同一车间中冲压工和下料工个体噪声暴露的测量与评价

目的　测量和评价同一车间中冲压工和下料工的环境噪声水平和个体噪声暴露水平。方法　用声级计在工人工作位耳高度测量 1min等效声级 (LAeq·1min) ,用个体计量仪测量工人 8h个体噪声暴露的等效声级 (LAeq·8h)。结果　冲压机和剪板机分别安装在车间的不同区域 ,各设备间无隔声装置。冲压工和下料工的个体噪声暴露水平随时间而不断变化 ,有代表性的采样时间难以确定 ,而用个体计量仪收集LAeq·8h的噪声暴露数据稳定性较好。冲压工和下料工工作位的LAeq·1min均为 (92 5± 2 1)dB(A) ,个体噪声暴露水平LAeq·8h分别为 (95 3± 2 5)dB(A)和 (95 2± 3 5)dB(A) ,LAeq·8h的测定数值高于LAeq·1min2 7～ 2 8dB(A) ,P <0 0 1。结论　在同一车间工作的冲压工和下料工的工作环境噪声水平相似、个体噪声暴露水平相似 ,个体噪声暴露水平明显高于环境噪声的测量数值。个体噪声暴露的测量更适合于类似复杂噪声环境中工作人员的噪声暴露评价     

纺织厂挡车工个体噪声暴露测量的评价

目的比较个体计量仪与声级计评价挡车工噪声暴露的异同。方法用个体计量仪采集一工作日内挡车工的噪声暴露动态资料并将数据传输至微机存储和分析。选择前纺、细纱、布机车间使用不同类型机器的6组挡车工作为观察对象,每组3～5人,分别在早、中、晚班各测量1个班次的个体噪声暴露数据。同时采用网格法和普通声级计测量噪声水平。结果个体计量仪测定结果显示,挡车工在一个工作日内噪声暴露的水平是稳定的：对同一组档车工的测量结果表明,挡车工个体间噪声暴露水平的变异大于不同工作日之间的变异。个体计量仪测量的噪声暴露水平等于或高于声级计测量的结果,最大可达4．6dB（A）。结论噪声个体计量仪可以连续动态记录挡车工的实际噪声暴露,其结果高于或等于声级计定点测量结果。在今后噪声暴露评价时应考虑采用这种测量方法。     

纺织厂工人个体噪声暴露测量数据的分布规律

目的观察纺织厂不同车间工人个体噪声暴露测量数据的分布规律。方法用SH-126记录式声级计测量工人8 h等效连续A声级(L_(Aeq·8h)),分层后观察各车间L(Aeq·8h)的分布特点,并计算L(Aeq·8h)的均数、几何均数、中位数、偏度和峰度,做Kolmogorov-Smirnov正态性检验。结果布机车间、细纱车间和前纺车间工人个体噪声暴露L(Aeq·8h)测量数据的构成均接近于正态分布,偏度小于±0．5,峰度为0．119～1．232,Kolmogorov-Smirnov正态性检验的P值均大于0．20,L(Aeq·8h)的均数、几何均数和中位数非常接近。结论纺织厂工人个体噪声暴露测量的数据基本符合正态分布。     

两类噪声作业工人个体噪声暴露特点的观察

[目的]观察和比较接触稳态噪声和非稳态噪声工人个体之间、工作日之间个体噪声暴露的特点和规律。[方法]应用噪声个体计量仪分别测量了4名细纱车间挡车工(稳态噪声)和4名机械加工车间工人(非稳态噪声)3个工作日(班次)的个体噪声暴露,用工作期间的8h等效声级(LAeq.8h)作为评价指标。[结果]两组工人个体噪声暴露的时间图显示其工作环境噪声性质分别为典型的稳态噪声和非稳态噪声。稳态噪声组12人次个体噪声暴露的LAeq.8h最大、最小值和差值分别为99.2、92.8和6.4dB(A);非稳态噪声组相应数值为89.9、83.1和6.8dB(A)。稳态噪声组每名工人3个班次个体噪声暴露均数的最大值和最小值为(98.0±1.1)、(94.3±1.5)dB(A),非稳态噪声组为(87.9±1.0)、(85.1±1.5)dB(A)。稳态噪声组4名工人每个班次个体噪声暴露均数的最大值和最小值为(96.6±1.9)、(95.8±2.0)dB(A),非稳态噪声组为(87.1±3.0)、(86.1±2.1)dB(A)。[结论]在接触稳态噪声和非稳态噪声的两组人群中,1名工人1次或多次个体噪声暴露测量结果不能准确评估该工人所在人群的噪声暴露水平,多名工人1次个体噪声暴露测量的平均值可以作为评估该组工人所在人群的噪声暴露水平的依据。     

噪声测量时点数量对8h等效声级估算误差影响的模拟研究

目的探讨噪声测量时点数量与工作日噪声暴露(LAeq. 8 h)评估准确性的关系。方法采用SH126型记录式声级计,在某纺织厂测量59个8 h工作班次的噪声水平,其中挡车班次25个、机修班次34个。对每一班次的测量均按10 min间隔顺序记录48个10 min等效连续A声级(LAeq.10 min)。为模拟日常工作中根据特定时点短时噪声测量结果估算LAeq.8 h的方法,应用区组随机抽样程序进行8轮抽样,分别从59组数据中抽取1、2、3、4、5、6、7、8个LAeq.10 min,根据抽样结果估算8个LAeq. 8 h。用估算LAeq.8 h与真实LAeq.8 h(根据全部48个LAeq.10 min计算得出)之差的绝对值反映LAeq.8 h估算误差,评价增加测量时点对LAeq估算误差的影响。结果挡车工、机修工噪声暴露方式明显不同,前者为典型稳态噪声暴露,而后者表现为非稳态噪声暴露。当测量时点为1时,挡车工暴露估算误差为(1.00±1.33)dB,而机修工为(8.62±11.90)dB。两类暴露LAeq.8 h估算误差均随测量时点增加而下降,在测量时点数达3~4个时,下降曲线逐渐平坦。测量时点数目相等时,机修工暴露估算误差均大于挡车工。结论按单一时点的测量结果估算非稳态噪声LAeq.8 h可能会导致较大误差,增加测量时点可减少估算误差。就稳态噪声暴露而言,增加测量时点去除LAeq.8 h估算误差的意义较小。     

两种测量方法评价稳态噪声暴露与高频听力损伤的剂量-反应关系

目的 比较环境噪声水平、个体噪声暴露和累积噪声暴露量评价稳 态噪声所致听力损伤剂量－反应关系的优劣。方法 用个体计量仪采集8小时工作期间挡车工的噪声暴露数据,并将数据传输至微机存储和分析。选择细砂、布机车间使用不同类型机器的4组工人作为观察对象,每组选择3－5人,分别在早、中、晚班各测量1个班次的个体噪声暴露数据;用网格法和普通声级计测量每组工人工作环境的噪声水平,同时对该纺织厂接触稳态噪声的163名工人进行了问卷和听力检查。结果 经年龄、性别校正后的高频听力损伤患病率为64．4％;语频听力损伤患病率为2．5％,其中高频听力损伤患病率随噪声暴露的剂量增大而升高,呈现典型的剂量－反应关系。经趋势卡方检验和和Logistic回归模型拟合,累积噪声暴露量评价剂量－反应关系的效果优于噪声级,个体噪声暴露的效果优于环境噪声水平。结论 个体噪声暴露和累积噪声暴露量是评价稳态噪声暴露与高频听力损伤剂量－反应关系最好的暴露评价指标。     

个体采样检测法评价某纺织厂挡车工职业病危害因素接触水平

目的 采用个体采样检测法评价某纺织厂挡车工职业病危害因素接触水平,分析比较噪声定点检测计算岗位工人的8h等效连续A声级与个体检测结果.方法 按国家规定的测量方法要求对调查对象进行粉尘与噪声个体采样检测,并选择粗纱、细纱、络筒和布机4个工种,每个工种抽取3名工人在进行个体噪声检测,据其巡回操作范围按照区域布点法进行定点...     

非稳态噪声工作场所噪声暴露测量与评价

[目的]测量和评价非稳态噪声工作场所的8h等效连续A声级（LAeq.8h）、1min等效连续A声级（LAeq.8h）和全天等效声级估算值（LAeq.8h）。[方法]采用个人声暴露计测量LAeq.8h,用声级计测量LAeq.8h。和每个时间段的噪声值,计算出全天的等效声级（LAeq.8h）。应用LAeq.8h和LAeq.8h、LAeq.8T分别测量某输油管道加工厂和某家用电器制造厂239名工人的个体噪声（接触）和相应作业场所噪声（暴露）水平。[结果]两家工厂LAeq.8h均值分别为（89．7±3.8）dB（A）和（90．5±5．7）dB（A）,分别高于LAeqT的（88．0±2．4）dB（A）和（89．2±3．6）dB（A）（P〈O．05或P〈0．01）。与LAeq.8h相比,LAeq.1min采样时间点存在抽样误差。绝大多数工作岗位的LAeq.1min与LAeq.8h均值差大于3dB（A）,所有工作岗位的LAeq.8T均值与LAeq.8h均值差均小于3．0dB（A）。[结论]LAeq.8h能反映在非稳态噪声工作场所工人实际接触噪声暴露水平,LAeq.T比较符合作业工人实际噪声接触水平LAeq.1min。会低估或高估工人噪声暴露水平。     

轧钢作业噪声个体采样与定点采样结果对比

为准确评估轧钢作业噪声暴露水平,采用个体采样和定点采样两种测试方法对轧钢作业某些接触非稳态噪声的工种进行测量,并对结果进行对比。采用NoiseproDLX个体噪声剂量计和HS5671A积分声级计对白班(8:00~16:00)工人进行个体和定点分时段采样,并计算8 h等效A声级。结果显示,轧钢作业噪声主要是非稳态噪声,5个观察对象定点采样计算8 h等效A声级>85 dB(A),而个体噪声暴露水平<85 dB(A)。提示,对于轧钢作业非稳态噪声的测量,采用个体噪声剂量计测量更真实、可靠,特别是测量结果接近国家职业接触限值或工人作业地点轮换频繁时,更能准确评估轧钢作业噪声暴露水平。     

冷轧厂工人个体噪声暴露测量的初步分析

目的采用个体噪声暴露测量方法,了解冷轧厂工人噪声暴露的水平和特点,为防治轧钢工的噪声职业危害提供基础数据。方法以轧钢厂4个主要工艺中的11个工种为分组单位,每组抽取3～5人,用SH-126记录式个体声剂量计对白班（8：00至16：00）工人进行个体噪声暴露测量,同时填写工时记录,计算8h等效A声级。结果轧钢厂现场复杂,噪声源数量多、不稳定,工人同时受到多个噪声源的影响,个体噪声暴露声压级波动大。53名工人中个体噪声暴露最大值为100．0dB（A）。最小值为81．2dB（A）;噪声暴露水平最高的头部焊工为94．20dB（A）,最低的纵切剪切工为89．02dB（A）;质量枪验工组内极差最大,为16．3dB（A）;轧机主操作上极差最小,为2．3dB（A）。提示采取个体噪声暴露测量方法能比较准确、完整地反映冷轧厂作业工人的复杂噪声暴露情况。结论冷轧厂个体噪声暴露均超过85dB（A）,应加强噪声防护。个体噪声剂量计是以工人为主体,反映个体的噪声暴露情况和接触水平。     

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。     

Confidence intervals for the mean of sound exposure levels

This text transposes standard statistical estimators of the mean and its confidence intervals to the field of occupational noise exposure, assuming that the samples are independent and lognormally distributed. The hypothesis of lognormality is applied to the values of A-weighted sound exposure as defined in ISO 1999 and expressed in Pa(2).h, which is equivalent to the currently accepted hypothesis of normality applied to the values of equivalent continuous A-weighted sound pressure level L(Aeq,T) expressed in dB(A). By expressing the initial data and results in dB(A), the text provides an unbiased estimator of the mean sound exposure level and tables of confidence intervals according to the sample size n and the standard deviation S(L) of the L(Aeq,T) measured values. The values of the following confidence intervals are given: exact one-sided upper and lower 95 and 97.5% confidence intervals and exact two-sided symmetrical 95% confidence interval. These results are compared with the approximate two-sided symmetrical 95% confidence interval proposed in standard, ISO 9612. This comparison demonstrates that the use of the approximate confidence interval can markedly underestimate the upper limit of the confidence interval when n is small and if S(L) is above 3 dB(A).     

Assessment of telephone operators' exposure to sound through headphones

We estimated the level of noise that telephone operators were exposed to through headphones by a two-step method using an artificial ear technique and a manikin technique. In the artificial ear technique, the sound pressure level (Leq) of the total work hours was 81.5 dB, whereas the Leq of the total duration of phone calls was 89.3 dB. Therefore, we conducted a more accurate measurement by the manikin technique (ISO11904-2). By this method, we could simulate the headphone-wearing condition of the workers and convert the measurements to a diffuse-field related L(Aeq). By this manikin technique, the corrected L(Aeq) of the total work hours was 68.3 dB, whereas the corrected L(Aeq) of the total duration of call was 76.6 dB, which was below the standard of the Occupational Exposure Limits of the Japan Society of Occupational Health. We confirmed that in a workplace where the background noise is low (51.3 dBA), a good signal-noise ratio is maintained so that operators don't have to listen to loud sounds through headphones. Neither the gender nor the type of the telephone equipment of the callers affected the sound pressure levels.     

地铁站勤务人员个体噪声暴露的监测与分析

目的 采用个体噪声暴露测量方法,了解地铁站勤务人员噪声暴露的水平和特点,为地铁站勤务人员的噪声职业危害控制提供依据。方法 以城市地铁某线路6个站点的4类岗位勤务人员为对象,用记录式噪声个体计量仪对地铁运行时间段内各岗位勤务人员进行个体噪声暴露测量。结果 城市地铁站的现场复杂,噪声源数量多、不稳定。在受检的48名勤务人员中,车站机房岗位的工作班内加权平均等效A声级（LAeq）水平最高为（81．8±2．5）dB（A）,车站控制岗位班内加权平均LAeq最低为（68．7±1．8）dB（A）;车站厅巡岗位班内加权平均LAeq水平极差最大为8．1dB（A）,车站控制岗位班内加权平均IAeq水平极差最小为4．0dB（A）。结论 地铁站勤务人员个体噪声暴露极不均一,用个体噪声暴露测量方法能较灵敏、完整地反映地铁站勤务人员的复杂噪声暴露状况。     

Saliva Cortisol and Exposure to Aircraft Noise in Six European Countries

Background

Several studies show an association between exposure to aircraft or road traffic noise and cardiovascular effects, which may be mediated by a noise-induced release of stress hormones.

Objective

Our objective was to assess saliva cortisol concentration in relation to exposure to aircraft noise.

Method

A multicenter cross-sectional study, HYENA (Hypertension and Exposure to Noise near Airports), comprising 4,861 persons was carried out in six European countries. In a subgroup of 439 study participants, selected to enhance the contrast in exposure to aircraft noise, saliva cortisol was assessed three times (morning, lunch, and evening) during 1 day.

Results

We observed an elevation of 6.07 nmol/L [95% confidence interval (CI), 2.32–9.81 nmol/L] in morning saliva cortisol level in women exposed to aircraft noise at an average 24-hr sound level (L_Aeq,24h) > 60 dB, compared with women exposed to L_Aeq,24h ≤ 50 dB, corresponding to an increase of 34%. Employment status appeared to modify the response. We found no association between noise exposure and saliva cortisol levels in men.

Conclusions

Our results suggest that exposure to aircraft noise increases morning saliva cortisol levels in women, which could be of relevance for noise-related cardiovascular effects.     

Association between Ambient Noise Exposure and School Performance of Children Living in An Urban Area: A Cross-Sectional Population-Based Study

Most of the studies investigating the effects of the external noise on children’s school performance have concerned pupils in schools exposed to high levels due to aircraft or freeway traffic noise. However, little is known about the consequences of the chronic ambient noise exposure at a level commonly encountered in residential urban areas. This study aimed to assess the relationship between the school performance of 8- to 9-year-old-children living in an urban environment and their chronic ambient noise exposure at home and at school. The children’s school performances on the national standardized assessment test in French and mathematics were compared with the environmental noise levels. Children’s exposure to ambient noise was calculated in front of their bedrooms (L_den) and schools (L_Aeq,day) using noise prediction modeling. Questionnaires were distributed to the families to collect potential confounding factors. Among the 746 respondent children, 586 were included in multilevel analyses. On average, the L_Aeq,day at school was 51.5 dB (SD= 4.5 dB; range = 38–58 dB) and the outdoor L_den at home was 56.4 dB (SD= 4.4 dB; range = 44–69 dB). L_Aeq,day at school was associated with impaired mathematics score (p = 0.02) or impaired French score (p = 0.01). For a + 10 dB gap, the French and mathematics scores were on average lower by about 5.5 points. L_den at home was significantly associated with impaired French performance when considered alone (p < 10⁻³) and was borderline significant when the combined home-school exposure was considered (p = 0.06). The magnitude of the observed effect on school performance may appear modest, but should be considered in light of the number of people who are potentially chronically exposed to similar environmental noise levels.     

Cinemas - do they pose a risk to hearing?

Noise measurements were made in cinemas during the showing of four films, to establish whether the noise levels from films might pose a risk of damage to hearing. The L(Aeq) levels for the full playing time of each film were all below 80 dB(A). Noise levels did sometimes exceed 90 dB(A) but this was never for more than a total of two minutes, and was usually for only a few seconds. Repeat L(Aeq) levels for the same films were shown to vary by 3-4 dB across different cinemas. Based on this limited sample of films and cinemas, there is no evidence that sound levels in cinemas cause permanent damage to hearing.     

应用纯音测听诊断职业性噪声聋的可靠性和有效性

对6年以上工龄的青年织布女工108人(216耳)连续二次纯音测听的资料表明:第一次和第二次的听阈均值差除个别频率(8KHz左耳为3.5dB)外,其余各频率都在-0.3～0.5dB范围内;最大标准差于2KHz处为17.4dB,在3KHz和8KHz处分别为18.5dB、20.1dB。据此认为一次纯音测听的记录可作为职业性噪声聋诊断和评价听力损失程度的初步依据,必要时可用阻抗计测试镫骨肌反射阈和听觉脑干诱发反应测听以排除中耳疾患和非器质性聋。2例女工脱离噪声环境疗养2周,每隔一周复查听力一次,结果三次测听的语频均值出现21.7和13.3dB的差值,考虑系暂时性阈移的恢复。作者们对1980年卫生部门颁发的“噪声性聋调查方法”提出了改进意见。