【摘要】 目的用不同转换系数调整脉冲噪声所致工人高频听力损失剂量-反应关系曲线。方法以32名接触脉冲噪声的机械制造工人和163名接触稳态噪声的纺织工人为观察对象,用个体计量仪采集工人8 h工作期间的噪声暴露数据,计算8 h等效声级(LAeq.8h),并按不同转换系数(ER)将LAeq.8h和噪声作业工龄合并为累积噪声暴露量(CNE)。用常规方法测量工人左右耳气导听阈,按GBZ49-2002对听阈作年龄性别校正,并诊断是否为高频听力损失。结果用ER=3计算,脉冲噪声组的CNE[(103.2±4.2)dB(A).年]明显低于稳态噪声组[110.6±6.0 dB(A).年],P<0.01。增大ER值,脉冲噪声组的CNE升高,当ER=5.5时脉冲噪声组的CNE与稳态噪声组的CNE(ER=3)相似[110.3 dB(A).年vs 110.6 dB(A).年]。脉冲噪声噪声组高频听力损失患病率(68.8%)与稳态噪声组(65.0%)相似,P>0.05。两组CNE与高频听力损失患病率间均存在典型的剂量-反应关系,均P<0.01。用ER=3计算,脉冲噪声100~109 dB(A).年组的高频听力损失患病率(76.9%,90.9%)明显高于稳态噪声组(30.4%,50.0%,P<0.05);脉冲噪声组用ER=5.5计算CNE时,各组间高频听力损失患病率与稳态噪声组(ER=3)相比(0%vs 11.1%,33.3%vs 30.4%,70.0%vs50.0%,62.5%vs 79.5%,100.0%vs 90.4%)差异均无统计学意义(P>0.05)。Logistic回归模型显示,ER=3时脉冲噪声组CNE与高频听力损失患病率的剂量-反应关系曲线与稳态噪声组相比出现曲线左移,斜率增大;增大ER值,脉冲噪声组曲线右移,斜率减小,当ER=6时脉冲噪声组的剂量-反应关系曲线与稳态噪声组(ER=3)的曲线基本重合。结论脉冲噪声所致高频听力损失的危害在能量相同的情况下大于稳态噪声。增大ER值可以使脉冲噪声组的剂量-反应关系曲线与稳态噪声组基本重合。更多还原

【Abstract】 Objective To explore a new method to evaluate the dose-response relationship between the noise exposure and prevalence of noise induced high frequency hearing loss.Methods Physical examination and questionnaire survey were conducted among 32 mechanical workers,12 males and 20 females,aged 35.1±7.2,exposed to industrial impulse noise（impulse noise group）,and 163 textile workers,82 males and 81 females,aged 31.5±8.7,exposed continuous noise（continuous noise group）.SH-126 dosimeter was used to measure the A weighted equal sound level in continuous eight working hours(L_Aeq.8h) so as to evaluate the individual noise exposure.Cumulative noise exposure（CNE） was calculated with the values of L_Aeq.8h and noise working year adjusted by different exchange rates（ERs） for each worker.Hearing threshold was measured by audiometer with routine method and adjusted by age and gender according to GBZ49-2002.High frequency hearing loss was diagnosed based on the GBZ49-2002 for each worker.Results According to the equal energy rule,with the ER=3 the CNE of the impulse noise group was [103.2 dB（A）·year±4.2dB（A）·year],significantly lower than that of the continuous noise group [110.6±6.0dB（A）·year,P<0.05].With the ER=5.5,the CNE of the impulse noise group was 110.3±6.6 dB（A）·year,not significantly different from that of the continuous noise group [110.6±6.0dB（A）·year].The high frequency hearing loss prevalence of the impulse noise group was 68.8%,not significantly different that of the continuous noise group（65%,P>0.05）.Trend chi square test showed significant differences in the relationship between CNE and hearing loss prevalence among the impulse noise group with the ER=3,the impulse noise group with the ER=5.5,and continuous noise group（all P<0.01）.With the ER=3,the high frequency hearing loss prevalence of the impulse noise group with the CNE of 100-104 dB（A）·year was 76.9%,significant higher than that of the continuous noise group（30.4%,P<0.05）;and the high frequency hearing loss prevalence of the impulse noise group with the CNE of 105-108 dB（A）·year was 90.9%,significantly higher than that of the continuous noise group（50.0%,P<0.05）.With the ER=5.5,there was no difference in the prevalence of high frequency hearing loss between the continuous noise group and impulse noise group.Logistic regression model showed that with the ER=3,the dose-response curve of the impulse noise group presented a left shift and with a slope sharper than that of the continuous noise group.With the ER increasing the dose-response curve of the impulse noise group showed a right shift and with a gradually lowering slope.When the ER equaled to 6 in the impulse noise group and equaled to 3 in the continuous noise group,the two dose-response curves were almost superposed.Conclusion Impulse noise causes more serious damage in causing high frequency hearing loss than continuous noise according to equal energy rule.Increasing the ER value in the impulse noise group adjusts the dose-response curve to be close to that of the continuous noise group.更多还原