Dwelling features and occupants’ behaviours as predictors of airborne fungi contamination levels in overcrowded dormitories: A case study in Shanghai,China

Abstract

Airborne fungal pollution poses significant indoor health risks, particularly in overcrowded dwellings. However, its observable predictors remain unclear, hindering the development of cost-effective prevention measures. This study aimed to establish relationships between indoor fungal aerosols and factors such as dwelling features and occupants’ behaviours. Air samples were collected from 45 university dormitories in Shanghai in July 2019 (used for model construction) and eight dormitories in July 2023 (used for model testing), alongside surveys of 132 occupants. Results showed that 82.2% of rooms exceeded the World Health Organization's acceptable fungal level of 500 CFU/m³, yet only 15% of occupants reported musty smells. Higher fungal levels were associated with lower floor levels, frequent takeout consumption, and infrequent room cleaning (P < 0.05). Fungi that can deposit in the lower respiratory tract were more prevalent in low-floor and north-facing rooms (P < 0.05). Allergenic fungi, for example, Penicillium spp. and Aspergillus spp., were more common in low-floor rooms or those with occasional air-conditioner use (P < 0.05). Ordinal regression analysis identified floor level, takeout eating, room cleaning and air-conditioner use as key predictors, achieving 94% accuracy in detecting highly contaminated rooms. These findings suggested that modifying living habits can help mitigate fungal exposure.