Urban roadside particulate air pollution, deposited on tree leaf surfaces (Lime: Tilia europaea; Sycamore: Acer pseudoplatanus), has been monitored (July 2003 to November 2003) by mineral magnetic technologies. The nature of this work is particularly important because particulate pollution affects human health (i.e. cardio-vascular and respiratory systems). Leaves were collected from four roadside locations and a woodland park within the City of Wolverhampton, West Midlands, U.K. Data analyses reveal that significant (p <0.001) site-specific differences are chiefly attributed to differences in types of traffic management and associated vehicular behaviour, but may also be influenced by the type of vehicular engine (notably diesel) and localised conditions. Moreover, evidence suggests magnetic concentration parameters are a surrogate for particulate air pollution. Given the speed, measurement sensitivity and non-destructive nature of the technique, it is proposed this low-cost approach offers some advantages over other technologies currently used to monitor urban roadside particulate pollution.