Indoor aerosol water content and phase state in U.S. residences: impacts of relative humidity, aerosol mass and composition, and mechanical system operation

2020 ◽  
Vol 22 (10) ◽  
pp. 2031-2057
Author(s):  
Bryan E. Cummings ◽  
Ying Li ◽  
Peter F. DeCarlo ◽  
Manabu Shiraiwa ◽  
Michael S. Waring
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Water Content ◽  
Mechanical System ◽  
Phase State ◽  
Organic Aerosol ◽  
System Operation ◽  
Aerosol Mass ◽  
Inorganic Aerosol ◽  
Indoor Aerosol

Hygroscopic particulate matter constituents promote uptake of aerosol water, depending on relative humidity, which can constrain qualities such as organic aerosol phase state and inorganic aerosol deliquescence and efflorescence.

scholarly journals Organic aerosol source apportionment by offline-AMS over a full year in Marseille

2017 ◽  
Author(s):  
Carlo Bozzetti ◽  
Imad El Haddad ◽  
Dalia Salameh ◽  
Kaspar Rudolf Daellenbach ◽  
Paola Fermo ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Mediterranean Sea ◽  
Source Apportionment ◽  
Organic Aerosol ◽  
Aerodynamic Diameter ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Aerosol Source

Abstract. We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France) which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). PM2.5 (particulate matter with an aerodynamic diameter

scholarly journals Constructing a data-driven receptor model for organic and inorganic aerosol – a synthesis analysis of eight mass spectrometric data sets from a boreal forest site

2019 ◽  
Vol 19 (6) ◽  
pp. 3645-3672 ◽  
Author(s):  
Mikko Äijälä ◽  
Kaspar R. Daellenbach ◽  
Francesco Canonaco ◽  
Liine Heikkinen ◽  
Heikki Junninen ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Organic Aerosol ◽  
Mass Spectrometric ◽  
Chemical Components ◽  
Forest Site ◽  
Aerosol Composition ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Aerosol Mass ◽  
Inorganic Aerosol

Abstract. The interactions between organic and inorganic aerosol chemical components are integral to understanding and modelling climate and health-relevant aerosol physicochemical properties, such as volatility, hygroscopicity, light scattering and toxicity. This study presents a synthesis analysis for eight data sets, of non-refractory aerosol composition, measured at a boreal forest site. The measurements, performed with an aerosol mass spectrometer, cover in total around 9 months over the course of 3 years. In our statistical analysis, we use the complete organic and inorganic unit-resolution mass spectra, as opposed to the more common approach of only including the organic fraction. The analysis is based on iterative, combined use of (1) data reduction, (2) classification and (3) scaling tools, producing a data-driven chemical mass balance type of model capable of describing site-specific aerosol composition. The receptor model we constructed was able to explain 83±8 % of variation in data, which increased to 96±3 % when signals from low signal-to-noise variables were not considered. The resulting interpretation of an extensive set of aerosol mass spectrometric data infers seven distinct aerosol chemical components for a rural boreal forest site: ammonium sulfate (35±7 % of mass), low and semi-volatile oxidised organic aerosols (27±8 % and 12±7 %), biomass burning organic aerosol (11±7 %), a nitrate-containing organic aerosol type (7±2 %), ammonium nitrate (5±2 %), and hydrocarbon-like organic aerosol (3±1 %). Some of the additionally observed, rare outlier aerosol types likely emerge due to surface ionisation effects and likely represent amine compounds from an unknown source and alkaline metals from emissions of a nearby district heating plant. Compared to traditional, ion-balance-based inorganics apportionment schemes for aerosol mass spectrometer data, our statistics-based method provides an improved, more robust approach, yielding readily useful information for the modelling of submicron atmospheric aerosols physical and chemical properties. The results also shed light on the division between organic and inorganic aerosol types and dynamics of salt formation in aerosol. Equally importantly, the combined methodology exemplifies an iterative analysis, using consequent analysis steps by a combination of statistical methods. Such an approach offers new ways to home in on physicochemically sensible solutions with minimal need for a priori information or analyst interference. We therefore suggest that similar statistics-based approaches offer significant potential for un- or semi-supervised machine-learning applications in future analyses of aerosol mass spectrometric data.

Organic functional group composition of particulate matter from fresh and aged wood burning and coal combustion

2020 ◽  
Author(s):  
Amir Yazdani ◽  
Nikunj Dudani ◽  
Satoshi Takahama ◽  
Amelie Bertrand ◽  
André S. H. Prévôt ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Particulate Matter ◽  
Infrared Spectra ◽  
Atmospheric Aerosols ◽  
Coal Combustion ◽  
Organic Aerosol ◽  
High Abundance ◽  
Mid Infrared ◽  
Aerosol Mass ◽  
Wood Burning

<p>Particulate matter (PM) affects visibility and climate through light scattering, direct and indirect radiative forcing, and affecting cloud formation [1]. In addition, exposure to ambient fine PM is estimated to have caused 8.9 million deaths worldwide in 2015 [2]. Organic matter (OM), can make up more than half of total fine atmospheric PM, and yet its composition, formation mechanisms, and adverse health effects are not fully characterized due to its sheer compositional complexity. Biomass burning (e.g., residential wood burning, wildfires, and prescribed burning) and coal combustion (for heat and power generation) are two major OM sources, for which the impact of atmospheric aging - including secondary organic aerosol (SOA) formation - is not yet fully clear [3].</p><p>In this study, we investigated the effect of aging on composition and mass concentration of organic aerosols of wood burning (WB) and coal combustion (CC) emissions using two complementary methods, i.e., mid-infrared spectroscopy and aerosol mass spectrometry (AMS). For this purpose, primary aerosols were injected into the Paul Scherrer Institute (PSI) environmental chamber and aged using hydroxyl and nitrate radicals to simulate day-time and night-time oxidation processes in the atmosphere. In these experiments, aerosols reached an oxidative age comparable to that of atmospheric aerosols. A time-of-flight AMS instrument was used to measure the high-time-resolution composition of non-refractory fine PM, while we collected PM<sub>1 </sub>aerosols on PTFE filters before and after four hours of aging for off-line Fourier transform-infrared spectroscopy (FT-IR) measurements.</p><p>AMS and FT-IR estimates of organic aerosol mass concentration were highly correlated (r<sup>2</sup>=0.92); both indicating an approximately three-fold increase in organic aerosol concentration after aging. The OM/OC ratio, indicating the extent of oxidation also agreed closely between the two instruments and increased, on average, from 1.6 (before aging) to 2 (after aging). Mid-infrared spectroscopy, which is able to differentiate among oxygenated species, shows a distinct functional group composition for aged WB aerosols (high abundance of carboxylic acids) and CC aerosols (high abundance of non-acid carbonyls) and detects considerable amounts polycyclic aromatic hydrocarbons (PAHs) for both sources. Mid-infrared spectra of fresh WB and CC aerosols are reminiscent of their parent compounds with differences in specific functional groups suggesting the dominant oxidation pathways for each emission source. Finally, the comparison of mid-infrared spectra of aged WB aerosols in the environmental chamber with that of ambient samples affected by residential wood burning and wildfires reveals interesting similarities regarding the high abundance of alcohols and visible signatures of lignin. This finding is useful for interpreting sources of atmospheric aerosols and better interpretation of their complex mid-infrared spectra.</p><p>--------------------------</p><p>REFERENCES</p><p>[1] M. Hallquist et al., “The formation, properties and impact of secondary organic aerosol: current and emerging issues,” Atmos Chem Phys, 2009.</p><p>[2] R. Burnett et al., “Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter,” Proc. Natl. Acad. Sci., 2018.</p><p>[3] A. Bertrand et al., “Primary emissions and secondary aerosol production potential from woodstoves for residential heating: Influence of the stove technology and combustion efficiency,” Atmos. Environ., 2017.</p>

scholarly journals Temperature-induced volatility of molecular markers in ambient airborne particulate matter

2010 ◽  
Vol 10 (8) ◽  
pp. 20329-20353
Author(s):  
C. R. Ruehl ◽  
W. A. Ham ◽  
M. J. Kleeman
Keyword(s):  
Molecular Markers ◽  
Particulate Matter ◽  
Airborne Particulate Matter ◽  
Organic Aerosol ◽  
Urban Site ◽  
Atmospheric Conditions ◽  
Ambient Conditions ◽  
Aerosol Mass ◽  
Polycyclic Aromatic ◽  
Effective Saturation

Abstract. Molecular markers are organic compounds used to represent known sources of particulate matter (PM) in statistical source apportionment studies. The utility of molecular markers depends on, among other things, their ability to represent PM volatility under realistic atmospheric conditions. We measured the particle-phase concentrations and temperature-induced volatility of commonly-used molecular markers in California's heavily polluted San Joaqin Valley. Concentrations of elemental carbon, organic carbon, levoglucosan, and polycyclic aromatic hydrocarbons were not reduced by mild (~10 K) heating. In contrast, both hopane/sterane and n-alkane concentrations were reduced, especially during the summer sampling events at the urban site. These results suggest that hopanes and steranes have effective saturation concentrations ~1 μg m−3, and therefore can be considered semi-volatile in realistic ambient conditions. The volatility behavior of n-alkanes during the urban summer is consistent with that predicted for absorption by suberic acid (a C8 diacid) using a group contribution modelling method. Observations can also be matched by an absorbent whose composition is based on recently-obtained high-resolution aerosol mass spectrometer factors (approximately 33% "hydrocarbon-like" and 67% oxygenated organic aerosol). The diminished volatility of the n-alkanes, hopanes, and steranes during rural and/or winter experiments could be explained by a more oxygenated absorbing phase along with a non-absorptive partitioning mechanism, such as adsorption to soot. This suggests that the temperature-induced volatility of large hydrocarbons in PM is most important if a relatively non-polar absorbing organic phase exists. While the activity coefficients of most organic aerosol compounds may be close to unity, the assumption of ideality for large hydrocarbons (e.g., hopanes) may result in large errors in partitioning calculations.

scholarly journals Humidity-dependent phase state of SOA particles from biogenic and anthropogenic precursors

2012 ◽  
Vol 12 (2) ◽  
pp. 4447-4476 ◽  
Author(s):  
E. Saukko ◽  
A. T. Lambe ◽  
P. Massoli ◽  
J. P. Wright ◽  
D. R. Croasdale ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Phase State ◽  
Steel Substrate ◽  
Phase Changes ◽  
Aerosol Mass Spectrometer ◽  
Oxidation Level ◽  
Aerosol Mass ◽  
Wide Range ◽  
Volatile Organic ◽  
Semi Solid

Abstract. The physical phase state (solid, semi-solid, or liquid) of secondary organic aerosol (SOA) particles has important implications for a number of atmospheric processes. We report the phase state of SOA particles spanning a wide range of oxygen to carbon ratios (O/C), used here as a surrogate for SOA oxidation level, produced in a flow tube reactor by photo-oxidation of various atmospherically relevant surrogate anthropogenic and biogenic volatile organic compounds (VOCs). The phase state of laboratory-generated SOA was determined by the particle bounce behavior after inertial impaction on a polished steel substrate. The measured bounce fraction was evaluated as a function of relative humidity and SOA oxidation level (O/C) measured by an Aerodyne high resolution time of flight aerosol mass spectrometer (HR-ToF AMS). The main findings of the study are: (1) Biogenic and anthropogenic SOA particles are found to be solid or semi-solid until a relative humidity of at least 50 % RH at impaction is reached. (2) Long-chain alkanes produce liquid SOA particles when generated at low oxidation level of O/C<0.2, but at higher oxidation levels they solidify. (3) Increasing sulphuric acid (H2SO4) within the SOA particles reduces the threshold of humidity-induced phase changes. (4) The bounce behavior of the various SOA systems did not show a consistent linear relationship with the particle O/C. Rather, the molar mass of the gas-phase VOC precursor showed a positive correlation with the resistance to the RH-induced phase change of the formed SOA particles.

scholarly journals Characterization and source apportionment of organic aerosol using offline aerosol mass spectrometry

2016 ◽  
Vol 9 (1) ◽  
pp. 23-39 ◽  
Author(s):  
K. R. Daellenbach ◽  
C. Bozzetti ◽  
A. Křepelová ◽  
F. Canonaco ◽  
R. Wolf ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Source Apportionment ◽  
Organic Aerosol ◽  
Transmission Efficiency ◽  
Water Soluble ◽  
Spatially Resolved ◽  
Aerosol Mass ◽  
Online Measurements ◽  
Rural Sites ◽  
Pm2.5 And Pm10

Abstract. Field deployments of the Aerodyne Aerosol Mass Spectrometer (AMS) have significantly advanced real-time measurements and source apportionment of non-refractory particulate matter. However, the cost and complex maintenance requirements of the AMS make its deployment at sufficient sites to determine regional characteristics impractical. Furthermore, the negligible transmission efficiency of the AMS inlet for supermicron particles significantly limits the characterization of their chemical nature and contributing sources. In this study, we utilize the AMS to characterize the water-soluble organic fingerprint of ambient particles collected onto conventional quartz filters, which are routinely sampled at many air quality sites. The method was applied to 256 particulate matter (PM) filter samples (PM1, PM2.5, and PM10, i.e., PM with aerodynamic diameters smaller than 1, 2.5, and 10 µm, respectively), collected at 16 urban and rural sites during summer and winter. We show that the results obtained by the present technique compare well with those from co-located online measurements, e.g., AMS or Aerosol Chemical Speciation Monitor (ACSM). The bulk recoveries of organic aerosol (60–91 %) achieved using this technique, together with low detection limits (0.8 µg of organic aerosol on the analyzed filter fraction) allow its application to environmental samples. We will discuss the recovery variability of individual hydrocarbon ions, ions containing oxygen, and other ions. The performance of such data in source apportionment is assessed in comparison to ACSM data. Recoveries of organic components related to different sources as traffic, wood burning, and secondary organic aerosol are presented. This technique, while subjected to the limitations inherent to filter-based measurements (e.g., filter artifacts and limited time resolution) may be used to enhance the AMS capabilities in measuring size-fractionated, spatially resolved long-term data sets.

scholarly journals Constructing a data-driven receptor model for organic and inorganic aerosol – a synthesis analysis of eight mass spectrometric data sets from a boreal forest site

2018 ◽  
Author(s):  
Mikko Äijälä ◽  
Kaspar R. Daellenbach ◽  
Francesco Canonaco ◽  
Liine Heikkinen ◽  
Heikki Junninen ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Organic Aerosol ◽  
Mass Spectrometric ◽  
Chemical Components ◽  
Forest Site ◽  
Aerosol Composition ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Aerosol Mass ◽  
Inorganic Aerosol

Abstract. The interactions between organic and inorganic aerosol chemical components are integral to understanding and modelling climate and health-relevant aerosol physicochemical properties, such as volatility, hygroscopicity, light scattering and toxicity. This study presents a synthesis analysis for eight data sets, of non-refractory aerosol composition, measured at a boreal forest site. The measurements, performed with an aerosol mass spectrometer, cover in total around 9 months over the course of 3 years. In our statistical analysis, we use the complete organic and inorganic unit-resolution mass spectra, as opposed to the more common approach of only including the organic fraction. The analysis is based on iterative, combined use of (1) data reduction, (2) classification and (3) scaling tools, producing a data-driven chemical mass balance type of model capable of describing site-specific aerosol composition. The receptor model we constructed was able to explain 83 ± 8 % of variation in data, increased to 96 ± 3 % when signals from low signal-to-noise variables were not considered. The resulting interpretation of an extensive set of aerosol mass spectrometric data infers seven distinct aerosol chemical components for a rural boreal forest site: ammonium sulphate (35 % of mass), low and semi-volatile oxidised organic aerosols (27 and 12 %), biomass burning organic aerosol (11 %), a nitrate containing organic aerosol type (7 %), ammonium nitrate (5 %), and hydrocarbon-like organic aerosol (3 %). Some of the additionally observed, rare outlier aerosol types likely emerge due to surface ionisation effects, and likely represent amine compounds from an unknown source and alkaline metals from emissions of a nearby district heating plant. Compared to traditional, simplistic inorganics apportionment methods for aerosol mass spectrometer data, our statistics-based method provides an improved, more robust approach, yielding readily useful information for the modelling of submicron atmospheric aerosols physical and chemical properties. The results also shed light on the division between organic and inorganic aerosol types and dynamics of salt formation in aerosol. Equally importantly, the combined methodology exemplifies an iterative analysis, using consequent analysis steps by a combination of statistical methods. Such an approach offers new ways to home in on physicochemically sensible solutions with minimal need for a priori information or analyst interference. We therefore suggest that similar statistics-based approaches offer significant potential for un/semi supervised machine-learning applications in future analyses of aerosol mass spectrometric data.

scholarly journals Humidity-dependent phase state of SOA particles from biogenic and anthropogenic precursors

2012 ◽  
Vol 12 (16) ◽  
pp. 7517-7529 ◽  
Author(s):  
E. Saukko ◽  
A. T. Lambe ◽  
P. Massoli ◽  
T. Koop ◽  
J. P. Wright ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Phase State ◽  
Steel Substrate ◽  
Amorphous Solid ◽  
Aerosol Mass Spectrometer ◽  
Oxidation Level ◽  
Aerosol Mass ◽  
Wide Range ◽  
Volatile Organic ◽  
Semi Solid

Abstract. The physical phase state (solid, semi-solid, or liquid) of secondary organic aerosol (SOA) particles has important implications for a number of atmospheric processes. We report the phase state of SOA particles spanning a wide range of oxygen to carbon ratios (O / C), used here as a surrogate for SOA oxidation level, produced in a flow tube reactor by photo-oxidation of various atmospherically relevant surrogate anthropogenic and biogenic volatile organic compounds (VOCs). The phase state of laboratory-generated SOA was determined by the particle bounce behavior after inertial impaction on a polished steel substrate. The measured bounce fraction was evaluated as a function of relative humidity and SOA oxidation level (O / C) measured by an Aerodyne high resolution time of flight aerosol mass spectrometer (HR-ToF AMS). The main findings of the study are: (1) biogenic and anthropogenic SOA particles are found to be amorphous solid or semi-solid based on the measured bounced fraction (BF), which was typically higher than 0.6 on a 0 to 1 scale. A decrease in the BF is observed for most systems after the SOA is exposed to relative humidity of at least 80% RH, corresponding to a RH at impaction of 55%. (2) Long-chain alkanes have a low BF (indicating a "liquid-like", less viscous phase) particles at low oxidation levels (BF < 0.2 ± 0.05 for O / C = 0.1). However, BF increases substantially upon increasing oxidation. (3) Increasing the concentration of sulphuric acid (H2SO4) in solid SOA particles (here tested for longifolene SOA) causes a decrease in BF levels. (4) In the majority of cases the bounce behavior of the various SOA systems did not show correlation with the particle O / C. Rather, the molar mass of the gas-phase VOC precursor showed a positive correlation with the resistance to the RH-induced phase change of the formed SOA particles.

scholarly journals Sources and atmospheric processing of wintertime aerosols in Seoul, Korea: Insights from real-time measurements using a high-resolution aerosol mass spectrometer

2016 ◽  
Author(s):  
Hwajin Kim ◽  
Qi Zhang ◽  
Gwi-Nam Bae ◽  
Jin Young Kim ◽  
Seung Bok Lee
Keyword(s):  
Particulate Matter ◽  
High Resolution ◽  
Real Time ◽  
Mass Spectrometer ◽  
Organic Aerosol ◽  
Meteorological Conditions ◽  
Emission Sources ◽  
Aerosol Mass Spectrometer ◽  
Atmospheric Processes ◽  
Aerosol Mass

Abstract. Highly time-resolved chemical characterization of non-refractory submicrometer particulate matter (NR-PM1) was conducted in Seoul, the capital and largest metropolis of Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The measurements were performed during winter, when elevated particulate matter (PM) pollution events are often observed. This is the first time that detailed real-time aerosol measurement results are reported from Seoul, Korea, which reveal valuable insights into the sources and atmospheric processes that contribute to PM pollution in this region. The average concentration of submicron aerosol (PM1 = NR - PM1 + black carbon (BC)) was 27.5 µg m−3, and the total mass was dominated by organics (44 %), followed by nitrate (24 %) and sulfate (10 %). The average atomic ratios of oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), and nitrogen-to-carbon (N / C) of organic aerosol (OA) were 0.37, 1.79, and 0.022, respectively, which gives that average organic mass-to-carbon (OM / OC) ratio of 1.67. The concentrations (2.6–90.7 µg m−3) and composition of PM1 varied dynamically during the measurement period, due to the influences of different meteorological conditions, emission sources, and air mass origins. Five distinct sources of OA were identified via positive matrix factorization (PMF) analysis of the HR-ToF-AMS data: vehicle emissions represented by a hydrocarbon like OA factor (HOA; O / C = 0.06), cooking activities represented by a cooking OA factor (COA; O / C = 0.15), wood combustion represented by a biomass burning OA factor (BBOA; O / C = 0.34), and secondary organic aerosol (SOA) represented by a semi-volatile oxygenated OA factor (SV-OOA; O / C = 0.56) and a low volatility oxygenated OA factor (LV-OOA; O / C = 0.68). On average, primary OA (POA = HOA + COA + BBOA) accounted for 59 % the OA mass whereas SV-OOA and LV-OOA contributed 15 % and 26 %, respectively. Our results indicate that air quality in Seoul during winter is influenced strongly by secondary aerosol formation with sulfate, nitrate, ammonium, SV-OOA, and LV-OOA together accounting for 64 % of the PM1 mass during this study. However, aerosol sources and composition were found to be significantly different between clean and polluted periods. During stagnant periods with low wind speed (WS) and high relative humidity (RH), PM concentration was generally high (average ± 1σ = 43.6 ± 12.4 µg m−3) with enhanced fractions of nitrate (27 %) and SV-OOA (8 %), which suggested a strong influence from local production of secondary aerosol. Low PM loading periods (12.6 ± 7.1 µg m−3) tended to occurred under higher WS and lower RH conditions and appeared to be more strongly influenced by regional air masses, as indicated by higher mass fractions of sulfate (12 %) and LV-OOA (21 %) in PM1. Overall, our results indicate that PM pollutants in urban Korea originate from complex emission sources and atmospheric processes and that their concentrations and composition are controlled by various factors including meteorological conditions, local anthropogenic emissions, and upwind sources.

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