Our air quality research in the Munich subway (Germany) focused primarily on characterizing the spatio-temporal variability of aerosols, identifying sources and hot-spots of pollution, and evaluating the personal exposure of citizens. We constructed a novel modular measurement system, which can be used as a backpack or trolley, equipped with professional instruments for aerosol measurement and sampling both during metro rides and platform stays in the breathing zone of citizens. We have developed a methodology that allows a comprehensive characterization of the metro system based on mobile measurements in high time resolution, which is easy to use, so that it can be applied to different metro systems that have not yet been characterized. Results from Munich will be presented, some of which have been published in the journal Atmospheric Environment as a first study from Munich. We will also present our new method for automatic characterization and classification of metro aerosol particles from samples using SEM-EDX, which was recently published in STOTEN. Based on this method, the size distribution of elemental composition on aerosol particles can be determined, which can be crucial for accurate source identification and health risk assessment. In Munich, PM10 concentrations reached up to hundreds of micrograms/m3 with considerable spatial variability. The temporal variability of PM was less significant. The dynamics of aerosols during rides was high and we found, for example, that the exposure of people in new trains with active ventilation was almost identical to that in old trains with open windows due to the absence of filters. More than 90% of the PM was formed by iron oxides from abrasion of wheels, brakes and rails. However, we also found sub-100 nm iron oxide particles that could potentially pose a health risk. Our research activity in the Munich subway system is ongoing.      «

Our air quality research in the Munich subway (Germany) focused primarily on characterizing the spatio-temporal variability of aerosols, identifying sources and hot-spots of pollution, and evaluating the personal exposure of citizens. We constructed a novel modular measurement system, which can be used as a backpack or trolley, equipped with professional instruments for aerosol measurement and sampling both during metro rides and platform stays in the breathing zone of citizens. We have develope...     »