Use of an atmospheric simulation chamber for bioaerosol investigation: a feasibility study

Environmental simulation chambers (atmospheric/smog chambers) are small- to large-scale facilities (with volumes ranging between a few to several hundred cubic meters), where atmospheric conditions can be monitored in real time under control to reproduce realistic environments and to study interactions among their constituents. Up to now, they have been used mainly to study chemical and photochemical processes that occur in the atmosphere, such as ozone formation and cloud chemistry, but the high versatility of these facilities allows for a wider application covering all fields of atmospheric aerosol science. The biological component of atmospheric aerosol (bioaerosol) is a relevant subject of scientific investigation requiring expertise in both atmospheric science and biology. It raises a strong interest in the scientific community due to its link with human health and the relevant role that biological particles are supposed to play in ice nuclei formation and cloud condensation. Nevertheless, the mechanisms of interaction between bioaerosols and other aerosols, the behavior of airborne microorganisms in different atmospheric conditions and the impact of bioaerosols on radiation and clouds are still poorly known and require deeper investigation. In this work, we present the results of a feasibility study of the use of an atmospheric chamber facility to study bioaerosols under differing atmospheric conditions. Here, we present the experimental setup and the protocol to inject, analyze and extract Bacillus subtilis strain in the Experimental Multiphasic Atmospheric Simulation Chamber, and we investigate the sensitivity of this tool to possible changes in bacteria viability by varying the atmospheric conditions.