第九届全国生物气溶胶研讨会

  Atmospheric wet deposition can effectively remove air pollutants, allowing harmful components of particulate matter to enter terrestrial ecosystems. This study examines the pollution characteristics of atmospheric pollutants and biological components during a haze-snowfall event in winter in a northern Chinese city. Findings reveal peak PM_2.5 values of 309 µg/m³ during severe pollution phases and high concentrations of water-soluble ions and microorganisms. The microbial community composition demonstrated dynamic changes in tandem with pollution intensification to snowfall. Prior to snowfall, the dominant phylum was Pseudomonadota (83.2%), and the dominant genera were Sphingomonas (16.3%), Bradyrhizobium (13.5%), Afipia (7.8%), Phyllobacterium (10.6%), and Caulobacter (9.7%). Post-snowfall, the dominant phylum was Pseudomonadota (44.1%), Bacillota (23.0%), and Bacteroidota (22.5%), and the dominant genera were Prevotella (28.2%), Aliiarcobacter (11.7%), Staphylococcus (10.6%), Pseudomonas (8.0%), Shigella (7.5%), and Parabacteroides (6.0%). Harmful bioaerosol components, including pathogenic bacteria such as Afipia broomeae, Tsukamurella tyrosinosolvens, Escherichia coli, Aliiarcobacter cryaerophilus, Staphylococcus aureus, and Parabacteroides distasonis and ARGs (macB, tetA (48), evgS, adeL), were enriched in snowfall samples. The proportion of pathogenic bacteria in snow water samples reached up to 75.3%. The KEGG function prediction marked a robust enrichment of metabolic pathways associated with Human Diseases subsequent to snowfall. Concurrently, there was an observed increase in the proportion of pathogenic bacteria and abundance of ARGs in clean samples post-snowfall, which could potentially be attributed to upper atmospheric transport. This research sheds light on the distribution characteristics of pathogenic microorganisms and ARGs within particulate matter and snow water samples, offering preliminary insights into the enrichment and transport patterns of high-risk bioaerosol components facilitated by wet deposition during severe air pollution. Moreover, the findings underscore that bioaerosols in clean days exhibit elevated levels of pathogenic bacteria and ARGs, highlighting an urgent need for further exploration of their potential health risks.