Seppäläinen A M, Tola S, Hernberg S, Kock B
Arch Environ Health. 1975 Apr;30(4):180-3. doi: 10.1080/00039896.1975.10666672.
Electrophysiological methods revealed subclinical neuropathy in 26 workers, exposed from 1 to 17 years to lead and whose blood lead (PbB) values had never exceeded 70mu/100ml, as ascertained by checking the monitor reports of the factory and by careful exposure history. The PbB determinations had been tested repeatedly and had been found valid. The main findings were slowing of the maximal motor conduction velocities of the median and ulnar nerves and particularly the conduction velocity of the slower fibers of the ulnar nerve. Electromyographical abnormalities comprised fibrillations, diminution of the number of motor units on maximal contraction, and an abnormally long duration of the units. Earlier similar measurements from heavily exposed workers had been even more abnormal. Thus, a dose-response relationship exists on a group basis. Since the regular monitoring of PbBs in most workers during their entire period of exposure excludes the possibility of a body burden out of proportion to the PbB slight neurological damage is produced at exposures hitherto regarded as quite safe.
电生理方法显示，26名工人存在亚临床神经病变。这些工人接触铅1至17年，通过查阅工厂监测报告和详细的接触史确定其血铅（PbB）值从未超过70微克/100毫升。血铅测定经过多次检测，结果有效。主要发现为正中神经和尺神经的最大运动传导速度减慢，尤其是尺神经较慢纤维的传导速度。肌电图异常包括纤维颤动、最大收缩时运动单位数量减少以及运动单位持续时间异常延长。此前对重度接触工人进行的类似测量结果更为异常。因此，从群体角度存在剂量反应关系。由于在大多数工人的整个接触期间定期监测血铅，排除了体内铅负荷与血铅不成比例的可能性，所以在迄今被认为相当安全的接触水平下也会产生轻微神经损伤。
