Characterization of Airborne Microbial Aerosols during a Long-range Transported Dust Event in Eastern China: Bacterial Community, Influencing Factors, and Potential Health Effects

Samples of atmospheric microbial aerosols were collected before, during, and after a dust invasion in Shanghai and analyzed using 16S rRNA high-throughput sequencing. The bacterial community structures in the mixed pollutive aerosols and dust were characterized, and the key environmental factors were identified. The dominant phyla were Proteobacteria, Actinomycetes, and Firmicutes, and the relative abundance of Acidobacteria increased significantly during the episode. Additionally, marked differences in the relative abundances of the 22 detected genera were observed between the three sampling stages: The dominant genera were Rubellimicrobium and Paracoccus prior to the arrival of the dust but became Deinococcus and Chroococcidiopsis during the invasion and then Clostridium and Deinococcus afterward. Notably, the relative abundance of Cyanobacteria, which is known to cause hepatotoxicity and promote tumor growth in humans, grew substantially during the event. Finally, statistical analysis revealed the largest environmental factors affecting the bacterial communities to be wind speed and the SO2, SO42-, NO3-, PM10, NH4+, and Ca-2(+) concentrations.