機車維修技工多環芳香烴之暴露與健康風險評估

Exposure and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons for Motorcycle Mechanics

本研究針對20家機車維修進行16種氣相與固相多環芳香烴（PAHs）之採樣與定量分析。作業場所之氣相與固相多環芳香烴濃度分別為3,690±1,457 and 38.3±15.3 ng/m^3。估算之benzo[a]pyrene等價濃度（BaP_(eq)）為29.6±33.0 ng/m^3，相對應之肺癌致癌風險為2.1×10^(-3).低分子量之PAHs主要以氣相存在；相反的，高分子量之PAHs則以固相（微粒）態存在。其中Naphthalene是主要之物種，佔PAHs總量的99.9%，此結果與不同機車引擎型態之排放一致。Naphthalene之室內外比例（I/O）為1.54，顯示其主要產生源為室內維修作業產生，非道路交通造成。居住於車維修行上方樓層之住戶暴露於PAHs之時間可能比機車維修技工更長而造成潛在較高的健康風險而需要更進一步的研究。

A total of 16 polycyclic aromatic hydrocarbons (PAHs) in gas and particle phase were quantified in 20 motorcycle repair workshops (Taiwan). The average indoor gaseous and particle PAHs levels were 3,690 ±1,457 and 38.3 ±15.3 ng/m^3, respectively. The estimated benzo[a]pyrene equivalent (BaP_(eq)) was 29.6 ± 33.0 ng/m^3, corresponding to a lung cancer risk of 2.1×10^(-3). Low-molecular-weight PAHs existed primarily in the gas phase, whereas high-molecular-weight PAHs were a significant fraction of the total particle phase PAHs. Naphthalene was the predominated species at 99.9% of the total PAHs, consistent with measured PAHs emissions from motorcycles of different engine types. The indoor/outdoor (I/O) ratio of naphthalene was 1.54, indicating that this particular PAHs was generated by the maintenance and repair activities inside the motorcycle workshops rather than from outdoor motor vehicle emissions. Residents living in homes over a motorcycle workshop might be exposed to PAHs for longer durations than mechanics, thus their potential exposure and related health risk warrants a further detailed investigation.