铁路发电车噪声作业环境对乘务员的听力和心血管系统的影响

目的了解噪声对发电车乘务员的听力损害程度及对心血管系统的影响。方法对272名发电车乘务员进行血压、心电图、纯音气导听阈检查。结果血压正常、正常高值、高血压检出率分别为21．7％、55．9％、22．4％，心电图异常主要表现为心律的改变、左室高电压及电轴左偏、ST段和T波异常。纯音气导听阈检查结果显示，接触噪声工龄10～19a年双耳高频平均听阈≥40dB的检出率（12．6％）明显高于接噪工龄〈10a的检出率（3．4％），差异有统计学意义（X2=5．71，P〈0．05）。双耳高频平均听阈在26～39dB的检出率为18．3％，并且接噪工龄10～19a、≥20a双耳高频平均听阈在26～39dB的检出率（分别为22．5％、29．4％）明显高于〈10a的检出率（9．0％），差异有统计学意义（X2分别为7．13、5．53，P〈0．01和〈0．05）。结论噪声对发电车乘务员听力的损害随接噪工龄增加而加重，应重视该岗位作业人员血压在正常高值及纯音听阈在26—39dB范围检出率较高这一情况。应在隔音降噪、合理安排作息时间等防护方面做积极努力。

Effect of noise on hearing and cardiovascular system of attendant in generator car of train

[ Objective] To understand the effect of noise on hearing and cardiovascular system of generator car attendant. [ Methods ] Blood pressure, electrocardiogram, pure tone air conduction hearing threshold examination were performed on 272 generation car attendants. [ Results] The detection rate of normal blood pressure, high limit, hypertension was 21.7%, 55.9%, 22.4%. Abnormal electrocardiogram were mainly manifested as rhythm changes, high voltage of left ventricular and left axis deviation, ST segment and T wave abnormality. Pure tone air conduction hearing threshold examination showed the detection rate of bin- aural high frequency average hearing threshold greater than 40 dB of attendants with noise exposure length of 10-19 years （ 12. 6% ）was higher than that of attendants with noise exposure length 〈 10 years （3.4%） , the difference was significant （X2 =5.71, P 〈 0.05 ）. The detection rate of the binaural high frequency average hearing threshold between 26-39 dB was 18. 3%. And the detection rates of binaural high frequency average hearing threshold between 26-39 dB of attendants with noise exposure length of 10-19 years （22.5% ） and≥20 years （29.4% } were significantly higher than that of attendants with exposure length 〈 10 years （ 9. 0% ） , the differences were significant （ X2 = 7.13, X2 = 5.53, P 〈 0.01, P 〈 0.05 ）. reasing of noise exposure length. The phenomenon of high normal blood pressure and high detection rate of pure tone hearing threshold between 26-39 dB should attract attentions Active efforts should be made on the sound insulation and noise reduction, reasonable arrangements for work and rest time.