Hearing Loss in Aircraft Maintenance Works Exposed to Noise, n-Hexane, and Methyl Ethyl Ketone

• Main Authors: Shun-Xin Qiu-Wei, 邱魏順鑫
• Other Authors: 吳聰能
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/70051461984182258462

碩士 === 中國醫藥大學 === 環境醫學研究所碩士班 === 97 === Noise has been documented as the most important hazard about hearing loss, especially at occupational settings. Aircraft maintenance workers are at the high risk of hearing loss associated with a great amount of noise exposure at work such as regular check of airplane taking off and landing. Organic solvents exposure has been noted as an additional factor of hearing loss among aircraft maintenance workers. Previous studies have revealed that organic solvents related occupational hearing loss might be due to the ototoxicity after exposure in workers. N-hexane and MEK are the most frequently used solvents during the aircraft maintenance process. To the best of our knowledge, limited studies have been conducted on the hearing loss associated with n-hexane and/or MEK exposure and the interaction of with noise among aircraft maintenance workers. The purpose of this study is to investigate whether among aircraft maintenance workers exposed to noise, n-hexane, and MEK are at elevated risk of hearing loss. The aircraft maintenance workers in Taiwan were recruited as the subjects of this study. We classified these subjects into seven exposure groups based on their exposure profiles of noise, n-hexane, and MEK, including noise exposure only (group 1), n-hexane exposure group (group 2), MEK exposure only (group 3), noise and n-hexane co-exposure (group 4), noise and MEK co-exposure (group 5), noise, n-hexane, and MEK co-exposure (group 6), and non-exposure (group 7). Hearing loss examination was used to estimate the status of hearing impairment among workers. Information on demographics and potential confounders were collected using questionnaires. Linear regression models were used to estimate the risk of hearing loss among exposure groups controlling for potential confounders. The results showed that the ranges of hearing threshold loss of the all exposure groups on left and right ears were 3.1~9.0、3.8~11.8、2.8~8.8、2.7~8.4、3.6~14、2.7~9.6 dB, respectively; The prevalence of hearing loss among the corresponding exposure groups were 33.3%、35.1%、21.7%、32%、33.3%、34.5%, respectively. After adjustment of confounders, the threshold of hearing loss significantly increased as the exposure level increased. The results of this study indicate that exposure to occupational noise and organic solvents increased the risk of hearing loss for the aircraft maintenance workers. The aircraft maintenance workers are encouraged to use personal protective equipments at the work. We suggest that hearing conservation programs should be implemented for these aircraft maintenance workers.