Hernberg S, Seppäläinen A M, Mantere P
Ann Acad Med Singap. 1984 Apr;13(2 Suppl):378-82.
A prospective follow-up study on new lead workers who entered a storage battery factory was carried out between 1975 and 1981. Nerve conduction velocities and psychological performance were recorded before the commencement of exposure and after one, two, and four years of work, respectively. Out of an initial number of 89 workers, 23 were available for the 1-year, 16 for the 2-year and 11 for the 4-year re-examination. The reference group comprised non-exposed workers of a cable manufacturing plant and an electrical power plant. Especially the sensory conduction velocities of the median nerve decreased during the 2-year follow-up. When divided into two groups according to the median Pb-B values (27-30 micrograms/100 ml), the higher exposure group showed slower values for several motor and sensory conduction velocities at the 1- and 2-year examination as compared with the lower group. Also visual intelligence and visuomotor functions had impaired significantly. The learning effect for some psychological tests which was clearly evident among the referents, was almost absent among the lead workers. After four years only 11 lead workers remained. This together with selection in the drop-out, resulted in that the group differences found for conduction velocities and psychological tests did not reach statistical significance anymore.
1975年至1981年间，对进入一家蓄电池厂的新铅作业工人进行了一项前瞻性随访研究。分别在接触铅之前以及工作1年、2年和4年后记录神经传导速度和心理表现。最初的89名工人中，23人接受了1年复查，16人接受了2年复查，11人接受了4年复查。参照组包括一家电缆制造厂和一家发电厂的未接触铅的工人。在2年随访期间，尤其是正中神经的感觉传导速度下降。根据血铅中位数水平（27 - 30微克/100毫升）分为两组后，高暴露组在1年和2年检查时的几种运动和感觉传导速度值比低暴露组慢。视觉智力和视运动功能也有显著损害。在参照组中明显的一些心理测试的学习效应，在铅作业工人中几乎不存在。4年后仅剩下11名铅作业工人。这以及失访中的选择因素，导致在传导速度和心理测试中发现的组间差异不再具有统计学意义。
