New excavations at Pompeii: Analyzing the alteration risks of mural paintings recently retrieved from burial

Abstract

This work reports on a multidisciplinary study conducted by the IBeA Research Group on mural paintings from Pompeii (Casa dei Pittori al Lavoro, Insula dei Casti Amanti) as they were being retrieved from burial.

In detail, in-situ spectroscopic analysis (Raman, infrared and X-ray fluorescence spectroscopies) were combined with thermographic imaging to evaluate the composition of the paintings and their alteration products. These results guided the collection of micrometric samples, which were subsequently analyzed in the laboratory using Raman, Fourier Transform Infrared Spectroscopy and Ionic Chromatography techniques.

To assist conservators in the selection of the optimal preservation procedures, the analytical results obtained in this work proved that the investigated paintings are threatened by two main alteration pathways. The first alteration is related to the formation of saline efflorescence on the lower parts of the walls. This phenomenon may be due to the presence of a shallow water table in the vicinity of the house, but more studies should be conducted. Regarding the second alteration pathway, biological remains were detected on the wall paintings, which may be attributed to the presence of volcanic debris acting as a substrate for biological colonization. However, further studies are required to confirm this hypothesis.

While providing the Archaeological Park of Pompeii with the analytical results needed to plan tailored conservation treatments, this work demonstrates that cultural heritage conservation can strongly benefit from the synergistic collaboration between restorers and conservation scientists.