title: An analysis of the black crusts from the Seville Cathedral: a challenge to deepen the understanding of the relationships among microstructure, microchemical features and pollution sources.
abstract: The Cathedral of Seville is one of the most important buildings in the whole of southern Spain. It suffers, like most of the historical buildings located in urban environments, from several degradation phenomena related to the high pollution level. Undoubtedly, the formation of black crusts plays a crucial role in the decay of the stone materials belonging to the church. Their formation occurs mainly on carbonate building materials, whose interaction with a sulfur oxide-enriched atmosphere leads to the transformation of calcium carbonate (calcite) into calcium sulfate dihydrate (gypsum) which, together with embedded carbonaceous particles, forms the black crusts on the stone surface. To better understand the composition and the formation dynamics of this degradation product and to identify the pollutant sources and evaluate their impact on the stone material, an analytical study was carried out on the black crust samples collected from different areas of the building. For a complete characterization of the black crusts, several techniques were used, including laser ablation inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, micro infrared spectroscopy, optical and scanning electron microscopy. This battery of tests provided information about the nature and distribution of the mineralogical phases and the elements within the crusts and the crust-substrate interface, contributing to the identification of the major pollution sources responsible for the deterioration of the monument over time. In addition, the results revealed a relation among the height of sampling, the surface exposure and the concentration of heavy metals. Finally, information has been provided about the origin of the concentration gradients of some metals.
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy. Electronic address: silvestro.ruffolo@unical.it.
authors.forename: Silvestro A
authors.initials: SA
authors.lastname: Ruffolo
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy; Dipartimento di Scienze Biologiche, Geologiche e Ambientali-Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Comite
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Mauro F
authors.initials: MF
authors.lastname: La Russa
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy; Dipartimento di Scienze Biologiche, Geologiche e Ambientali-Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania, Italy.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Belfiore
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Barca
authors.affiliation: Istituto di Scienze dell'Atmosfera e del Clima, ISAC-CNR, Via Gobetti 101, 40129 Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bonazza
authors.affiliation: Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS, Italy.
authors.forename: Gino M
authors.initials: GM
authors.lastname: Crisci
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali-Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Pezzino
authors.affiliation: Istituto di Scienze dell'Atmosfera e del Clima, ISAC-CNR, Via Gobetti 101, 40129 Bologna, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sabbioni
mesh_terms: D002119:Calcium Carbonate / Q000032:analysis; D002133:Calcium Sulfate / Q000032:analysis; D002410:Catholicism; D003116:Color; D003252:Construction Materials / Q000032:analysis*; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000032:analysis* / Q000706:statistics & numerical data; D013030:Spain
chemical_list: D002119:Calcium Carbonate; D002133:Calcium Sulfate
keywords: Black crusts; Environmental pollution; Heavy metals; LA-ICP-MS analysis; Seville Cathedral