Intercomparison Experiment of Water-Insoluble Carbonaceous Particles in Snow in a High-Mountain Environment (1598 m a.s.l.)

The harmonization of sampling, sample preparation and laboratory analysis methods to detect carbon compounds in snow requires detailed documentation of those methods and their uncertainties. Moreover, intercomparison experiments are needed to reveal differences and quantify the uncertainties further. Here, we document our sampling, filtering, and analysis protocols used in the intercomparison experiment from three laboratories to detect water-insoluble carbon in seasonal surface snow in the high-mountain environment at Kolm Saigurn (47.067842° N, 12.98394° E, alt 1598 m a.s.l.), Austria. The participating laboratories were TU Wien (Austria), the University of Florence (Italy), and the Finnish Meteorological Institute (Finland). For the carbon analysis, the NIOSH5040 and EUSAAR2 protocols of the OCEC thermal-optical method were used. The median of the measured concentrations of total carbon (TC) was 323 ppb, organic carbon (OC) 308 ppb, and elemental carbon (EC) 16 ppb. The methods and protocols used in this experiment did not reveal large differences between the laboratories, and the TC, OC, and EC values of four inter-comparison locations, five meters apart, did not show meter-scale horizontal variability in surface snow. The results suggest that the presented methods are applicable for future research and monitoring of carbonaceous particles in snow. Moreover, a recommendation on the key parameters that an intercomparison experiment participant should be asked for is presented to help future investigations on carbonaceous particles in snow. The work contributes to the harmonization of the methods for measuring the snow chemistry of seasonal snow deposited on the ground

Seasonal Variability of PM10 Chemical Composition Including 1,3,5-triphenylbenzene, Marker of Plastic Combustion and Toxicity in Wadowice, South Poland

ABSTRACT The objective of this research was to evaluate the seasonal variation of the chemical composition of PM10 including polycyclic aromatic hydrocarbons (PAHs) and 1,3,5-triphenylbenzene (135TPB), which is a well known marker of plastic combustion. The presented work is a part of the project concerning assessment of air quality of small cities around Krakow agglomeration. Monitoring campaign was conducted between February and October 2017 in Wadowice, a small city in Krakow agglomeration, South Poland. To widen the knowledge of Krakow's agglomeration air quality, other aerosol chemical components were analyzed. Ion chromatography (IC) was used for analysis of cations and anions, while gas chromatography-mass spectrometry (GC-MS) was used for PAHs. Samples were also analyzed for OC/EC (organic/elemental carbon) by thermal-optical analysis with a Sunset Laboratory carbon analyzer, Sunset Inc. The co-combustion of plastic in addition to conventional fuels and the respective impact on air quality is evaluated via the concentration of the marker compound 135TPB. Co-combustion of plastics with fuels resulted in a higher abundance of fluorene and most of 4–6 ring PAHs, in agreement with recent literature. Authors proved that other sources besides plastic burning, including road transport, residential heating, residential combustion, industrial emissions, affect the air quality in South Poland. The modeling tool Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), developed by NOAA's Air Resources Laboratory, was used to define the possible areas outside Wadowice contributing to urban air pollution

Secretory protein beta-lactoglobulin in cattle stable dust may contribute to the allergy-protective farm effect

15 Pág.Growing up on a cattle farm and consuming raw cow's milk protects against asthma and allergies. We expect a cattle-specific protein as active component in this farm effect.This study was supported by the Austrian Science Fund FWF (SFB F4606-B28 and MCCA W1248-B30 to EJJ), in part by Biomedical International R+D GmbH, Vienna, Austria, and by Bencard Allergie GmbH, Munich, Germany.Peer reviewe

Seasonality of the particle number concentration and size distribution : a global analysis retrieved from the network of Global Atmosphere Watch (GAW) near-surface observatories

Aerosol particles are a complex component of the atmospheric system which influence climate directly by interacting with solar radiation, and indirectly by contributing to cloud formation. The variety of their sources, as well as the multiple transformations they may undergo during their transport (including wet and dry deposition), result in significant spatial and temporal variability of their properties. Documenting this variability is essential to provide a proper representation of aerosols and cloud condensation nuclei (CCN) in climate models. Using measurements conducted in 2016 or 2017 at 62 ground-based stations around the world, this study provides the most up-to-date picture of the spatial distribution of particle number concentration (N-tot) and number size distribution (PNSD, from 39 sites). A sensitivity study was first performed to assess the impact of data availability on N-tot's annual and seasonal statistics, as well as on the analysis of its diel cycle. Thresholds of 50% and 60% were set at the seasonal and annual scale, respectively, for the study of the corresponding statistics, and a slightly higher coverage (75 %) was required to document the diel cycle. Although some observations are common to a majority of sites, the variety of environments characterizing these stations made it possible to highlight contrasting findings, which, among other factors, seem to be significantly related to the level of anthropogenic influence. The concentrations measured at polar sites are the lowest (similar to 10(2) cm(-3)) and show a clear seasonality, which is also visible in the shape of the PNSD, while diel cycles are in general less evident, due notably to the absence of a regular day-night cycle in some seasons. In contrast, the concentrations characteristic of urban environments are the highest (similar to 10(3)-10(4) cm(-3)) and do not show pronounced seasonal variations, whereas diel cycles tend to be very regular over the year at these stations. The remaining sites, including mountain and non-urban continental and coastal stations, do not exhibit as obvious common behaviour as polar and urban sites and display, on average, intermediate N-tot (similar to 10(2)-10(3) cm(-3)). Particle concentrations measured at mountain sites, however, are generally lower compared to nearby lowland sites, and tend to exhibit somewhat more pronounced seasonal variations as a likely result of the strong impact of the atmospheric boundary layer (ABL) influence in connection with the topography of the sites. ABL dynamics also likely contribute to the diel cycle of N-tot observed at these stations. Based on available PNSD measurements, CCN-sized particles (considered here as either >50 nm or >100 nm) can represent from a few percent to almost all of N-tot, corresponding to seasonal medians on the order of similar to 10 to 1000 cm(-3), with seasonal patterns and a hierarchy of the site types broadly similar to those observed for N-tot. Overall, this work illustrates the importance of in situ measurements, in particular for the study of aerosol physical properties, and thus strongly supports the development of a broad global network of near surface observatories to increase and homogenize the spatial coverage of the measurements, and guarantee as well data availability and quality. The results of this study also provide a valuable, freely available and easy to use support for model comparison and validation, with the ultimate goal of contributing to improvement of the representation of aerosol-cloud interactions in models, and, therefore, of the evaluation of the impact of aerosol particles on climate.Peer reviewe

Desert Dust Contribution to PM10 Loads in Styria (Southern Austria) and Impact on Exceedance of Limit Values from 2013–2018

From a legislators point of view, the contribution of natural sources to PM10 loads is relevant since their impact can be subtracted from the daily limit value of PM10 as regulated in a working staff paper by the European Commission (EC), supporting the European Air Quality Directive (2008/50/EC). This work investigates its applicability for two stations in Austria over a time period of six years (2013 to 2018), as the occurrence of long-range transport of desert dust is observed on a regular base. Different stations and different statistical parameters were evaluated to determine the regional background load and subsequently the net dust load (NDL). Results reveal an adapted approach of the methodology described by the EC, using the +/− 15-day mean average of the PM10 at the regional background station, together with threshold criteria to identify only desert dust affected days. The results of calculated NDLs were in good agreement with crustal loads determined on filter samples during two desert dust events in 2016. Thus, the application of the EC method for a region in Central Europe, which experiences a regular but less pronounced impact of desert dust than stations in the Mediterranean, is discussed

Solvent effects on extraction of polycyclic aromatic hydrocarbons in ambient aerosol samples

Polycyclic Aromatic Hydrocarbons (PAHs) in the ambient particulate matter pose one of the most important issues in the focus of environmental management. The concentration of their representative, Benzo(a)pyrene (BaP), undergoes limitations according to European Union directive. However, a successful control over the pollution levels and their sources is limited by the high uncertainty of analytical and statistical approaches used for their characterization. Here we compare differences in PAH concentrations related to the use of different solvents in the course of ultrasonic extraction of a certified reference material (PM10-like PAH mixture) and filter samples of ambient particulate matter collected in Austria for the CG-MS PAH analysis. Using solvents of increasing polarity: Cyclohexane (0,006), Toluene (0,099), Dichloromethane (0,309), Acetone (0,43) and Acetonitrile (0,460), as well as mixtures of those, filters representing high and low concentrations of particulate matter were investigated. Although some scatter of the obtained concentrations was observed no trend related to the polarity of the solvent became visible. Regarding the reproducibility, which can be expected of PAH analysis no significant difference between the different solvents was determined. This result is valid for all compounds under investigation

Solvent effects on extraction of polycyclic aromatic hydrocarbons in ambient aerosol samples

Polycyclic Aromatic Hydrocarbons (PAHs) in the ambient particulate matter pose one of the most important issues in the focus of environmental management. The concentration of their representative, Benzo(a)pyrene (BaP), undergoes limitations according to European Union directive. However, a successful control over the pollution levels and their sources is limited by the high uncertainty of analytical and statistical approaches used for their characterization. Here we compare differences in PAH concentrations related to the use of different solvents in the course of ultrasonic extraction of a certified reference material (PM10-like PAH mixture) and filter samples of ambient particulate matter collected in Austria for the CG-MS PAH analysis. Using solvents of increasing polarity: Cyclohexane (0,006), Toluene (0,099), Dichloromethane (0,309), Acetone (0,43) and Acetonitrile (0,460), as well as mixtures of those, filters representing high and low concentrations of particulate matter were investigated. Although some scatter of the obtained concentrations was observed no trend related to the polarity of the solvent became visible. Regarding the reproducibility, which can be expected of PAH analysis no significant difference between the different solvents was determined. This result is valid for all compounds under investigation