Airborne platinum concentrations in Munich city buses

Airborne platinum concentrations sampled over 4 h in local buses in Munich during regular rides were analyzed by adsorptive stripping voltammetry. The detection limit was 0.5 pg/m3, related to an air-sampling of 5 m3. In 96 samples from 1993 and 1994 we found a mean concentration of 7.3 pg/m3 (S.D. 6.5). The route with highest traffic showed 33.0 pg/m3 compared to 3.0 pg/m3 at a suburban bus route.