Emission characterizations and environmental impacts of off-road vehicles

Abstract

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 × 10−8 to 1.3 × 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.