A new study assessing indoor air quality in 11 Portuguese elementary schools found persistent fungal contamination across both rural and urban classrooms, with airborne fungi dominated by the respirable size range that can reach the lower airways. Cladosporium and Penicillium species were the most common cultured isolates, while Aspergillus detection rose at higher incubation temperatures.
The researchers also screened for azole resistance and detected resistant Aspergillus across school environments, including gymnasiums where the Fumigati section accounted for the entire population on one filter-based screen. Contamination varied by season and by ventilation strategy, with rural schools and naturally ventilated buildings carrying higher fungal loads on certain media.
The authors frame the work as a response to a gap in standardized methods for assessing fungal pathogenicity, toxigenicity, and resistance in school buildings, where children spend most of their waking hours and are particularly vulnerable to environmental exposures.