林務工人之手－－手臂振動量測與其危害評估

The Assessment and Evaluation of the Hand-Arm Vibration Exposure of the Forest Worker

本研究之目的在對國內針對林場鏈鋸工作者暴露於手－－手臂振動支暴露危害評估。本研究先行針對台灣九大林場之林務工人進行問卷調查，調查其鏈鋸之使用之廠牌、型號及其操作時間，以確定量測之種類後，根據ISO 7505(1986)及DIN 45675(1987)之規範來進行實驗振動量測。利用問卷調查各林場主要使用之11種鏈鋸，以手－－手臂振動測定儀器包括振動檢波器(RION PV-93)、振動分析器(RION VM-19A)、振動波記錄器(SONY PC 204AX)、1/3八音度頻譜分析儀(RION SA-27)、電源供應器及轉速測定器等量測設備，依據國際規範以引擎轉速區分成Idling（怠速）、Full load（滿載）、Racing（競速）三種不同操作狀態進行振動加速度測量，將所得鏈鋸之振動量及勞工暴露時間資料以ISO 5349(2001)之規範與本國「勞工安全衛生設施規則」加以評估其危害情形。 結果發現鏈鋸在引擎轉速加大時，其主要振動發生頻率也趨向高頻區；以ISO 5349之規範評估，鏈鋸之振動量a(Superscript eq(8))集中於5.38~11.44m/s^2之間，依ISO 5349(2001)推估10%罹患白指病機率之工作年資為2.40~5.34年。英國健康與安全部在2005年7月6日所發佈工作振動防治法規定手－－手臂振動暴露限值為5.0m/s^2，本研究採樣之鏈鋸的振動加速度值大部份都超過許多，雇主需針對此情形利用調整工時、提供並指導確實配戴防振手套及防音防護具、並對鏈鋸及鋸齒加強維修以減少勞工之振動暴露劑量。

The aim of this research is to measure and evaluate the quantity of the hand-arm vibration of chainsaw for the forest workers. Firstly, this research carried out questionnaire investigation including the brand, the type and the operating time of chain saw in the nine major forest farm in Taiwan, then the acceleration of vibration were measured and evaluated according to the standard of ISO 7505(1986) and DIN 45675(1987). There are eleven kinds of chain saw used mainly in the forest, the measure the handsarm vibration, the instruments included the vibration accelerometer (RION PV-93), vibration meter (RION VM-19A), digital wave form recorder (SONY PC 204AX), the third octave band frequency analyzer (RION SA-27), and the rotational speed meter were used. The operating conditions were distinguish into Idle, Full load and Racing state the outcome of the measurement of vibration were evaluated with the standard of ISO 5349(2001) and ”The Regulation of Laborer's Safe & Hygiene Facility”. It was found when the higher rotational speed of cylinder of chain saw, the noted vibration acceleration move toward the higher frequency. Dominated the range from While mostly concentrating on 5.38 to 11.44m/s^2. According to the ISO 5349(2001) the vibration acceleration of these chain saws 10% of the operators may cause white finger disease in 2.40 to 5.34 years. The exposure limot value (ELV) according to ”The Control of Vibration at Work Regulations 2005” of Britain's Health and Safety Executive is 5.0m/s^2. The acceleration of vibration of the chain saw in this study exceeds this ELV. The employer needs to adjust the working type, to instruct the employee, offer the effective antivibration glove, and offer earplug for laborers to reduce the vibration and noise exposure.