职业噪声暴露对作业工人听力损失的影响及机制探讨

多年来,职业噪声暴露导致听力损失一直是职业医学和公共卫生讨论和研究的重点课题,国内外专家学者从不同角度探讨并报道其损伤靶器官、影响因素及预防措施,采取各种方法(包括动物实验和人群流行病学调查)对发病机制和治疗手段进行论证并提出假说,现综述如下.1职业噪声暴露致听力损失1.1职业噪声人群听力损失检出率:噪声对听觉器官产生听力损失,已得到广泛认同:从不同行业各种文献报道统计,职业噪声暴露所致听力损失率均＞25％.其中,钢铁行业[1]听力损失率最高,均＞60％,其前景不容乐观.1.2职业噪声人群听力损失特点:(1)噪声强度越高,听力损伤越严重,所致永久性听阈位移及暂时性听力损失也越严重,这已为国内外学者所公认.(2)噪声听力损失随工龄的增加而增加,有学者在工业噪声作业人员听力损失情况的调查中发现,将所有噪声作业人员按工龄分为3个组,工龄＞10年的听损检出率为20.4％,10～20年的为34.8％,20年以上的为43.2％,且各工龄组间差异有高度显著性,即随着工龄的增加,高频听力损失的检出率明显增高.考虑接触噪声时间越长,接触噪声机会越多,噪声累积暴露量也增多,对听觉系统的损伤加重.(3)噪声性耳聋患者重度聋和全聋的较少,原因可能是随着接触噪声的工龄增加,听力损伤加重,听阈提高.听阈提高后对噪声的敏感性降低,表现为永久性听阈位移值降低,是机体的一种保护性反应[2].     

某陶瓷厂噪声作业工人听力损失的调查分析

目的 研究陶瓷厂噪声对作业人员听力的影响.方法 采用丹麦GST-68型纯音听力计,测定82例接触噪声工人(噪声组)和48例非接触噪声工人(对照组)的听力.结果 测定18个噪声点,噪声强度平均(85.7±6.6)dB(A)[71.4～95.2 dB(A)],其中有15个点超标,超标率88.3％.噪声组听力损失检出率51.22％,明显高于对照组(10.42％),差异有极显著性(P＜0.01).接触噪声工龄＜3年、3～5年、＞6年组听力损失检出率分别为16.67％、77.14％和81.82％,听力损失检出率随接触噪声工龄的增加而升高,差异有极显著性(P＜0.01).结论 陶瓷企业噪声引起作业工人听力损失,应做好预防工作.     

男性噪声作业工人血糖水平与职业性噪声性听力损失的关系研究

目的 探讨男性噪声作业工人血糖水平与职业性噪声性听力损失(noise-induced hearing loss, NIHL)之间的关系。方法 收集某汽车制造企业在岗工人的体检资料,以工龄≥1年的男性噪声作业人员为研究对象,将研究对象分为听力正常组、听力损失组、高频听力损失组和高频伴语频听力损失组,采用logistic回归模型分析研究对象NIHL的影响因素以及高血糖与NIHL之间的关系。结果 在2735名噪声作业工人中发生听力损失993人(36.3%),其中包括高频听力损失929人(34.0%)和高频伴语频听力损失64人(2.3%)。随着年龄增长,噪声作业工人听力损失检出率、高频听力损失检出率和高频伴语频听力损失检出率均呈上升趋势(χ_趋势²=146.563、120.397、49.340,P<0.05);随着工龄增长,噪声作业工人听力损失检出率、高频听力损失检出率均呈上升趋势(χ_趋势²=57.447、60.167,P<0.05)。饮酒是噪声作业工人听力损失、高频听力损失的危险因素(P<...     

120例噪声作业工人听力调查

为了解噪声作业对工作身体健康危害情况，我们对１２０名从事噪声作业工人定期进行体验结果体验，结果分的如下：１ 对象与方法１．１ 调查对象：某石化公司炼油厂从事噪声作业工人１２０名，其中女１６人，男１０４人。年龄２５～５２岁，平均４０岁。接触噪声工龄５～３２年，平均１９年。根据各车间噪声强度不同分成五组：Ａ组２６人（加氢车间），Ｂ组２４人（排水车间），Ｃ组３１人（催化车间），Ｄ组３７人（油品车间）。１．２ 方法；１．２．１ 对作业环境进行现场劳动卫生学调查使用美国ＦＡ－１８听力检测仪。检查时注意以下两点…     

某钢铁公司轧钢工人噪声暴露与听力损失的调查

<正>噪声是影响范围很广的一种生产性有害因素,随着现代工业生产的不断发展,噪声污染日益加重。听觉系统损伤是噪声对机体产生的最主要危害,也是一种特异性危害[1]。由此     

某纺织厂噪声作业工人听力损失与工龄、累积噪声暴露量关系的调查

目的调查某纺织厂噪声作业工人的听力损失与稳态噪声暴露、工龄和累积噪声暴露量的关系。方法采用横断面研究方法,于2010年2月～2011年1月对某纺织厂60名暴露职业噪声超过1年的工人进行调查,测量他们工作环境的噪声水平,调查他们的年龄、性别、工作年限、平均每天噪声工作时间、每周工作天数,并计算累积噪声暴露时间,同时测量他们的听力水平。结果对工作环境测定的14个点的噪声强度均超过国家标准。60名作业工人听力损失的检出率为28.33%,听力损失检出率随工龄的增加呈显著上升趋势（P=0.043）,听力损失的检出率（P=0.021）以及损伤程度（P=0.013）均与累积噪声暴露量呈显著正关联。结论纺织厂工人长期暴露职业噪声可导致听力损失,提示应加强纺织厂工作环境噪声的控制,促进工人的听力健康。     

哈尔滨市某液化气厂接触噪声工人听力损伤情况调查分析

噪声作为一种常见职业危害因素，其危害作用于多系统，如神经系统、循环系统、生殖系统等。但是噪声对人体的影响最直接、最严重的表现仍为听力的损伤。为更加详细了解噪声对听力影响的情况，特对哈尔滨市某液化汽厂工人进行劳动卫生学调查分析，其结果如下。     

挖泥船作业噪声对工人听力影响的调查

噪声是生产环境中一种严重的有害因素 ,其主要危害是造成接触者听力的损伤 .为了解挖泥船作业噪声对工人听力的影响 ,加强个人防护 ,我们对郑州市黄河游览区挖泥船作业者进行了职业卫生学调查 ,现报告如下 :1　对象及方法1 1　对象　选择挖泥船上工作人员 32人为调查对象 ,噪声暴露史为 1～ 2 0年 ,年龄为 2 2～ 5 7岁 ,且无影响听力的服药、疾病史 ,以及其他非噪声致聋因素。1 2　调查方法1 2 1　噪声强度的测度　噪声根据WS/T6 9— 1996《作业场所噪声测量规范》 ,用ND2型精密声级计现场测定 (ND2型精密声级计 2 0 0 2年 3月经中国计…     

某纺织厂噪声作业工人心电图改变调查分析

为了解噪声作业对工人心电图的影响 ,我们对某纺织厂接触噪声作业的 2 2 6名工人做心电图检查 ,现将结果报告如下。1　对象与方法1.1　对象 :某纺织厂接触噪声作业工龄 1a以上 ,年龄 2 0～ 4 0岁的 2 2 6名 (男性 38名 ,女性 188名 )工人 (接触组 ) ,平均年龄 30岁 ,平均工龄 7     

探讨噪声性耳聋及防护措施研究

目的探讨噪声强度及工龄对工人听力所产生的危害及其防护措施。方法选择100名噪声环境下作业工人对其进行职业流行学调查,另将100名不接触噪声作业后勤及行政人员为对照组,在隔音室内检查其双耳的纯音听力。结果工人听力的损伤与噪声强度和工龄的增加而成正比例的增长,同时以高频听力损伤为主。结论目前噪声性耳聋还没有特别有效的治疗方法,应以防护为主。     

Influence of age on noise- and styrene-induced hearing loss in the Long-Evans rat

This paper reviews different investigations carried out with Long–Evans rats on the influence of age on the ototoxicity induced by styrene and on the vulnerability to noise. The first part of this article is focused on the differences in auditory susceptibility to noise (92 or 97 dB octave band noise centered at 8 kHz, 6 h/day, 5 days/week, 4 weeks) and styrene (700 ppm, 6 h/d, 5 d/w, 4 w) between young (three and half months) and old (24 months) Long–Evans rats. Auditory evoked potential measures revealed that the old rats tend to be more sensitive than young rats to higher noise levels (97 dB), but equally vulnerable to moderate levels (92 dB). By contrast, the aged rats were virtually insensitive to 700 ppm styrene compared to the young animals.

Two additional studies were performed controlling and examining the influence of body weight and post-natal age on the sensitivity to styrene. Rats of the same age (21 weeks) and but having different body weight (310 g versus 410 g) did not show any difference of sensitivity to 700 ppm styrene, whereas 14-week-old rats with the same body weight as 21-week-old rats (350 g) revealed increased sensitivity to styrene. These results show that weight does not play a key role in the sensitivity to styrene, and suggest a long period of increased sensitivity to styrene during the first months of life.     

茂名市噪声作业工人听力损伤状况调查研究

目的了解茂名市石油公司化工分部噪声作业对工人听力水平的影响,为采取防护措施提供依据。方法对现场作业进行噪声测试,对工人进行听力损伤测试。结果噪声作业工人的听力损伤率均随累积接触噪声工龄的增加而升高,1年～组,5年～组、10年～组、20年～组、30～35年组发病率分别为27．2％、36．3％、56．3％、52-3％、18．2％,呈明显的剂量一反应关系（P〈0．01）。重度听力损伤随着工龄的增加而加重（P〈0．05）。结论茂名市石油公司化工分部的高强度噪声对作业工人听觉系统有明显的损害。     

Acrylonitrile potentiates hearing loss and cochlear damage induced by moderate noise exposure in rats

The diversity of chemical and drugs that can potentiate noise-induced hearing loss (NIHL) has impeded efforts to predict such interactions. We have hypothesized that chemical contaminants that disrupt intrinsic antioxidant defenses hold significant risk for potentiating NIHL. If this is true, then acrylonitrile (ACN) would be expected to potentiate NIHL. ACN, one of the 50 most commonly used chemicals in the United States, is metabolized via two pathways that are likely to disrupt intrinsic reactive oxygen species (ROS) buffering systems: (1) it conjugates glutathione, depleting this important antioxidant rapidly; (2) a second pathway involves the formation of cyanide, which can inhibit superoxide dismutase. We hypothesized that moderate noise exposure, that does not produce permanent hearing loss by itself, could initiate oxidative stress and that ACN could render the inner ear more sensitive to noise by disrupting intrinsic antioxidant defenses. Temporary and persistent effects of ACN alone (50 mg/kg, sc 5 days), noise alone (95 or 97 dB octave band noise, 4 h/day for 5 days), or ACN in combination with noise were determined using distortion product otoacoustic emissions (DPOAEs) and compound action potential (CAP) amplitudes. Histopathological damage to hair cells resulting from these treatments was also investigated using surface preparations of the organ of Corti. Individually, neither ACN nor noise exposures caused any permanent hearing or hair cell loss; only a reversible temporary threshold shift was measured in noise-exposed animals. However, when given in combination, ACN and noise induced permanent threshold shifts (13-16 dB between 7 and 40 kHz) and a decrease in DPOAE amplitudes (up to 25 dB at 19 kHz), as well as significant outer hair cell (OHC) loss (up to 20% in the first row between 13 and 47 kHz). This investigation demonstrates that ACN can potentiate NIHL at noise levels that are realistic in terms of human exposure, and that the OHCs are the main target of toxicity. While the exact mechanism is unknown, the results are consistent with the hypothesis of ROS involvement in NIHL at moderate levels.     

某棉纺厂噪声作业工人听力的调查

目的研究棉纺厂中高强度噪声对作业人员听力的影响。方法对茂名市某棉纺厂工作场所进行卫生学调查及对195名接触噪声工作人员的听力进行分析,并与108名对照组人员进行比较。结果作业场所共检测110个噪声点,噪声强度为80．1～96．0（85．3±2．6）dB（A）,其中有42个点超过同家标准,超标率为38．2％,作业人员听力损失为26．2％,明显高于对照组的5．6％（P〈0．01）,并且听力损伤随接触噪声工龄的增加而增加。结论棉纺厂作业人员在该作业环境下工作,听力有明显损失。     

头面部外伤导致听力损失的临床分析

目的：分析头面部外伤所致听力损害的临床特点及其可能的因果关系。方法：通过对头面部遭受外力（包括气压和声压）作用后有听力下降的781例（793耳）病例进行临床分析。结果：感音神经性聋343例（43．9％）,传导性耳聋134例（17．2％）,混合性聋247例（31．6％）,正常57例（7．3％）。其中轻度听力下降201例（25．7％）,中度听力下降352例（45．1％）,中重度听力下降208例（26．6％）,重度听力下降16例（2．1％）,极重度听力下降4例（0．5％）。结论：头面部外伤引起的听力下降可表现为各种类型及不同程度,并与受伤原因及部位存在直接或间接的因果关系。     

Using zebrafish as a model to study the role of epigenetics in hearing loss

Introduction: The rapid progress of bioinformatics and high-throughput screening techniques in recent years has led to the identification of many candidate genes and small-molecule drugs that have the potential to make significant contributions to our understanding of the developmental and pathological processes of hearing, but it remains unclear how these genes and regulatory factors are coordinated. Increasing evidence suggests that epigenetic mechanisms are essential for establishing gene expression profiles and likely play an important role in the development of inner ear and in the pathology of hearing-associated diseases. Zebrafish are a valuable and tractable in vivo model organism for monitoring changes in the epigenome and for identifying new epigenetic processes and drug molecules that can influence vertebrate development.

Areas covered: In this review, the authors focus on zebrafish as a model to summarize recent findings concerning the roles of epigenetics in the development, regeneration, and protection of hair cells.

Expert opinion: Using the zebrafish model in combination with high-throughput screening and genome-editing technologies to investigate the function of epigenetics in hearing is crucial to help us better understand the molecular and genetic mechanisms of auditory development and function. It will also contribute to the development of new strategies to restore hearing loss.