Assessment of exposure to fungi in archives and libraries based on analyses of filter and nasal samples: preliminary investigation

The aim of this study was to characterize the occupational exposure to inhalable dust and airborne fungi among archive and library workers based on qualitative and quantitative analyses of stationary and personal filter samples as well as nasal swabs. The study was carried out in 3 archives and 2 libraries and involved 9 workers of these institutions. Airborne fungi and inhalable dust samples were collected by stationary and personal measurements using filter samplers. Additionally, the nasal swabs from workers were taken after work-shift and microbiologically analysed. The average concentrations of inhalable dust and airborne fungi were 49 µg/m³ (SD = 91) and 299 CFU/m³ (SD = 579), respectively. Both dust and bioaerosol concentrations obtained using personal measurements were significantly higher than that measured by stationary sampling. The correlation analysis showed strong relationships between the concentrations of inhalable dust and airborne fungi (R = 0.57; p < 0.001). The fungal concentrations in swab samples from archive workers (median: 104 CFU/ml) were significantly higher than that in swabs from librarians (median: 1.4 CFU/ml). Among the airborne fungi, the widest spectrum of species was found among Penicillium and Aspergillus (including pathogenic A. fumigatus) genera. However, in samples from archives, yeast-like fungi from Sporidiobolus and Candida (including pathogenic C. albicans) genera predominated among isolated mycobiota. The results of this study revealed that airborne fungi were able to efficiently contaminate the nasal cavity of archive and library employees. The analysis of nasal swabs can be considered as an important analytical tool supporting the assessment of workers’ exposure to bioaerosols.