Characterization of Airborne Fungal Diversity in Nunavik Housing Using Activated Air Sampling

Airborne fungi are key components of indoor bioaerosols and play an important role in indoor air quality; however, the indoor microbiota in Arctic and subarctic homes remains poorly characterized. Here, we characterized fungal bioaerosols in 56 residential buildings in Nunavik, Québec, Canada, using an activated air sampling approach combined with ITS2 amplicon-based sequencing. Activated air sampling consists of resuspending settled dust and mixing airborne particles prior to collection to capture a more representative indoor fungal burden. To our knowledge, this is the first study combining activated air sampling and ITS2 sequencing to describe indoor airborne fungal diversity in Nunavik dwellings. Our findings revealed seasonal variations in air samples, with richness and diversity significantly lower in winter compared to summer. Seasonal differences in fungal communities likely reflect a combination of environmental and building-related factors, including variations in hygrothermal conditions, ventilation patterns, outdoor air exchange, and occupant activities. The distinctive characteristics of Nunavik dwellings may further contribute to the seasonal structuring of fungal communities. These findings improve understanding of indoor airborne fungal dynamics in subarctic housing and underscore the importance of considering northern-specific housing and climatic conditions in indoor air quality assessments. To our knowledge, this work provides the first sequencing-based characterization of airborne fungal communities in Nunavik dwellings using activated air sampling. The findings highlight the importance of seasonality and subarctic-specific housing characteristics on indoor fungal bioaerosol dynamics. This work improves understanding of fungal bioaerosols in northern housing and provides a foundation for future indoor air quality assessments in subarctic and Arctic communities.