勞工暴露於有機溶劑蒸氣在不同作業姿勢下濃度差異之研究

Study in Labor Expose Organic solvents vapor of Concentration Difference in Different Operating posture

葉超仁(Chau-Ren Yeh)

指導教授 ： 顏慶堂

中山醫學大學/健康管理學院/職業安全衛生學系碩士班/碩士(2015年)

https://doi.org/10.6834/CSMU.2015.00075

摘要

目前職業衛生的暴露評估方法，主要在描述暴露濃度、暴露時間和頻率、暴露途徑、暴露人群多寡、物質特性與種類，以及測量或評估過程中的不確定性。然而忽略勞工作業姿勢或作業點高度的差異，可能造成評估暴露劑量上的誤差。現有的化學品分級管理的評估方法可能還存在著許多問題，例如評估項目中並沒有將勞工因作業姿勢，而造成有害物暴露濃度的差異納入評估範圍中。這樣的評估結果可能會錯估現場危害物質的實際濃度，嚴重的結果就是導致工作場所中潛藏著高危害區域，增加職業災害或職業病的發生率。
本研究目的在評估勞工暴露於有機溶劑蒸氣之作業環境下，因作業姿勢不同所產生的暴露濃度差異，並且加入通風措施條件進行相互比較。除了探討影響危害物質散佈狀態的原因，最後將討論結果與現行化學品分級管理評估方法項目進行比對，針對現行制度或方法之不足的部分提供相關建議。
本研究以採樣腔模擬勞工在不同條件下，有機溶劑蒸氣之暴露評估，設計規劃包含有通風和無通風、坐姿和站姿等四組操作條件。選擇丙酮、丁酮、乙酸乙酯、乙酸丁酯、甲苯及二甲苯等六種具有揮發性的有機物質做為測定對象。以個人式空氣採樣泵進行採樣，樣品以GC/FID進行分析。
本研究證明通風措施確實能改善作業環境空氣品質，以坐姿作業而言，有通風和無通風條件下的有害物濃度差異在3到9倍，在站姿作業下有害物的濃度差異也有2倍至3倍的濃度差距，因此目前的分級管理模式將通風措施納入評估項目中是正確的。針對勞工作業姿勢相對於有害物暴露的評估結果，證明在無通風和有通風的環境下，坐姿的有害物暴露濃度均高於站姿。在無通風條件下坐姿的暴露濃度大約為站姿暴露濃度的4倍到7倍之間，在有通風條件下，坐姿的暴露濃度大約為站姿的1.5倍。
本研究建議在未來化學品分級管理評估項目中，應該要將作業姿勢所產生的暴露差異納入評估範圍內，避免錯誤的評估方法造成勞工持續暴露於超出容許濃度標準的有害環境下作業而不知。
關鍵字：職業暴露評估、有機溶劑蒸氣、作業姿勢、分級管理

關鍵字

職業暴露評估 ； 有機溶劑蒸氣 ； 作業姿勢 ； 分級管理

並列摘要

The current assessment methods of occupational health exposure are mainly to describe the exposure concentration, exposure time and frequency, routes of exposure, the amount of exposed population, substances characteristics and types, and the uncertainty of process of measuring or assessing. However, ignoring labor working postures or the differences of operating point height may cause errors on the assessment of exposure doses. Current assessment methods of Chemicals Control Banding (CCB) may still hide many problems. One example is that the assessment items do not include the harmful substance exposure concentration differences caused by different operating postures. Such assessment may incorrectly estimate the actual concentration of hazardous substances in the field, and serious consequences are leading workplace to high-risk areas, increasing the incidence of occupational diseases.

The purpose of this study was to assess the differences of exposure concentrations caused by various working postures within organic solvent vapors. Ventilation was also included as one comparing factor. This study also investigated the reasons why hazardous substances dispersed. Finally the discussed outcome will be compared with the current CCB projects, providing relevant recommendations for some of the existing system or method deficiencies.

This study is an exposure assessment of organic solvent vapors on workers, using the sampling chamber to simulate different operating conditions. Designing plans included four sets of operating conditions: with ventilation and without, sitting and standing. Six volatile organic materials were the test targets, including acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, toluene and xylene. Personal air sampling pump was used to collect samples, which were then analyzed by GC/ FID.

This study demonstrates that ventilation can really improve the operating environment on air quality. In sitting operations, the concentrations of harmful substances could reach a difference, in proportion, of 3-to-9 times between the conditions of ventilation and no ventilation. In standing operations, there is also a difference of 2 to 3 times in the concentration of harmful substances. Therefore, the current CCB is correct to have incorporated ventilation measures in the assessment project. According to the assessment results between labor work posture and hazardous substance exposure, it is supported that sitting posture led to higher exposure concentrations than standing posture, whether it is with ventilation or without. Under no ventilation conditions, sitting posture caused the exposure concentration approximately between 4-to-7 times higher than standing exposure did. In ventilation conditions, sitting posture exposure concentration is about 1.5 times higher than standing.

This study suggests that in the future CCB assessment project, the exposure difference caused by operating postures should be incorporated into the scope of the assessment. Hopefully it could protect workers from being continuously exposed to hazardous, overly-concentrated substances due to the false assessment methods.

Keywords: Occupational exposure assessment, Organic solvent vapors, Operation Posture, Control Banding

並列關鍵字

Occupational exposure assessment ； Organic solvent vapors ； Operation Posture ； Control Banding

參考文獻

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