The current questions on the airborne transmission of SARS-CoV-2 particularly show that dispersion predictions for biological agents from their sources are very important in order to assess infection risks but also sensitising and toxic exposures.
Dispersion predictions for bacteria have so far been based on cultivation-dependent approaches by either performing onsite measurements or using dispersion calculations based on cultivation-dependent source strength results.
The project results show that the cultivation-dependent investigations are by far not sufficient to determine the dispersion behaviour of e.g. bacteria of the genus Staphylococcus (lead parameter for bioaerosols in animal husbandry facilities) from their source. This observation was only possible through the application of molecular-biological and biochemical/microscopic methods which had been successfully established in project for the differentiation of living and dead biological agents. The results also showed that, the loss of cultivability in the simulated airborne state occurs significantly before the onset of death for the investigated Staphylococcus spec.
On the basis of the half-lives determined for different climatic conditions for the survivability and cultivability of the lead biological agents, it was possible to determine or improve propagation forecasts together with the Office for Nature, Environment and Consumer Protection in North Rhine Westphalia (Landesamt für Umwelt und Verbraucherschutz Nordrhein-Westfalen). For future investigations, it is generally recommended to introduce the newly established investigation methods for dispersal measurements in order to obtain more detailed statements on the dispersal behaviour for many other biochemicals. The results obtained show that the methods can be used in the field of standardisation for workplace measurements.
Unit 4.7 "Biological Agents"
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