Surface and stratigraphic analysis of black crusts using Laser Induced Breakdown Spectroscopy

The interaction between atmospheric pollutants and architectural cultural heritage leads to several degradation processes, mainly the formation of black crusts. Numerous studies have highlighted that their elemental composition can be used to determine the main pollutant sources of the surrounding areas. Therefore, black crusts may represent actual “registries of pollution sources” and may help to understand the evolution of these sources and their impact throughout the years. In this study, a first-ever application of the LIBS technique for the study of black crusts is carried out in order to evaluate the feasibility of this technique (surface analysis) and the in-depth distribution of the elements in the black crusts (stratigraphic analysis). The elemental profile of the black crusts enabled to detect the main pollution sources of the surrounding areas and the ariation of their impact throughout the years.