Microbial environmental monitoring in museums: preventive conservation of graphic collections.

The model was tested in the National Institute of Graphic Arts (Istituto Nazionale per la Grafica - ING) in Rome, on a collection of ancient drawings belonging to the Fondo Corsini. The integrated system relies on: 1) biological aerosol monitoring with active and passive methods; 2) sampling fungal spores with a spore trap (Hirst type); 3) monitoring allergens with dust sampling; 4) monitoring airborne particles with a laser particle counter; 5) microbial sampling of surfaces (cultural objects and furnishing materials) with non-destructive and non-invasive techniques using nitrocellulose membrane filters; 6) microclimatic monitoring with multi data-logger for continuous measurements of air temperature, relative humidity, air velocity, radiant temperature; 7) Computational Fluid Dynamics (CFD) application for transient simulations for the study of air and surface temperature distribution, air velocity field, local perturbations, dust and particle re-suspension processes and pollutant diffusion that are closely connected to indoor air quality for heritage paper conservation. This research is a pilot study which focuses on the biological contamination of the graphic collections and is a contribution to standardizing a system of diagnosis-intervention for the preventive conservation of cultural heritage artworks of organic nature kept in indoor environments (i.e. museums, libraries and archives).