A magnetic biomonitoring approach for assessing and limiting the impact of particulate matter in cultural heritage sites

WINKLER, A.; CHAPARRO, M.A.E.; BOLDRIGHINI, F.; BUITRAGO POSADA, D.; CACIAGLI, S.; GRIFONI, L.; LAPENTA, V.; LOPPI, S.; MARTE, F.; MARIÉ, D.C.; PENSABENE BUEMI, L.; RUSSO, A.; SPAGNUOLO, L.; STRANO, G.; TASCON, M.; SGAMELLOTTI, A.

Minneapolis

Conferencia; 13th IRM Conference on Rock Magnetism; 2023

University of Minnesota

In urban contexts, Cultural Heritage (CH) is heavily threatened by particulate matter(PM) which acts on the surfaces, creating dark layers, abrasion of materials, depletion, anddiscoloration, with consequent functional and aesthetical losses. Therefore, protection ofcultural heritage from air pollution is of primary importance, since pollution can penetratethrough the normal and conditioned air circulation and visitors constantly introduce andre-suspend particles.In Winkler et al., 2022, it was tested for the first time the use of magnetic biomonitoringtechniques for the preventive conservation of Villa Farnesina (Rome, Italy). Plantleaves and lichen transplants were respectively sampled and exposed at increasing distancesfrom the main congested road. Also, an outdoor vs. indoor mixed sampling designaimed to assess the impact of vehicular PM on the Villa Loggias, painted by RaphaelSanzio was introduced. Plant leaves are important for their role in accumulating and removingair pollutants, thus providing crucial ecosystem services that limit the adverseimpact of PM on cultural heritage within urban contexts. Here, we report the first resultsobtained at further CH sites, in the framework of the project CHIOMA (Cultural HeritageInvestigations and Observations: a Multidisciplinary Approach), which expandedthe work at Villa Farnesina.Magnetic measurements include mass and in-situ volume susceptibility measurements,determined with Agico KLY5 and ZH SM150 and SM30 meters, respectively. The domainstate and magnetic grain-size of the samples are qualitatively compared to theoreticalmagnetite and to exhaust and not-exhaust vehicular emissions according to the “Dayplot”, while FORC diagrams are used for identifying magnetic mineral components accordingto their domain status and magnetic interactions. The magnetic analyses are alsointerpreted as proxies of the content of trace metals as Al, Ba, Cd, Cr, Cu, Fe, Ni, Sb, Snand Zn, which are evaluated by ICP-MS at University of Siena.Two extensive plant samplings and a lichen exposure were carried out at the PalatinoHill of Parco Archeologico del Colosseo, the main archeological site of Rome, facing abusy road (Via dei Cerchi). Lichen transplants were also exposed at the Peggy Guggenheim Collection in Venice, to explore these methodologies in an aquatic context that isout of the typical traffic site investigated with a magnetic biomonitoring approach.A further case study involves the Museo Nacional de Bellas Artes and the MuseoHistórico Nacional of Buenos Aires, where the bioaccumulation properties of local andMediterranean trees and lichen species are compared, to test their capabilities in providingecosystem services. This study, planned as a cooperation between INGV and CONICETpaleomagnetic and environmental magnetism laboratories, will also work as an intercalibrationtest for establishing a magnetic biomonitoring protocol. Finally, new tests aregoing on at the Cathedral of Florence and Terme di Diocleziano in Rome, where differentenvironmental and vehicular traffic conditions can be found.