Indoor and outdoor air quality in street corner kiosks in a large metropolitan area.

Poor air quality in workplaces constitutes a great concern on human health as a good fraction of our time is spent at work. In Greece, very unique workplaces are the street corner kiosks, which are freestanding boxes placed on sidewalks next to city streets and vehicular traffic, where one can find many consumer goods. As such, its employees are exposed to both outdoor and indoor air pollutants.

Aerosol characterization and peculiarities of source apportionment in Moscow, the largest and northernmost European megacity.

High population and a wide range of activities in a megacity lead to large-scale ecological consequences which require the assessment with respect to distinct characteristics of climate, location, fuel consumption, and emission sources. In-depth study of aerosol characteristics was carried out in Moscow, the largest megacity in Europe, during the cold period (autumn and winter) and in spring. PM chemical speciation based on carbonaceous matter, water-soluble ions, and elements was carried out to reconstruct the PM mass and evaluate the primary and secondary aerosol contribution.

Wildfire plume ageing in the Photochemical Large Aerosol Chamber (PHOTO-LAC).

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m and provide its figures of merit.

Elemental composition of atmospheric PM during COVID-19 lockdown and recovery periods in Moscow (April-July 2020).

Changes in the concentrations of PM-bound potentially toxic elements (PTEs) during the COVID-19 lockdown period and after the revocation of restrictions were analyzed using the data received at the Aerosol Complex of Moscow State University in April-July 2020. During the lockdown, the input of biomass combustion products enriched in PTEs from the Moscow region hindered the decrease in pollutant concentrations. After the introduction of the self-isolation regime, lower concentrations of most PTEs occurred due to the decrease in anthropogenic activity and the rainy meteorological conditions.

Industrial and wildfire aerosol pollution over world heritage Lake Baikal.

Lake Baikal is the biggest reservoir of fresh water with unique flora and fauna; presently it is negatively affected by climate change, water warming, industrial emissions, shipping, touristic activities, and Siberian forest fires. The assessment of air pollution - related Baikal's ecosystem damage is an unsolved problem. Ship, based expedition exploring the Baikal atmospheric aerosol loading, was performed over the lake area in July 2018.

Impact of Restrictive Measures during the Covid-19 Pandemic on Aerosol Pollution of the Atmosphere of the Moscow Megalopolis.

The COVID-19 pandemic has led to self-isolation and business interruptions around the world. On the basis of measurements of concentrations of an indicator of aerosol emissions from fuel combustion products-black carbon-it is shown that the decrease in economic activity had a significant effect on the pollution of the Moscow atmosphere. The decrease in the intensity of the traffic and the change in the operating mode of industrial and heat-and-power enterprises of the city during the period of restrictive measures in the spring of 2020 were determined by the dynamics of the daily and weekly trend of black carbon levels.

Effects of braking conditions on nanoparticle emissions from passenger car friction brakes.

Automobile friction brakes generate, in addition to coarse particles generated by mechanical processes, highly variable amount of nanoparticles from high temperature processes. The effects of braking conditions - speed, deceleration rate, brake rotor temperatures - on nanoparticle production were investigated here, aiming to provide practical guidance for reducing emissions through driving style and traffic management. Typical brake pads and a rotor from a common passenger car were subjected, on a brake dynamometer, to three runs of the WLTP brake cycle developed for brake wear particle measurements.

Burden of disease at the same limit of exposure to airborne polycyclic aromatic hydrocarbons varies significantly across countries depending on the gap in longevity.

Atmospheric polycyclic aromatic hydrocarbons (PAHs) disproportionately affect human health across the globe, and differential exposure is believed to drive the unequal health burden. Therefore, this study assessed and compared the burden of disease, in disability-adjusted life years (DALYs), at the same level (or limit) of exposure to atmospheric PAHs in nine countries. We calculated the DALYs per person-year per ng/m of benzo[a]pyrene from ten cancers and thirty-four non-cancer adverse outcomes using published toxicity information and country-specific disease severity.

East Siberian Arctic background and black carbon polluted aerosols at HMO Tiksi.

Assessment of Arctic pollution is hampered by a lack of aerosol studies in Northern Siberia. Black carbon observations were carried out at the Hydrometeorological Observatory Tiksi, a coast of Laptev sea, from September 2014 to September 2016. Aerosol sampling was accompanied by physico-chemical characterization.

Black Carbon Sources Constrained by Observations in the Russian High Arctic.

Understanding the role of short-lived climate forcers such as black carbon (BC) at high northern latitudes in climate change is hampered by the scarcity of surface observations in the Russian Arctic. In this study, highly time-resolved Equivalent BC (EBC) measurements during a ship campaign in the White, Barents, and Kara Seas in October 2015 are presented. The measured EBC concentrations are compared with BC concentrations simulated with a Lagrangian particle dispersion model coupled with a recently completed global emission inventory to quantify the origin of the Arctic BC.

FTIR analysis of surface functionalities on particulate matter produced by off-road diesel engines operating on diesel and biofuel.

Fourier transform infrared spectroscopy is applied as a powerful analytic technique for the evaluation of the chemical composition of combustion aerosols emitted by off-road engines fuelled by diesel and biofuels. Particles produced by burning diesel, heated rapeseed oil (RO), RO with ethylhexylnitrate, and heated palm oil were sampled from exhausts of representative in-use diesel engines. Multicomponent composition of diesel and biofuel particles reveal the chemistry related to a variety of functional groups containing carbon, hydrogen, oxygen, sulfur, and nitrogen.

Microscopic characterization of individual particles from multicomponent ship exhaust.

Particles sampled from the main and auxiliary ship diesel engine exhausts during a measurement campaign aboard a cargo ship are studied by SEM and energy-dispersive X-ray (EDX) microanalysis. Cluster analysis (CA) is applied to characterize the particles by separating them into distinct groups of similar morphology and chemical composition, representative of the particle types in the exhaust from the main and auxiliary engines. Raman microspectroscopy, Fourier transform infrared (FTIR) spectroscopy, inductively coupled plasma mass spectrometry and ion chromatography provide the criteria for the clustering of a large data set of individual particles.

Cerium dioxide nanoparticles can interfere with the associated cellular mechanistic response to diesel exhaust exposure.

The aim of this study was to compare the biological response of a sophisticated in vitro 3D co-culture model of the epithelial airway barrier to a co-exposure of CeO(2) NPs and diesel exhaust using a realistic air-liquid exposure system. Independent of the individual effects of either diesel exhaust or CeO(2) NPs investigation observed that a combined exposure of CeO(2) NPs and diesel exhaust did not cause a significant cytotoxic effect or alter cellular morphology after exposure to diesel exhaust for 2h at 20μg/ml (low dose) or for 6h at 60μg/ml (high dose), and a subsequent 6h exposure to an aerosolized solution of CeO(2) NPs at the same doses. A significant loss in the reduced intracellular glutathione level was recorded, although a significant increase in the oxidative marker HMOX-1 was found after exposure to a low and high dose respectively.

Quantification of the hygroscopic effect of soot aging in the atmosphere: laboratory simulations.

We use a laboratory approach for the quantification of the water uptake by particles with varying amounts of sulfates to simulate the aging of fossil fuel combustion particles in the atmosphere. Diesel fuel and aviation kerosene laboratory-made soots are chosen as representative of the hydrophobic fraction of diesel and aircraft engine-emitted particulates and commercial carbon blacks are used as surrogates for industry emissions. The transformation of soot hydration properties from hydrophobic, through hydrophilic, to hygroscopic is demonstrated based on the amount of water uptake by the laboratory-produced EC soot covered by sulfates as the amount of sulfate increases.

Ship particulate pollutants: characterization in terms of environmental implication.

A major aspect of monitoring the atmosphere is the quantification of man-made pollution and their interactions with the environment. Key physico-chemical characteristics of diesel exhaust particulates of sea-going ship emissions are presented with respect to morphology, microstructure, and chemical composition. Heavy fuel oil (HFO)-derived particles exhibit extremely complex chemistry.

Water interaction with laboratory-simulated fossil fuel combustion particles.

To clarify the impact of fossil fuel combustion particles' composition on their capacity to take up water, we apply a laboratory approach in which the method of deposition of compounds, identified in the particulate coverage of diesel and aircraft engine soot particles, is developed. It is found that near-monolayer organic/inorganic coverage of the soot particles may be represented by three groups of fossil fuel combustion-derived particulate matter with respect to their Hansh's coefficients related to hydrophilic properties. Water adsorption measurements show that nonpolar organics (aliphatic and aromatic hydrocarbons) lead to hydrophobization of the soot surface.

Cloud condensation nuclei and ice nucleation activity of hydrophobic and hydrophilic soot particles.

Cloud condensation nuclei (CCN) activity and ice nucleation behavior (for temperatures View Article and Find Full Text PDF

Water interaction with hydrophobic and hydrophilic soot particles.

The interaction of water with laboratory soots possessing a range of properties relevant for atmospheric studies is examined by two complementary methods: gravimetrical measurement of water uptake coupled with chemical composition and porosity analysis and HTDMA (humidified tandem differential mobility analyzer) inference of water uptake accompanied by separate TEM (transmission electron microscopy) analysis of single particles. The first method clarifies the mechanism of water uptake for bulk soot and allows the classification of soot with respect to its hygroscopicity. The second method highlights the dependence of the soot aerosol growth factor on relative humidity (RH) for quasi-monodisperse particles.

Uptake of HNO3 on hexane and aviation kerosene soots.

The uptake of HNO(3) on aviation kerosene (TC-1) soot was measured as a function of temperature (253-295 K) and the partial pressure of HNO(3), and the uptake of HNO(3) on hexane soot was studied at 295 K and over a limited partial pressure of HNO(3). The HNO(3) uptake was mostly reversible and did not release measurable amounts of gas-phase products such as HONO, NO(3), NO(2) or N(2)O(5). The heat of adsorption of HNO(3) on soot was dependent on the surface coverage.

Wetting and hydration of insoluble soot particles in the upper troposphere.

Wettability and hydration are determined for aircraft combustor and laboratory-made soots which are used as surrogates for the insoluble part of aircraft-generated black carbon particles in the upper troposphere (UT). The measured water/ice contact angles on the soot surfaces are in the range 60-80 degrees. Factors influencing the soot wetting show a tremendous dependence on the surface chemical composition and microstructure.

Ion-soot interaction: a possible mechanism of ion removal in aircraft plume.

The phenomenon of the ion-soot interaction in the aircraft plume at the ground conditions is investigated. The ion-soot attachment coefficients, taking into account the polarization of the soot particles in the ion electric field, are calculated. It is shown that the ion-soot attachment may play the important role in the evolution of the ion concentrations in the plume.