低水平铅对职业接触人群免疫功能影响

Effects of low level lead on the immune function of occupationally exposed workers

目的探讨体内长期低水平铅负荷对职业接触人群免疫功能的影响。方法采用方便抽样法,选取某蓄电池厂2009-2018年10年内血铅水平均≥300μg/L但<400μg/L的57名铅作业工人为观察组,以该厂相同年份内血铅水平均<100μg/L的61名后勤人员为对照组。测定2组人群血铅水平,并测定免疫指标,包括血清免疫球蛋白(Ig)G、IgA、IgM、补体(C)3、C4、C-反应蛋白(CRP)、肿瘤坏死因子α(TNF-α)水平和血中间细胞(MID)计数、MID比值(MID%),计算免疫指标异常率。结果观察组人群血铅水平中位数(M)为338μg/L。与对照组比较,观察组人群IgA(M:2.3 vs 1.9 g/L)、C3[(10.8±1.7)vs(10.1±1.5)mg/L]和C4(M:2.6 vs 2.3 mg/L)水平均降低(P<0.05),IgG异常率升高(1.6%vs 14.0%,P<0.05)。2组人群其余免疫指标分别比较,差异均无统计学意义(P>0.05)。血铅水平与C3水平呈负相关,与TNF-α水平呈正相关(Spearman相关系数分别为-0.20、0.19,P<0.05)。结论低水平铅可能对接触人员的免疫系统产生影响。

Objective To explore the effect of long-term low-level lead load on the immune function of occupationally exposed workers.Methods The convenient sampling method was used to select 57 lead-exposed workers as the observation group.These workers had the blood lead level of≥300μg/L and<400μg/L.They worked in a battery plant from 2009 to 2018.Another 61 none-lead exposed logistical personnel with blood lead level of<100μg/L were selected as the control group.The blood lead levels and immune function indicators were detected in these 2 groups,including serum immunoglobulin(Ig)G,IgA,IgM,complement(C)3,C4,C-reactive protein(CRP),tumor necrosis factor alpha(TNF-α)level,blood intermediate cell(MID)count and MID ratio(MID%).The abnormal rates of the above immune indexes were calculated.Results The median blood lead level in the observation group was 338μg/L.The levels of IgA(M:2.3 vs 1.9 g/L),C3[(10.8±1.7)vs(10.1±1.5)mg/L]and C4(M:2.6 vs 2.3 mg/L)of observation group decrease(P<0.05),the abnormal rate of IgG increased(1.6%vs 14.0%,P<0.05),compared with the control group.The other immune indexes of these two groups were compared,and the differences showed no statistical significance(P>0.05).Blood lead level was negatively correlated with C3 level and positively correlated with TNF-αlevel(Spearman correlation coefficients were-0.20,0.19,P<0.05).Conclusion Low level lead might have an impact on the immune system of lead-exposed workers.