Solliway B M, Schaffer A, Pratt H, Yannai S
Department of Food Engineering and Biotechnology, Technion-Israel Institute of Technology, Haifa, Israel.
Environ Res. 1994 Nov;67(2):168-82. doi: 10.1006/enrs.1994.1072.
Visual event-related potentials, generated while performing a target detection (oddball) task, were successfully evaluated in 21 out of 34 individuals occupationally exposed to lead and 40 out of 56 nonexposed controls who were examined. The blood lead level of the lead-exposed subjects ranged from a mean of 29 to 53 micrograms Pb/dl blood in three exposed subgroups, while that of the control group was 7.7 micrograms Pb/dl blood. The latencies of the N2 and P300 components of the visual event-related potential were significantly longer in the lead-exposed subjects. Both the N2 and P300 latencies significantly correlated with the blood lead levels of the subjects. In addition, the P300 latency correlated with the concentration of delta-aminolevulinic acid (delta-ALA) in urine. This in part could be due to elevated delta-ALA levels interacting with gamma-aminobutyric acid (GABA) receptor neurons. The results indicate that lead affects mental function even at permitted levels of exposure. They strengthen the conclusion, based on biochemical and hematological assays, that the maximum permitted blood lead level of 50 micrograms Pb/dl blood is not safe and should be reduced.
在34名职业性接触铅的个体中，有21人成功完成了目标检测（异常球）任务并对视觉事件相关电位进行了评估；在接受检查的56名未接触铅的对照组中，有40人完成了该任务并进行了评估。在三个接触铅的亚组中，接触铅的受试者的血铅水平范围为平均每分升血液含29至53微克铅，而对照组的血铅水平为每分升血液7.7微克铅。视觉事件相关电位的N2和P300成分的潜伏期在接触铅的受试者中明显更长。N2和P300的潜伏期均与受试者的血铅水平显著相关。此外，P300潜伏期与尿中δ-氨基乙酰丙酸（δ-ALA）的浓度相关。这部分可能是由于δ-ALA水平升高与γ-氨基丁酸（GABA）受体神经元相互作用所致。结果表明，即使在允许的接触水平下，铅也会影响心理功能。这些结果强化了基于生化和血液学检测得出的结论，即每分升血液50微克铅的最大允许血铅水平并不安全，应该降低。
