Fog droplets—an atmospheric source of secondary biological aerosol particles

The occurrence of airborne biological particles (bacteria, yeasts and moulds) in fog water and the influence of temperature and fog chemical composition and acidity on their concentration are described in this paper. Our results show that the concentration of airborne bacteria and yeasts is enriched in foggy conditions up to two orders of magnitude compared to clear air conditions, while concentration of moulds is not influenced by the presence of fog. These results support the hypothesis that fog droplets act as culture media for airborne biological particles, i.e. they represent an atmospheric source of secondary biological particles.