Distribution and impact of bacterial and fungal aerosols in public gathering locations of Wuhan in winter in 2024

Bacterial and fungal aerosols are widely distributed in the air, and pose a significant threat to human health. In many densely populated and active locations such as subways, supermarkets, fast food restaurants, hospital registration halls, and the other locations, the bacterial and fungal contamination in indoor air cannot be ignored. To understand the concentration distribution of bacterial and fungal aerosols with different particle sizes in these crowded locations, the on-site sampling and experimental analysis were first conducted on bacterial and fungal aerosols in four types of locations, and other related environmental parameters were tested in Wuhan during the winter of 2024. Then, the concentration levels and distribution characteristics of bacterial and fungal aerosols in different locations were analyzed. Finally, the concentration levels of microbial aerosols in different locations and their potential health risks were evaluated. The results indicated: ① The average concentration ordering of bacterial aerosols was fast food restaurant > supermarket > hospital > subway, and the average concentration of fungal aerosols was supermarket > fast food restaurant > hospital > subway. ② The median diameter ordering of bacterial aerosols was hospital > subway > fast food restaurant > supermarket, and that of fungal aerosols was fast food restaurant > hospital > subway > supermarket. ③ In the air of the four types of locations, the average level of bacterial aerosols was low, while the level of fungal aerosols was lower in supermarkets than that in subways, hospital halls, and fast food restaurants. ④ The health impact coefficient of microbial aerosols in all locations was significantly less than 1, indicating a low health risk. This study provides valuable insights for the evaluating of environmental air quality in personnel gathering locations, and provide data support for the formulation of public health policies.