Rosner, G.G.RosnerArtelt, S.S.ArteltMangelsdorf, I.I.MangelsdorfMerget, R.R.Merget2022-03-032022-03-031998https://publica.fraunhofer.de/handle/publica/193162We estimated ambient air concentrations of platinum by applying dispersion models as well as recent emission factors that have been derived from engine test bench experiments with three-way, monolith-type catalytic converters. Predicted concentrations in various exposure scenarios range from 4 pg/m3 (street canyon, typical conditions) up to 112 pg/m3 (express-motorway, severe conditions). These values agree well with the few measurements of platinum ambient air concentrations. Platinum es emitted from catalytic converters in very small amounts (ng/km range) and is mainly in the oxidation state 0 (elemental platinum). The nanocrystalline platinum particles are attached to microm-sized aluminium oxide particles. Whether free ultrafine platinum particles may be emitted and result in biological effects has not been studied sufficiently.enCatalytic convertersenvironmental exposureenvironmental healthenvironmental protectionenvironmental toxicologyplatinumplatinum compoundsrisk assessmenttoxicity615610620616journal article