Search

This research deals with the characterization of black crusts collected from the Dome of Monza (Milan, Italy). Air pollution is responsible for the degradation of historical buildings surfaces. In urban and industrial areas, the degradation process is accelerated, due to carbonaceous particles and heavy metals emitted by combustion processes which contribute to the formation of black crust (BCs). In this study the characterization of BC was performed using different analytical techniques such as: HRSEM-EDX, IC, LA-ICP/MS and digital image analysis. In particular, the research focused on the study of "heavy metals" which contribute to the identify the main sources of pollution responsible for the surface's deterioration over time. BCs variability in composition also depends on the exposure of the analyzed surfaces. [ABSTRACT FROM AUTHOR]

• Black crusts from cathedral of Monza have been analysed by several techniques. • The effect of urban air pollution on the surface of the façade of the cathedral of Monza was assessed. • Black crusts composition reflects the air pollution situation in surrounding area. This study focuses on the characterization of black crusts collected from the Monza cathedral located in the homonymous city (N Italy), a hot spot from the point of view of the atmospheric pollution. Black crusts and substrate marble specimens were analyzed by a multi-analytical approach including X-ray Diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Stereomicroscopy (SM), Polarized Light Microscopy (PLM), High Resolution Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (HRSEM-EDX) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP/MS). The characterization of the carbon fraction (organic carbon, OC, and elemental carbon, EC) was performed using a new approach based on the use of Carbon Hydrogen Nitrogen (CHN) analysis and Thermogravimetric Analysis (TGA). The integrated approach allowed the identification of the pollution sources responsible for black crusts forming process. The precise identification of the main substances responsible for the surface degradation phenomena, in particular those leading to the blackening and disintegration of the carbonate substrates, is essential for the definition of conservative intervention and maintenance strategies, as well as for the development of emission reduction policies on a local scale. [ABSTRACT FROM AUTHOR]