Evaluation of physical/chemical synergistic influence of the working environmental factor on hearing, and the application to the comfortable environment.

工作环境因素对听力的物理/化学协同影响评价及其在舒适环境中的应用。

基本信息

批准号：
11670384
负责人：
MIYASHITA Kazuhisa
金额：
$ 2.43万
依托单位：
Wakayama Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670384/
关键词：
Hearing Auditory Brainstem Response (ABR)Noise Organic Solvents Combined effect Synergistic effect 相乗影響

项目摘要

To clarify of evaluation of physical/chemical synergistic influence of the working environmental factor on hearing, and the application to the comfortable environment, animal experiments were carried out, and the male workers were examined.The subjects were male guinea pigs. Hearing threshold was measured by auditory brainstem response. The first experiment was only for methanol exposure, and methanol inhalation levels were 500 ppm, 900 ppm, 1500 ppm, 1900 ppm, 2400 ppm and 3000 ppm. The results of the first experiment demonstrated that methanol inhalation more than 1900ppm dose-dependently increased the hearing threshold. The second experiment was only for noise exposure, and noise exposure levels were 90, 100 and 105 dB SPL. The detection threshold in the 105 dB group was significantly increased. In the third experiment, guinea pigs were exposed to 1500 ppm or 1900 ppm methanol as sub-ototoxic concentration following 100 dB SPL white noise as sub-ototoxic level. In the combined group … More , the marked increase in the detection threshold was observed. The increase detection threshold was the greatest in the group of 1900 ppm methanol combined with noise.We measured hearing level and upper limit of hearing in 93 male workers occupationally exposed to organic solvents and noise. Environmental monitoring, biological monitoring and noise level measurement in workplaces were done. Most exposure level of organic solvents and/or noise were within the occupational exposure limits. The prevalence rate of upper limit of hearing below 75th percentile curve was higher in workers exposed to organic solvents and noise, and the upper limit of hearing was reduced in workers who were exposed for 5 years or more. This reduction was dose-dependent and was related to styrene concentrations in breathing-zone air and mandelic acid concentrations in urine. The results suggest that the probable synergistic effect of organic solvents and noise on hearing should be considered even when the exposures are within the occupational exposure limits. Less

为了明确工作环境因素对听力的物理/化学协同影响的评价及其在舒适环境中的应用，进行了动物实验，以雄性豚鼠为研究对象，测量了听力阈值。通过听觉脑干反应，第一个实验仅针对甲醇暴露，甲醇吸入水平为500 ppm、900 ppm、1500 ppm、1900 ppm， 2400 ppm 和 3000 ppm 第一个实验的结果表明，吸入超过 1900 ppm 的甲醇会剂量依赖性地增加听力阈值。第二个实验仅针对噪声暴露，噪声暴露水平为 90、100 和 105 dB SPL 检测。在第三个实验中，105 dB 组的阈值显着增加，豚鼠暴露于 1500 ppm 或 1500 ppm 的环境中。 1900 ppm 甲醇为亚耳毒性浓度，随后 100 dB SPL 白噪声为亚耳毒性水平。在组合组中，观察到检测阈值显着增加，检测阈值的增加在 1900 ppm 组中最大。对93名职业接触有机溶剂和噪声的男性工人进行了听力水平和听力上限的测量，进行了工作场所的环境监测、生物监测和噪声水平测量。大部分有机溶剂和/或噪声暴露水平在职业暴露限值之内。接触有机溶剂和噪声的工人听力上限低于75%的患病率较高，接触有机溶剂和噪声的工人听力上限降低。暴露时间为 5 年或以上的人，这种减少是剂量依赖性的，并且与呼吸区空气中的苯乙烯浓度和尿液中的扁桃酸浓度有关。被认为是均匀的当暴露量在职业暴露限值以内时。