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Cultural heritage (CH) is heavily threatened by air pollution, especially by airborne particulate matter (PM), that acts on the surfaces of fine arts, causing artistic loss. Therefore, the monitoring of air quality assumes a central role for the preventive conservation of CH.In this study, magnetic and chemical biomonitoring of PM was applied at the Peggy Guggenheim Collection, a contemporary and modern art museum in Venice, Italy. It is located in an aquatic context, where the PM sources are considerably different, with respect to the usual vehicular-dominated urban emissions.Lichen biomonitoring is a well-established technique for the assessment of air quality, especially where PM collecting devices cannot be operated for aesthetic and practical reasons.Samples of the lichen species Evernia prunastri were collected from a pristine area and exposed for three months (November 2022–February 2023) at increasing distances from the Grand Canal, planning an outdoor vs. indoor sampling design, for outlining the diffusion of airborne PM inside the museum.In combination with lichen exposure, the leaves of Pittosporum tobira hedges were sampled for determining their efficiency as bioaccumulators.The magnetic properties of lichens showed a moderate bioaccumulation of magnetite-like particles outdoors. Conversely, the magnetic properties of the indoor samples were like those of the unexposed ones, indicating a negligible accumulation of metallic particles indoors. Pittosporum tobira leaves mostly showed diamagnetic properties, resulting an ineffective species for preventing conservation purposes. Chemical analysis did not show any significant difference between unexposed, indoor and outdoor samples. A directional gradient of bioaccumulation was not evident, thus implying that the sources of metallic PM are distant or diffused, with respect to the site.The joint use of magnetic and chemical analyses was useful for evaluating the negligible impact of airborne particulate pollution arising from the Grand Canal towards the Halls of the Collection.

Non-invasive optical spectroscopical analyses were conducted on the three main walls of Alexander and Roxane’s Wedding Room in Villa Farnesina, Rome. The north and the east walls were frescoed by Sodoma in 1519. The decoration of the third wall was subsequent and neither the author nor the period is known. The north and east walls underwent various restorations, some even very invasive. For these reasons, the supposed remaining original parts of the two walls by Sodoma were studied and compared with the third one, aiming to obtain more information about its author and epoch. The results show the use of the same pigments for the three walls. In particular, the same yellow pigments including lead antimonate, the use of enamel blue with Bi impurities whose use is time-limited, and the use of a certain kind of purple hematite. The commonality in the pictorial technique also emerged, especially in the yellow parts, painted in the same way on each wall. This information, and documentary sources, reinforce the hypothesis that the third wall was decorated shortly after the death of Agostino Chigi by someone who was well-acquainted with the materials and techniques used by Sodoma for the other two walls.

Abstract Maya blue is a hybrid pigment where an organic component, indigo, is incorporated in a porous clay. Despite its widespread use in the Mesoamerican artistic production and numerous studies devoted to understand the type of interactions between indigo and the host framework, its technology has not been completely unravelled yet. In this study portable non-invasive UV–vis reflection spectroscopy is proposed as a robust method for in situ investigation of Maya blue pigments. Laboratory mock-ups of powder Maya blue have been prepared employing different synthesis procedures (varying the nature of: clays, indigo–clay ratios, heating temperatures and time). The goodness of the prepared Maya blue samples—namely the occurrence of indigo–clay interactions—have been probed by micro-Raman spectroscopy and related UV–vis spectral markers have been identified. DFT calculations as well have been performed to deeply explain UV–vis profiles. The set of spectral markers have been finally exploited to interpret spectra recorded on Mesoamerican pictorial codices, through a multi-technique approach based on exploring the UV–Vis properties of the blue paint supported by the FT-IR vibrational study of the inorganic clays. The characterization of blue colours on pre-Hispanic and colonial Mesoamerican codices contribute to a better understanding of the compositional variability of these painting materials and to point out the existence of different technological traditions of colour preparation in ancient Mesoamerica.

A multidisciplinary approach is often the only way to assess the state of the cultural heritage, thus involving different specialist expertise and techniques. The paper shows the paired use of terrestrial laser scanning (TLS) and geophysical monitoring (GM) to detect past effects and analyse the actual vibration levels induced by traffic on cultural heritage. The case study is the Villa Farnesina, one of the most important Renaissance buildings commissioned by the banker Agostino Chigi. The Villa contains frescoes attributed to Raphael and other famous 16th century artists, and it is located a few meters from the Lungotevere, which is one of the busiest roads in the historic centre of Rome. Testimonies report the damages caused by the construction of the embankment of the Tiber River, as well as by the traffic in the second half of the 20th century, so much so as to require requalification of the road artery. The TLS survey allows for detecting cracks and deteriorations of the frescoes, although these were subjected to restoration activities over the time, whereas the (GM) allows analysing actual vibrations induced by traffic at the different floors and outside the Villa. Although the measured vibration limits, as velocity peaks in defined frequency ranges, are below the thresholds established by international codes, the importance of the wall paintings and their already-shown susceptibility to damage suggest keeping the building under constant monitoring.