次声对豚鼠心功能影响的研究

目的研究8Hz/120dB、16Hz/120dB次声间断暴露下对豚鼠心功能的影响。方法将72只豚鼠分为对照组及8Hz/120dB、16Hz/120dB2个次声实验组,每个实验组按暴露天数不同各设4个亚组:1d组、7d组、14d组、21d组,每亚组8只豚鼠。暴露后应用超声检测21项心功能指标,并观察心肺组织病理改变。结果 8Hz/120dB实验组与对照组比较各项心功能指标无显著差异(P0.05)。16Hz/120dB实验组左心室舒张期末内径(LVEDd)、左心室舒张期末容积(LVEDV)、左室射血分值(LVEF)、小轴缩短率(FS)、肺动脉瓣流速(PV)较对照组显著下降(P0.05),且均在第1d至第7d时显著降低(P0.05),第14d后恢复(P0.05);右心室Tei指数(RV-Tei)在第7d较对照组显著上升(P0.05),第14d恢复(P0.05)。16Hz实验组较8Hz实验组心肺病理损害明显。结论次声对豚鼠心功能及心肺的病理损害频率在16Hz较8Hz明显;次声对豚鼠心功能损害随时间出现动态变化;LVEDd、LVEDV、LVEF、FS、PV、RV-Tei可做为该暴露条件下心功能损害的评价指标。     

次声对小鼠肾上腺皮质束状带多边形细胞3-β羟甾脱氢酶和酸性磷酸酶的影响

目的研究次声对小鼠肾上腺皮质束状带多边形细胞酸性磷酸酶(acid phosphatase,ACP)、3-β羟甾脱氢酶(3-βhydroxysteroid dehydrogenase,3-βHSDH)的生物学效应。方法观察小鼠在频率8、16 Hz,不同声压级80、90、100、110、120、130 dB次声第1、7、14天暴露和停止暴露的14天后对肾上腺皮质束状带多边形细胞ACP、3-βHSDH的影响。结果单次1 h暴露,8 Hz组随声压级的升高,3-βHSDH活力增强,至130 dB时,出现酶活力异常降低,同时提示100 dB时出现多边形细胞损伤;16Hz组,80dB时小鼠3-βHSDH活力与对照组的差异无统计学意义(P>0.05),但已提示存在细胞损伤,100 dB时开始出现3-βHSDH活力增强,细胞损伤持续存在。持续次声暴露,8 Hz中、低声压级随暴露时间延长,3-βHSDH活力先增强后降低,高声压级时酶活力持续为低水平,中、高声压级均提示出现细胞损伤;16 Hz低声压级暴露表现同8 Hz低声压级,中、高声压级3-βHSDH活力持续降低,同时提示存在细胞损伤。8Hz、90 dB及130 dB次声连续暴露14 d后停止暴露,经14d间隔,多边形细胞表现为从有局部损伤迹象到有一定程度恢复,但原来暴露声压级越高,恢复程度越差。结论次声对小鼠肾上腺皮质束状带多边形细胞的生物学效应在一定作用强度范围内,可较明显地反映其频率作用特性;高强度、大剂量次声作用时,其特性常被严重的损伤效应所掩盖。脱离次声一段时间后,肾上腺皮质束状带的细胞有一定程度恢复,但原来暴露的声压级越高,恢复的程度越差。     

次声对动物生物效应的研究

本文报告了次声对动物生物效应的研究。实验结果显示小鼠或豚鼠暴露在8或16Hz,135dB次声时,引起小鼠肺脏不同程度充血、出血;豚鼠鼓膜出血、穿孔或听小骨局部脱位。Wistar大鼠暴露在8或16Hz,110～135dB 20分钟,其血浆或血清ACTH和皮质醇含量随压强增加而增加。其中大鼠暴露在8或16Hz,135或125dB组,其血浆或血清ACTH含量与对照组比较差异非常显著(P<0.01)和差异显著(P<0.05);同样大鼠暴露在8或16Hz,135dB组,其血清皮质醇含量与对照组比较也有非常显著性差异(P<0.01)。     

次声对大鼠肺组织损伤及肺氧合功能的影响

目的：观察次声对肺的损伤作用及对动物血氧分压（PaO2)和动脉血氧饱和度（SaO2)的影响。方法：将300只SD大鼠随机分为正常对照组和次声作用1次,3次,7次,14次,21次共6组,次声作用组置本校研制的次声压力舱内致伤,以8Hz和16Hz次声,声压级分别为90,100,110,120,130dB,每次作用2h,透射电镜下观察肺超微结构的改变,同时观察PaO2和SaO2的改变。结果：8Hz,90-110dB单次作用对肺部的超微结构基本无影响;8Hz,120-130dB作用后,肺组织形态学发生改变,而PaO2和SaO2无明显变化。16Hz,90dB的次声单次作用,即可引起肺组织的损伤,随着声压级的增大,肺组织的影响程度更为明显;8Hz,120,130dB和16Hz,90,130dB的次声多次作用后,PaO2和SaO2明显下降,与正常对照组相比,差异有显著性（P＜0．01）,在3次,7次组其形态学的变化表现最为明显,随着作用次数的增加,其损伤并未继续加重,表现出适应性反应。结论：肺损伤的最小阈值8Hz为120dB,16Hz为90dB。即在一定作用强度范围内,可较明显地反映其频率作用的特性,次声损伤阈值的累积作用证明细胞发生变化的性质和程度主要与次声作用的声压强度和时间（作用次数）有关。     

次声对生物中枢神经系统的影响

在自然界、生产和生活环境中存在着大量的次声源。随着工业、交通、环保运动及科学技术的发展和需要,次声对生物体特别是对人体的影响受到许多国家的重视,并进行了相关研究。但至今,对次声的生物学效应研究还不十分详细,其损伤作用的研究结果也不尽一致。现就次声对中枢神经系统的作用效应作一综述。一、次声的物理性质次声为频率10-4～20Ｈｚ的弹性波,是由各种物体振动产生的,通过各种介质的分子做稀疏或紧密的交替波向四周扩散传播,传播速度与可听声一样,其本质与可听声、超声没有不同,但在另一方面,由于其频率低,决定了它具有与可听声、…     

次声对豚鼠凝血功能的影响

目的 研究16 Hz、120 dB,16 Hz、125 dB次声暴露后豚鼠凝血功能的变化规律,探讨次声造成生物体循环系统损害的机制.方法 将豚鼠分为对照组及16 Hz、120 dB,16 Hz、125 dB 2个暴露组,每个暴露组均按暴露时间再分成1、7、14、21 d 4个时间亚组,每个亚组8只豚鼠.各个暴露亚组每日暴露1.5 h,分别连续暴露相应的天数后抽取血样测定凝血功能相关指标及血清中一氧化氮(NO)含量.结果 16 Hz、125 dB组凝血酶原时间(PT)、国际标准化比率(INR)分别为(31.16±3.05)s和2.53±1.21,较对照组[(21.36±0.10)s、1.65±0.07]明显延长,差异有统计学意义(P＜0.05);血清中NO含量[(88.304±52.601)μmol/L]较对照组[(30.943±26.864)μmol/L]明显升高,差异有统计学意义(P＜0.05).16 Hz、125 dB组暴露14 d时PT和INR较对照组明显延长,并持续至第21天.16 Hz、125 dB组暴露7 d时血清中NO含量较对照组明显升高,且第14天继续升高,差异均有统计学意义(P＜0.05),21天时有下降趋势.结论 16 Hz、125 dB次声暴露后豚鼠凝血功能减退,INR及PT可做为评价次声对凝血功能影响的指标.

Abstract：

Objective To study the change of the blood coagulation function of guinea pigs exposed to 16 Hz/120 dB, 16 Hz/125 dB infrasound and to explore the mechanism of circulation system damage.Methods Seventy-two guinea pigs were divided into 3 groups: the control group, the group exposed to 16 Hz/120 dB infrasound for 1.5 h a day and the group exposed to 16 Hz/125 dB infrasound for 1.5 h a day. Each exposure group was divided into 4 sub-groups (8 guinea pigs a sub-group) which were exposed to infrasound for 1, 7, 14 and 21 d, respectively. The coagulation function and serum nitric oxide (NO) were measured for control group and all sub-groups after exposure to infrasound. Results The prothrombin time (PT),international normalized ratio (INR) and serum NO of group exposed to 16 Hz/125 dB infrasound were (31.16±3.05) s, 2.53±1.21 and (88.304±52.601)μmol/L, respectively, which were significantly higher than those [(21.36±0.10) s, 1.65±0.07 and (30.943±26.864) μ mol[L] of control group (P＜0.05). PT and INR of sub-groups exposed to 16 Hz/125 dB infrasound for 14 and 21 d were significantly higher than those of control group. NO of sub-groups exposed to 16 Hz/125 dB infrasound for 1 week and 2 weeks were significantly higher than that of control group (P＜0.05), but NO of sub-group exposed to 16 Hz/125 dB infrasound for 3 weeks decreased slightly. Conclusion The blood coagulation function of guinea pigs exposed to 16 Hz/125 dB infrasound decreased, PT and INR may be used as the indexes to assess of blood coagulation function change induced by the infrasound exposure.     

电厂运行工身体健康状况调查

[目的]探讨电厂噪声对作业人员身体健康的影响.[方法]选择62名运行工为观察组,另选该厂非运行工声60名作业人员为对照组.检测两组作业人员环境噪声强度,观察组40 h的等效声级为84 dB(A),对照组为65dB(A).询问临床症状,测定心电图、血压、肝功、血常规、小便常规及作B超、胸片检查.[结果]两组作业环境噪声强度均未超过职业接触限值.观察组头晕头痛、失眠多梦、心悸胸闷、耳鸣、心电图异常率、ST-改变,血压偏高明显高于对照组(P＜0.01),其他指标两组间比较差异不明显(P＞0.05).[结论]结果提示在现场噪声强度未超过职业接触限值的情况下,作业人员的身体健康已受到一定影响,建议运行工在巡视时应佩戴防噪声用品,以保护身体健康.     

强电磁辐射对暴露人群健康的影响

目的 通过现场调查,探讨电磁辐射对某部队作业人群健康的影响,为该人群健康促进策略及措施的制定提供依据.方法 采用微波漏能仪测定作业环境的微波平均功率密度;以微波辐射强度为指示,监测该军事作业环境的电磁辐射强度;对观察人群进行常规体格检查;以作业环境暴露和作业任务为依据,分为暴露组(n=117)和非暴露组(n=123),对比分析2组人群的体检数据.结果 不同作业环境中微波平均功率密度为3.30～193.70μW/cm2,多数作业区微波强度超卫生标准2倍以上;在强电磁辐射暴露组健康查体指标中,心电图异常率为15.4％、血常规异常率为39.3％,均明显高于对照组(分别为5.7％和20.3％).结论 该军事作业环境电磁辐射较强,对作业人员身体健康已产生一定影响,应采取有效的防护措施.     

噪声对某部作业人员睡眠及焦虑影响

目的了解噪声对某部作业人员的睡眠及焦虑影响情况，为针对性地采取有效措施，改善其焦虑状态并提高其睡眠质量提供参考依据。方法对某部作业环境噪声强度进行实地检测，随机抽取某部75名作业人员和20名安保人员，利用焦虑心理测试量表和睡眠测试量表进行问卷调查。结果检测结果表明，作业区人员活动频繁场所的噪声可达77.9-113.3dB（A），峰值噪声最高可达137.0dB（A）。作业人员的焦虑状态与安保人员比较，差异有显著性（P〈0.05）。在存在焦虑的人员中，有69.7%存在睡眠障碍或睡眠质量下降；在睡眠异常的人员中，有76.7%存在特质焦虑或状态焦虑。结论 噪声环境可能会影响作业人员的心理状态和睡眠质量，应设法采取有效措施进行干预。     

长期接触中低强度噪声对作业人员心电图及听力的影响

目的探讨中低强度高频噪声对作业人员心电图及听力的影响。方法对某石油化工公司炼油车间作业环境进行卫生学调查及对249名接触噪声人员的心电图及听力进行分析,并与92名对照组进行比较。结果作业现场共测95个噪声点,噪声强度为53.6～98.0(81.7±5.8)dB(A),其中有15个点超过国家卫生标准,超标率为15.8%;作业组人员心电图总异常率为28.1%,明显高于对照组的16.3%(P<0.05),尤其是窦性心律不齐较明显(11.6%);作业人员的听力损失为18.9%,明显高于对照组的7.6%(P<0.01);其损害程度随着工龄的增加而增加,特别是工龄在15年以上的更明显。结论作业人员长期在平均噪声强度低于卫生标准下工作,仍可有一定程度的心电图改变和听力损失。     

Effects of infrasound on gastric mucosal blood flow in rats

To clarify the effects of infrasound on gastric mucosal blood flow, rats were exposed to infrasound for 20 minutes. The sounds were pure tones of 8, 16 and 32 Hz, at sound levels ranging from 80 dB to 130 dB. Gastric mucosal blood flow was determined by the inhaled hydrogen gas clearance method. Norepinephrine and epinephrine concentrations in the plasma were also measured. The exposed rats showed decreased gastric mucosal blood flow with increasing sound levels of infrasound at each octave-band frequency. To significantly decrease the gastric mucosal blood flow, infrasound at 32, 16 and 8 Hz needed sound levels of 100, 110 and 130 dB, respectively. These findings suggest that, as the frequency of infrasound decreases, an increased sound level is necessary to decrease the gastric mucosal blood flow. The norepinephrine and epinephrine concentrations in the plasma were 0.65±0.47n.g/ml and 0.35±0.43 ng/ml, respectively, in the control rats, while the corresponding values were 0.91±0.87 ng/ml and 0.74±0.81 ng/ml, respectively, in the exposed rats. There were significant increases (p>0.05) in norepinephrine and epinephrine. Thus, it is probable that exposure to infrasound stimulates the sympathetic nervous system and causes a decrease in gastric mucosal blood flow.     

Hearing at low and infrasonic frequencies

The human perception of sound at frequencies below 200 Hz is reviewed. Knowledge about our perception of this frequency range is important, since much of the sound we are exposed to in our everyday environment contains significant energy in this range. Sound at 20-200 Hz is called low-frequency sound, while for sound below 20 Hz the term infrasound is used. The hearing becomes gradually less sensitive for decreasing frequency, but despite the general understanding that infrasound is inaudible, humans can perceive infrasound, if the level is sufficiently high. The ear is the primary organ for sensing infrasound, but at levels somewhat above the hearing threshold it is possible to feel vibrations in various parts of the body. The threshold of hearing is standardized for frequencies down to 20 Hz, but there is a reasonably good agreement between investigations below this frequency. It is not only the sensitivity but also the perceived character of a sound that changes with decreasing frequency. Pure tones become gradually less continuous, the tonal sensation ceases around 20 Hz, and below 10 Hz it is possible to perceive the single cycles of the sound. A sensation of pressure at the eardrums also occurs. The dynamic range of the auditory system decreases with decreasing frequency. This compression can be seen in the equal-loudness-level contours, and it implies that a slight increase in level can change the perceived loudness from barely audible to loud. Combined with the natural spread in thresholds, it may have the effect that a sound, which is inaudible to some people, may be loud to others. Some investigations give evidence of persons with an extraordinary sensitivity in the low and infrasonic frequency range, but further research is needed in order to confirm and explain this phenomenon.     

噪声对工人神经行为功能的影响

本文采用ＷＨＯ推荐的神经行为核心测验组合对９３名噪声作业工人进行测定，发现在八小时等连续Ａ声级８２ｄＢ噪声强度下，工人已经出现了情感状态特征改变，反应速度减慢，听，记忆和视觉感知能力下降，在进行多因素分析时，情感状态特性的改变与接触噪声密切相关，而与性别，年龄，工龄，吸烟，文化程度等温杂因素无关，结果提示，神经行为功能测试在噪声对机体影响方面，可作为早期评介指标。     

Effects of peak levels and number of impulses to hearing among forge hammering workers

The purpose of the study was to (1) compare measured and estimated hearing loss among forge hammering workers by applying models for risk assessment based on measurements of impulse noise, and (2) model the hazardous effects of impulse noise on hearing. Noise exposure and hearing loss among forge hammering workers were studied at two forge workshops of an automobile company, where the equivalent sound pressure levels (104 and 105 dB) were the same, but the peak levels and degree of impulsiveness were significantly different. The hearing threshold levels of selected groups of workers (97 and 235 workers) were determined. Comparison between the measured and expected hearing losses defined according to the ISO standard revealed 2 dB difference in excessive hearing loss (1 dB and 3 dB for the workers of workshop 1 and 2, respectively). The excessive hearing loss equals an increase of 3.5 years of exposure. The hearing loss of workers exposed to low impulsive noise could be predicted well using ISO 1999-1990. The hearing loss of workers exposed to high impulsive noise correlated significantly with the peak levels and the number of impulses in combination.     

A study on the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise

To investigate the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise, we conducted two experiments. In Experiment 1, eight male subjects were exposed to seven types of low-frequency noise stimuli: two pure tones [a 31.5-Hz, 100-dB(SPL) tone and a 50-Hz, 100-dB(SPL) tone] and five complex noises composed of the pure tones. For the complex noise stimuli, the sound pressure level of one tonal component was 100 dB(SPL) and that of another one was either 90, 95, or 100 dB(SPL). Vibration induced on the body surface was measured at five locations, and the correlation with the subjective rating of the vibratory sensation at each site of measurement was examined. In Experiment 2, the correlation between the body surface vibration and the vibratory sensation was similarly examined using seven types of noise stimuli composed of a 25-Hz tone and a 50-Hz tone. In both the experiments, we found that at the chest and the abdomen, the rating of the vibratory sensation was in close correlation with the vibration acceleration level (VAL) of the body surface vibration measured at each corresponding location. This was consistent with our previous results and suggested that at the trunk of the body (the chest and the abdomen), the mechanoreception of body vibrations plays an important role in the experience of the vibratory sensation in persons exposed to high-level low-frequency noise. At the head, however, no close correlation was found between the rating of the vibratory sensation and the VAL of body surface vibration. This suggested that at the head, the perceptual mechanisms of vibration induced by high-level low-frequency noise were different from those in the trunk of the body.     

甲醛与噪声对神经行为功能影响的联合作用探讨

目的：为探讨甲醛、噪声以及甲醛与噪声联合作用对作业工人神经行为功能的影响。方法：本文使用世界卫生组织推荐的神经行为功能核心测试组合检测项目（ＷＨＯ－ＮＣＴＢ）,分别对从事接触甲醛作业（５５名）、噪声作业（６８名）、甲醛加噪声作用（９６名）工人及对照组（７８名）进行神经行为功能的测试,并进行统计分析。结果：甲醛和噪声对神经行为功能均有影响。在甲醛与噪声联合作用中对神经行为功能的影响有增强作用。结论：     

铅接触对工人神经行为功能的影响

目的评价铅接触对工人精神及神经行为功能的改变及其接触水平-效应关系.方法采用 SCL-90症状自评量表和计算机化神经行为评价系统(NES-C)对65名铅接触工人和65名对照工人进行精神及神经行为功能状况调查,同时测定铅接触工人血铅、尿铅浓度.结果 SCL-90症状自评量表结果显示,铅作业工人阳性项目数平均57.2,对照工人为15.0,两者差异有非常显著意义(P＜0.001);神经行为功能测试结果显示,与对照组相比,信息感知、记忆能力差异有非常显著意义(P＜0.001);尿铅浓度与躯体化、强迫、焦虑和偏执因子分间存在正相关.结论职业性铅接触可影响工人的精神和神经行为功能,尿铅浓度与心理卫生状态存在一定接触水平-效应关系.     

某甲醇厂作业人员健康状况调查分析

目的 分析某甲醇作业场所作业人员健康情况,为职业卫生管理提供依据。 方法 选择该厂工龄1年以上,同时接触甲醇和噪声的113名作业人员为接触组,单纯接触噪声的101名作业人员为对照组,比较两组各体检指标的差异。 结果 作业场所空气中甲醇浓度较低,时间加权平均浓度为0.9~18.3 mg/m3,短时间接触浓度为1.7~37.2 mg/m3。甲醇作业人员现场接触噪声的8 h等效声级在57.5~86.3 dB (A)之间,非甲醇作业人员现场接触噪声的8 h等效声级在56.9~89.2 dB (A)之间,两组差异无统计学意义(P>0.05)。接触组头痛、视物模糊、头晕、多梦、眼痛咽痛、皮肤瘙痒等自觉症状发生率高于对照组,肝功能异常、脂肪肝的发生率也高于对照组,差异均有统计学意义(P<0.05或0.01);部分甲醇作业人员出现手部皮肤粗糙现象。 结论 长期低浓度接触甲醇能对接触人员健康造成损害,但本次调查的作业人员体检结果要好于同类文献报道,这与该企业职业卫生管理工作相对到位有关。