刨路作業人員結晶型游離二氧化矽暴露特性調查

The investigation on exposure characteristics of crystalline free silica of pavement milling operator

刨路作業中作業人員會暴露於高粉塵與結晶型游離二氧化矽的環境中，本研究主要針對刨路作業環境中總粉塵、可呼吸性粉塵以及可呼吸性粉塵結晶型游離二氧化矽進行採樣分析，以瞭解刨路作業作業人員中粉塵與可呼吸性結晶型游離二氧化矽之暴露情形。方法：選取10條平面道路作為銑刨作業之採樣標的，採樣分為區域採樣與個人採樣，個人採樣是由作業人員配戴個人採樣器，並依行政院勞動部公告之採樣分析建議方法進行採樣，總粉塵與可呼吸性粉塵為建議方法CLA4002與CLA4001，可呼吸性結晶游離二氧化矽則以CLA4003進行之|區域採樣則是利用腳架配載採樣器，並以相同建議方法於刨路前一日作業進行背景濃度採樣。結果：在10條刨路作業道路中，刨刀確認員、駕駛員、人孔確認員總粉塵平均濃度為2.77±1.71mg/m^3、3.74±2.54 mg/m^3、0.76±0.59 mg/m^3|可呼吸性粉塵平均濃度為1.20±0.80 mg/m^3、1.60±0.93 mg/m^3、0.33±0.25 mg/m^3|刨刀確認員與駕駛員之可呼吸性結晶型游離二氧化矽平均濃度為0.53±0.29 mg/m^3與0.73±0.44 mg/m^3，人孔確認員由於暴露時間較短，僅一條道路檢出0.10 mg/m^3外，其餘均為未檢出。在檢出之結果中，三種粉塵中個人暴露均顯著高於背景值。以我國之第一種粉塵容許標準來看，刨刀確認員與駕駛員超過容許值之比例為75%及90%|另以美國NIOSH針對可呼吸性結晶游離二氧化矽暴露濃度建議值0.05 mg/m^3為基準，本研究調查之刨刀確認員與駕駛員暴露濃度超過建議值之比例為89%及100%。結論：刨路作業產生高量之可呼吸性結晶游離二氧化矽，使得作業人員確實暴露危害中，因此實應加強作業人員個人防護以及開發粉塵防護裝置等職業衛生措施，方能保障作業人員健康。

Objectives: Pavement milling process produces high concentrations of dust and free crystalline silica during. This study aimed to explore the exposure of total dust, respirable dust and respirable free crystalline silica for workers during the pavement milling operation. Methods: Ten roads were selected as the sampling sites. Both milling-site samples and personal samples were collected and analyzed according to methods CLA4002, CLA4001, and CLA 4003 recommended by the Ministry of Labor, the Executive Yuan. Results: During the pavement milling process on the 10 roads, the average total dust concentrations in samples collected by cutter confirmers, drivers, and manhole confirmers were 2.77±1.71 mg/m^3, 3.74±2.54 mg/m^3, and 0.76±0.59 mg/m^3, respectively. The corresponding average exposed respirable dust concentrations were 1.20±0.80 mg/m^3, 1.60±0.93 mg/m^3, and 0.33±0.25 mg/m^3, respectively. The respirable crystalline free silica exposure concentrations of cutter confirmers and drivers were 0.53±0.29 mg/m^3 and 0.73±0.44 mg/ m^3, respectively. Due to the short exposure time, only one sample of respirable free crystalline silica was collected for the manhole confirmer, with a concentration of 0.10 mg/m^3. The results also showed that these three kinds of dust concentrations of personal exposure were significantly higher than the background concentrations. The cutter confirmer and the driver with exposure of respiratory dust exceeding the Taiwan's permissible exposure limit accounted for 75% and 90%, respectively, or exceeding the US NIOSH recommended value of 0.05 mg/m^3 accounted for 89% and 100%, respectively. Conclusions: Workers are exposed to the hazardous respirable free crystalline silica during the process of milling roads. Personal protective equipment and dust protection devices should be strengthened to ensure the health of workers.