Associated Polycyclic Aromatic Hydrocarbon and 1 Mutagenicity Emissions from Motorcycles

a Department of Environmental Engineering and Management, Chaoyang University of 6 Technology, Wufong, Taichung 41349, Taiwan. 7 b Department of Environmental Engineering and Science, Feng Chia University, Taichung 8 100, Taiwan. 9 c Division of Environmental Health and Occupational Medicine, National Health Research 10 Institutes 11 d Department of Occupational Safety and Health, Chung Shan Medical University. Taichung 12 402, Taiwan. 13 14 Abstract In this study, PM2.5 in diluted exhausts of motorcycles are collected and emission 15 characteristics of PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) and 16 mutagenicities are investigated. The measured mutagenicity emission factors with metabolic 17 activation for new fuel injection, used fuel injection, new carburetor and used carburetor 18 motorcycles are 7.77  10 4 , 1.18  10 5 , 1.32  10 5 and 1.15  10 5 rev/km, respectively. The 19 mutagenicity emission factors with metabolic activation are higher than the corresponding 20 values without metabolic activation. The average PAH emission factors are 12.3, 16.3, 25.5 21 and 26.5 μg/km for new and used fuel-injection motorcycles, and new and used 22 carburetor-operated motorcycles, respectively. The correlation coefficients between PAHs and 23 mutagenicity emission factors are higher with metabolic activation (0.59) than that without 24 metabolic activation (0.31). 25 26