Mold severity and fungal communities in university dormitories: The role of building characteristics and living habits

Abstract

Indoor mold exposure and its fungal communities are linked to various diseases, drawing massive attention. Epidemiological studies often assess visible mold and mold odor (mold severity) to evaluate indoor mold exposure. However, the ambiguous relationship between mold severity and fungal community complicates the understanding of mechanisms beneath mold exposure and health outcomes. This study aimed to 1) characterize the diversity and composition of mycobiomes from visible mold in living spaces and bathrooms of university dormitories; and 2) investigate the associations between mold severity, fungal community of visible mold, building characteristics (e.g., floor level, orientation), occupant features (e.g., number of occupants) and living habits (e.g., ventilation habits). Results showed that dominant genera included Aspergillus, Cladosporium, Knufia and Neodevriesia, with Neodevriesia being reported in bathrooms for the first time. Bathrooms exhibited a higher proportion of yeast or yeast-like fungi compared to living spaces. Additionally, variations in fungal communities were primarily shaped by building characteristics, while mold severity was mainly driven by living habits. Notably, mold severity was negatively correlated with fungal richness and diversity, and it was associated with distinct fungal community structures. This study highlights the mold issue in university dormitories and provides a foundation for future research on the mechanisms linking mold exposure to health impacts.