Emission characterizations and environmental impacts of off-road vehicles

This study measured particulate matter (PM) and gaseous pollutants in the exhaust of off-road vehicles (excavators, bulldozers) during idling and working. The fingerprint of metals in PM and the emission factors of off-road vehicles were investigated. The concentrations of total PM (TPM), PM10, and PM2.5 were 14-251, 12-181, and 10-163 mg m(-3), respectively, for two kinds of off-road vehicles. PM10 occupied 60-70% of TPM, while PM2.5 accounted for 80-90%of PM10. The calculated emission factors were 0.64-0.94, 0.53-0.79, and 0.32-0.49 g BHP-1 h(-1) for TPM, PM10, and PM2.5, respectively. Metallic elements of PM were analyzed in order to evaluate the carcinogenic and non-carcinogenic risks. The results showed that the emission of total metallic elements from the excavator and two bulldozers are 2.7 and 7.9-22.6 mg m(-3), respectively, and the dominant components are Zn, Fe, and Al. The total carcinogenic risk of Cd and Pb decreased from 9.4 x 10(-8) to 1.3 x 10(-8) with increasing the distance from 0 to 150 m away from the three off-road vehicles (one excavator, and two bulldozers). The non-carcinogenic risk of both Cd and Pb is lower than the limits (hazard index = 1), which is considered acceptable.