Benzene Toluene and Xylene in Exhaust from Motorcycles

Abstract

In this study, benzene, toluene and xylene from gasoline and exhaust emission were measured for 44 in-use motorcycles. The motorcycle samples were considered based on  both engine type (two and four-stroke) and engine age (old, moderately old, and new). The age of engine was determined as follow: new motorcycles were those which were less than 5 years old, moderately old motorcycles were in range of 5-10 years old and old motorcycles were more than 10 years old. Tedlar bag was used to collect the sample of exhaust emission at idle condition. The samples were analyzed using gas chromatography with flame ionization detection (GC/FID). The study revealed that the two-stroke motorcycles emitted hydrocarbon (benzene, toluene and xylene) about 3-4 times higher than the averages of four-stroke motorcycles. The average concentrations of benzene, toluene and xylene from the old two-stroke motorcycles were found to be 116.2, 261.7 and 39.2 ppm respectively. For new four-stroke motorcycles, the concentrations of the three chemicals were found to be 11.7, 29.0 and 7.6 ppm respectively. These results indicate that there was a significant increase in air pollutant emissions with engine age at significant level (a) = 0.05.