Dynamics of Accumulation of Aerosols and Microscopic Fungi Spores in the Air of a Hermetic Inhabited Object during a Four-Month Isolation Experiment SIRIUS-19

Abstract

A four-month experiment which reproduced the main temporal characteristics of the real space flight to the Moon in a medico-technical complex has been carried out. The content of aerosols in the indoor air of the hermetic inhabited object was continuously monitored using a Handheld 3016 laser aerosol counter (Lighthouse WS Co, United States). The number of particles was counted automatically, and the number of viable propagules and the species composition of the fungal population were determined by seeding. The results obtained by these two methods were compared, the regularities in dynamics of neutral particles and micromycete spores, as well as their relationship with the crew activity were revealed, and a possibility to use a particle counter on a spacecraft as an indicator of the microbiological situation was analyzed. A general tendency of an increase in the content of fungal spores in the air of the examined premises was observed from 2--5 at the beginning of the experiment to 287 ± 36 CFU/m3 closer to its end; however, this value did not exceed the sanitary standard recommended by WHO. Species potentially harmful for human health (Aspergillus fumigatus, A. niger and A. sydowii) were detected, but their spore load was extremely low. indoor air, spaceships, microbiological contamination, aerosol particle counter The work was supported by the National Research Center "Kurchatov Institute" (decree no. 1807 from 14.08.2019) and by the Moscow State University (grant for Leading Scientific Schools «Depository of the Living Systems» within the framework of the MSU Development Program).