ACTRIS ACSM intercomparison - Part 2 : Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December similar to 2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f(44)), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f(44) in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the factors (HOA: 14.3 +/- 2.2 %, COA: 15.0 +/- 3.4 %, OOA: 41.5 +/- 5.7 %, BBOA: 29.3 +/- 5.0 %). Factors which tend to be subject to minor factor mixing (in this case COA) have higher relative uncertainties than factors which are recognised more readily like the OOA. Averaged over all factors and instruments the relative first SD from the mean of a source extracted with ME-2 was 17.2 %.Peer reviewe

ACTRIS ACSM intercomparison - Part 1 : Reproducibility of concentration and fragment results from 13 individual Quadrupole Aerosol Chemical Speciation Monitors (Q-ACSM) and consistency with co-located instruments

As part of the European ACTRIS project, the first large Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM) intercomparison study was conducted in the region of Paris for 3 weeks during the late-fall-early-winter period (November-December 2013). The first week was dedicated to the tuning and calibration of each instrument, whereas the second and third were dedicated to side-by-side comparison in ambient conditions with co-located instruments providing independent information on submicron aerosol optical, physical, and chemical properties. Near real-time measurements of the major chemical species (organic matter, sulfate, nitrate, ammonium, and chloride) in the non-refractory submicron aerosols (NR-PM1) were obtained here from 13 Q-ACSM. The results show that these instruments can produce highly comparable and robust measurements of the NR-PM1 total mass and its major components. Taking the median of the 13 Q-ACSM as a reference for this study, strong correlations (r(2) > 0.9) were observed systematically for each individual Q-ACSM across all chemical families except for chloride for which three Q-ACSMs showing weak correlations partly due to the very low concentrations during the study. Reproducibility expanded uncertainties of Q-ACSM concentration measurements were determined using appropriate methodologies defined by the International Standard Organization (ISO 17025, 1999) and were found to be 9, 15, 19, 28, and 36% for NR-PM1, nitrate, organic matter, sulfate, and ammonium, respectively. However, discrepancies were observed in the relative concentrations of the constituent mass fragments for each chemical component. In particular, significant differences were observed for the organic fragment at mass-to-charge ratio 44, which is a key parameter describing the oxidation state of organic aerosol. Following this first major intercomparison exercise of a large number of Q-ACSMs, detailed intercomparison results are presented, along with a discussion of some recommendations about best calibration practices, standardized data processing, and data treatment.Peer reviewe

Caracterizacion de ciclos de evolucion de contaminantes en una zona costera mediterranea en situaciones de verano

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

OC/EC ratio observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbon

This study explores a large set of OC and EC measurements in PM(10) and PM(2.5) aerosol samples, undertaken with a long term constant analytical methodology, to evaluate the capability of the OC/EC minimum ratio to represent the ratio between the OC and EC aerosol components resulting from fossil fuel combustion (OC(ff)/EC(ff)). The data set covers a wide geographical area in Europe, but with a particular focus upon Portugal, Spain and the United Kingdom, and includes a great variety of sites: urban (background, kerbside and tunnel), industrial, rural and remote. The highest minimum ratios were found in samples from remote and rural sites. Urban background sites have shown spatially and temporally consistent minimum ratios, of around 1.0 for PM(10) and 0.7 for PM(2.5).The consistency of results has suggested that the method could be used as a tool to derive the ratio between OC and EC from fossil fuel combustion and consequently to differentiate OC from primary and secondary sources. To explore this capability, OC and EC measurements were performed in a busy roadway tunnel in central Lisbon. The OC/EC ratio, which reflected the composition of vehicle combustion emissions, was in the range of 03-0.4. Ratios of OC/EC in roadside increment air (roadside minus urban background) in Birmingham, UK also lie within the range 03-0.4. Additional measurements were performed under heavy traffic conditions at two double kerbside sites located in the centre of Lisbon and Madrid. The OC/EC minimum ratios observed at both sites were found to be between those of the tunnel and those of urban background air, suggesting that minimum values commonly obtained for this parameter in open urban atmospheres over-predict the direct emissions of OC(ff) from road transport. Possible reasons for this discrepancy are explored. (C) 2011 Elsevier Ltd. All rights reserved

Methodology for measuring environmental health within Europe. Health Risk from Environmental Pollution Levels in Urban Systems (HEREPLUS)

Background: The European Commission funds a European research project titled "Health Risk from Environmental Pollution Levels in Urban Systems" (HEREPLUS) that focuses on environmental health within Europe. The HEREPLUS project was presented at the 16th EUPHA conference in Lisbon in November 2008 within a workshop named "The assessment of the effect of air pollution on population and environmental health: the integration of epidemiology and geographical information system (GIS)". Methods: The HEREPLUS project aims to measure the correlation between air pollution (especially ozone and particulate matter), meteorology, vegetation and human health in four European cities (Rome, Madrid, Athens and Dresden) by using a Geoinformation System to develop risk maps and subsequently guidelines to reduce air pollution and number of diseases. Results: The project started in September 2008 and a large, structured, relational database has been developed and completed. A literature review including national as well as international scientific literature goes on and will be completed in April 2009. Final results will be presented and published in 2011. Conclusions: Detailed scientific knowledge is important and needed to implement environmental programmes with the overall aim to protect human population against environmental related diseases

Improving indoor air quality through an air purifier able to reduce aerosol particulate matter (PM) and volatile organic compounds (VOCs): Experimental results

The adverse effects of fine particulate matter (PM) and many volatile organic compounds (VOCs) on human health are well known. Fine particles are, in fact, those most capable of penetrating in depth into the respiratory system. People spend most of their time indoors where concentrations of some pollutants are sometimes higher than outdoors. Therefore, there is the need to ensure a healthy indoor environment and for this purpose the use of an air purifier can be a valuable aid especially now since it was demonstrated that indoor air quality has a high impact on spreading of viral infections such as that due to SARS-COVID19. In this study, we tested a commercial system that can be used as an air purifier. In particular it was verified its efficiency in reducing concentrations of PM10 (particles with aerodynamic diameter less than 10 μm), PM2.5 (particles with aerodynamic diameter less than 2.5 μm), PM1 (particles with aerodynamic diameter less than 1 μm), and particles number in the range 0.3 μm–10 μm. Furthermore, its capacity in reducing VOCs concentration was also checked. PM measurements were carried out by means of a portable optical particle counter (OPC) instrument simulating the working conditions typical of a household environment. In particular we showed that the tested air purifier significantly reduced both PM10 and PM2.5 by 16.8 and 7.25 times respectively that corresponds to a reduction of about 90% and 80%. A clear reduction of VOCs concentrations was also observed since a decrease of over 50% of these gaseous substances was achieved

The role of outdoor and indoor air quality in the spread of SARS-CoV-2: Overview and recommendations by the research group on COVID-19 and particulate matter (RESCOP commission)

26There are important questions surrounding the potential contribution of outdoor and indoor air quality in the transmission of SARS-CoV-2 and perpetuation of COVID-19 epidemic waves. Environmental health may be a critical component of COVID-19 prevention. The public health community and health agencies should consider the evolving evidence in their recommendations and statements, and work to issue occupational guidelines. Evidence coming from the current epidemiological and experimental research is expected to add knowledge about virus diffusion, COVID-19 severity in most polluted areas, inter-personal distance requirements and need for wearing face masks in indoor or outdoor environments. The COVID-19 pandemic has highlighted the need for maintaining particulate matter concentrations at low levels for multiple health-related reasons, which may also include the spread of SARS-CoV-2. Indoor environments represent even a more crucial challenge to cope with, as it is easier for the SARS-COV2 to spread, remain vital and infect other subjects in closed spaces in the presence of already infected asymptomatic or mildly symptomatic people. The potential merits of preventive measures, such as CO2 monitoring associated with natural or controlled mechanical ventilation and air purification, for schools, indoor public places (restaurants, offices, hotels, museums, theatres/cinemas etc.) and transportations need to be carefully considered. Hospital settings and nursing/retirement homes as well as emergency rooms, infectious diseases divisions and ambulances represent higher risk indoor environments and may require additional monitoring and specific decontamination strategies based on mechanical ventilation or air purification.mixedembargoed_20240228Piscitelli P.; Miani A.; Setti L.; De Gennaro G.; Rodo X.; Artinano B.; Vara E.; Rancan L.; Arias J.; Passarini F.; Barbieri P.; Pallavicini A.; Parente A.; D'Oro E.C.; De Maio C.; Saladino F.; Borelli M.; Colicino E.; Goncalves L.M.G.; Di Tanna G.; Colao A.; Leonardi G.S.; Baccarelli A.; Dominici F.; Ioannidis J.P.A.; Domingo J.L.Piscitelli, P.; Miani, A.; Setti, L.; De Gennaro, G.; Rodo, X.; Artinano, B.; Vara, E.; Rancan, L.; Arias, J.; Passarini, F.; Barbieri, P.; Pallavicini, A.; Parente, A.; D'Oro, E. C.; De Maio, C.; Saladino, F.; Borelli, M.; Colicino, E.; Goncalves, L. M. G.; Di Tanna, G.; Colao, A.; Leonardi, G. S.; Baccarelli, A.; Dominici, F.; Ioannidis, J. P. A.; Domingo, J. L

Results of the first-ever ACSM intercomparison study from the ACTRIS-ACSM network

International audienceAs part of the EU-FP7 ACTRIS program, a large international intercomparison study of 15 aerosol mass spectrometers (13 Q-ACSM, 1 ToF-ACSM and 1 HR-ToF-AMS) has been performed from 15 Nov. to 2 Dec. 2013 at the LSCE in-situ atmospheric platform which is part of the French SIRTA observatory (http://sirta.ipsl.fr) located at 20km southwest of Paris. During this period, each instrument measured the major non-refractory submicron aerosols (NR-PM1) components (organic matter, nitrate, sulfate, and ammonium) in ambient air. The accuracy of Q-ACSM instruments was determined by comparison with various co-located instruments (TEOM-FDMS, SMPS, OPC, OC-EC Sunset Field analyzer, PILS-IC, aethalometers, nephelometers, and filter sampling). The measurement precision was also evaluated by intercomparing the correlation of absolute mass concentrations for all the NR-PM1 species. The ACSM analytical uncertainties were then estimated by applying a statistical approach in order to evaluate the analytical standard deviations between ACSMs and to highlight any bias or influencing factor on the ACSM measurements. For this purpose, the Z-score indicator representing performance criteria was used making it possible to measure its relative deviation to the assigned value. Fig. 1 summarizes the Z-Score results applied to the 13 Q-ACSM datasets for the major chemical species of the NR-PM1. All the ACSMs present satisfactory Z-Score values (a Z-Score value of 3 is considered as the limit value) whatever the considered parameter highlighting the instrument precision