Aims : The symposium aims to highlight the latest concerns regarding the increasing impact of urban traffic-derived air pollution, notably particulate matter and diesel exhaust particles (DEP), on human respiratory and cardiovascular health. By the end of the session, delegates will be aware of the issues that relate to the impact of the source, size fraction, and components of particulate matter on their bioreactivity and effect on pulmonary and cardiovascular health; how the addition of commercial nanoceria can modulate diesel exhaust particle physicochemistry and bioreactivity; the mechanisms by which inhaled particulate matter might induce adverse respiratory and cardiovascular effects; novel data regarding the impact of gasoline-derived particles on normal and diseased human respiratory epithelium; and novel insights into the role of DEP activation of transient receptor potential (TRP) ion channels in sensory nerve activation and cough.