Aerobiological investigations applied to the conservation of cultural heritage

Aerobiological investigations of cultural heritage may be helpful in the choice of possible intervention for the prevention of biological degradation of works of art. This paper reports on three aerobiological studies that aim to control the diffusion of fungi responsible for damage to mural paintings. In the crypt of the Duomo at Anagni (near Rome), a source of airborne fungi responsible for degradation of the mural paintings was identified. The influence of architectural structure on the impact and propagation of the fungal spores was examined. The reduction of aerodiffused microflora was controlled after disinfection. In the hypogean Basilica of San Clemente, in the centre of Rome, an aerobiological analysis allowed evaluation of the effects of the closure of some air locks. In the Chapel of the Crucifixion of Sacromonte, at Varallo Sesia (near Vercelli), the periods of highest diffusion of a microfungus deteriorating mural paintings (Cladosporium sphaerospermum Penz.) were identified by taking into account the seasonal variations. Two entrance doors to the chapel were mainly responsible for the presence of the aerodiffused microflora. These studies show that the passive sampling method of sedimentation may represent a useful support in the study of airborne fungi which deteriorate mural paintings. In environments scarcely disturbed from a microclimatic point of view, aerobiological sampling by gravitational deposition can give helpful information at a qualitative and semi-quantitative level.