Abstract:
Airborne polycyclic aromatic hydrocarbons (PAHs) arising from diesel exhaust emissions are of concern due to
their significant human health and environmental impacts. Engine dynamometer experiments with a light duty
diesel engine were conducted to measure PAH emissions representative of developing country conditions, and
thereby determine emission factors at two different engine operating modes that are representative of idling and
severe real-world conditions, respectively. We employed a portable denuder device for the simultaneous sampling of gaseous and particulate PAH emissions, the components of which were subsequently individually
thermally desorbed and analysed by two-dimensional gas chromatography with time-of-flight mass spectrometric detection (TD-GCxGC-ToF-MS). Results indicated that PAH emission factors differed significantly for the
different modes of engine operation with the highest emission factor being for idle mode with a total PAH
emission factor of 1181.14 μg/kg. Under real-world conditions, it is expected that further variance in emission
factors will be introduced as a result of brake and tyre wear, different engine technologies, engine age and
maintenance, as well as fuel quality and measurement methods
