Lecture

Bioaerosol and Atmospheric Simulation Chambers: state of the art and future developments

  • 11.04.2024 at 13:50 - 14:10
  • ICM Saal 4b
  • Language: English
  • Type: Lecture

Lecture description

Bioaerosols are particles in the air that consist of aero-disperse living organisms or fragments of living organisms. These particles can vary in size from small viruses and bacteria to larger fungal spores and pollen. They are generated by natural processes, such as the release of spores from plants or fungi, as well as by human activities such as coughing, sneezing and other respiratory activities. Bioaerosols can have both positive and negative effects. On the positive side, they play a role in natural processes such as pollination and seed dispersal. On the negative side, exposure to certain bioaerosols can pose a health risk, especially for people with respiratory diseases or allergies. Bioaerosols can also contribute to the spread of infectious diseases. In general, studying aerosols in the field can be challenging due to the dynamic and complex nature of aerosol particles such as variability and diversity, transport and dispersion, meteorological conditions, etc. For this reason, conducting experiments in an atmospheric simulation chamber allows researchers to control and manipulate environmental conditions to simulate real-world scenarios; moreover, atmospheric conditions can be maintained and monitored in real time over a period long enough to mimic realistic environments and study the interactions between their constituents. Here we present the results of several experiments carried out at ChAMBRe (Chamber for Aerosol Modelling and Bio-aerosol Research), an atmospheric simulation chamber operated by INFN at the Department of Physics of the University of Genoa, Italy. One line of research at ChAMBRe is focused on studying the behaviour of airborne bacteria under different atmospheric and air quality conditions. A multi-step protocol was developed and tested to cultivate a suitable population of bacteria, including E. coli, B. subtilis, B. licheniformis, and P. fluorescens [1]. The bacteria are nebulized and injected into ChAMBRe, where they are exposed to varying gas concentrations. The total bacteria concentration is measured inside ChAMBRe using a WIBS-NEO instrument. The viable concentration is determined by active sampling on Petri dishes using an Andersen impactor, and then counting the colonies forming units (CFU). A liquid impinger is used to maintain the integrity of the microorganisms and their physiological state and to investigate a sampling strategy that can assess viability and cultivability simultaneously, including the VBNC status (viable but not cultivable). The results of impactor experiments and preliminary assessments with live and dead assays examined by fluorescence microscopy are presented here.

Literature:
[1] Vernocchi, V., et al. Airborne bacteria viability and air quality: a protocol to quantitatively investigate the possible correlation by an atmospheric simulation chamber, Atmos. Meas. Tech., 16, 5479–5493.

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