常有限。
