title: The Oceanus statue of the Fontana di Trevi (Rome): The analysis of black crust as a tool to investigate the urban air pollution and its impact on the stone degradation.
abstract: This paper deals with the analysis of black crust coming from the statue of Oceanus belonging to the Fontana di Trevi (Rome). This monument is undoubtedly one of the main touristic attractions of Rome. During the restoration held between 2014 and 2015, some diagnostic analyses had been carried out. It has been highlighted that the sheltered surfaces suffer the formation of black crust, especially on the marble statues. The possibility to sample those degradation products, together with the unaltered substrate, represented an excellent opportunity to characterize the marble itself, to assess the impact of the urban air pollution on the stone material, and to detect the pollutant on a precise timescale. In fact, it is known that the previous restoration of the fountain had been carried out between 1989 and 1991 then, information about the air pollution over the last 25years can be highlighted, because it has been proved that black crusts act as passive samplers of pollution. In order to fully characterize those samples, several techniques were used, including optical and scanning electron microscopy, X-ray diffraction, laser ablation inductively coupled plasma mass spectrometry, infrared spectroscopy and ion chromatography. Furthermore, a new methodology based on CHN (Carbon, Hydrogen, Nitrogen) analysis has been developed for the quantification of the two main constituents of the carbonaceous fraction present in the black crusts, i.e. OC (organic carbon) and EC (elemental carbon). This integrated approach proposed in the present study allowed us to gain information about the mineralogical phases and the elements within the crusts and at the crust-substrate interface, giving the possibility to identify the pollution sources causing the stone decay within the monument.
authors.affiliation: Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Rende, Italy.
authors.forename: Mauro F
authors.initials: MF
authors.lastname: La Russa
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Fermo
authors.affiliation: Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Rende, Italy; Dipartimento di Chimica, Università degli Studi di Milano, Milan, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Comite
authors.affiliation: Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania, Catania, Italy.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Belfiore
authors.affiliation: Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Rende, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Barca
authors.affiliation: Sovraintendenza Capitolina, Rome, Italy.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Cerioni
authors.affiliation: Sovraintendenza Capitolina, Rome, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: De Santis
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, Milan, Italy.
authors.forename: Lorena Francesca
authors.initials: LF
authors.lastname: Barbagallo
authors.affiliation: Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Rende, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Ricca
authors.affiliation: Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Rende, Italy. Electronic address: silvestro.ruffolo@unical.it.
authors.forename: Silvestro A
authors.initials: SA
authors.lastname: Ruffolo
keywords: Black crusts; Carbonaceous fraction analysis; Environmental pollution; Fontana di Trevi; Heavy metals; Stone degradation