中低剂量稳态噪声对工人高频听力损伤的影响

本文在１２０名接触中低剂量稳态噪声、未出现语频听力损伤的工人中发现高频听力损伤４２人（经年龄性别较正，患病率３５．０％），累积噪声暴露量由＜７５ｄＢ（Ａ）增加至＞９５ｄＢ（Ａ）时高频听力损伤患病率由６．３％上升至５３．３％。用Ｌｏｇｉｓｔｉｃ回归模型进一步观察到累积噪声暴露量增加１ｄＢ（Ａ）时调整后的ＯｄｄｓＲａｔｉｏ为１．１３６（Ｐ＝０．００１），证实中低剂量稳态噪声暴露与高频听力损伤之间仍存在剂量——反应关系。同时，这一规律与过去在中高剂量噪声暴露的人群中观察到高频听力损伤的剂量——反应关系互相衔接。作者认为长期接触中低剂量稳态噪声仍可以在一定程度上引起高频听力损伤，对这一部分人群的防护也应予以注意。     

中低剂量噪声暴露与工人高频听力损伤的剂量-反应关系

本文在１２０名接触中低剂量噪声，未出现语频听损的工人中发现高频听力损作４２人，累积噪声暴露量由〈７５ｄＢ增加至〉９５ｄＢ时，高频听力损伤患病率由６．３％上升至５３．３％。用Ｌｏｇｉｓｔｉｃ回归模型进一步观察到累积噪声暴露量增加１ｄＢ（Ａ）时，调整后的Ｏｄｄｓ Ｒａｔｉｏ为１．１３６，证实中低剂量噪声暴露与高频听力损伤存在剂量－反应关系，长期中低剂量噪声可在一定程度上引起高频听力损伤。     

中低剂量噪声暴露与工人高频听力损伤的剂量－反应关系

本文在１２０名接触中低剂量噪声、未出现语频听损的工人中发现高频听力损伤４２人（经年龄性别校正，患病率３５．０％），累积噪声暴露量由＜７５ｄＢ（Ａ）增加至＞９５ｄＢ（Ａ）时，高频听力损伤患病率由６．３％上升至５３．３％。用Ｌｏｇｉｓｔｉｃ回归模型进一步观察到累积噪声暴露量增加１ｄＢ（Ａ）时，调整后的ＯｄｄｓＲａｔｉｏ为１．１３６（Ｐ＝０．００１），证实中低剂量噪声暴露与高频听力损伤之间存在剂量－反应关系，长期接触中低剂量噪声可在一定程度上引起高频听力损伤。     

飞机维修男工噪声暴露与听力损失患病率的剂量-反应关系

目的 探讨男性飞机维修人员噪声暴露与噪声性听力损失(NIHL)患病率之间的剂量．反应关系。方法 飞机维修人员按工作性质、地点、工种和班次分为不同亚组。每组选择3-5人,用SH126个体计量仪测定工作班次噪声暴露。同时对290名男性飞机维修人员进行了问卷调查和听力检查。结果 飞机维修男工8h连续等效A声级(LAcq．8h)平均值为89．1dB(A)。经年龄、性别校正的高频听力损伤患病率为48．6％,语频听力损伤患病率为6．6％。按噪声级分组,NIHL患病率未表现出随剂量增加而升高的趋势。按噪声级与工龄合并后的累积噪声暴露量分组,高频、语频．听力损伤患病率均随噪声暴露增加而升高,经卡方趋势检验发现,CNELAcq-8h评价剂量一反应关系优于CNELAcq．10min。结论 飞机维修人员噪声暴露与NIHL患病率之间存在剂量．反应关系;CNELAcq.8h是评价噪声暴露的良好指标,在非稳态噪声评价中同样适用。     

脉冲与稳态噪声引起工人听力损伤的差异

对接触脉冲噪声和稳态噪声的７７１名工人调查发现，年龄性别校正后的高频听力损伤患病率为６０．４％、语频为５．４％。听力损伤患病率随噪声暴露的剂量增大而升高，有剂量—反应关系。接触脉冲噪声工人的高频听力损伤患病率（６２．４％，３４５／５５３）高于稳态噪声（５５．５％，１２１／２１８），但无显著差异；而语频听力损伤患病率（６．７％，３７／５５３）明显高于稳态噪声（２．３％，５／２１８）。脉冲噪声引起的听力损伤曲线出现左移，表明它对听觉系统的危险性高于稳态噪声。     

听力损伤的累积噪声暴露阈值研究

目的根据不同累积噪声暴露量与工人语频听力损伤发生率间的关系,探讨和评价引起职业性听力损失的临界累积噪声暴露阈值.方法应用Logistic回归模型分析1 435名不同累积噪声暴露强度的听阈数据.结果语频损伤和高频损失发生率随暴露水平而增高;累积噪声暴露量与语频损伤发生率的Logistic回归分析显示,听阈水平随累积噪声暴露量增高而上升并有明显相关性;预测模型显示语频损伤的临界累积噪声暴露阈值为100dB(A).结论听力损伤的临界累积噪声暴露阈值100dB(A)与我国现执行的噪声卫生标准具有一致性,可探讨作为对个体职业噪声暴露危害程度警告的阈值指标.     

稳态噪声与非稳态噪声所致工人听力损害的对比研究

目的评价两种不同性质的噪声对工人听力损害的差异方法对35家企业的稳态噪声接触1年以上工人共1421人,非稳态噪声(除脉冲噪声之外)接触1年以上冲压工人共957人进行纯音听力测试,并对35家接触噪声企业进行职业卫生学调查。结果在1421名稳态噪声组检出观察对象131例,患病率为9.2%,职业性噪声聋98人,患病率为6.8%;在957名非稳态噪声组检出观察对象74例,患病率为7.7%,职业性噪声聋60人,患病率为6.3%。两组比较差异无统计学意义(P0.05)。两组高频和语频听力损失的患病率随累积噪声暴露量的增大而增大,呈剂量-反应关系。结论在累积噪声暴露量接触水平一致的情况下,稳态噪声与非稳态噪声(除脉冲噪声之外)对引起的听力损失差异无统计学意义。     

接触非稳态噪声与听力损伤的剂量-反应关系研究

目的为评价接触非稳态噪声与听力损伤的剂量-反应关系和探索非稳态噪声接触剂量的描述指标提供科学依据。方法通过问卷调查收集调查对象的基本信息,用个人噪声剂量计记录噪声接触水平,并对调查对象进行纯音听力测试。结果204名机械作业工人接触噪声符合非稳态特征,LAeq.8h为80.6～112.3dB(A);语频听力损伤患病率为17.2%,高频听力损伤患病率为59.3%。接触非稳态噪声与高频、语频听力损伤患病率均呈现剂量-反应关系(趋势卡方检验P<0.01)。Logistic回归分析显示,SLAeq.2s、RLAeq.2s、四分位数间距LAeq.2s与高频损伤,SLAeq.2s指标存在统计学关联(P<0.01),而RLAeq.2s、四分位数间距LAeq.2s与高频听力损伤无关联(P>0.01)。结论接触非稳态噪声较稳态噪声对语频听力损伤更为敏感;累计噪声接触量指标同样适用于非稳态噪声,用于评价噪声接触、预测听力损伤水平;今后研究中可以尝试采用SLAeq.2s作为描述不同性质的非稳态噪声波动性指标。     

冲床噪声与稳态噪声致工人高频听力损害的对比研究

目的 了解冲床噪声对工人高频率段听力的影响,并与稳态噪声进行对比.方法 接触冲床噪声的38名锻压车间工人为冲床噪声接触组,62名接触稳态噪声的拉丝、磨粉等工人为稳态噪声组.用个人声暴露计采集工作期间噪声暴露数据,计算40h等效声级(LEX,W)和累积噪声暴露量(CNE).按GBZ 49-2007《职业性噪声聋诊断标准》对工人测试听力并计算和判定结果.结果 冲床噪声接触组CNE[(97.0±6.4) dB (A)·年]与稳态噪声接触组CNE [(97.6±5.7)dB(A)·年]比较,差异无统计学意义(P＞0.05).冲床噪声接触组高频听力损失率(55.3％)明显高于稳态噪声(32.3％),差异有统计学意义(CMHX2=6.928,P=0.0085);冲床噪声接触组于CNE 95～104 dB(A)·年内损失率(13/19,68.4％)明显高于稳态噪声组( 13/37,35.1％),差异有统计学意义(P=0.018).logistic回归模型显示,冲床噪声组、稳态噪声组CNE与高频听力损失率均呈剂量-反应关系(P＜0.01).结论 应用个体噪声暴露数据计算时,在能量相同的情况下,冲床噪声所致高频听力损失的危害大于稳态噪声.     

用个体暴露评价脉冲噪声与稳态噪声所致高频听力损失的关系

目的用个体噪声暴露测量数据比较工业脉冲噪声与稳态噪声所致高频听力损失剂量反应关系的异同。方法1998至1999年,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,用噪声剂量计采集8h工作期间的噪声暴露数据,计算8h等效声级(LAeq.8h),并按等能量原理将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GBZ492002对听阈做年龄性别校正,并诊断是否为高频听力损失。结果脉冲噪声组的CNE[(103.2±4.2)dB(A)·年]明显低于稳态噪声组[(110.6±6.0)dB(A)·年],脉冲噪声组高频听力损失患病率(68.8%)与稳态噪声组(65.0%)相似,分层分析和趋势卡方检验证实,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,差异有统计学意义;脉冲噪声100～104和105～109dB(A)·年两组的高频听力损失患病率(76.9%和90.9%)高出稳态噪声组(30.4%和50.0%)约1倍。logistic回归模型显示,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。结论采用个体噪声暴露数据计算时,在能量相同的情况下,脉冲噪声所致高频听力损失的危害大于稳态噪声。     

某纺织厂噪声作业工人听力损失调查

目的:通过对某纺织厂噪声强度监测和对作业人员的听力检测,掌握噪声强度及听力损失的发生情况,为采取积极有效的防护措施提供依据。方法:用HS6288系列噪声分析仪监测作业场所噪声强度,并进行频谱分析,计算累积噪声暴露量(CNE);对某纺织厂接触噪声作业的无耳疾患的931人进行听力检测;用EpiData建立数据库,SAS软件8.0统计包进行统计分析。结果:该厂噪声车间的连续等效A声级均超过了85db(A),主要为中高频噪声;噪声作业人员有高频听力损失264人,检出率为28.36%,语频听力损失9人,检出率为0.97%;高频和语频听力损失的发生率均随累积接触噪声剂量的增加而升高;听力损失发生率及程度与工龄密切相关;织一车间和织二车间噪声平均>100dB(A),高频听损率分别为43.68%和42.62%,在强噪声车间作业戴耳塞者高频听损检出率低于不戴耳塞者,但高频听力损失的检出率仍然明显高于其他车间;听力损失曲线以高频凹陷谷点为3kHz及4 kHz的“V”字型为主,占高频听力损失的73.0%。结论:该厂噪声污染较严重,对作业人员听力已经产生了明显影响,应采取积极的综合预防性措施来控制噪声对作业人员健康的影响。     

广州市部分企业噪声作业工人听力损失现况分析

目的对广州市部分企业噪声作业工人听力损失现况进行分析,以达到保护工人听力的目的。方法以部分企业长期接触噪声的440名工人为研究对象,测量等效A声级(LAeq)。按等能量原则将LAeq和噪声作业工龄合并计算累积噪声暴露量(CNE);用logistic回归模型分析听力损失的相关因素。结果作业环境噪声强度超标率为41.20%,噪声强度均值为(89.30±4.57)dB(A)。440例噪声作业工人听力损失检出率为23.86%,听力损失与耳塞防护、工龄、年龄和CNE存在正相关关系(P0.05)。非条件logistic回归分析结果显示,年龄、工龄可能是听力损失的危险因素(偏回归系数为正值,OR值1)。结论在有佩戴耳塞防护的情况下,CNE作为听力损失的评价指标不敏感,佩戴耳塞仍是目前最好的防护措施。     

累积噪声暴露与听力损伤的相关性调查

[目的 ]探讨噪声对作业工人健康影响职业危害剂量问题 ,提供噪声暴露与听力损失的剂量—反应关系资料。[方法 ]对 170名生产性噪声作业工人进行听力检查 ,引用累积噪声暴露量 (CNE)进行分析。 [结果 ]随累积噪声暴露量的增加 ,听力损失随之增加 ,二者间有高度正相关性 (r =0 95 76) ,且随累积噪声暴露量的增加 ,持续接触噪声和间断接触噪声对听力损失影响的差异有显著性 (P <0 0 5或P <0 0 1)。 [结论 ]累积噪声暴露量在噪声研究及噪声防治中有重要应用价值。     

Noise exposures of rail workers at a North American chemical facility

BACKGROUND: Both continuous and impact noise exposures of rail yards and railways have been historically understudied. We summarize noise exposures to rail workers at a large chemical facility in North America. METHODS: Rail workers were surveyed over the course of three 12-hr shifts. Personal noise dosimeters were used to derive a 12-hr time-weighted average (L(AVG)), an 8-hr time-weighted average (L(TWA)), and a percent dose. Peak and maximum sound levels were also recorded during each sampling period. Six workers were sampled on three separate days for a total of 18 full-shift noise samples. RESULTS: Full-shift noise exposures were all below the Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) and action level for a 12-hr workday. Peak impact sound levels exceeded 140 dB in 17 of 18 samples (94%) with a mean peak sound level of 143.9 dB. Maximum continuous sound levels were greater than 115 dBA in 4 of 18 samples (22%) with a mean maximum sound level of 113.1 dBA. The source of peak impact sound levels was a daily exposure to a concussion caused by a sudden break in a freight airline. CONCLUSIONS: Rail workers at this facility are at risk of noise induced hearing loss from high impact noise exposures. Peak impact and maximum continuous sound levels can be attenuated through the use of hearing protection or by increasing distances from railroad noise sources.     

Do ambient noise exposure levels predict hearing loss in a modern industrial cohort?

Background

Much of what is known about the exposure–response relationship between occupational noise exposures and hearing loss comes from cross‐sectional studies conducted before the widespread implementation of workplace hearing conservation programmes. Little is known about the current relationship of ambient noise exposure measurements to hearing loss risk.

Aim

To examine the relationship between rates of high frequency hearing loss and measured levels of noise exposure in a modern industrial workforce.

Methods

Ten‐year hearing loss rates were determined for 6217 employees of an aluminium manufacturing company. Industrial hygiene and human resources records allowed for reconstruction of individual noise exposures. Hearing loss rates were compared to ANSI 3.44 predictions based on age and noise exposure. Associations between hearing loss, noise exposure, and covariate risk factors were assessed using multivariate regression.

Results

Workers in higher ambient noise jobs tended to experience less high frequency hearing loss than co‐workers exposed at lower noise levels. This trend was also seen in stratified analyses of white males and non‐hunters. At higher noise exposure levels, the magnitude of hearing loss was less than predicted by ANSI 3.44 formulae. There was no indication that a healthy worker effect could explain these findings. The majority of 10 dB standard threshold shifts (STS) occurred in workers whose calculated ambient noise exposures were less than or equal to 85 dBA.

Conclusions

In this modern industrial cohort, hearing conservation efforts appear to be reducing hearing loss rates, especially at higher ambient noise levels. This could be related to differential use of hearing protection. The greatest burden of preventable occupational hearing loss was found in workers whose noise exposure averaged 85 dBA or less. To further reduce rates of occupational hearing loss, hearing conservation programmes may require innovative approaches targeting workers with noise exposures close to 85 dBA.     

Audiometric notch as a sign of noise induced hearing loss

OBJECTIVES—To investigate the relation between different types of exposure to noise and a classic sign of noise induced hearing loss (NIHL), the audiometric notch.METHODS—The study sample had exposure to both continuous and impulse noise and was drawn from a population of electrical transmission workers. Audiograms, taken as part of a hearing conservation programme, were read by three clinicians experienced in the assessment of NIHL. Working independently and using their clinical judgment, they were asked to identify localised increases in the threshold of hearing (audiometric notches) which they would attribute to noise, had a suitable history of exposure been elicited. Prevalent cases of NIHL were identified by the presence of a notch in either ear. Risk factors for NIHL were assessed by a questionnaire which sought information about exposure to air blast circuit breaker noise; firearms; explosions, and continuous noise. The odds of exposure to these factors in those with and without hearing loss were calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.RESULTS—Of the 648 questionnaires sent out 357 were returned, a response rate of 55%. Of these, at least two out of the three assessors identified 175 (49%) people with a notch at any audiometric frequency. There was no association between these cases and the NIHL risk factors identified by the questionnaire, but a further frequency specific analysis showed a small proportion of people (15 (4%)) with notches at 4 kHz who had the expected associations with exposure to noise and a significant OR for firearms of 4.25 (95% CI 1.28 to 14.1). The much larger proportion of people with 6 kHz notches (110 (31%)) did not show these associations.CONCLUSIONS—To diagnose NIHL it is important to elicit a detailed and accurate history of exposure to noise: although the notch at 4 kHz is a well established clinical sign and may be valuable in confirming the diagnosis, the 6 kHz notch is variable and of limited importance.