Resumen
This paper presents a different point of view on the conservation of the built heritage, adding ionizing radiation to the most well-known digital documentation dataset. Igneous building materials characterize most of the built heritage in the Campania region, and in a large part of southern Italy. The ionizing radiations proceeding from these materials can produce stochastic biological effects on the exposed living beings. The research team designed and tested a technical-scientific protocol to survey and analyse this natural phenomenon in association with the use of geological material for building purposes. Geographical Information Systems (GISs), City Information Modelling (CIM), and Building Information Modelling (BIM) are the digital tools used to manage the construction entities and their characteristics, and then to represent the thematic data as false-colour images. The emission spectra of fair-faced or plastered materials as a fingerprint of their nature is proposed as a non-invasive method. Due to both the huge presence of historical buildings and an intense touristic flow, the main square of Pompei has been selected as a study area.