Ecology of Airborne Microorganisms: Understanding the Impact of Haze and Sandstorms on Bacterial Community Structure and Pathogenicity

The adverse health effects of air pollutants are closely associated with their components, including bioaerosols. However, the characteristics of bioaerosols during pollution processes are not yet fully understood. Here, we investigated the 2- to 6-hly dynamics of bacterial aerosols over a short period that spanned one instance of haze and one sandstorm. 16S rRNA gene (rDNA) sequencing was used to identify the total bacteria, and 16S rRNA (rRNA) sequencing was applied to characterize the actively metabolizing bacteria. The results revealed the highest bacterial diversity in sandstorm air and the lowest bacterial diversity in haze air, with markedly different community structures. Moreover, substantial dissimilarity was detected between the communities of total bacteria and active bacteria within the sandstorm air, with less abundant bacteria dominating the active bacterial population. Selective pressure played a pivotal role in shaping the composition of active bacteria during sandstorms and the total bacterial community in hazy air, thereby enabling potential interactions between airborne microorganisms and chemical components. Additionally, functional prediction analysis suggested increased pathogenicity in the active bacteria of sandstorm air. These insights into the aggregated hourly dynamics and activity of bacterial aerosols during pollution processes underscore the importance of further research into the complex interactions between bioaerosols and air pollutants.