This paper presents a summary of research conducted on the short-term health benefits arising from the introduction of vehicle exhaust catalysts (VECs) to petrol-fuelled cars in the UK. We carried out an evaluation of the environmental and health benefits from a reduction in emissions through this mandated technology against its costs, for urban areas of Great Britain. We made an ex post assessment - based on available data to 1998 - and an ex ante assessment - projected to 2005, when full penetration of VECs into the car fleet is anticipated. The results indicate substantial health benefits from VECs that are likely to exceed their costs significantly: by 1998, when no more than half the car fleet had catalysts installed, the net societal health benefits were around £500 million, while by 2005, the benefits could reach £2 billion. We also found through environmental surveys, that although lead concentrations in road dusts have fallen by 50% in urban areas, platinum accumulations near roads have risen up to 90-fold higher than natural background levels. This suggests that although as yet there is no evidence of adverse health effects from platinum, further monitoring may be warranted. © 2005 Institute of Materials, Minerals and Mining and Australasian Institute of Mining and Metallurgy.