Recent increases in platinum metals in the environment from vehicle catalytic converters

The natural and anthropogenic sources of platinum metals in the environment are reviewed with particular emphasis on platinum from vehicle exhaust catalysts (VECs). Reported increases world-wide in platinum metal concentrations in a number of environmental media over recent time are discussed. Estimations of the emission rates for platinum from petrol (gasoline) powered cars in the literature have been made from both test rig and environmental considerations. Using such emission rates, it is estimated that the total input of Pt from UK traffic during the years 1993-1999 varied between about 250 kg and 120 kg. World-wide, the annual input into the environment is estimated to be between 0·5 × 106 and 1·5 × 106 kg. The health implications of such inputs of platinum metals into the environment are considered. At present, there is no evidence for adverse effects on human health, although the effects of long-term inhalation and ingestion of PGE containing particulates is not known. Potential impacts on the environment, in particular microflora, are also important, since it is known that some PGE compounds have effects on micro-organisms at very low concentrations. © 2005 Institute of Materials, Minerals and Mining and Australasian Institute of Mining and Metallurgy.