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

ABSTRACT The atmospheric microbial aerosols samples during the invasion of dust into Shanghai were analyzed using the 16s rRNA high throughput sequencing technique. The characteristics of bacterial community structure in the mixed polluted aerosols with dust and the influencing environmental factors were revealed. On the phylum level, the dominant groups of atmospheric bacteria were Proteobacteria, Actinomycetes, and Firmicutes, and the relative abundance of Acidobacteria increased significantly during the invasion of dust. At the genus level, the dominant ones were Rubellimicrobium and Paracoccus before the dust arrival, while they changed to Deinococcus and Chroococcidiopsis during the dust invasion, and Clostridium and Deinococcus after the passing of dust. In addition, significant differences of the relative abundances were found in 22 genus among the samples before, during, and after the dust.   Based on the analysis of bacterial groups and key environmental factors, it was found that the seven main environmental factors related to bacterial groups were wind speed, SO2, SO42-, NO3-, PM10, NH4+, and Ca2+. It should be emphasized that the relative abundance of Cyanobacteria increased significantly during dust invasion as Cyanobacteria is known to have hepatotoxicity and tumor promotion effect for humans.