Imre Salma

Eötvös Loránd University · Department of Analytical Chemistry

Realistic median particle number size distributions were derived by a differential mobility particle sizer in a diameter range of 6-1000 nm for near-city background, city centre, street canyon and road tunnel environments in Budapest. Deposition of inhaled particles within airway generations of an adult woman was determined by a stochastic lung dep...

Number size distributions of atmospheric aerosol particles in the mobility diameter range from 10 to 1000 nm were determined in Budapest, Prague and Vienna for a one-year-long period. Particle number concentrations in various size fractions, their diurnal and seasonal variations, mean size distributions and some properties of new particle formation...

This study aims to picture the phenomenology of urban ambient total lung deposited surface area (LDSA) (including head/throat (HA), tracheobronchial (TB), and alveolar (ALV) regions) based on multiple path particle dosimetry (MPPD) model during 2017-2019 period collected from urban background (UB, n = 15), traffic (TR, n = 6), suburban background (...

Oxidative potential (OP) is an emerging health-related metric which integrates several physicochemical properties of particulate matter (PM) that are involved in the pathogenesis of the diseases resulting from the exposure to PM. Daily PM2.5-fraction aerosol samples collected in the rural background of the Carpathian Basin and in the suburban area...

Particle number concentrations and size distributions resulting from the firework displays held in Budapest, Hungary every year on St. Stephen's Day were studied over a period of seven years. In the year most impacted, the total particle number concentration reached its peak measured level of 369 × 103 cm-3 5 min after the end of the display, and r...

The 2017–2019 hourly particle number size distributions (PNSD) from 26 sites in Europe and 1 in the US were evaluated focusing on 16 urban background (UB) and 6 traffic (TR) sites in the framework of Research Infrastructures services reinforcing air quality monitoring capacities in European URBAN & industrial areaS (RI-URBANS) project. The main obj...

Oxidative potential (OP) is an emerging health-related metric which integrates several physicochem-ical properties of particulate matter (PM) that are involved in the pathogenesis of the diseases resulting from exposure to PM. Daily PM 2.5-fraction aerosol samples collected in the rural background of the Carpathian Basin and in the suburban area an...

Secondary organic carbon (SOC) was derived using elemental carbon (EC) tracer method for primary organic carbon (OC) in daily aerosol samples collected in the regional background environment, suburban area, and central part of Budapest in each season. The estimation approaches of the OC/EC ratio for the major emission sources required for the trace...

Atmospheric new particle formation (NPF) has been observed to take place in practice all around the world. In continental locations, typically about 10–40% of the days are so-called NPF event days characterized by a clear particle formation and growth that continue for several hours, occurring mostly during daytime. The other days are either non-ev...

The aim of this study was to estimate and refine the potential sources of carbon in the atmospheric PM2.5 fraction aerosol at three sampling sites in Hungary. Quantification of total, organic and elemental carbon (TC, OC and EC, respectively), as well as radiocarbon (14C) and stable carbon isotope analyses were performed on exposed filters collecte...

Particle matter is one of the criteria air pollutants which have the most considerable effect on human health in cities. Its legislation and regulation are mostly based on mass. We showed here that the total number of particles and the particle number concentrations in different size fractions seem to be efficient quantities for air quality monitor...

The 2017-2019 hourly particle number size distributions (PNSD) from 26 sites in Europe and 1 in the US were evaluated focusing on 16 urban background (UB) and 6 traffic (TR) sites in the framework of Research Infrastructures services reinforcing air quality monitoring capacities in European URBAN & industrial areaS (RI-URBANS) project. The main obj...

This research aims to understand the role of the initial hygroscopicity of aerosol particles, scavenging mechanisms and of aqueous chemistry in the evolution of the aerosol size distribution. A box model with a size resolving moving bin scheme is used to simulate the fog events over Budapest (Hungary) and Delhi (India). The results from the study a...

Total, regional and local deposition fractions of urban-type aerosol particles with diameters of 50, 75, 110 and 145 nm were modelled and studied in their dry state and after their hygroscopic growth using a Stochastic Lung Model and a Computational Fluid and Particle Dynamics method. Healthy subjects and patients with severe chronic obstructive pu...

Collocated measurements using a condensation particle counter, differential mobility particle sizer and cloud condensation nuclei counter were realised in parallel in central Budapest from 15 April 2019 to 14 April 2020 to gain insight into the cloud activation properties of urban aerosol particles. The median total particle number concentration wa...

The occurrence frequency of regional atmospheric new aerosol particle formation and consecutive growth events (fNPF) were studied with respect to vegetation activity, aerosol properties, air pollutants and meteorological data in Budapest over the time interval from 2008 to 2018. The data set evaluated contained results of in situ measurements on th...

Faster than expected Iodine species are one of only a handful of atmospheric vapors known to make new aerosol particles, which play a central role in controlling the radiative forcing of climate. He et al. report experimental evidence from the CERN Cosmics Leaving Outdoor Droplets, or CLOUD, chamber demonstrating that iodic acid and iodous acid rap...

Motor vehicle road traffic in central Budapest was reduced by approximately 50 % of its ordinary level for several weeks as a consequence of various limitation measures introduced to mitigate the first outbreak of the COVID-19 pandemic in 2020. The situation was utilised to assess the real potentials of urban traffic on air quality. Concentrations...

Occurrence frequency (fNPF) of regional atmospheric new aerosol particle formation (NPF) and consecutive growth events were studied with respect to vegetation activity, aerosol properties, air pollutants and meteorological data in Budapest over the time interval of 2008-2018. The data set evaluated contained results of in situ measurements on land...

Multiple atmospheric properties were measured semi-continuously in the Budapest platform for Aerosol Research and Training laboratory, which represents the urban background for the time interval of 2008–2018. Data of 6 full measurement years during a decennial time interval were subjected to statistical time trend analyses by an advanced dynamic li...

Sulfuric acid has been shown to be a key driver for new particle formation and subsequent growth in various environments, mainly due to its low volatility. However, direct measurements of gas-phase sulfuric acid are oftentimes not available, and the current sulfuric acid proxies cannot predict, for example, its nighttime concentrations or result in...

Abstract. Multiple atmospheric properties were measured semi-continuously in the Budapest platform for Aerosol Research and Training Laboratory for a time interval of 2008–2018. Dataset of 6 full measurement years during a decennial time interval were subjected to statistical time trend analyses by an advanced dynamic linear model and a generalized...

Fine-fraction aerosol samples were collected, and air pollutants and meteorological properties were measured in situ in the regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest, in each season for a 1-year-long time interval. The samples were analysed for PM2.5 mass, organic carbon...

Abstract. Sulphuric acid has been shown to be a key driver for new particle formation and subsequent growth in various environments mainly due to its low volatility. However, direct measurements of gas-phase sulphuric acid are oftentimes not available, and the current sulphuric acid proxies cannot predict for example its nighttime concentrations or...

Fine-fraction aerosol samples were collected, air pollutants and meteorological properties were measured in-situ in regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest in each season for 1 year-long time interval. The samples were analysed for PM2.5 mass, organic carbon (OC), eleme...

Aerosol samples were collected by a MOUDI cascade impactor in central Budapest in winter 2017, and were analysed by GC–MS and AAS methods for major monosaccharide anhydrides, i.e. levoglucosan (LVG), mannosan (MAN) and galactosan (GAN), and for K, which are important chemical markers for biomass burning (BB) emissions. Their median atmospheric conc...

Dynamic properties, i.e. particle formation rate J6 and particle diameter growth rate GR10, and timing properties, i.e. starting time (t1) and duration time interval (Δt) of 247 quantifiable atmospheric new aerosol particle formation (NPF) and growth events identified in the city centre and near-city background of Budapest over 6 full measurement y...

Atmospheric new particle formation (NPF) is an important phenomenon in terms of global particle number concentrations. Here we investigated the frequency of NPF, formation rates of 10 nm particles, and growth rates in the size range of 10–25 nm using at least 1 year of aerosol number size-distribution observations at 36 different locations around t...

Dynamic properties, i.e. particle formation rate J6 and particle diameter growth rate GR10, and timing properties, i.e. starting time (t1) and duration time interval (Δt) of 247 quantifiable (class 1A) atmospheric new particle formation (NPF) and consecutive particle diameter growth events identified in the city centre and near-city background of B...

Atmospheric new particle formation (NPF) is an important phenomenon in terms of the global particle number concentrations. Here we investigated the frequency of NPF, formation rates of 10 nm particles and growth rates in the size range of 10–25 nm using at least one year of aerosol number size-distribution observations at 36 different locations aro...

Hygroscopic and volatile properties of atmospheric aerosol particles with dry diameters of (20), 50, 75, 110 and 145 nm were determined in situ by using a volatility–hygroscopicity tandem differential mobility analyser (VH-TDMA) system with a relative humidity of 90 % and denuding temperature of 270 °C in central Budapest during 2 months in winter...

Simultaneous particle number size distribution measurements were performed in the urban environment of Budapest, Vienna, and Prague, three Central European cities located within 450 km of each other. The measurement days from the continuous, 2-year long campaign were classified for new particle formation (NPF) events using an adapted classification...

Effects of a new aerosol particle formation (NPF) and particle diameter growth process as a single source of atmospheric particle number concentrations were evaluated and quantified on the basis of experimental data sets obtained from particle number size distribution measurements in the city centre and near-city background of Budapest for 5 years....

An intensive aerosol measurement and sample collection campaign was conducted in central Budapest in a mild winter for 2 weeks. The online instruments included an FDMS-TEOM, RT-OC/EC analyser, DMPS, gas pollutant analysers and meteorological sensors. The aerosol samples were collected on quartz fibre filters by a low-volume sampler using the tandem...

Hygroscopic and volatile properties of atmospheric aerosol particles with dry diameters of (20), 50, 75, 110 and 145 nm were determined in situ by using a VH-TDMA system with a relative humidity of 90 % and denuding temperature of 270 °C in central Budapest during two months in winter 2014–2015. The probability density function of the hygroscopic g...

Effects of new aerosol particle formation (NPF) and particle diameter growth process as a single source on atmospheric particle number concentrations were evaluated and quantified on the basis of experimental data sets obtained from particle number size distribution measurements in the city centre and near-city background of Budapest for 5 years. N...

An intensive aerosol measurement and sample collection campaign was conducted in central Budapest in a mild winter for two weeks. The on-line instruments included a FDMS-TEOM, Aethalometer, photoacoustic spectrometer, RT-OC/EC analyser, DMPS, gas pollutant analysers and meteorological sensors. The aerosol samples were collected on quartz fibre filt...

Secondary aerosol particle production via new particle formation (NPF) has been shown to be a major contributor to the global aerosol load. NPF has also been observed frequently in urban environments. Here, we investigate the effect of regional NPF on urban aerosol load under well-defined atmospheric conditions. The Carpathian Basin, the largest or...

Budapest platform for Aerosol Research and Training (BpART) was created for advancing long-term on-line atmospheric measurements and intensive aerosol sample collection campaigns in Budapest. A joint study including atmospheric chemistry or physics, meteorology, and fluid dynamics on several-year-long data sets obtained at the platform confirmed th...

Secondary aerosol particle production via new particle formation (NPF) has been shown to be a major source for global aerosol load. It has been also observed frequently in urban environments affecting the human health. Here, we investigate the effect of regional NPF on urban aerosol load under well-defined atmospheric conditions. The Carpathian Bas...

Budapest platform for Aerosol Research and Training (BpART) was created for advancing long-term on-line atmospheric measurements and intensive aerosol sample collection campaigns in Budapest. A joint study including atmospheric chemistry/physics, meteorology and fluid dynamics on several-year long data sets obtained at the platform confirmed that t...

Particle number size distributions were measured by differential mobility particle sizer in the diameter range of 6–1000 nm in the near-city background and city centre of Budapest continuously for two years. The city is situated in the middle part of the Carpathian Basin, which is a topographically discrete unit in the southeastern part of central...

Particle number size distributions were measured by differential mobility particle sizer in the diameter range of 6-1000 nm in the near-city background and city centre of Budapest continuously for two years. The city is situated in the middle part of the Carpathian Basin, which is a topographically discrete unit in the southeast Central Europe. Yea...

Aerosol samples were collected with a micro-orifice uniform deposit impactor in an aerodynamic diameter (AD) range of 0.5–10 μm in central Budapest, Hungary for 12 days. Aqueous aerosol extracts and atmospheric humic-like substances (HULIS) were obtained from the combined aerosol samples for each impactor stage. Water-soluble organic carbon (WSOC)...

Humic-like substances (HULIS) are ubiquitously present in the troposphere and make up a major fraction of continental fine-sized water-soluble organic compounds. They are regarded as material with strong polar, acidic and chromophoric properties; however, structural information at the individual component level is rather limited. In the present stu...

We used flow-switching type differential mobility particle sizer in a diameter range of 6-1000 nm and vehicle counting detectors with a time resolution of 10 min for 15 days in July 2010 in the Castle District Tunnel, Budapest. The total particle number concentrations varied from 5.1 × 10 3 to 465 × 10 3 cm -3 with a median of 143 × 10 3 cm -3. The...

Number concentrations of atmospheric aerosol particles were measured by a flow-switching type differential mobility particle sizer in an electrical mobility diameter range of 6–1000 nm in 30 channels near central Budapest with a time resolution of 10 min continuously from 3 November 2008 to 2 November 2009. Daily median number concentrations of par...

Number concentrations of atmospheric aerosol particles were measured by a flow-switching type differential mobility particle sizer in an electrical mobility diameter range of 6–1000 nm in 30 channels near central Budapest with a time resolution of 10 min continuously from 3 November 2008 to 2 November 2009. Daily median number concentrations of par...

This paper synthesizes data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities at more than 60 natural background, rural, near-city, urban, and kerbside sites across Europe. The data include simultaneously measured PM10 and/or PM2.5 mass o...

Aerosol water extracts and atmospheric humic-like substances (HULIS) obtained from PM2.5-fraction aerosol samples collected in a rural/continental background environment and in an urban environment in spring and summer, and at a tropical site that was heavily impacted by biomass burning were studied. HULIS was obtained as the water-soluble, methano...

This paper synthesizes data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities at more than 60 natural background, rural, near-city, urban, and kerbside sites across Europe. The data include simultaneously measured PM10 and/or PM2.5 mass o...

Atmospheric new particle formation events were analyzed based on particle size distributions measured with a Differential Mobility Particle Sizer (DMPS) and an Air Ion Spectrometer (AIS) during the BIOSOL (Formation mechanisms, marker compounds, and source apportionment for biogenic atmospheric aerosols) campaign on 22 May-29 June 2006 at the K-pus...

Metropolitan underground railway transport systems are a very important part of the urban traffic since they carry millions of passengers per day in a number of cities around the world. They represent a segregated traffic microenvironment because of their closed character and restricted ventilation, lack of sunlight, specific emission sources and m...

Aerosol samples in PM10–2.0 and PM2.0 size fractions were collected on the platform of a metropolitan underground railway station in central Budapest. Individual aerosol particles were studied using atomic force microscopy, scanning electron microscopy and transmission electron microscopy with energy-dispersive X-ray spectrometry and electron diffr...

This work recompiles studies that have been done with respect to hygroscopic growth in the regime of high relative humidities and with respect to activation for different kinds of particle at LACIS (Leipzig Aerosol Cloud Interaction Simulator) during the last few years. The particles examined consisted of a mixture of succinic acid and ammonium sul...

The carboxyl groups of atmospheric humic-like substances (HULIS) are of special interest because they influence the solubility in water, affect the water activity and surface tension of droplets in the air, and allow formation of chelates with biologically active elements. Experimentally determined abundances of the carboxyl group within HULIS by f...

Urban-type PM_2.5-fraction aerosol samples were collected and samples of pure atmospheric humic-like substances (HULIS) were isolated from them. Atmospheric concentrations of organic carbon (OC), water soluble organic carbon (WSOC) and HULIS were determined, and UV/Vis spectroscopic properties, solubility and conductivity of HULIS in aque...

Urban-type PM2.5-fraction aerosol samples were collected and samples of pure atmospheric humic-like substances (HULIS) were isolated from them. Atmospheric concentrations of organic carbon (OC), water soluble organic carbon (WSOC) and HULIS were determined, and UV/Vis spectroscopic properties, solubility and conductivity of HULIS in aqueous samples...

Recently, atmospheric humic matter or humic-like substances (HULIS) have been found in the water-soluble fraction of atmospheric aerosol sampled at different locations. Most of these locations were continental, non-urban sites. Therefore, in this work HULIS was studied in urban and marine environments. The atmospheric concentration varied over a wi...

Aerosol samples were collected using a stacked filter unit (SFU) for PM10-2.0 and PM2.0 size fractions on the platform of a metropolitan underground railway station in downtown Budapest. Temporal variations in the PM10 mass concentration and wind speed and direction were determined with time resolutions of 30 and 4 s using a tapered-element oscilla...

The hygroscopic growth and activation of two HULIS and one Aerosol-Water-Extract sample, prepared from urban-type aerosol, were investigated. All samples were extracted from filters, redissolved in water and atomized for the investigations presented here. The hygroscopic growth measurements were done using LACIS (Leipzig Aerosol Cloud Interaction S...