This study collected atmospheric bioaerosol samples under different Air Quality Index (AQI) levels in a coastal area. By integrating real-time quantitative PCR and high-throughput sequencing techniques, we systematically analyzed the distribution characteristics of total DNA, bacterial DNA, antibiotic resistance genes (ARGs), and metal resistance genes (MRGs), alongside the microbial community structure. This analysis elucidates the pollution characteristics of coastal atmospheric bioaerosols and their response patterns to changes in air quality. The results showed that the concentrations of total DNA and bacterial DNA were highest under good air quality conditions (66.67 and 29.83 ng/m³, respectively), while microbial α-diversity peaked under moderate pollution. Notably, the concentration of ARGs increased significantly as air quality improved, exhibiting strong positive correlations with O₃ and NO₂ levels. This finding suggests that ARGs may primarily exist on the surface of fine particulate matter or be influenced by external transport mechanisms. Conversely, the distribution of MRGs was highly synchronized with variations in bacterial DNA concentration (R=0.88), suggesting their predominant intracellular occurrence within bacteria. The bacterial community was overwhelmingly dominated by Proteobacteria, with its structure varying significantly across different AQI levels. This study reveals the pollution characteristics of coastal atmospheric bioaerosols and their response mechanisms to air quality changes, thereby providing a scientific basis for health risk assessment and pollution control of bioaerosols in coastal regions.
He et al. (Fri,) studied this question.