职业铅接触对神经传导影响的危害评价

Risk assessment of nerve conduction velocity in workers exposed to lead

目的 对职业铅接触工人进行接触评估,探讨职业铅接触所致神经传导速度变化的危害特征,研究职业铅接触与铅致神经传导速度影响的剂量-效应关系,进行职业铅接触对神经传导速度影响的危害评价.方法 测定职业铅接触工人的外剂量、内剂量（血铅、尿铅）、运动神经及感觉神经传导速度,采用基准剂量（BMD）法计算外剂最、血铅和尿铅基准剂量下限（BMDL）值,分析铅接触指标与神经传导速度之间的剂量-反应关系.结果 铅接触组的感觉神经传导速度有不同程度降低.正中神经、尺神经、腓浅神经的感觉神经传导速度的血铅BMDL值分别为456.99、332.36、468.38μg,L;其尿铅BMDL值分别为14.05、9.19、13.57μg/gCr. 结论 内剂量能更好地反映人群对铅的接触水平,与尿铅相比,血铅更能敏感地反映铅接触人群感觉神经传导速度效应指标的改变.尺神经传导速度相对敏感,可作为铅接触高危人群的筛选指标.

Objective To explore the dose-effect relationship between lead exposure and nerve conduction velocity, and to assess risk characteristics of nerve conduction velocity induced by lead exposure.Methods The external dose, internal dose （blood lead, urine lead） and the conduction velocity of peripheral nerve were examined. The benchmark dose of a population exposed to occupational lead was estimated to develop risk assessment of nerve conduction velocity in worker exposed to lead by use of BMDS（ version 1.3.3）.The BMDL in terms of blood lead and urine lead was calculated. Results There was correlation between blood lead and urine lead. The sense nerve conduction velocity was decreased significantly in the group of lead exposure workers（P〈0.05）. The BMDLs-05 for median nerve conduct velocity, ulnar nerve conduction velocity, and superficial peroneal nerve conduction velocity in terms of blood lead were 456.99, 332.36 and 468.38μ/L respectively; the BMDLs-05 in terms of urine lead were 14.1, 9.2 and 13.6 μ/gCr respectively. Conclusion The internal dose is the better index to reflect the level of lead exposure. Blood lead is identified as a specific and sensitive biomarker for sense nerve conduction velocity reduction. Ulnar nerve conduction velocity can be used as highly sensitive biomarkers to screen the high risk population of lead exposure.