title: Evaluation of black crust formation and soiling process on historical buildings from the Bilbao metropolitan area (north of Spain) using SEM-EDS and Raman microscopy.
abstract: In the present work, several building materials suffering from black crusts and soiled surfaces were evaluated by scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDS) and micro-Raman spectroscopy. The goal was to examine the elemental and molecular composition, the distribution on the samples, and the morphology of endogenous and exogenous compounds on those black crusts and soiled surfaces. The black crusts were deposited over different building materials such as limestone, sandstone, and brick that constitute a small construction called "malacate" as well as over a limestone substrate of a cemetery gate. Both constructions are dated back to the beginning of the twentieth century. The samples of soiling were taken from the façade of a building constructed in the 1980s. The analytical evaluation allowed in a first stage the determination of the composition and the observation of the morphology of soiling and black crusts. In addition, the evaluation of the compositions of the soiling and black crusts of different grade and formation allowed the assessment of the main weathering phenomena that the buildings have suffered, which were found to be sulfate impact, marine aerosol impact, depositions of metallic particles, crustal particulate matter depositions, carbonaceous particles, biodeterioration, and vandalism.
authors.affiliation: Department of Geography, History and Archaeology, Faculty of Arts, University of the Basque Country UPV/EHU, 01006, Vitoria-Gasteiz, Basque Country, Spain.
authors.forename: Estefanía
authors.initials: E
authors.lastname: Calparsoro
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country UPV/EHU, P.O. Box 450, 01080, Vitoria-Gasteiz, Basque Country, Spain. maite.maguregui@ehu.es.
authors.forename: Maite
authors.initials: M
authors.lastname: Maguregui
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU, P.O. Box 644, 48080, Bilbao, Basque Country, Spain.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Giakoumaki
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU, P.O. Box 644, 48080, Bilbao, Basque Country, Spain.
authors.forename: Héctor
authors.initials: H
authors.lastname: Morillas
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU, P.O. Box 644, 48080, Bilbao, Basque Country, Spain.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Madariaga
mesh_terms: D003252:Construction Materials; D008855:Microscopy, Electron, Scanning; D052638:Particulate Matter; D013030:Spain; D013052:Spectrometry, X-Ray Emission
chemical_list: D052638:Particulate Matter
keywords: Bilbao metropolitan area historical buildings; Black crust; Greenhouse acid gases; Raman microscopy; SEM-EDS; Soiling