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This large-format, magnificently illustrated book shows the portraits and monuments that are the artistic masterpiece of antiquity in a new light . It traces the profiles of 34 Kings and queens to present an in-depth picture of the history and art of ancient Egypt and its pharaohs.

Mountainous regions are often considered pristine environments; however they can be affected by pollutants emitted in more populated and industrialised areas, transported by regional winds. Based on experimental evidence, further supported by modelling tools, here we demonstrate and quantify the impact of air masses transported from the Po Valley, a European atmospheric pollution hotspot, to the northwestern Alps. This is achieved through a detailed investigation of the phenomenology of near-range (a few hundred kilometres), trans-regional transport, exploiting synergies of multi-sensor observations mainly focussed on particulate matter. The explored dataset includes vertically resolved data from atmospheric profiling techniques (automated lidar ceilometers, ALCs), vertically integrated aerosol properties from ground (sun photometer) and space, and in situ measurements (PM10 and PM2.5, relevant chemical analyses, and aerosol size distribution). During the frequent advection episodes from the Po basin, all the physical quantities observed by the instrumental setup are found to significantly increase: the scattering ratio from ALC reaches values >30, aerosol optical depth (AOD) triples, surface PM10 reaches concentrations >100 µg m−3 even in rural areas, and contributions to PM10 by secondary inorganic compounds such as nitrate, ammonium, and sulfate increase up to 28 %, 8 %, and 17 %, respectively. Results also indicate that the aerosol advected from the Po Valley is hygroscopic, smaller in size, and less light-absorbing compared to the aerosol type locally emitted in the northwestern Italian Alps. In this work, the phenomenon is exemplified through detailed analysis and discussion of three case studies, selected for their clarity and relevance within the wider dataset, the latter being fully exploited in a companion paper quantifying the impact of this phenomenology over the long-term (Diémoz et al., 2019). For the three case studies investigated, a high-resolution numerical weather prediction model (COSMO) and a Lagrangian tool (LAGRANTO) are employed to understand the meteorological mechanisms favouring transport and to demonstrate the Po Valley origin of the air masses. In addition, a chemical transport model (FARM) is used to further support the observations and to partition the contributions of local and non-local sources. Results show that the simulations are important to the understanding of the phenomenon under investigation. However, in quantitative terms, modelled PM10 concentrations are 4–5 times lower than the ones retrieved from the ALC and maxima are anticipated in time by 6–7 h. Underestimated concentrations are likely mainly due to deficiencies in the emission inventory and to water uptake of the advected particles not fully reproduced by FARM, while timing mismatches are likely an effect of suboptimal simulation of up-valley and down-valley winds by COSMO. The advected aerosol is shown to remarkably degrade the air quality of the Alpine region, with potential negative effects on human health, climate, and ecosystems, as well as on the touristic development of the investigated area. The findings of the present study could also help design mitigation strategies at the trans-regional scale in the Po basin and suggest an observation-based approach to evaluate the outcome of their implementation.

The most important parameter to obtain an appropriate preservation condition of museum environments concerns the indoor air quality. The exposure of artwork and materials to gaseous and particulate pollutants introduced by visitors and either indoor or outdoor sources contributes to their decay. In this work, we evaluated the possible monitoring of the visitors’ influence using the stable carbon isotopic ratio of CO 2 and the concentration of NH 3 as a real-time tool. The study was done in the Refectory of Santa Maria delle Grazie (Milan, Italy) which houses one of the most important paintings of Leonardo da Vinci, the Last Supper, and had more than 400,000 visitors in 2019. The results confirmed a good correlation between the presence of tourists inside the museum and the variation of δ 13 C value during the visits and the closure of the museum. The variation of indoor atmospheric δ 13 C was influenced by the presence of visitors in the Refectory and delineates the way done from the entrance to the exit. In the same way, the concentration of NH 3 was influenced by the presence of visitors and confirmed the role of this one on preservation methodology for indoor air quality in the museum. This new methodology can be used as a supplemental and non-invasive tool to help in calibrating microclimatic conditions through the ventilation rate and air filtration systems in the museum and to manage the number of visitors per turn.

This study evaluated the reliability of an electronic nose in monitoring odour concentration near a wastewater treatment plant and examined the correlation between four sensor readings and odour intensity. The electronic nose chemical sensors are related to the concentration of the following chemical species: two values for the concentration of VOCs recorded via the PID sensor (VPID) and the EC sensor (VEC), and concentrations of sulfuric acid (VH2S) and benzene (VC6H6). Using Random Forest and least squares regression analysis, the study identifies VH2S and VC6H6 as key contributors to odour concentration (CcOD). Three Random Forest models (RF0, RF1, RF2), with different characteristics for splitting between the test set and the training set, were tested, with RF1 showing superior predictive performance due to its training approach. All models highlighted VH2S and VC6H6 as significant predictors, while VPID and VEC had less influence. A significant correlation between odour concentration and specific chemical sensor readings was found, particularly for VH2S and VC6H6. However, predicting odour concentrations below 1000 ouE/m3 proved challenging. Linear regression further confirmed the importance of VH2S and VC6H6, with a moderate R-squared value of 0.70, explaining 70% of the variability in odour concentration. The study demonstrated the effectiveness of combining Random Forest and least squares regression for robust and interpretable results. Future research should focus on expanding the dataset and incorporating additional variables to enhance model accuracy. The findings underscore the necessity of specific sensor training and standardised procedures for accurate odour monitoring and characterisation.

During the summers of 2011 and 2012, two scientific cruises were carried out over the Arctic Ocean aiming at the determination of the aerosol chemical composition in this pristine environment. First, mass spectrometry was applied to study the concentration and gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. Experimental and modelled data of phase partitioning were compared: results demonstrated an equilibrium between gas and particle phase for PAHs, while n-alkanes showed a particle-oriented partitioning, due to the local marine origin of them, confirmed by the extremely low value of their carbon preference index. Moreover, the inorganic and organic ions (carboxylic acids and amines) concentrations, together with those of elemental carbon (EC) and organic matter (OM), were analyzed: 63% of aerosol was composed of ionic compounds (>90% from sea-salt) and the OM content was very high (30.5%; close to 29.0% of Cl−) in agreement with n-alkanes’ marine signature. Furthermore, the amines’ (dimethylamine, trimethylamine, diethylamine) concentrations were 3.98 ± 1.21, 1.70 ± 0.82, and 1.06 ± 0.56 p.p.t.v., respectively, fully in keeping with concentration values used in the CLOUD (Cosmics Leaving OUtdoor Droplet)-chamber experiments to simulate the ambient nucleation rate in a H2SO4-DMA-H2O system, showing the amines’ importance in polar regions to promote new particle formation. Finally, high resolution mass spectrometry was applied to determine trace elements, including Rare Earth Elements (REEs), highlighting the dominant natural versus anthropic inputs for trace metals (e.g., Fe, Mn, Ti vs. As, Cd, Ni) and possible signatures of such anthropic activity.

Formaldehyde (H−CHO) is a chemical compound extremely common in many industrial productions. However, in 2004, it was reclassified as carcinogenic (H350) and mutagenic (H341). Therefore, stringent limitations on emissions were implemented; among them, the lowest limit (3 mg/m3) was adopted by some Italian Local Competent Authorities. Up to now, no European-validated method for emission control was available, and for this reason, a specific working group (WG 40) has been created in the framework of the European Committee for Standardization Technical Committees 264 (CEN TC 264) to publish a qualified method for the quantification of Formaldehyde emissions from stationary sources (i.e., power stations, incinerators, petrochemicals, and industrial plants that uses combustion for their energetic purposes). Some preliminary trial tests were conducted to evaluate (1) the sampling protocol, and (2) the analytical technique. From a measurement perspective, two methods were selected: EPA 323—VDI 3862-6 and VDI 3862-2. Every new method prepared by CEN shall be verified before publication in the field and in real conditions to verify its metrological properties (i.e., precision, biases, reproducibility, and repeatability), costs and the training needs for involved personnel. With this aim, two measuring campaigns were conducted, and some important conclusions emerged concerning the H−CHO sampling procedure. Due to high water levels normally present, condensation during sampling is critical and can cause unpredictable errors; wet traps (impingers) give good responses. The sampling in pure water appeared unstable, but using an H2SO4 solution solved this issue, thus being recommended.

Atmospheric aerosols play an important role in Earth’s radiative balance, directly interacting with solar radiation or influencing cloud formation and properties. In order to assess their radiative impact, it is necessary to accurately characterise their optical properties, together with their spatial and vertical distribution. The information on aerosol vertical profile is often scarce, in particular in mountainous, complex terrains. This study presents the first attempt to evaluate the shortwave aerosol direct radiative effect in the Aosta Valley, a mountainous region in the Northwestern Italian Alps. Ground-based, remote sensing instruments (a sky radiometer and an Automated Lidar Ceilometer) are used to derive two descriptions of the aerosol properties and vertical distribution: a first, more accurate description, which includes the whole spectral information about the aerosol extinction coefficient, phase function and single scattering albedo; a second, more approximate one, which only relies on spectrally constant values of aerosol single scattering albedo and asymmetry factor. This information is used as input for radiative transfer simulations, which allow to estimate, in cloudless conditions, the shortwave aerosol direct radiative effect and the vertical profile of the instantaneous heating rates in the lower layers of the atmosphere. The simulations obtained with the two descriptions do not differ significantly: they highlight a strong surface dimming (between − 25 and − 50 W m− 2) due to the presence of aerosol, with a considerable radiative absorption inside the atmospheric column (around + 30 W m− 2), and an overall small cooling effect for the Earth-atmospheric system. The absorption of solar radiation within the atmospheric column due to aerosol leads to instantaneous heating rates up to 1.5 K day− 1 in the tropospheric layers below 6 km a.s.l. These results show that, in some conditions, the shortwave aerosol direct radiative effect can be considerable even in this Alpine environment, usually considered as relatively pristine (yearly average PM10 concentration about 20 μg m− 3).

The reliability of the national power grid is a key issue in modern society. Atmospheric aerosols are the main cause of the reduction in the performance of insulators and the increase in the possibility of flashovers, resulting in power line failures. Under high ambient humidity, the water-soluble compounds of atmospheric aerosols collected on the insulators’ surface can dissociate in ions and form a conductive layer, which may lead to flashover events. With a view to investigating the processes that drive these phenomena, the chemical composition of aerosol deposits on insulators in Italy was determined by ion chromatography analysis and thermos-optical and X-ray techniques. In addition, a synthetic aerosol with the same analyzed chemical composition was generated in a laboratory and deposited on PTFE filters and glass specimens allowing us to determine the deliquescence and crystallization relative humidity and the conductive effect in an aerosol exposure chamber. The results evidenced the presence of a hazardous inorganic ion layer, which generates a sharp phase transition of the aerosol deposit as a function of the ambient relative humidity; this layer poses a dangerous threat to the reliability of the power grid, increasing the probability of flashover events where the conductive layer facilitates the flow of electrical current across the insulator surface, potentially causing power outages or damage to the power lines.

Biomass burning related aerosol episodes are becoming a serious threat to the radiative balance of the Arctic region. Since early July 2017 intense wildfires were recorded between August and September in Canada and Greenland, covering an area up to 4674 km2 in size. This paper describes the impact of these biomass burning (BB) events measured over Svalbard, using an ensemble of ground-based, columnar, and vertically-resolved techniques. BB influenced the aerosol chemistry via nitrates and oxalates, which exhibited an increase in their concentrations in all of size fractions, indicating the BB origin of particles. The absorption coefficient data (530 nm) at ground reached values up to 0.6 Mm–1, highlighting the impact of these BB events when compared to average Arctic background values, which do not exceed 0.05 Mm–1. The absorption behavior is fundamental as implies a subsequent atmospheric heating. At the same time, the AERONET Aerosol Optical Depth (AOD) data showed high values at stations located close to or in Canada (AOD over 2.0). Similarly, increased values of AODs were then observed in Svalbard, e.g., in Hornsund (daily average AODs exceeded 0.14 and reached hourly values up to 0.5). Elevated values of AODs were then registered in Sodankylä and Andenes (daily average AODs exceeding 0.150) a few days after the Svalbard observation of the event highlighting the BB columnar magnitude, which is crucial for the radiative impact. All the reported data suggest to rank the summer 2017 plume of aerosols as one of the biggest atmosphere related environmental problems over Svalbard region in last 10 years.

Light-absorbing aerosols (LAA) impact the atmosphere by heating it. Their effect in the Arctic was investigated during two summer Arctic oceanographic campaigns (2018 and 2019) around the Svalbard Archipelago in order to unravel the differences between the Arctic background and the local anthropic settlements. Therefore, the LAA heating rate (HR) was experimentally determined. Both the chemical composition and high-resolution measurements highlighted substantial differences between the Arctic Ocean background (average eBC concentration of 11.7 ± 0.1 ng/m3) and the human settlements, among which the most impacting appeared to be Tromsø and Isfjorden (mean eBC of 99.4 ± 3.1 ng/m3). Consequently, the HR in Isfjorden (8.2 × 10−3 ± 0.3 × 10−3 K/day) was one order of magnitude higher than in the pristine background conditions (0.8 × 10−3 ± 0.9 × 10−5 K/day). Therefore, we conclude that the direct climate impact of local LAA sources on the Arctic atmosphere is not negligible and may rise in the future due to ice retreat and enhanced marine traffic.