The public transport system is subject to special climatic conditions with a large number of passengers in a confined space. It is practically impossible to determine pathogenic substances with the necessary time resolution in such a dynamic system. However, other parameters that are easy to measure allow the assessment of the ventilation efficiency in a passenger compartment. Consequently, the time profiles of temperature, relative humidity, carbon dioxide and particles in various transport systems were monitored with high time resolution in local public transport buses and trains in the Brunswick/Hanover region. Moreover, space-saving sensors were developed with which the air quality in the passenger areas can not only be monitored online efficiently, but which also record location-based effects, like stops and stations, using built-in GPS.
Salthammer et al. (Sat,) studied this question.