Characterisation of particulate matter of traffic origin in Singapore

Abstract

Airborne particles exert a range of adverse effects on human health. Recent toxicological investigations suggest that exposure to atmospheric ultrafine particles (aerodynamic diameter < 100 nm) may be responsible for cardio-pulmonary problems of those living in urban areas. Thousands of ultrafine particles may present within each cubic centimetre of outdoor air but only accounts for a negligible fraction of the particles mass concentration. For that reason, emission control strategies designed to attain ambient air quality standards do not necessarily have to reduce ultrafine particle concentrations to meet the required mass concentration limits. Emission of such particles from the traffic sector is of particular concern in Singapore. A comprehensive field study was conducted in pollution a??hot-spotsa?? to investigate the characteristics of ultrafine particles emitted from on-road vehicles to obtain useful information for development of effective emission control strategies. Potential health effects due to exposure to these particles were also assessed under real-world conditions.