Características de la atmósfera del Bilbao metropolitano

En este trabajo se identifican los compuestos característicos de la atmósfera de Bilbao, se presentan las concentraciones obtenidas experimentalmente y en función a estas y los gradientes observados se identifican posibles focos de emisión

Identification of metals and metalloids as hazardous elements in PM2.5 and PM10 collected in a coastal environment affected by diffuse contamination

The nature of the PM2.5 and PM10 varies enormously depending on the anthropogenic activities developed in the surrounding environment. These particles can include Hazardous Elements (HEs), such as heavy metals, which can be considered dangerous for the human health. For this reason, determining the nature of those HEs that are present in the surrounding atmosphere can help to comprehend possible emission sources and to establish new strategies to reduce air pollution. In this work, a cost-effective self-made passive sampler (SMPS) was tested as a tool to collect different size of PM containing metals as HEs. The SMPS was installed in a 20th century historic building (Punta Begona Galleries, Getxo, ~ Basque Country, Spain), located just in front of the sea and thus, immersed in a coastal environment. This location is affected by the activities developed in a marina and in a port, and by the diffuse influence of several industries and a power station. The annual average for PM10 and PM2.5 were approximately 22 mg/ m3 and 10 mg/m3 , respectively. For develop this study, non-invasive elemental (Scanning Electron Microscope coupled to Energy Dispersive X-ray Spectrometry) and molecular (Raman microscopy) microspectroscopic techniques were used. Thanks to this methodology it was possible to determine in PM10 and PM2.5, the presence of heavy metals such as Fe, Cr, Ti, Pb, Zn, Ce, etc., most of them as oxides but also embedded in different aggregations with aluminosilicates, phosphates, halides, sulfates, etc

The influence of marine environment on the conservation state of Built Heritage: an overview study

Marine aerosol is a chemical complex system formed by inorganic salts and organic matter, together with airborne particulate matter from the surrounding environment. The primary particles transported in the marine aerosol can experiment different chemical reactions in the atmosphere, promoting the so-called Secondary Marine Aerosol particles. These kinds of particles (nitrates, sulfates, chlorides etc.), together with the natural crustal or mineral particles and the metallic airborne particulate matter emitted by anthropogenic sources (road traffic, industry, etc.) form clusters which then can be deposited on building materials from a specific construction following dry deposition processes. Apart from that, the acid aerosols (e.g. CO2, SO2, NOX, etc.) present in urban-industrial environments, coming also from anthropogenic sources, can be deposited in the buildings following dry or a wet deposition mechanisms. The interactions of these natural and anthropogenic stressors with building materials can promote different kind of pathologies. In this overview, the negative influence of different marine environments (direct or diffuse influence), with or without the influence of an urban-industrial area (direct or diffuse), on the conservation state of historical constructions including a wide variety of building materials (sandstones, limestones, artificial stones, bricks, plasters, cementitious materials, etc.) is presented

Characterization of restoration lime mortars and decay by-products in the Meditation area of Machu Picchu archaeological site

Machu Picchu citadel is the main archaeological Inca sanctuary widely known around the world, and a World Heritage Site of high cultural and natural value. For its construction a whitish granitic rock, extracted from the “Vilcapampa or Vilcabamba” batholith formation was used. During time, some of the granitic rocks from the natural stonewalls of the Meditation area of the Archaeological Park were restored. For the restoration works done in the 50s' a specific lime mortar called Clarobesa was used. After the inclusion of this joining mortar, many efflorescences are nowadays visible in the mortar itself and on the surface of the edges of the annexed rocks. To evaluate the possible impact of these salts crystallizations in the conservation state of these natural stonewalls, a multi-analytical methodology was designed and applied. With a combination of non-invasive and destructive techniques such as X-ray Diffraction, Raman microscopy, Scanning Electron Microscope coupled to an Energy Dispersive X-ray Spectrometer and ion chromatography, the mineralogical composition and the nature/concentration of the soluble salts present in the Clarobesa mortar was determined. The experimental results suggest that Clarobesa mortar is a hydraulic lime mortar. The study of salts crystallizations by Raman microscopy allowed identifying the presence of calcium sulfates with different hydration waters and also nitrates. In some samples, the concentration of sulfates was high, reaching values up to 10% w/w. Although the concentration of nitrates is not extremely high, a clear contribution of ammonium nitrates coming from the decomposition of the nearby vegetation was assessed. Since the Clarobesa mortar can be considered an important input of ions that can migrate to the joined granitic rocks, in the future, it will be recommendable to monitor possible changes in the conservation state of the joined rocks

Evaluating sulfates and nitrates as enemies of the recent constructions: Spectroscopic and thermodynamical study

Salt crystallization is one of the major problems currently faced by the field of architecture and construction. Its effects are devastating to the extent that they may even lead to loss of material. Although many innovative and resistant materials have been developed in the last years, in most of the constructions, salt crystallization is a persistent problem. Salts crystallizations are formed by the dissolution and subsequent precipitation of the soluble salts present in the material itself or due to the formation of new ones because of the reaction between original components of the building materials with salts coming from infiltration waters or with acid aerosols present in the atmosphere. Among others, some of the most common salts that can crystallize in the building materials are nitrates and sulfates. Both of them are soluble compounds, which can mobilize throughout the material easily, reprecipitate, and generate volume changes responsible for fissures, fractures, and even the loss of building material. In this work, a specific study of salts crystallizations in a recent construction erected in 2013 in Amorebieta (Basque Country, North of Spain) using a different kind of materials has been studied. The materials affected by salts are joint mortars, which in a first step were characterized by X‐ray diffraction and Raman microscopy to determine the mineralogical composition. In a second step, a soluble salts tests by ion chromatography was applied to approach quantitatively the impact of the salts. Finally, in a third step, the reactions that give rise to the decay products (thenardite, nitrocalcite, and/or epsomite mainly) were proposed and confirmed through a thermodynamic modellin

Evaluation of the role of biocolonizations in the conservation state of Machu Picchu (Peru): The Sacred Rock

Machu Picchu Inca sanctuary (Cusco Region, Peru) was constructed on a granitic plateau, better known as Vilcabamba batholith. One of the most important carved granitic rocks from this archaeological site is the Sacred Rock, used by Inca citizens for religious rituals. Due to the location and climatic conditions, different rocks from this archaeological site are affected by biocolonizations. Concretely, the Sacred Rock shows flaking and delamination problems. In this work, a non-destructive multi analytical methodology has been applied to determine the possible role of the biodeteriogens, forming the biological patina on the Sacred Rock, in the previously mentioned conservation problems. Before characterizing the biological patina, a mineralogical characterization of the granitic substrate was conducted using X-ray Diffraction, Raman microscopy (RM) and micro energy dispersive X-ray fluorescence spectrometry. For the identification of the main biodeteriogens in the biofilm, Phase Contrast Microscopy was used. RM also allowed to determine the distribution (imaging) and the penetration (depth profiling) of the biogenic pigments present in the biopatina. Thanks to this study, it was possible to asses that some colonizers are growing on inner areas of the rock, reinforcing their possible assistance in the delamination. Moreover, the in-depth distribution of a wide variety of carotenoids in the patinas allowed to approach the penetration ability of the main biodeteriogens and the diffusion of these biogenic pigments to the inner areas of the rocky substrate

In-Situ Analytical Study Of Bricks Exposed To Marine Environment Using Hand-Held X-Ray Fluorescence Spectrometry And Related Laboratory Techniques

In this work, the degradation processes that take place in bricks exposed to marine environments have been studied. Taking into account the importance of this building material where the silicates present in the final product act as stabilizer in the porous material itself, it is necessary to understand the decay processes that occur in these aggressive environments. As is known, the marine aerosol carries different types of salts, such as chlorides, sulfates, nitrates, etc., present in surrounding environment exerting a negative influence on the materials producing cracking and disintegration processes of the material and consequently loss of brick wall stability. Nowadays the development of portable devices is taking much more importance helping researchers to resolve problems in the field in a fast and easy way. In order to extract fast and satisfactory results about the conservation state of different bricks from Punta Begoña Galleries (Getxo, Basque Country, Spain), an in-situ analytical methodology was developed based on the use of hand-held Energy Dispersive X-ray fluorescence spectrometry (HH-ED-XRF) assisted with other laboratory techniques (μ-ED-XRF and X-Ray Diffraction) in order to corroborate and complement the information obtained in-situ. This construction undergoes the influence of marine aerosol, industrial port, power generation plants, and a fuel refinery among others. The pathologies visually observable in these bricks are disintegration, breakup and detachment of the bricks. The presence of deterioration compounds in the bricks has been studied according to the orientations of the bricks inside the construction

Impact assessment of metals on soils from Machu Picchu archaeological site

Machu Picchu is an archaeological Inca sanctuary from the 15th century, located 2430 m above the sea level in the Cusco Region, Peru. In 1983, it was declared World Heritage Site by UNESCO. The surroundings and soils from the entire archaeological site are carefully preserved together with its grass parks. Due to the importance of the archaeological city and its surroundings, the Decentralized Culture Directorate of Cusco-PAN Machu Picchu decided to carry out a careful monitoring study in order to determine the ecological status of the soils. In this work, elemental and molecular characterization of 17 soils collected along the entire park was performed by means of X-ray Diffraction (XRD) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after acidic digestion assisted by microwave energy. Thanks to the combination of these analytical techniques, it was possible to obtain the mineral composition and metal concentrations of all soils from these 17 sampling points. Finally, different statistical treatments were carried out in order to confirm the ecological status of the different sampling points from Machu Picchu archaeological site concluding that soils are not impacted

A comprehensive study of biofilms growing on the built heritage of a caribbean industrial city in correlation with construction materials

Biodeteriogens growing on constructions belonging to the built heritage is one of the leading natural pathologies that cause aesthetical and in some cases, physical-geochemical problems in the materials. In this study, for the first time, the chemical composition of construction materials of the built heritage from an industrialized city (Barranquilla) of Colombia have been evaluated in correlation with the algal, cyanobacterial and fungal biodeteriogens present in biofilms by applying a multianalytical methodology. To achieve this objective, samples of biofilms and construction material were taken from different historical and modern constructions. For the mineralogical characterization of the construction materials, X-ray diffraction, Raman microscopy and energy dispersive X-ray fluorescence spectrometry (EDXRF) were used. In addition, microscopic observations and cultures were employed for the microbiological characterization. Most of the construction materials analyzed belong to calcareous mortars, and others to different types of cement (portlandite, ettringite and larnite identification). The EDXRF analysis through single point and imaging strategies allowed to identify differences in the elemental composition of the external and internal parts of the materials. The role of certain elements in the mortars, which will assist the growth of specific microorganisms, is also discussed in this work. The main biodeteriogens identified in the biofilms were cyanobacteria Oscillatoria sp., Lyngbya sp., Leptolyngbya sp. and Ascomycota Aspergillus niger, Aspergillus fumigatus, Penicillium sp. and Fusarium sp fungi. These microorganisms promote biodeterioration processes causing aesthetic, physical and chemical damage to the façades of the studied buildings. The mineralogical composition of the construction material together with environmental conditions contributes to the development of biofilms on the constructions and monuments of Barranquilla city. The results obtained in this study will be used in the future to design and implement conservation protocols and strategies useful to preserve the built heritage of Caribbean cities with similar climate conditions, geographical position and kind of construction material

In situ non-invasive multianalytical methodology to characterize mosaic tesserae from the House of Gilded Cupids, Pompeii

Mosaics, one of the most important decorative artworks in the Roman culture, were usually elaborated with a set of tesserae joined with lime or others binders to form geometric or figurative decorations. The identification of both substrate and colored compounds of the tesserae is a challenge for chemists and archaeologists. In this work, two mosaics present in the House of Gilded Cupids from the Archaeological Park of Pompeii were analyzed in situ by non destructive techniques. Raman and Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopies were used for the molecular and mineralogical characterization, and hand-held energy dispersive X-ray fluorescence (HH-EDXRF) spectrometry and Laser Induced Breakdown Spectroscopy (LIBS) for the elemental analysis. LIBS in-depth analysis was performed to obtain insights about the thickness of the pictorial layer determining that the thickness of red and orange pictorial layers was higher than 140 μm. The results showed that white tesserae were mainly composed by calcite, while local black colored volcanic rocks were used to manufacture black tesserae. Red and orange tesserae were composed by a calcite-based matrix with a hematite pictorial layer applied over it. Orange color was obtained by diluting hematite in the calcite matrix. Principal component analysis (PCA) of the XRF data was performed to observe differences and/or similarities between the analyzed mosaics; the samples projection of the PCA showed clear groupings.Iker Marcaida is grateful to the Basque Government who funded his predoctoral fellowship. This work has been supported by the project MADyLIN (BIA2017‑87063‑P) funded by the Spanish Agency for Research AEI (MINEICO‑FEDER/ UE)