| 摘要: | 目的：本研究採橫斷式研究(cross-sectional study)設計，評估噪音暴露對於製造業員工聽力損失與噪音和冠心症風險的關係，並探討個人防護具的使用情況，對聽力損失的影響為何。
方法：以台灣某製造業1202名員工作為研究族群，收集於民國101年所進行的環境噪音之資料，並區分作業環境為高噪音暴露組(≧85分貝)及低噪音暴露組(<85分貝)。以純音聽力檢查結果作為聽力損失情形之依據。聽力損失量測使用M25純音聽力儀，測量其左右耳500Hz、1000Hz、2000Hz、3000Hz、4000Hz、6000Hz及8000Hz之純音聽力結果。問卷收集勞工生活習慣資料及依員工一般健康檢查結果，使用Framingham Scale預估其冠心症事件風險。本研究共1200名員工納入資料分析。利用統計軟體SAS 9.3版，使用列聯表、卡方檢定、邏輯斯回歸等分法，進行噪音暴露對聽力損失情形和冠心症風險之相關分析，再探討個人防護具的使用情況，對聽力損失的影響為何。
結果：我們發現在噪音與聽力損失方面，勞工暴露在噪音85分貝以上時，聽力在高頻4K、6K Hz部分平均值分別為37.46及43.59相較於低頻0.5K、1K及2K(平均值分別為25.12、21.36及20.5)呈現明顯損失，4K與6K的聽力損失達40dB以上者占60.18%。聽力量測方面於6000Hz明顯呈現凹谷現象，此為噪音引起之聽力損失之特徵。高噪音暴露組相較於低噪音暴露組別，對於雙耳聽力損失之暴露勝算比為3.59（95%信賴區間2.41-5.35），在調整性別、教育程度、是否抽菸及防護具使用等干擾因子後的暴露勝算比為2.96（95%信賴區間1.40-6.25）。若於上班期間全程配戴與未確實配戴防護具，其高噪音暴露相較於低噪音暴露組的聽力損失勝算比分別為3.05（95%信賴區間1.14-8.17）及5.24（95%信賴區間1.81-15.20）。而在調整性別、教育程度及是否抽菸等干擾因子後，損失勝算比分別為3.29（95%信賴區間1.18-9.19）及3.11（95%信賴區間1.01-9.53）。高噪音暴露對於低噪音暴露組，對未來十年內發生冠心症事件風險大於等於10%之暴露勝算比調整性別、教育程度、是否抽菸及防護具使用等干擾因子後，為1.96（95%信賴區間0.69-5.62）。
結論：本研究結果顯示不同噪音暴露等級與聽力損失有顯著相關及正確的個人防護具使用，可降低聽力損失情形。研究結果也指出，高噪音暴露組相對於低噪音暴露組，對未來十年發生冠心症事件可能有較高的風險。建議雇主應加強教育訓練增加員工對正確配戴防護具的認知並透過行政管理強化使用行為。
Objectives: The purpose of this study was mainly to explore the relationship of noise exposure to hearing loss and risk of coronary heart disease and to investigate the effect of PPE wearing upon hearing loss.
Methods: A cross-sectional study of employees working at a manufacturing company was conducted in August 2012. The 1,200 participants were divided into 2 groups according to the different kinds of exposure at (1) high noise level (≧85 dB), (2) low noise level (<85 dB). Past medical history, PPE wearing and other factors which might affect hearing were recalled by questionnaire. The hearing threshold, covering the frequencies at 0.5K Hz, 1K Hz, 2K Hz, 3K Hz, 4K Hz, 6K Hz and 8K Hz, was measured by using pure tone audiometer. The risk of coronary heart disease was predicted through analysis of Framingham risk score. The methods used for statistical analysis included contingency tables, Chi-square, logistic regression with the aid of a SAS package version 9.3.
Results: With respect to the prevelance of noise exposure with hearing impairment, approximately 60.18% of employees working at the place with an exposure at high noise level had an average hearing loss of 40 decibels or above in 4K Hz and 6K Hz. Also, this study revealed that hearing loss at high frequencies(4K Hz, 6K Hz) on those participants was considerably greater than that at low frequencies(0.5K Hz, 1K Hz, 2K Hz) in which the result of hearing threshold showing notch in frequency noise of 6K Hz interpreted obviously the characteristic of noise-induced hearing loss. The odds ratio for hearing impairment due to workplace with an exposure at high noise level was 3.59 (95% CI: 2.41-5.35) and it was 2.96 (95% CI: 1.40-6.25) after adjusting sex, education, smoke and PPE wearing. Furthermore, the odds ratio for hearing loss of participants working at the place with an exposure at the high noise level because of full-time PPE wearing and part-time PPE wearing were 3.05 (95% CI: 1.14-8.17) and 5.24 (95% CI: 1.81-15.20) respectively. Those risks of hearing impairment were 3.29 (95% CI: 1.18-9.19) and 3.11 (95% CI: 1.01-9.53) after adjustment for sex, education and smoke. The prevelance of coronary heart disease in the future 10 years for the participants of this study working at the place with an exposure at high noise level was 1.96 (95% CI: 0.69-5.62) after an adjustment for interfering factors.
Conclusions: This study showed that the noise exposure level of employees was significantly associated with the hearing loss. The effect of PPE wearing upon hearing impairment came out significantly in which an appropriate use of PPE could contribute to mitigation of hearing loss. The risk of coronary heart disease for the employees working at the place with an exposure at high noise level might be higher than that at low noise level. According the finding in this study, hearing protection program should be implemented periodically in the company to prevent the employees from sever noise-induced hearing loss. |
