铅对接噪工人听力损伤协同作用的观察

Observation on synergistic effect of lead and noise exposure on hearing loss of workers

目的观察铅对接触噪声工人听力损伤的协同作用及可能机制。方法选择年龄、工龄及接触噪声强度相近的观察组和对照组工人,测定两组工人的单耳单频听阈、血清中超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量,同时测定两组工人血中铅含量,并比较两组数据差异。结果观察组的单耳听阈在4和6 k Hz,明显高于对照组,两者比较,差异有统计学意义(P<0.05);观察组和对照组的血中铅浓度分别为(1.9±0.7)和(0.8±0.2)μmol/L,两者比较,差异有统计学意义(P<0.01);观察组和对照组的血清中SOD含量分别为(67.2±15.3)和(64.7±13.6)U/ml,两者比较,差异无统计学意义(P>0.05);观察组和对照组的血清中MDA含量分别为(7.31±3.36)和(6.53±2.78)μmol/L,两者比较,差异有统计学意义(P<0.05)。结论铅对接触噪声工人听力损伤具有协同作用,自由基损害可能是其机制之一。

[Objective] To observe the synergistic effect of lead and noise exposure on hearing loss of workers, analyze the possible mechanism.[Methods] The workers whose age, working age and exposed noise intensity were similar were recruited in the observation group and the control group. The monaural frequency hearing threshold, activity of serum superoxide dismutase（ SOD）, content of serum malondialdehyde（ MDA）, and the lead level in blood of two groups were tested and compared.[Results] The monaural frequency hearing thresholds of the observation group were 4 k Hz and 6 k Hz respectively, which were higher than those of the control group, and the differences were statistically significant（ P〈0.05）. The lead level in blood of the observation group and the control group was（ 1.9 ±0.7） μmol/L and（ 0.8 ±0.2） μmol/L respectively, and the difference was statistically significant（ P〈0.01）. The serum SOD level of the observation group and the control group was（ 67.2±15.3） U/ml and（ 64.7±13.6） respectively, and the difference was not statistically significant（ P〉0.01）. The serum MDA content of the observation group and the control group was（ 7.31±3.36） μmol/L and（ 6.53±2.78） μmol/L respectively, and the difference was statistically significant（ P〈0.05）.[Conclusion] There is a synergistic effect of lead and noise exposure on hearing loss of workers, and the free radical harm may be one of the mechanisms.