Potential respiratory hazards of fungal exposure in the residential indoor environment: a systematic review

As concern over indoor environmental health increases, the health risks associated with microbial exposure have received growing attention. Fungi, as ubiquitous airborne microorganisms, release spores and metabolites that can trigger allergic responses and contribute to the onset or exacerbation of respiratory diseases such as asthma and rhinitis. However, systematic evaluations of the relationship between indoor fungal contamination and respiratory health remain limited, especially under real-world exposure conditions. This review was conducted via comprehensive literature search on Web of Science, PubMed, and Google Scholar, covering studies from 1990 to 2025. A total of 94 studies were included, comprising 31 on fungal sources, 48 on respiratory health impacts, and 15 on prevention strategies in residential environments. Findings show that building deterioration, especially causing Penicillium and Aspergillus proliferation, is a major fungal source, and building materials affect species distribution. Filamentous fungi from various environmental sources are associated with allergic rhinitis, asthma, tonsillitis, adenoid hypertrophy, and impaired lung function. Current mitigation approaches focus on chemical and physical control measures. This review provides an integrated overview of fungal exposure sources in indoor environments, their respiratory health implications, and the underlying mechanisms, offering scientific insights for prevention and control of fungus-related diseases in residential settings.