When Red Turns Black: Influence of the 79 AD Volcanic Eruption and Burial Environment on the Blackening/Darkening of Pompeian Cinnabar.

It is widely known that the vivid hue of red cinnabar can darken or turn black. Many authors have studied this transformation, but only a few in the context of the archeological site of Pompeii. In this work, the co-occurrence of different degradation patterns associated with Pompeian cinnabar-containing fresco paintings (alone or in combination with red/yellow ocher pigments) exposed to different types of environments (pre- and post-79 AD atmosphere) is reported. Results obtained from the in situ and laboratory multianalytical methodology revealed the existence of diverse transformation products in the Pompeian cinnabar, consistent with the impact of the environment. The effect of hydrogen sulfide and sulfur dioxide emitted during the 79 AD eruption on the cinnabar transformation was also evaluated by comparing the experimental evidence found on paintings exposed and not exposed to the post-79 AD atmosphere. Our results highlight that not all the darkened areas on the Pompeian cinnabar paintings are related to the transformation of the pigment itself, as clear evidence of darkening associated with the presence of manganese and iron oxide formation (rock varnish) on fragments buried before the 79 AD eruption has also been found.

Elucidation of the Chemical Role of the Pyroclastic Materials on the State of Conservation of Mural Paintings from Pompeii.

Pyroclastic strata have always been thought to protect the archaeological remains of the Vesuvian area (Italy), hence allowing their conservation throughout the centuries. In this work, we demonstrate that they constitute a potential threat for the conservation state of the mural paintings of Pompeii. The ions that could be leached from them and the ion-rich groundwater coming from the volcanic soil/rocks may contribute to salt crystallisation. Thermodynamic modelling not only allowed to predict which salts can precipitate from such leaching events but also assisted the identification of additional sources of sulfates and alkali metals to explain the formation of the sulfates identified in efflorescences from the mural paintings of Pompeii. For the future, fluorine, mainly related to a volcanic origin, can be proposed as a marker to monitor the extent of the impact in the mural paintings of Pompeii in situ.

Long-term in situ non-invasive spectroscopic monitoring of weathering processes in open-air prehistoric rock art sites.

In this work, an innovative non-destructive monitoring methodology based on the analysis over time of open-air rock art sites is presented. This approach is based on the combination of in situ spectroscopic and chemometric studies to diagnose and monitor the state of conservation of rock art sites. Data acquired over a period of time by non-invasive analytical techniques such as portable Raman spectrometry (RS) and handheld energy-dispersive X-ray fluorescence (HH-EDXRF) spectrometry are compared to detect physicochemical changes that could affect the rock painting integrity. To demonstrate the applicability of the proposed procedure, three analysis campaigns (between 2013 and 2016) were carried out, analyzing Levantine rock pictographs preserved in the rock shelter of Solana de las Covachas VI (Albacete, Spain; see Electronic Supplementary Material (ESM) Fig. S1). The analyzed areas showed different types of active weathering processes such as gypsum and calcium oxalate formation, giving rise to conservation issues such as painting fading, surface loss, microbial colonizations, and formation of crusts. Results evidence that the proposed methodology can be very useful to monitor chemical changes in the surface of the walls where the rock art is located, thus obtaining crucial information for its preservation and management.

Raman imaging to quantify the thermal transformation degree of Pompeian yellow ochre caused by the 79 AD Mount Vesuvius eruption.

Most of the wall paintings from Pompeii are decorated with red and yellow colors but the thermal impact of 79 AD Mount Vesuvius eruption promoted the partial transformation of some yellow-painted areas into red. The aim of this research is to develop a quantitative Raman imaging methodology to relate the transformation percentage of yellow ochre (goethite, α-FeOOH) into red color (hematite, α-Fe2O3) depending on the temperature, in order to apply it and estimate the temperature at which the pyroclastic flow impacted the walls of Pompeii. To model the thermal impact that took place in the year 79 AD, nine wall painting fragments recovered in the archeological site of Pompeii and which include yellow ochre pigment were subjected to thermal ageing experiments (exposition to temperatures from 200 to 400 °C every 25 °C). Before the experiments, elemental information of the fragments was obtained by micro-energy dispersive X-ray fluorescence (µ-ED-XRF). The fragments were characterized before and after the exposition using Raman microscopy to monitor the transformation degree from yellow to red. The quantitative Raman imaging methodology was developed and validated using synthetic pellets of goethite and hematite standards. The results showed almost no transformation (0.5% ± 0.4) at 200 °C. However, at 225 °C, some color transformation (26.9% ± 2.8) was observed. The most remarkable color change was detected at temperatures between 250 °C (transformation of 46.7% ± 1.7) and 275 °C (transformation of 101.1% ± 1.2). At this last temperature, the transformation is totally completed since from 275 to 400 °C the transformation percentage remained constant.

Usefulness of a Dual Macro- and Micro-Energy-Dispersive X-Ray Fluorescence Spectrometer to Develop Quantitative Methodologies for Historic Mortar and Related Materials Characterization.

Wavelength dispersive X-ray fluorescence (WD-XRF) spectrometry has been widely used for elemental quantification of mortars and cements. In this kind of instrument, samples are usually prepared as pellets or fused beads and the whole volume of sample is measured at once. In this work, the usefulness of a dual energy dispersive X-ray fluorescence spectrometer (ED-XRF), working at two lateral resolutions (1 mm and 25 µm) for macro and microanalysis respectively, to develop quantitative methods for the elemental characterization of mortars and concretes is demonstrated. A crucial step before developing any quantitative method with this kind of spectrometers is to verify the homogeneity of the standards at these two lateral resolutions. This new ED-XRF quantitative method also demonstrated the importance of matrix effects in the accuracy of the results being necessary to use Certified Reference Materials as standards. The results obtained with the ED-XRF quantitative method were compared with the ones obtained with two WD-XRF quantitative methods employing two different sample preparation strategies (pellets and fused beads). The selected ED-XRF and both WD-XRF quantitative methods were applied to the analysis of real mortars. The accuracy of the ED-XRF results turn out to be similar to the one achieved by WD-XRF, except for the lightest elements (Na and Mg). The results described in this work proved that µ-ED-XRF spectrometers can be used not only for acquiring high resolution elemental map distributions, but also to perform accurate quantitative studies avoiding the use of more sophisticated WD-XRF systems or the acid extraction/alkaline fusion required as destructive pretreatment in Inductively coupled plasma mass spectrometry based procedures.

Non-destructive characterisation of the Elephant Moraine 83227 meteorite using confocal Raman, micro-energy-dispersive X-ray fluorescence and Raman-scanning electron microscope-energy-dispersive X-ray microscopies.

The application of a non-destructive analytical procedure to characterise the mineral phases in meteorites is a key issue in order to preserve this type of scarce materials. In the present work, the Elephant Moraine 83227 meteorite, found in Antarctica in 1983 and originated from 4 Vesta asteroid, was analysed by micro-Raman spectroscopy, micro-energy-dispersive X-ray fluorescence and the structural and chemical analyser (Raman spectroscopy coupled with scanning electron microscopy-energy-dispersive spectroscopy) working in both point-by-point and image modes. The combination of all these techniques allows the extraction of, at the same time, elemental, molecular and structural data of the studied microscopic area of the meteorite. The most relevant results of the Elephant Moraine 83227 were the finding of tridymite for the first time in a 4 Vesta meteorite, along with quartz, which means that the meteorite suffered high temperatures at a certain point. Moreover, both feldspar and pyroxene were found as the main mineral phases in the sample. Ilmenite, apatite, chromite and elemental sulphur were also detected as secondary minerals. Finally, calcite was found as a weathering product, which was probably formed in terrestrial weathering processes of the pyroxene present in the sample. Besides, Raman spectroscopy provided information about the conditions that the meteorite experienced; the displacements in some feldspar Raman bands were used to estimate the temperature and pressure conditions to which the Elephant Moraine 83227 was subjected, because we obtained both low and high formation temperature feldspar.

Development of X-ray Fluorescence Quantitative Methodologies To Analyze Aqueous and Acid Extracts from Building Materials Belonging to Cultural Heritage.

Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is widely used in art and cultural heritage for direct measurements and elemental quantification of solid samples. However, in the literature there are not works dealing with the quantitative application of ED-XRF to liquid extracts coming from samples belonging to cultural heritage. In this work, a novel methodology based on the use of ED-XRF spectrometry after thin film deposition on special sample retainers and a subsequent evaporation was developed to quantify light elements (Z ≤ 20) in aqueous extracts and heavy elements (Z > 20) in acid extracts, coming from materials and degradation products belonging to built heritage (mortars, black crusts, and calcium carbonate formations). For this purpose, special sample retainers were used instead of more common adsorbent filter papers. Three different ED-XRF calibration methodologies were designed as elemental quantification tools and "green chemistry" alternatives to conventional techniques. On the one hand, the developed external ED-XRF calibration methodology for elements with Z ≤ 20 was proposed as an alternative to ion chromatography to obtain information about the degradation processes that the building materials suffered. On the other hand, the external ED-XRF calibration for elements with Z > 20 in acid extracts was optimized as a faster and cleaner quantification alternative to inductively coupled plasma mass spectrometry (ICPMS). Finally, with the aim to reduce the matrix effect and to improve the quantitative results for elements with Z > 20 in acid extracts, a novel ED-XRF calibration methodology based on standard additions was successfully designed and applied to real samples belonging to built heritage.

Influence of the Cation Adducts in the Analysis of Matrix-Assisted Laser Desorption Ionization Imaging Mass Spectrometry Data from Injury Models of Rat Spinal Cord.

Imaging mass spectrometry (IMS) is quickly becoming a technique of reference to visualize the lipid distribution in tissue sections. Still, many questions remain open, and data analysis has to be optimized to avoid interpretation pitfalls. Here we analyze how the variation on the [Na+]/[K+] relative abundance affects the detection of lipids between sections of spinal cord of (uninjured) control rats and of models of spinal cord demyelination and traumatic contusion injury. The [M + Na]+/[M + K]+ adducts ratio remained approximately constant along transversal and longitudinal sections of spinal cord from control animals, but it strongly changed depending on the type of lesion. A substantial increase in the abundance of [M + Na]+ adducts was observed in samples from spinal cord with demyelination, while the intensity of the [M + K]+ adducts was stronger in those sections from mechanically injured spinal cords. Such changes masked the modifications in the lipid profile due to the injury and only after summing the signal intensity of all adducts and corresponding monoprotonated molecular ions of each detected lipid in a single variable, it was possible to unveil the real changes in the lipid profile due to the lesion. Such lipids included glycerophospholipids (both diacyl and aryl-acyl), sphingolipids, and nonpolar lipids (diacyl and triacylglycerols), which are the main lipid classes detected in positive-ion mode. Furthermore, the results demonstrate the sensitivity of the technique toward modification in tissue homeostasis and that the [M + Na]+/[M + K]+ ratio may be used to detect alterations in such homeostasis.

Optimization of sample treatment for the identification of anthraquinone dyes by surface-enhanced Raman spectroscopy.

The study and characterization of old artifacts such as pigments requires the use of techniques that need a small amount of sample to perform the analysis because of the high value of these samples. In recent years, organic molecules such as anthraquinone dyes have been identified by surface-enhanced Raman spectroscopy (SERS). However, different sample treatments must be applied to isolate the organic dye from the mordant, which produces great fluorescence in the Raman measurements. In this work, optimization of sample treatment for the SERS analysis of anthraquinone dyes was performed. Sample mass, the organic solvent, and its volume were optimized and different slide materials and excitation lasers were compared to choose the best conditions for the identification of the dyes. The optimization of sample treatment resulted in 5 mg of sample as the optimum amount. Further, two consecutive extractions with 0.5 mL of ethyl acetate was the best option for the extraction of the dye. A quartz slide was used instead of a glass slide to reduce background signal, and an excitation laser of 532 nm offers better results than one of 785 nm. The optimized method was applied to the characterization of the dyes used in Pompeian pink and purple lake pigments. Alizarin and purpurin anthraquinone dyes, obtained from madder lake, were identified as the organic colorants. The SERS results were confirmed by those obtained by means of UV-visible spectroscopy. Graphical Abstract ᅟ.

In situ X-ray fluorescence-based method to differentiate among red ochre pigments and yellow ochre pigments thermally transformed to red pigments of wall paintings from Pompeii.

Most of the magnificent wall paintings from the ancient city of Pompeii are decorated with red and yellow colors coming from the ochre pigments used. The thermal impact of the pyroclastic flow from the eruption of Vesuvius, in AD 79, promoted the transformation of some yellow painted areas to red. In this work, original red ochre, original yellow ochre, and transformed yellow ochre (nowadays showing a red color) of wall paintings from Pompeian houses (House of Marcus Lucretius and House of Gilded Cupids) were analyzed by means of a handheld energy-dispersive X-ray fluorescence spectrometer to develop a fast method that allows chemical differentiation of the original red ochre and the transformed yellow ochre. Principal component analysis of the multivariate obtained data showed that arsenic is the tracer element to distinguish between both red colored ochres. Moreover, Pompeian raw red and yellow ochre pigments recovered from the burial were analyzed in the laboratory with use of a benchtop energy-dispersive X-ray fluorescence spectrometer to confirm the elemental composition and the conclusions drawn from the in situ analysis according to the yellow ochre pigment transformation in real Pompeian wall paintings.

Multispectroscopic and Isotopic Ratio Analysis To Characterize the Inorganic Binder Used on Pompeian Pink and Purple Lake Pigments.

Because of the fact that pigments are not ubiquitous in the archeological record, the application of noninvasive analytical methods is a necessity. In this work, pink and purple lake pigments recovered from the excavations of the ancient city of Pompeii (Campania, Italy) and preserved in their original bowls at the Naples National Archaeological Museum (Italy) were analyzed to characterize the composition of their inorganic binders (mordants). In situ preliminary analyses using a hand-held energy dispersive X-ray fluorescence spectrometer (HH-ED-XRF) allowed us to determine the use of an aluminosilicate enriched in Cu and Pb. Scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM-EDS) and benchtop ED-XRF analyses confirmed these results, while inductively coupled plasma mass spectrometry (ICPMS) allowed one to determine the concentration of major, minor, and trace elements. The use of other techniques such as X-ray diffraction (XRD), and micro-Raman and infrared spectroscopies allowed one to characterize the pigments at the molecular level. The high concentration of Cu detected in the pigments (1228-12937 µg g(-1)) could be related to the addition of Cu salts to obtain the desired final hue. The concentrations of Pb (987-2083 µg g(-1)) was also remarkable. Lead isotopic ratio analysis ((206)Pb/(207)Pb) suggested a possible origin related to the leaching of the ancient lead pipes from Pompeii and the subsequent transfer to the buried pigments or to the inorganic binder. Molecular analysis also showed that the binder is composed of an allophane-like clay. Moreover, it was possible to determine that to obtain the final purple hue of a specific pigment, Pompeian blue pigment was also mixed into the dyed clay.

The cauliflower-like black crusts on sandstones: A natural passive sampler to evaluate the surrounding environmental pollution.

Black crust in buildings can be formed as a result of different kind of chemical and physical reactions between the stone surface and environmental factors (e.g. acid aerosols emitted to the atmosphere, airborne particulate matter, etc.). Moreover, biological colonizations can also be present on them. This kind of pathology is widely present in limestones, but fewer are the case study dealing with the characterization of black crusts on sandstones. In this work we present an innovative methodology based on the use of cauliflower-like black crusts formed on sandstone material as natural passive sampler to evaluate the environmental pollution related with the emission of natural (crustal particles and marine aerosol particles) and metallic elements in the airborne particulate matter from the surrounding atmosphere. To illustrate its usefulness, different cauliflower-like black crusts growing in areas protected from the rain growing in an historical construction, La Galea Fortress, made up of sandstone and placed in the Abra Bay (Getxo, Basque Country, Spain) were characterized. This area suffers the anthropogenic emissions coming from the surrounding industry, traffic, sea port, and the natural ones coming from the surrounding marine atmosphere. The applied analytical methodology began with a previous elemental in situ screening in order to evaluate and compare the presence of the metals trapped in black crusts from different orientations using a hand-held energy dispersive X-Ray Fluorescence spectrometer. After this preliminary study, samples of black crusts were taken in order to characterize them in the laboratory using molecular techniques (Raman spectroscopy and XRD) and elemental techniques (ICP-MS, SEM-EDS and micro energy dispersive X-Ray Fluorescence). With the last two elemental techniques, imaging analyses were performed at different lateral resolutions in order to observe the distribution of the metals and other kind of particles trapped in the black crust samples. Additionally, a biological colonization found beneath the black crusts was also characterized using Phase Contrast microscopy.

A novel method for the identification of inorganic and organic gunshot residue particles of lead-free ammunitions from the hands of shooters using scanning laser ablation-ICPMS and Raman micro-spectroscopy.

A method based on scanning laser ablation and inductively coupled plasma-mass spectrometry (SLA-ICPMS) and Raman micro-spectroscopy for the detection and identification of compounds consistent with gunshot residue particles (GSR) has been developed. The method has been applied to the characterization of particles resulting from the discharge of firearms using lead-free ammunition. Modified tape lifts were used to collect the inorganic and organic residues from skin surfaces in a single sample. Using SLA-ICPMS, aggregates related to the composition of the ammunition, such as Cu-Zn-Sn, Zr-Sr, Cu-Zn, Al-Ti, or Al-Sr-Zr were detected, but this composition is only consistent with GSR from lead-free ammunitions. Additional evidence was provided by micro-Raman spectroscopy, which identified the characteristic organic groups of the particles as centralite, diphenylamine or their nitrated derivatives, which are indicative of GSR.

Evaluation of antimony availability in a mining context: Impact for the environment, and for mineral exploration and exploitation.

This work aims to establish Sb mobility, its transfer to biota and its effect on soil health in a semi-arid climate. The results show the presence of stibnite (Sb2S3) as the main primary Sb compound, bindhemite (Pb2Sb2O6(O,OH)), and minor proportions of stibiconite (Sb3+(Sb5+)2O6(OH)) as oxidised Sb species. This research also observes very high total Sb contents in mining materials (max: 20,000 mg kg-1) and soils (400-3000 mg kg-1), with physical dispersion around mining materials restricted to 450 m. The soil-to-plant transfer is very low, (bioaccumulation factor: 0.0002-0.1520). Most Sb remains in a residual fraction (99.9%), a very low fraction is bound to Fe and Mn oxy-hydroxides or organic matter, and a negligible proportion of Sb is leachable. The higher Sb mobility rates has been found under oxidising conditions with a long contact time between solids and water. The main factors that explain the poor Sb mobility and dispersion in the mining area are the low annual rainfall rates that slow down the Sb mobilisation process and the scarce formation of oxidised Sb compounds. All these data suggest poor Sb (III) formation and a low toxicological risk in the area associated with past mining activities. The low mobility of Sb suggests advantages for future sustainable mining of such ore deposits in a semi-arid climate and is also indicative of the limitations of geochemical exploration in the search for new Sb deposits.

Elemental imaging approach to assess the ability of subaerial biofilms growing on constructions located in tropical climates as potential biomonitors of atmospheric heavy metals pollution.

Over the last decades, the concern about air pollution has increased significantly, especially in urban areas. Active sampling of air pollutants requires specific instrumentation not always available in all the laboratories. Passive sampling has a lower cost than active alternatives but still requires efforts to cover extensive areas. The use of biological systems as passive samplers might be a solution that provides information about air pollution to assist decision-makers in environmental health and urban planning. This study aims to employ subaerial biofilms (SABs) growing naturally on façades of historical and recent constructions as natural passive biomonitors of atmospheric heavy metals pollution. Concretely, SABs spontaneously growing on constructions located in a tropical climate, like the one of the city of Barranquilla (Colombia), have been used to develop the methodological approach here presented as an alternative to SABS grown under laboratory conditions. After a proper identification of the biocolonizers in the SAB through taxonomic and morphological observations, the study of the particulate matter accumulated on the SABs of five constructions was conducted under a multi-analytical approach based mainly on elemental imaging studies by micro Energy Dispersive X-ray fluorescence spectrometry (µ-EDXRF) and Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectrometry (SEM-EDS) techniques, trying to reduce the time needed and associated costs. This methodology allowed to discriminate metals that are part of the original structure of the SABs, from those coming from the anthropogenic emissions. The whole methodology applied assisted the identification of the main metallic particles that could be associated with nearby anthropogenic sources of emission such as Zn, Fe, Mn, Ni and Ti by SEM-EDS and by µ-EDXRF Ba, Sb, Sn, Cl and Br apart others; revealing that it could be used as a good alternative for a rapid screening of the atmospheric heavy metals pollution.

Thermodynamic and spectroscopic speciation to explain the blackening process of hematite formed by atmospheric SO2 impact: the case of Marcus Lucretius House (Pompeii).

After many decades exposed to a polluted environment, in some areas of Marcus Lucretius House, there are clear signs that plasters and hematite pigments are suffering deterioration. In the exhaustive analysis of the black layer covering the red pigment hematite it was possible to identify magnetite (Fe(3)O(4)) as responsible for the black colour, which always appears in combination with gypsum. Thermodynamic modelling stated that the presence of gypsum as well as the transformation of hematite into magnetite is a consequence of the attack of atmospheric SO(2).

Naturally growing grimmiaceae family mosses as passive biomonitors of heavy metals pollution in urban-industrial atmospheres from the Bilbao Metropolitan area.

In analytical chemistry, biomonitoring is known as the methodology, which consider the use of living organisms to monitor and assess the impact of different contaminants in a known area. This type of monitoring is a relatively inexpensive method and easy to implement, being a viable alternative to be developed in sites where there is no infrastructure/instruments for a convenctional air quality monitoring. These organisms, having the capability to monitor the pollution, are also known as passive biomonitors (PBs), since they are able to identify possible contamination sources without the need of any additional tool. In this work, a multianalytical methodology was applied to verify the usefulness of naturally growing Grimmia genus mosses as PBs of atmospheric heavy metals pollution. Once mosses were identified according to their morphology and taxonomy, thei ability to accumulate particulate matter (PM) was determined by SEM. EDS coupled to SEM also allowed to identify the main metallic particles deposited and finally, an acid digestion of the mosses and a subsequent ICP-MS study define more precisely the levels of metals accumulated on each collected moss. The study was focused on six sampling locations from the Bilbao Metropolitan area (Biscay, Basque Country, north of Spain). The experimental evidences obtained allowed to propose naturally growing Grimmia genus as PB of atmospheric heavy metals pollution and to identify the anthropogenic sources that contribute to the emission of the airborne particulate matter rich in metals, evaluating in this sense the atmospheric heavy metals pollution of the selected locations.

Chemometrics and elemental mapping by portable LIBS to identify the impact of volcanogenic and non-volcanogenic degradation sources on the mural paintings of Pompeii.

Crystallization of soluble salts is a common degradation phenomenon that threatens the mural paintings of Pompeii. There are many elements that contribute to the crystallization of salts on the walls of this archaeological site. Notably, the leachates of the pyroclastic materials ejected in 79 AD by Mount Vesuvius and local groundwater, rich in ions from the erosion of volcanic rocks. Both sources could contribute to increase the concentration of halides (fluorides and chlorides) and other salts in these walls. The distribution of volcanogenic salts and their impact on the conservation of Pompeian mural paintings have however not yet been fully disclosed. In this work, an analytical methodology useful to determine the impact of the main sources of degradation affecting the mural paintings of Pompeii is presented. This methodology combines the creation of qualitative distribution maps of the halogens (CaF and CaCl) and related alkali metals (Na and K) by portable Laser Induced Breakdown Spectroscopy (LIBS) and a subsequent Principal Component Analysis of these data. Such maps, together with the in-situ identification of sulfate salts by portable Raman spectroscopy, provided information about the migration and distribution of volcanogenic halides and the influence of ions coming from additional sources (marine aerosol and modern consolidation mortars). Additionally, the thermodynamic modeling developed using the experimentally determined ionic content of Pompeian rain- and groundwater allowed to determine their specific role in the formation of soluble salts in the mural paintings of Pompeii.

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.

PM10 spatial distribution and metals speciation study in the Bilbao metropolitan area during the 2017-2018 period.

Speciation of respirable particles is becoming increasingly important from an epidemiological and analytical point of view to determine the potential effects of air pollution on human health. For this reason, current laws and analytical sampling methods focus on particle size, as it turns out to be the main factor for the greater or lesser penetration into the airways. In this sense, particles of less than 10 µm in diameter (<10 µm), referred to as PM10, are the particles that have a higher capacity for access to the respiratory tract and, therefore, more significant effect on them. In this sense, one of the most important factors that have a key role in the PM10 atmospheric pollution effect is the dispersion effect with the direct influence of natural effects such as wind, rain, topography apart from others. In this work, PM10 data extracted from the Basque Government environmental stations (19 sampling points) in the Biscay province (Basque Country, north of Spain) were combined with the results obtained from the use of self-made passive samplers (SMPS) in the same sampling points areas and subsequently, the sample analysis with a non-invasive elemental technique (Scanning Electron Microscope coupled to Energy Dispersive X-ray Spectrometry) was carried out. Thanks to this methodology, it was possible to determine a wide variety of metals in PM10 such as Al, Fe, Cr, Ni, Pb, Zn, Ti, etc. Most of them present as oxides and others as part of natural aggregations such as quartz, aluminosilicates, phosphates etc.