The scientific framework
The biological component of atmospheric aerosol (bio-aerosol) is a relevant subject of scientific investigation but the mechanisms of interaction between bio-aerosols and other aerosols, the behavior of airborne micro-organisms in different atmospheric conditions and the impact of bio-aerosols on radiation and clouds are still poorly known and requires deeper investigation (Deprés et al Tellus B, 2012).
The scientific interest on this topic can be mainly ascribed to three aspects:
- the strong impact on human health;
- the climatological effects due to the important role that biological particles are supposed to play in ice nuclei formation and cloud condensation;
- the impact on plants and animals health, with relevant consequences on the economy related to agriculture and livestock.
A strong improvement in the understanding of microorganisms behavior in the atmosphere can be provided by atmospheric chamber experiments, that allow for a scientific intermediate approach between “in vitro” and “in vivo” analysis. Aerosol with realistic composition, including living micro-organisms, can be injected in artificial environments with controlled physical and chemical parameters and then accurately analyzed. In particular, a systematic approach can be used for a better description of micro-organisms viability, of colonies growing modulation of and other issues relevant to their spread and their pathogenicity (like biofilm and spore formation and endotoxin production).
Very promising results in this direction were obtained by the INFN-Genoa group and co-workers in a pilot experiment, performed at the CESAM facility thanks to the transnational access grant funded by Eurochamp-2 project, whose results have been recently published (Brotto et al, Aerobiologia, 2015). Moreover another very interesting paper by Amato and co-workers (Amato et al, ACP, 2015) published nearly at the same time, reports the results of simulation chamber experiments performed at AIDA facility to investigate bacteria viability and ice nucleation activity. Thus we can expect that wide perspectives will be opened up by the use of atmospheric chambers for the bio-aerosol investigation.
Objectives and expected results
The main scientific target is the description of biological micro-organisms behavior in the atmosphere and the development of an analysis and forecasting tool for socio-economic and healthcare applications. In particular the main result expected is a deeper understanding of the still unclear mechanisms that control the evolution of bioaerosols in atmosphere and in particular of their bacterial components. The numerical simulations approach used for air quality assessment will be also improved developing a specific software tool for the evaluation of biological characteristics of the atmospheric aerosol, focusing on population, animal and plants exposure to pathogens and health effects.