Bioaerosolkammer für legionellenhaltige Duschaerosole

A bioaerosol chamber for a targeted generation of Legionella containing shower aerosols was developed in a project funded by the Bavarian Health and Food Safety Authority. Until now, the risk assessment of shower bioaerosols was only considered by exposition models. The lack of bioaerosol shower chambers with which pathogenic Legionella spp. in showers could be handled was one reason. Legionella spp. are specified as biosafety level 2. Therefore, a bioaerosol shower chamber was integrated in a biosafety cabinet according to the chamber-in-chamber-principle. Thereby, the biosafety cabinet works under negative pressure. Shower bioaerosols were generated in the bioaerosol chamber and directly collected by impingement using the sampling head of Coriolis n in the biosafety cabinet. We found that 0.0006% of E. coli spiked in tap water were recovered in bioaerosols during our experiments. The system is now ready for further experiments with Legionella pneumophila. Experimental data on bioaerosol size distributions, the partitioning of Legionella spp. from tap water into shower aerosols as well as the microbiological activity are important to improve the risk analysis of Legionella containing shower aerosols.