[Further microbiological studies of the air in a newly built (under the pavement) section of the underground railway in Budapest].

In three subway stations, which are "sub-pavement" stations (Budapest), microbiological air analyses were simultaneously carried out by means of sedimentation and by the use of Krotow's impactor. In the course of the examinations, which lasted eight months, the following max. values were obtained on the agar plates: 78 colonies/dm2/h and 239 colonies/m3; the rates of incidence for pathogenic and indicator bacteria were 2.7 and 1.7 per 10 plates. The strongest airflow was 0.7 m/sec. These values were obtained at the "Nagy-várad tér" station, which forms a transition to the subway stations. The "stopper effect" was found to exist here as well, although not to such an extent as in the deep subway stations, but still more pronounced than in the other two "subpavement" stations "Esceri ut" and "Határ ut". The microbiological values are at any rate more favourable than in the subway stations dealt with in an earlier paper.