Self-assessment of hearing status and risk of noise-induced hearing loss in workers in a rolling stock plant

Noise measurements and questionnaire inquiries were carried out for 124 workers of a rolling stock plant to develop a hearing conservation program. On the basis of that data, the risk of noise-induced hearing loss (NIHL) was evaluated. Additionally, the workers' hearing ability was assessed with the (modified) Amsterdam inventory for auditory disability and handicap, (m)AIADH. The workers had been exposed to noise at A-weighted daily noise exposure levels of 74-110 dB for 1-40 years. Almost one third of the workers complained of hearing impairment and the (m)AIADH results showed some hearing difficulties in over half of them. The estimated risk of hearing loss over 25 dB in the frequency range of 3-6 kHz was 41-50% when the standard method of predicting NIHL specified in Standard No. ISO 1999:1990 was used. This risk increased to 50-67% when noise impulsiveness, coexposure to organic solvents, elevated blood pressure and smoking were included in calculations.     

Occupational noise exposure and hearing defects among sawmill workers in the south of Thailand

The aim of this study was to investigate occupational noise exposure and hearing defects among sawmill workers in the south of Thailand. Seven hundred sawmill workers participated, of which 335 (47.9%) were male. The mean age of the sawmill workers was 33.5 years (SD 10.2), and more than 60% were <35 years old; 75.1% of the workers had less than 5 years of work experience. Only about one in four workers (25%) had been trained in use of personal protective equipment (PPE), and half of the participants never or rarely wore PPE while working. The prevalence rate of noise-induced hearing loss (NIHL) was 22.8% (N?=?42). Male workers had significantly higher risk than female workers (odds ratio [OR]?=?2.21). Workers aged older than 25 years had significantly higher risks for NIHL (OR?=?3.51–12.42) than workers younger than 25 years. Sawing workers had higher risk for NIHL than office workers (OR?=?3.07).     

Theoretical predictions and actual hearing threshold levels in workers exposed to ultrasonic noise of impulsive character--a pilot study.

Results of standard pure-tone audiometry (PTA) were collected from 25 workers, mainly females, aged 23-58 years, exposed for 2-13 years to ultrasonic noise emitted by ultrasonic welders. Hearing tests were completed by evaluation of exposure to ultrasonic noise. The subjects' actual audiometric hearing threshold levels (HTLs) were compared with theoretical predictions calculated according to ISO 1999:1990. In 60% of cases sound pressure levels in the 10-40 kHz 1/3-octave bands at workstands exceeded Polish exposure limits for ultrasonic noise. Our comparison of predicted and measured HTLs suggests that the ISO 1999:1990 method, intended for audible noise, might also make it possible to predict reliably permanent hearing loss (in the 2000-6000 Hz frequency range) after exposure to ultrasonic noise. No significant progress of hearing impairment (assessed using PTA) in the operators of ultrasonic welders was noted. Nevertheless, further studies on the hearing status of workers exposed to ultrasonic noise are needed.     

职业噪声暴露测量方法探讨

噪声暴露是声压级与作用时间的综合结果。出于对听力保护的目的,积极推行声暴露的测量方法十分必要。本文通过对等效连续A计权声级、噪声暴露量、噪声剂量的测量和换算提出了对现行标准的理解和应用。     

我国纺织噪声暴露现状及听力损失情况预测

通过对国内纺织业从业人员数量、工龄的统计和企业实地噪声情况的调查，借鉴ISO1999—1975（E）和其它相关方法预测我国纺织行业噪声暴露情况和从业人员的听力损失情况。经过预测，结果显示纺织从业人员暴露于85dB以下噪声的约有289．3万人，85～95dB约有381．2万人，高于95dB约有329．5万人；对于听力损失的预测，采用悲观和乐观法分别进行预测，结果表明约有100．57万人和21．61万人患有听力损失；结合实际调研情况对预测数据进行修正，结果表明目前我国纺织行业约有70．96万人患有听力损失。     

Exposure to impulse noise at an explosives company: a case study

Impulse noise encountered in workplaces is a threat to hearing. The aim of this study was to assess the occupational exposure to impulse noise produced by detonation of dynamite on the premises of an explosives company. Test points were located on the blast test area (inside and outside the bunker) and in work buildings across the site. Noise propagation measurement was performed during 130 blast tests at nine measurement points. At every point, at least 10 separate measurements of A-weighted equivalent sound pressure level (L_Aeq), maximum A-weighted sound pressure level (L_Amax) and C-weighted peak sound pressure level (L_Cpeak) were made. Noise recorded in the blast test area exceeded occupational exposure limits (OELs). Noise levels measured in buildings did not exceed OELs. Results of the survey showed that for 62% of respondents, impulse noise causes difficulties in performing work. The most commonly reported symptoms include headaches, nervousness and irritability.     

Experimental study on explosion characteristics of ethanol-gasoline blended fuels

In the present work, a series of experiments have been performed to analyze the explosion characteristics of ethanol-gasoline with various blended ratios (0%, 5%, 10%, 15%, 30%, 50%, 70%, 80%, and 100%). A vented rectangular vessel with a cross-section of 100 mm × 100 mm, 600 mm long and a 40 mm diameter vent on the top is used to carry out the experiments. The flame propagation is recorded by a phantom high-speed camera with 5000 fps, while the histories of the explosion overpressure are measured by two PCB pressure sensors and the explosion sound pressure level is obtained by a CRY sound sensor. The results indicate that the maximum overpressure and flame propagation speed increases linearly as the blended ratio increases when the initial volume of blended fuel is 1.0 mL; While the change of explosion overpressure and flame propagation speed shows a trend of decreasing at first and then increasing as the concentration increases to 1.8 mL. It is also found that the peak of the sound pressure level exceeds 100 dB under all tests, which would damage the human's hearing. What's more, relationships between explosion overpressure and sound pressure level are examined, and the change of the maximum overpressure can be reflected to some extent by the measurement of the maximum sound pressure level. The study is significant to reveal the essential characteristic of the explosion venting process of ethanol-gasoline under different initial blended ratios, and the results would help deepen the understanding of ethanol-gasoline blended fuels explosion and the assessment of the explosion hazardous.     

Application of Prevention through Design for hearing loss in the mining industry

INTRODUCTION: Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. METHOD: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work-related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. RESULTS: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are "designed out" early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet-by-design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education.     

某新建城市轨道交通高架车站噪声现状-站台部分

为研究新建城市轨道交通高架站台噪声现状及特点,以及站台工作人员的累积噪声暴露量,选取某线的ZFL站、GML站和HQ站进行了实地测量。从噪声级、频谱和进出站列车时间与声级关系几方面对测量结果进行了分析。结果显示,站台列车进站LAeq值为78dB(A),出站LAeq值为79dB(A)。无列车通过时背景噪声LAeq值（白天）为66~74dB(A)。倍频程频谱分析得出,站台列车进站出站噪声具有宽频带噪声特征。时间历程分析得出,站台列车进站和出站的平均时间是30s和29s。进站第13s达到最大值LAF max 78~89dB(A)。出站第15s达到最大值LAF max 82~90dB(A)。站台工作人员白班噪声暴露量为LAeq 73dB(A),夜班噪声暴露量为LAeq 72dB(A)。     

Workers’ exposure to electric fields during the task ‘maintenance of an operating device of circuit breaker from a service platform’ at 110-kV substations

The objective of the study was to investigate occupational exposure to electric fields during the task ‘maintenance of an operating device of circuit breaker from a service platform’ at 110-kV substations. The aim was also to compare the results to Directive 2013/35/EU. At 16 substations, 255 electric field measurements were performed. The highest mean value of the electric fields was 9.6?kV?m^?1. At 63% of substations the maximum values were over 10.0?kV?m^?1, and at 31% of the substations the 75th percentiles were over 10.0?kV?m^?1, which is the low action level (AL) according to Directive 2013/35/EU. All measured values were below the high AL (20.0?kV?m^?1). In the future, it is important to take into account that the measurements were only taken at Finnish 110-kV substations; therefore, it is not possible to generalize these results to other countries and different types of substations.     

电子工业脉冲噪声对工人健康影响的调查研究

对电子行业接触脉冲噪声的冲压工进行了调查，其脉冲噪声水平波动在１０２～１１２ｄＢ（八）之间（峰值），对作业工人听力已产生不同程度的损伤，心电图在中高工龄组有改变。还分析了脉冲噪声引起听力损失与暴露时间有密切关系。提出了进一步加强安全监督管理的对策。     

高海拔矿井风机气动噪声数值模拟及实验研究

为研究高海拔矿井风机气动噪声规律，建立小型轴流风机三维物理模型，利用CFD软件对环境气压分别为1，0.9，0.8，0.7，0.6及0.5 atm时的风机模型进行定常模拟、非定常模拟及噪声计算，并通过自主设计的压变实验装置对上述不同环境气压条件下风机转数分别为500，1 000，1 500和2 000 rpm时的风机噪声进行测试，分析风机叶片附近监测点噪声频谱曲线及压变环境风机噪声实验数据，结果表明:风机转数和环境气压是影响风机气动噪声的2个重要因素；环境气压P一定时，风机转数n越大，各频率下的风机气动噪声声压级SPL越大，且风机噪声总声压级Lp和平均声压级Lavg均随风机转数n的增大呈对数函数增加；风机转数n不变时，随着海拔高度的升高，环境气压P降低，各频段下风机气动噪声声压级SPL均将减小，且风机噪声总声压级Lp和平均声压级Lavg随环境气压值P的降低呈线性函数减小，环境气压每降低0.1 atm，二者分别降低1.47和1.29 dB。     

Noise Control Strategies for Occupational Safety and Better Working Environments

Hearing impairment in humans due to occupational noise exposure is one of the significant occupational diseases in many countries. The equipment to measure noise levels and daily noise exposure in existing noisy environments is readily available and can be used to assess the risk of hearing damage. This article examines the currently legislated hearing damage risk criterion and compares the two main noise level-time trade-off schemes being used. The engineering methods for controlling excessive noise levels and techniques to either bring them below the hearing damage risk threshold or to within an acceptable range for the workplace requirement are discussed, together with the expected improvements by such measures.     

Noise and neurotoxic chemical exposure relationship to workplace traumatic injuries: A review

IntroductionMore than 5,000 fatalities and eight million injuries occurred in the workplace in 2007 at a cost of $6 billion and $186 billion, respectively. Neurotoxic chemicals are known to affect central nervous system functions among workers, which include balance and hearing disorders. However, it is not known if there is an association between exposure to noise and solvents and acute injuries. Method: A thorough review was conducted of the literature on the relationship between noise or solvent exposures and hearing loss with various health outcomes. Results: The search resulted in 41 studies. Health outcomes included: hearing loss, workplace injuries, absence from work due to sickness, fatalities, hospital admissions due to workplace accidents, traffic accidents, hypertension, balance, slip, trips, or falls, cognitive measures, or disability retirement. Important covariates in these studies were age of employee, type of industry or occupation, or length of employment. Discussion: Most authors that evaluated noise exposure concluded that higher exposure to noise resulted in more of the chosen health effect but the relationship is not well understood. Studies that evaluated hearing loss found that hearing loss was related to occupational injury, disability retirement, or traffic accidents. Studies that assessed both noise exposure and hearing loss as risk factors for occupational injuries reported that hearing loss was related to occupational injuries as much or more than noise exposure. Evidence suggests that solvent exposure is likely to be related to accidents or other health consequences such balance disorders. Conclusions: Many authors reported that noise exposures and hearing loss, respectively, are likely to be related to occupational accidents. Practical applications: The potential significance of the study is that findings could be used by managers to reduce injuries and the costs associated with those injures.     

某大型机加车间数控机床减噪工程测试与分析研究

为研究大型机加车间噪声减噪工程现状效果和特点,选取某大型机加车间数控机床为研究对象,对其进行减噪工程治理,现场实测了治理前和治理后的噪声数据,并对噪声测量结果进行分析。研究结果表明:数控机床操作人员8 h连续等效A声级从治理前的89.2 dB(A),降到治理后的74.3 dB(A),降低了16.7%.;数控机床操作岗位位置测点,在加工1个机件的测量时间段里,噪声值从治理前的85.9 dB(A),降到治理后的55.1 dB(A),降低了33.85%;对机加车间现场布置了67个测点,在加工1个机件的测量时间段里进行测量,得到该车间噪声治理前和治理后噪声分布图;对数控机床减噪工程治理前和治理后的频谱进行了分析,得出治理前和治理后各自的最大声级所在频段不随距离的改变而改变,高频减噪效果显著。     

电子封装行业化学有害因素职业暴露评价

以法规及风险评价模型为基础,对电子封装行业内通常使用的化学有害因素进行职业暴露分析,将健康风险进行分级、定量评价,得出结论:行业中回流焊工艺可能产生的铅烟、电镀车间存在的硝酸、失效分析中使用的氢氟酸等,其职业暴露风险为中等风险水平;但由于化学物质的健康危害等级HR因其固有性而相对不变,而其会随控制措施的效果高低而变化的暴露等级ER是一个可变的要素,不同企业的控制措施的水平高低不同,其最终的风险等级可能是不同的。行业中使用的氢氧化钾、氢氧化钠的职业暴露风险为低风险水平,前提也是在合理有效的控制措施环境下。因此,控制措施的水平就是决定风险等级的最重要因素。时时地运行和维护有效的控制措施,是确保风险水平不发生变化的关键。     

Assessment of the living and workplace health and safety conditions of site-resident construction workers in Tehran,Iran

Objectives. The purpose of this study was to assess living and workplace safety conditions of construction workers in Tehran, Iran. Methods. This cross-sectional study was conducted among 410 construction sites in a municipal area of Tehran whose municipal building permits were issued in 2011. Data on ventilation, workplace safety and hygiene were collected by direct observation and interviews with site foremen. Noise levels were estimated from 10 sound-level-meter stations in the municipality area. Results. Lack of ventilation in the workers’ rooms was abundant. Bathrooms were unhygienic and minimum requirements such as lighting and ventilation did not exist in 80% of the cases. In nearly 50% of large construction sites, sewage and garbage disposal were inappropriate. Elevator safety was poor at all sites and no measures for fall prevention were present in over 88% of active construction sites. This study showed that the mean 24-h equivalent continuous sound level L_eq was over 70?dB in 80% of the sites during weekdays. Conclusions. The results of this study revealed poor health and safety living and working conditions of construction workers in Tehran.     

A study in hospital noise - a case from Taiwan.

Hospitals are places that allow patients to rest and recover, and therefore must be quiet inside and in the surrounding neighborhood. One medical center was chosen as a sample hospital. This hospital was a tertiary care center during the 2003 outbreak of the severe acute respiratory syndrome (SARS) in Taiwan. The measurement results show that the noise level in the wards and stations was between 50.3 and 68.1 dB which exceeded the suggested hospital ward sound level. The quietest units were the Surgical Intensive Care Unit and recovery rooms with a noise level lower than 50 dB during the night. The higher noise levels were in the hall and pharmacy which were highly populated areas. This study analyzed the causes of this excessive noise and used noise reduction methods. The paired t test was performed and the results showed improvement methods were successful. This study found the noise levels reached 98.5-107.5 dB in power generator rooms and air-conditioning facilities, and suggests employees use ear plugs.