Assessing the fungal contamination of paper artefacts in museum reserve storage

Abstract

Fungal communities pose a significant threat to paper artefacts of cultural and historical importance, often proliferating under favourable environmental and nutritional conditions, such as within museum paper repositories. Their development is influenced by both macro- and microclimatic factors, as well as storage methods. The role of preventive conservation has gained recognition in reducing fungal-induced biodeterioration, with monitoring and the subsequent implementation of site-specific measures often being advantageous. This study assessed variations in fungal counts and taxa within the reserve collection of a Maltese museum, particularly within its plan chests. It also considered its transitional areas, which included a drying room used to isolate mould-infested paper artefacts. This was achieved using adhesive-coated spore traps and by combining passive-gravimetric, active-volumetric, and surface sampling methods, alongside thermohygrometric monitoring and self reporting of plan chest use. The results revealed that the thermohygrometric conditions remained near established environmental set-points, except within the drying room, potentially facilitating the continued viability of mould-infested artefacts. Airborne Aspergillus/Penicillium spp. was prevalent, this was followed by Chaetomium spp., Alternaria spp., and Cladosporium spp. among the fungi identified. The highest fungal counts were reported within the plan chests, yet elevated counts remained transient. Statistical analyses additionally found a negative association between Aspergillus/Penicillium spp. and actual humidity within the plan chests. Nonetheless, unaccounted nonroutine activities may have affected such findings. Based on the results, sitespecific recommendations were provided, namely lowering the reserve’s temperature and the drying room’s relative humidity, alongside the development of standard operating procedures for mould detection on paper.