Atmospheric pollution affects the reliability of electric power systems by contaminating insulators with aerosol deposits, increasing surface conductivity and the risk of flashover events. This study examines the chemical composition and phase transitions of these deposits using ISORROPIA II, a thermodynamic model. Unlike standard atmospheric aerosols, insulator deposits are ammonium-poor and rich in crustal species, leading to model discrepancies. Experimental validation in an Aerosol Exposure Chamber identified necessary coding refinements, improving ISORROPIA’s predictive accuracy. This research enhances predictive models for power grid maintenance, contributing to a more reliable Italian electric system by mitigating contamination-related risks.

A catalytic stripper integrated with a plate electrostatic aerosol classifier (CS+EAC) was designed. The electric field force within the EAC reduces the influence of thermophoretic forces on particles, resulting in improved particle penetration efficiency. The experimental results show that the penetration efficiencies of 23 nm-100 nm particles are all improved when 168 V is applied to the EAC. The 33% improvement at 23 nm and the smoother penetration efficiency curve across the 23–100 nm range will enable the portable emission measurement system (PEMS) to derive a particle concentration reduction factor that facilitates more accurate inversion of particle number concentration.

We present results from the CHOPIN (“Cleancloud Helmos OrograPhic site experimeNt”) campaign during autumn & spring (October 2024 – April 2025) at Mt.Helmos in the Peloponnese, Greece. In situ and remote sensing measurements distributed at 6 sites along the lee side of the Mt. Helmos, 4 at the Kalavrita ski Center (altitude ~ 1690 m), 1 at the foothills (altitude ~ 1747 m) and the Helmos Hellenic Atmospheric Aerosol and Climate Change station ((HAC)²) at the mountaintop (altitude ~ 2314 m) constrain aerosol-cloud interaction. We focus on the drivers of droplet formation and the degree to which clouds are aerosol- vs. velocity-limited.

In March 2024 a sampling campaign of surface snow was accomplished in North-western Greenland. Snow samples are filtered and analyzed by SEM and for ions and elements. In parallel PM10 samples are collected and chemically characterized. Dry deposition seems the main mechanism of dust deposition on the snow in the considered time range. By combining the measured dust concentration in the surface snow with modelled and measured reflectivity spectra we try to quantify the influence of deposited dust on the snow albedo. Besides, by chemical analysis of aerosol and snow samples, the possible source areas of mineral dust are investigated.

High-voltage electric transmission lines are subject to mechanical stress, weather conditions, atmospheric processes, and pollution, which affect the insulators. Particulate deposits cause inadequate insulation, flashover and failures. A model is being developed at RSE that predicts insulator contamination events through different thermodynamic, meteorological and atmospheric chemistry conditions. Chemical and microphysical characterization, along a vertical profile, of total suspended particulate and of insulator deposits, and source apportionment, were carried at a site of the Italian National Electricity System, aimed at providing experimental datasets for model predictions validation. Results and linkages with sources and weather conditions are discussed in this contribution.

The current study aims to integrate a methodology to quantify the translocation of UFPs from the nose to the olfactory (OLF) region and estimate the OLF deposition combined with an analysis of using different metrics for particles with an aerodynamic diameter smaller than 0.1 μm: mass (PM_0.1), number (PN_0.1), and surface concentration (PS_0.1). Simulations examined the source-specific impact from exposure to four distinct common urban sources: nucleation event, heating emissions, traffic emissions, and background levels. The estimation of the regional dose, clearance, and retention of UFPs in the HRT was also evaluated whilst the number of deposited particles per surface area/cell was estimated.

This study presents performance evaluation of a CEN-SMPS (CEN/TS 17434 (2020)) that will be used to identify high emitters vehicles in MITRAP project using a combined metric like total particle number (TPN) vs. solid particle number (SPN) . As the introduction of new European emission standards like Euro 6 have led to decrease in the GMDs of transport emissions (50-60 nm), the SMPS was evaluated under the novel fast-scanning mode (1-minute) for the scan range 10-237 nm. The SPN measured by the CEN-SMPS were comparatively closer (9-12% underestimation) to the reference CPC as compared to the TPN measured (17-18% underestimation).

Crop residue burning severely impacts air quality and health in India, despite regulations. This study measures black carbon (BC) at a rural stubble-burning site in Punjab and applies source apportionment techniques. The Aethalometer Model (AM), though widely used, identifies only two sources, limiting accuracy. To improve analysis, the Positive Matrix Factorization (PMF) model was also used. BC concentrations ranged from 1.45 to 85.0 µg/m³, averaging 12.6 µg/m³. AM estimated 48.5% BC from biomass burning and 51.5% from fossil fuels, while PMF identified five sources. The study found an average Absorption Ångström Exponent (AAE) of 1.7 ± 0.3.

Bioaerosols are airborne particles with biological origin. At the ASC-ChAMBRe, bioaerosol research focuses on the interaction between bacteria and air pollutants. We used different methods for ASC experiments, including monitoring bacteria total concentration with WIBS-NEO and investigating culturable/viable bacteria concentration through different approaches. These include a multi-step protocol using an Andersen impactor, an automatic custom-made tray for collecting bacteria by gravitation on petri dishes and a liquid impinger for bacterial collection on various media depending on the analytical methodology chosen for the subsequent characterization. Here we’ll present the experimental protocols, their characterization and further results.

This study compares the performance of two bioaerosol generators: the Sparging Liquid Aerosol Generator (SLAG) by CH Technologies (SLAG CH Tech.) and the 1520 Flow Focusing Monodisperse Aerosol Generator (FMAG) by TSI (1520 FMAG TSI) , focusing on the viability, culturability, and cells fragmentation of E. coli.

Fine particulate matter (PM2.5) and carbonaceous aerosols significantly affect atmospheric radiative balance and air quality due to their optical characteristics. In this study, we present a detailed look at how aerosols affect light and how they absorb light across different regions. Our research specifically investigates combustion aerosols from various urban and industrial sources, studying their absorption characteristics and impact by both in-situ and filter-based measurement methods. Such efforts allow us to study the impact of geographic and climatic factors on aerosol absorption and scattering characteristics, improving climate models and air quality assessment.

Several methods for in-situ aerosol absorption measurement exist, including optical light attenuation, photothermal interferometry, photo-acoustic spectroscopy, and extinction-minus-scattering. The STANBC project aims to establish a measurement framework for both the aerosol light absorption coefficient and its conversion to eBC mass concentration, ensuring measurement traceability, consistency, and comparability across different air quality monitoring networks in Europe. This work focuses on the comparison of different techniques for measuring light absorption and black carbon in the field. The campaign took at the at the National Center for Scientific Research “Demokritos” (DEM) monitoring station in Athens, Greece, from 25/09/2023 to 11/10/2023.

In response to the demand for high-temperature and high-concentration ultrafine particulate matter (UFPM) emissions from motor vehicles, this study independently developed an ultrafine particulate number (PN) monitor for motor vehicle exhausts, which is based on the scheme of ‘unipolar diffusion charging - flat plate electrostatic grading - differential microcurrent detection’ . Meanwhile, we have developed a set of calibration equipment for the PN monitor to meet the calibration requirements of the PN monitor.

In times of energetic transition, the resilience of the electrical system is fundamental. To give support in smartly managing the system servicing, insulators saline pollution phenomenon was studied by mean of a two-year experiment during which insulator chains were exposed outdoor. Unlike the current literature, a complete chemical approach, including Ion Chromatography and Thermal Optical analysis in Transmittance mode, was carried out. Seasonal trends could be linked to the role of the weathering and to thermodynamic evolutions of the deposits. This study represents a novelty for Italy and poses the fundamentals to manage the risk through modelling and alerting systems.

Despite the extensive knowledge on the toxicological effects of PM2.5 several grey areas remain. Among these, the understanding of the different toxicological effects of fresh versus aged particles remains poorly understood. Here we present the results obtained by coupling an online exposure module (Cultex RFS Compact) with an atmospheric simulation chamber (ChaMBRe). Ultrafine particles were produced by a lab scale laminar premixed flame using ethylene and a mixture of ethylene and ethanol. The results reported showed the importance of understanding the impact of aging processes on the toxicological properties of soot particles produced from both conventional fossil fuels and biofuels.

This study investigates the air-purifying potential of Myrtus communis, Nerium oleander, and Taxus baccata using the ChAMBRe atmospheric simulation chamber. Plants were exposed to NO₂, SOOT, DUST, and a MIX condition, with pollutant capture analyzed via scanning electron microscopy. M. communis was most effective at SOOT removal, while T. baccata and N. oleander excelled at capturing DUST. These differences persisted in mixed conditions, highlighting species-specific pollutant affinities. The findings provide valuable insights into plant-pollutant interactions, supporting urban greening strategies to improve air quality, particularly in port cities affected by high pollution levels.

Secondary organic aerosol (SOA) is important for air quality and climate. When SOA mixes with particles containing transition metals like Fe, metal-organic complexes can form, driving photochemical aging. We studied the photochemistry of α-pinene SOA formed on Fe-containing seed particles, at varying relative humidities (RH). Chemical morphology and photochemical reduction of single particles were analyzed by spectro-microscopy. SOA chemical composition and functionality varied with RH. Furthermore, Fe in SOA formed at high RH was readily photochemically reduced upon exposure to UV light, contrary to SOA formed at low RH. Demonstrating SOA formation conditions affect both chemical composition and photochemical aging.

This study focuses on detecting Saharan dust events (SDE) using in-situ aerosol optical properties and radiative forcing efficiency (RFE) at the high-altitude Helmos Hellenic Atmospheric Aerosol and Climate Change (HAC²) station in Greece. Intensive optical properties, including single scattering albedo (SSA), scattering Ångström exponent (SAE), absorption Ångström exponent (AAE), and single scattering albedo Ångström exponent (SSAAE), were assessed alongside the aerosol coarse-to-total volume concentration ratio (CV/TV). Metrics were validated using dust forecasts and air mass trajectories. During SDE, SAE and SSAAE decreased significantly, while CV/TV increased (>0.7), highlighting strong aerosol impacts on regional climate through more negative RFE.

In this study, we have designed and constructed a multifunctional bipolar electrospray aerosol generation platform, through which we systematically investigated both the charge distribution of resultant particles and the factors influencing the particle coalescence. A preliminary demonstration of the total charge measurements of sucrose particles generated by the developed bipolar ES platform as a function of feeding flow rate is presented in the article.

This study uses BLAnCA, an innovative, high-resolution laboratory instrument, to measure spectral absorption across the UV-NIR range of mineral dust samples from several arid areas around the world. The measurements reveal distinct optical properties tied to mineral composition.

We present a roadmap for providing standardised BC measurements, which follows a top-down approach, beginning with SI-traceable measurements of the aerosol absorption coefficient (babs) using in-situ reference methods with a target measurement uncertainty of ≤ 10 % (coverage factor k=2). Two measurement workshops have been successfully conducted, providing essential data to achieve the research goals: 1) two primary reference methods for aerosol light absorption have been tested and validated; these include photo-thermal interferometry and extinction-minus-scattering for at least two different wavelengths. 2) MACBC has been determined for different aerosol mixtures including bare BC, coated BC and externally mixed BC.

This study, part of the MI-TRAP EU Horizon project, employs real-time source apportionment (RT-SA) to analyze particulate matter (PM) pollution in Athens. Using the ACSM-Xact-Aethalometer (AXA) system and SoFi RT software, traffic emissions were identified as the dominant PM source, while secondary aerosols contributed over 50% of the total PM mass. Biomass burning, cooking, sea salt, and dust were also detected. A key advancement was the system’s ability to differentiate non-exhaust emissions, such as brake and tyre wear, based on their distinct temporal emission profiles. These results enhance urban air quality monitoring and support targeted pollution mitigation strategies.

Measurements were made of refractory black carbon with an extended range, single particle soot photometer, Droplet Measurement Technologies, LLC), at the Pituffik Space Base in northern Greenland, during the summer and autumn of 2024. The SP2XR measures light scattered from particles in the equivalent optical diameter (EOD) range from 100-500 nm, and mass concentration of rBC in the mass equivalent diameter (MED) range from 50 – 800 nm. In addition, an equivalent coating thickness is extracted, calculated from the EOD and MED. Measurements are being compared to a global reanalysis model and atmospheric backtrajectories to determine primary transport pathways.

A novel methodology is employed to investigate the impact of particle-specific features on resuspension, partnering a quadrupole electrodynamic trap for controlled particle fabrication and deposition with a small-scale 3D printed wind tunnel. The resuspension behaviour of two distinct particle morphologies featuring cubic structures were investigated and the resulting resuspension efficiencies demonstrate the challenges of resuspending non-spherical particles. Additional high optical and temporal resolution measurements of particle detachment were recorded with high frame rate imaging to analyse particle orientation, particle-surface contact and particle rotation during resuspension. Together these two methodologies advance our understanding of non-ideal resuspension phenomena.

Biofuels can emit ultrafine particles with distinct features compared to conventional fossil fuels. In this work, coagulation of soot nanoparticles was experimentally and numerically investigated using an atmospheric simulation chamber. Nanoparticles were produced in a laboratory flame of ethylene and ethylene/ethanol mixtures. Simulations based on Smoluchowski equation show that ethylene-flame particles coagulate with an enhancement factor β=2.2, while a larger β=2.6 is found for ethanol-doped flame. Fractal dimension optimization with a fixed β=2.2 also shows good agreement with experiments. These differences point to distinct surface functionalities potentially impacting particle-particle interaction or differences in particles' fractal properties to be further investigated.

The Helmos Hellenic Atmospheric Aerosol and Climate Change ((HAC)²) station in Greece (2314 m a.s.l.) is the only high-altitude station in the eastern Mediterranean, suitable for climate change-related studies. Two intensive campaigns with the scope of unravelling aerosol-cloud interactions took place at (HAC)2 station; the CALISHTO campaign during autumn-winter 2021-2022 and the CHOPIN campaign during autumn-winter 2024–2025. This study establishes a set of metrics for identifying the influence of Planetary Boundary Layer at (HAC)2 by a synergy of in-situ and remote sensing measurements and applying a statistical model to test their effectiveness.

Carbonaceous aerosols, comprising 20% to 50% of total aerosol mass, significantly impact climate and human health. This study examines the optical properties of aerosols from different fuel combustion processes, analyzing emissions for particle size distribution and carbon content. Experiments in the ChAMBRe chamber at Genoa University/INFN used a propane-fueled soot generator and a diesel engine running on conventional diesel and HVO. Diesel combustion produced the most light-absorbing particles, with MAC values up to 9.4 m² g⁻¹. Findings highlight the need for accurate correction factors in optical measurements and support real-time monitoring for environmental and workplace safety.

Here we present the results of several experiments, performed at ChAMBRe (Chamber for Aerosol Modelling and Bio-aerosol Research) with the aim to measure the optical properties and size distribution of aerosol generated by combustion of HVO (Hydrotreated Vegetable Oils) and diesel B7 (conformed to EN590).Results in terms of size distribution (NanoMoudi), optical properties (MWAA and BLAnCA) and EC/OC ratio (thermal-optical analyses) at each stage of fresh and aged aerosol will be presented at the conference.

Human exposure to the ultrafine fraction of particulate matter, (UFP), has serious health effects due to their ability to penetrate deep into the lungs. Traffic exhaust emissions are a major source of particulate matter in urban environments.

Volatility is one of the most important physical properties of aerosol particles, as it can provide real-time information on the particle mixing state for UFPs.

This work aims to study the volatility of aerosol particle number. The measurement campaign took place at a traffic site in Athens and compared with those recorded at a suburban research station located at the N.C.S.R. ‘Demokritos’.