Viable airborne fungi identified in a small town, public building in West Virginia

We spend about 90% of our time indoors.  The air we breathe contains fungi and other microbes.  Airborne fungal communities have been studied in air quality investigations of complaint buildings in response to occupant health issues, water damage, or visible mold growth; however, few studies of the airborne fungal community in non-complaint buildings have been conducted.  Moreover, almost all studies of indoor airborne fungal communities are conducted in large cities in urban locations.  This study describes a baseline survey of the viable airborne fungi found inside a public building in a small rural town.  Fungi were captured passively using an open plate method and isolates were identified to putative taxa through sequence of the nuclear ribosomal internal transcribed spacer (ITS) region.  We sampled in two different years (2020 and 2022) and sampled the outside airborne fungal community in 2022.  Eighteen fungal taxa were isolated from indoor air; five of these taxa were identified only in 2020, eight taxa were only identified in 2022, and five taxa were identified in both years.  Cladosporium was the most commonly isolated genus from indoor air. We isolated 17 different fungal taxa in 2022; nine were only captured indoors, four were only captured outside, and four were captured both indoors and outside.  This study provides a baseline survey of fungal taxa found inside a public building in a rural location, the variability between years, and the impact of outside air.