Airborne particles, bacterial and fungal communities insights of two museum exhibition halls with diverse air quality characteristics

Abstract

Airborne particles, bacteria and fungi consist main determinants of indoor air quality. In this study, these characteristics were investigated in two exhibition halls of the Historical Museum of Crete, in comparison with the outdoor environment. In Zacharias Portalakis (ZP) hall, three air purifiers were operating during museum opening hours, as opposed to El Greco (EG) hall. A significant part of ultrafine (< 1 μm) particles was efficiently removed by the air purifiers in ZP hall. Airborne coarse particles PN2.5–10 were associated with human occupancy in both halls, indicating transportation from visitors and resuspension as possible sources. Average airborne bacterial concentration was also lower in ZP than in EG hall, assessed by both molecular and culture-dependent methods. The bacterial and fungal communities of both indoor halls were distinct from the outdoor counterpart. Micrococcus and Staphylococcus, in terms of bacteria, and Alternaria and Malassezia, in terms of fungi, were the most abundant genera indoors, most of them being human-related. Hierarchical clustering of indoor samples indicated that EG hall bacteria were similar to ZP hall bacteria collected on the same day, but varied between different sampling dates. This observation, together with the bacterial beta-diversity analysis, implied that both indoor halls probably shared common bacterial source(s), while the respective fungal pattern of the two indoor halls was found significantly separated. The outdoor air contribution in EG and ZP hall bacterial profile presented a comparable fluctuation pattern; this was not observed for fungi, probably indicating the complexity of potential sources for different fungal taxa.

Deterioration-associated microbiome of a modern photographic artwork: the case of Skull and Crossbones by Robert Mapplethorpe

“…often form patinas or staining on gelatin positive print and negative films, as well as on the black and white albumen of paper photographs; a similar propension to colonize gelatin cellulose triacetate films was reported for Alternaria, particularly A. alternata [6] and Malassezia. Malassezia is one of the most frequently occurring genera in indoor samples of museum exhibition rooms [76]. Consistent with Sanger sequencing results, HTS results also showed a higher presence of Ascomycota species than Basidiomycota.…”

Indoor Microclimatic Conditions and Air Pollutant Concentrations in the Archaeological Museum of Abdera, Greece

“…The presence of the visitors was the main factor that increased their mass concentrations in all the examined size ranges. People provoke particle resuspension and emit airborne particles, including those of biological origin [3,40]. Indoor airborne particles endanger works of art, even if only by making them dirty.…”

“…Any object's stability is dependent on a specific range of RH values and fluctuations. Chemical, physical, or biological processes on the surface of the works of art are affected by AT and RH levels and their abrupt variations [3].…”

“…The presence of visitors is a significant indoor PM source. Particles with diverse sizes and chemical compositions, including those with biological origin, are emitted by people through their skin and through speaking or breathing, as well as from their clothes and their movements, which results in PM resuspension [3,[24][25][26][27]. The PM deposition rate on the works of art and the upcoming consequences depend on particle size, their concentration, and their chemical composition, as well as the near-surface air flow conditions [28][29][30][31].…”

The Interplay between Air Quality and Energy Efficiency in Museums, a Review

“…It should be noted that the average time for the reported atmospheric pollutant concentrations and the applied monitoring method varies by museum. Several studies, both old and new, have reported particle number concentrations and size distribution, PM chemical composition, VOCs, organic and inorganic acids, SO 2 , H 2 S, CO 2 , and microorganisms [16,17,28,32,[72][73][74][75][76][77][78][79][80]. Table 2 shows a small sample of such studies to demonstrate that the issue of elevated indoor air pollutants is always current.…”