Trattamento della contaminazione microbica in ambienti confinati mediante impiego di oli essenziali: il caso dell’Archivio di Stato di Torino

The case study presented in this article intends to illustrate the experimentation undertaken by the Turin State Archives, in collaboration with the Department of Applied Science and Technology of the Polytechnic University of Turin, aimed at testing the effectiveness of dispersing essential oils in the treatment of archival material compromised by the presence of deteriorating microorganisms. In particular, the efficacy of the essential oil of red thyme (Thymus vulgaris) was evaluated, with regard to its antimicrobial effect on filamentous fungi such as Alternaria alternata, Aspergillus niger and Penicillium frequentans, common contaminants in archives which were also detected, in noticeable concentrations, in the pilot room dedicated to the study. Analyses conducted in the laboratory on samples collected before, during and after the essential oil dispersion intervention returned significant results in terms of reducing the microbial load and slowing the growth of contaminating microorganisms. The data obtained therefore lead us to reflect on the advantages of using natural substances with recognised antimicrobial properties and suggest a path of renewal in the field of scientific research applied to the recovery of cultural heritage with methods that have a low environmental impact, are economically sustainable and safe for workers’ health.