Distribution and diversity of the fungal pollution in repositories of the provincial historical archive of Villa Clara, Cuba

Abstract

The aims of this study were 1) To characterize the mycobiota in four niches [indoor air from repositories (IA), outdoor air (OA), collected dust of indoor environments (CD) and documents surface (DS)] of the Provincial Historical Archive of Villa Clara, 2) To evaluate the settleable dust loadings, 3) To determine the similarity of the isolated taxa in the analyzed niches and 4) To predict the potential risk the isolated fungal species. Form indoor air of three repositories and the outdoor air were sampled in June, 2017 and March, 2018 using a SAS sampler and the indoor/outdoor (I/O) ratio was determined. The settled dust was collected passively during two years and the surface documents were sampled too. Sørensen's coefficient of similarity (QS) was calculated to compare the isolated taxa among the four studied niches. The extreme airborne fungal concentration in indoor environments was 515.5 CFU/m3 and the I/O ratios fluctuated from 1.0 to 1.5, evidencing a good environmental quality. The maximum settled dust load was 130.8 mg/m2/day with a top fungal concentration of 3x105 CFU/gdust, while the documents surface the highest concentration was 20 CFU/cm2. The obtained QSs were diverse: QS(IA-OA)=0.8-0.9, indicated a high species similarity; QS(IA-CD)=0.5-0.6, typical of moderate similarity; QS(IA-DS)=0.4, own of low similarity. This QS behavior showed that the repositories environment was strongly influenced by the outdoor environment. Aspergillus and Cladosporium were the predominant genera in indoor air, collected dust and documents surface. In these niches species predominance corresponding to the Aspergillus genus, in particular of the Flavi section was obtained. Some of the isolated species are opportunistic pathogens and toxigenic, and their concentrations were higher than the recommended, demonstrating the potential risk to which the archive personnel is exposed in a circumstantial way.