2024
Neukirchen, Carsten; Meiners, Thorsten; Bendl, Jan; Zimmermann, Ralf; Adam, Thomas. (2024). Automated SEM/EDX imaging for the in-depth characterization of non-exhaust traffic emissions from the Munich subway system. Science of The Total Environment, Volume 915.
Abstract
A SEM/EDX based automated measurement and classification algorithm was tested as a method for the in-depth analysis of micro-environments in the Munich subway using a custom build mobile measurements system. Sampling was conducted at platform stations, to investigate the personal exposure of commuters to subway particulate matter during platform stays. EDX spectra and morphological features of all analyzed particles were automatically obtained and particles were automatically classified based on pre-defined chemical and morphological boundaries. Source apportionment for individual particles, such as abrasion processes at the wheel-brake interface, was partially possible based on the established particle classes. An average of 98.87 ± 1.06 % of over 200,000 analyzed particles were automatically assigned to the pre-defined classes, with 84.68 ± 16.45 % of particles classified as highly ferruginous. Manual EDX analysis further revealed, that heavy metal rich particles were also present in the ultrafine size range well below 100 nm.
Graphical Abstract
URL
https://www.sciencedirect.com/science/article/pii/S0048969724001426?via%3Dihub
Wang, G.; Ruser, H.; Schade, J.; Passig, J.; Zimmermann, R.; Dollinger, G.; Adam, T. (2024). CNN-Based Aerosol Particle Classification Using 2D Representations of Single-Particle Mass Spectrometer Data. 2024 International Conference on Artificial Intelligence in Information and Communication (ICAIIC) (2024, Osaka).
Abstract
Single-particle mass spectrometry (SPMS) is a powerful real-time measurement technique to analyze the chemical composition of atmospheric aerosol particles: individual particles are desorbed and ionized to generate a bipolar mass spectrum that expresses the particle's chemical composition, giving clues to its origin and atmospheric processes. Popular approaches to classify SPMS data rely on clustering algorithms, resulting in the inability to achieve automated classification. Here, we present a modified deep learning approach for automatic classification of SPMS data in real-time. Before being processed by a convolutional neural network (CNN), the one-dimensional (1D) mass spectrum is converted into a two-dimensional (2D) representation, since in 2D, global and local features of the spectra are extracted more efficiently. Trained on real-world aerosol mass spectra from a month-long field measurement campaign, the proposed 2D-CNN model achieves a high mean classification accuracy of 92%, outperforming several well-known algorithms based on 2D-CNN, as well as a recently proposed 1D-CNN algorithm trained using 1D representations of mass spectra.
URL
Wang, G.; Ruser, H.; Schade, J.; Passig, J.; Adam, T.; Dollinger, G.; Zimmermann, R. (2024). Machine learning approaches for automatic classification of single-particle mass spectrometry data. Atmospheric Measurement Techniques, Vol. 17, S. 299–313.
Abstract
The chemical composition of aerosol particles is a key parameter for human health and climate effects. Single-particle mass spectrometry (SPMS) has evolved to a mature technology with unique chemical coverage and the capability to analyze the distribution of aerosol components in the particle ensemble in real time. With the fully automated characterization of the chemical profile of the aerosol particles, selective real-time monitoring of air quality could be performed, e.g., for urgent risk assessments due to particularly harmful pollutants. For aerosol particle classification, mostly unsupervised clustering algorithms (ART-2a, K-means and their derivatives) are used, which require manual postprocessing. In this work, we focus on supervised algorithms to tackle the problem of the automatic classification of large amounts of aerosol particle data. Supervised learning requires data with labels to train a predictive model. Therefore, we created a labeled benchmark dataset containing ∼ 24 000 particles with eight different coarse categories that were highly abundant at a measurement in summer in Central Europe: elemental carbon (EC), organic carbon and elemental carbon (OC-EC), potassium-rich (K-rich), calcium-rich (Ca-rich), iron-rich (Fe-rich), vanadium-rich (V-rich), magnesium-rich (Mg-rich) and sodium-rich (Na-rich). Using the chemical features of particles, the performance of the following classical supervised algorithms was tested: K-nearest neighbors, support vector machine, decision tree, random forest and multi-layer perceptron. This work shows that despite the entrenched position of unsupervised clustering algorithms in the field, the use of supervised algorithms has the potential to replace the manual step of clustering algorithms in many applications, where real-time data analysis is essential. For the classification of the eight classes, the prediction accuracy of several supervised algorithms exceeded 97 %. The trained model was used to classify ∼ 49 000 particles from a blind dataset in 0.2 s, taking into account also a class of “unclassified” particles. The predictions are highly consistent with the results obtained in a previous study using ART-2a.
Graphical Abstract
URL
https://amt.copernicus.org/articles/17/299/2024/
Streibel, T.; Jeong, S.; Bendl, J.; Saraji-Bozorgzad, M.; Sklorz, M.; Gehm, C.; Anders, L.; Passig, J.; Schade, J.; Etzien, U.; Adam, T.; Buchholz, B.; Schulz-Bull, D.E.; Zimmermann, R. (2024). Effects of Sulfur Scrubbers on Particulate Emissions from a Marine diesel engine. In: Proceedings of the 25th International Transport and Air Pollution (TAP) and the 3rd Shipping and Environment (SandE) Conference, Sjodin, Å., Moldanova, J., Laurelin, M., Cha, Y., Lundstrom, H. and Fontaras, G. (Eds.). S.288-291.
URL
https://publications.jrc.ec.europa.eu/repository/handle/JRC136825
Wang, G.; Ruser, H.; Schade, J.; Passig, J.; Adam, T.; Dollinger, G.; Zimmermann, R. (2024). In: Robustness Analysis for Classification of Aerosol Particles using Machine Learning with Two Different Single-Particle Mass Spectrometry Datasets. Proceedings of the 25th International Transport and Air Pollution (TAP) and the 3rd Shipping and Environment (SandE) Conference, Sjodin, Å., Moldanova, J., Laurelin, M., Cha, Y., Lundstrom, H. and Fontaras, G. (Eds.). S. 323-328.
Abstract
The chemical composition of aerosol particles in the air is successfully used to determine their origins, e.g. traffic emissions, biomass burning, or ship emissions. Single-Particle Mass Spectrometry (SPMS) is a sensitive measurement technique to analyze the chemical composition in real-time. The current mainstream classification methods in the SPMS community for handling these data require intensive manual post-processing, making an online analysis impossible. A few studies have demonstrated that supervised learning can perform automated classification of SPMS data with high accuracy, enabling selective air quality monitoring in real-time. However, the generalizability and reliability of those algorithms using SPMS data from different sources (e.g., different SPMS instruments, sampling locations, or weather conditions) are still key issues to be solved. This work investigates the classification generalization capacity (or robustness) of a multilayer perceptron network using two different datasets of SPMS data. The results show that the model trained on one dataset is sensitive to the disparate characteristic features of the other dataset, causing its prediction accuracy to decrease significantly. On the contrary, the model trained with data from both datasets performs strong robustness and adaptation to both datasets, with over 96 % correct classifications. The presented results underscore the feasibility and practicability of a uniform approach for automated profiling of data from different sources.
URL
https://publications.jrc.ec.europa.eu/repository/handle/JRC136825
Rohkamp, Marius; Rabl, Alexander; Gündling, Benedikt; Saraji-Bozorgzad, Mohammad Reza; Mull, Christopher; Bendl, Jan; Neukirchen, Carsten; Helcig, Christian; Adam, Thomas; Gümmer, Volker; Hupfer, Andreas. (2024). Detailed Gaseous and Particulate Emissions of an Allison 250-C20B Turboshaft Engine. Journal of Engineering for Gas Turbines and Power, Vol. 146, No. 4.
Abstract
Aviation is known to be one of the most significant contributors to air pollutants. This includes gaseous emissions, like carbon dioxide (CO2) and nitrogen oxides (NOx), and also particulate matter (PM), especially in the form of soot. This study conducted emission measurements on an Allison 250-C20B turboshaft engine operating on Jet A-1 fuel with a focus on gaseous compounds (e.g., ozone precursors) and PM. The different engine loading points were chosen based on the percentage thrust ratios of the International Civil Aviation Organization LTO-Cycle. A standard FTIR/O2/FID system to measure general gaseous combustion compounds, e.g., CO2, carbon monoxide (CO), unburned hydrocarbons (UHC), and NOx. For the investigation of the volatile organic compounds (VOC), which are known to act as ozone precursors, a gas chromatograph was applied. Different measurement methods were used to characterize the PM emissions. For the particle size distribution (PSD), we used two types of electrical mobility analyzers and an aerodynamic aerosol classifier. All measurement systems yielded comparable PSD results, indicating reliable results. The particle measurement methods all show increasing aerosol diameter modes (electrical and aerodynamic) with increased engine loading. The aerosol diameter modes were shifting from 29 nm to 65 nm. The size and shape of different individual particles were evaluated with a scanning electron microscope. A correlation between the injection system and the particle formation was established. Gaseous turboshaft engine emissions show high CO and UHC values at Ground Idle level. NOx levels were the highest at Take-Off conditions. Acetylene and ethylene were the most significant contributors to ozone formation.
URL
2023
Schade, Julian; Passig, Johannes; Rosewig, Ellen Iva; Irsig, Robert; Osterholz, Helena; Hovorka, Jan; Schulz-Bull, Detlef; Zimmermann, Ralf; Adam Thomas. (2023). Remote detection of ship exhaust plumes from different marine fuels by land-based and marine on-board measurements using single-particle spectrometry. European Aerosol Conference (2023, Malaga).
Abstract
Wang, Guanzhong; Ruser, Heinrich; Schade, Julian; Passig, Johannes; Adam Thomas; Dollinger, Günther; Zimmermann, Ralf. (2023). Machine learning approaches for automatic classification of single-particle mass spectometry data. EGUsphere [preprint].
Abstract
The chemical composition of aerosol particles is a key parameter for human health and climate effects. Single-particle mass spectrometry (SPMS) has evolved to a mature technology with unique chemical coverage and the capability to analyze the distribution of aerosol components in the particle ensemble in real-time. With the fully automated characterization of the chemical profile of the aerosol particles, selective real-time monitoring of air quality could be performed e.g. for urgent risk assessments due to particularly harmful pollutants. For aerosol particle classification, mostly unsupervised clustering algorithms (ART-2a, K-means and their derivatives) are used, which require manual post-processing. In this work, we focus on supervised algorithms to tackle the problem of automatic classification of large amounts of aerosol particle data. Supervised learning requires data with labels to train a predictive model. Therefore, we created a labeled benchmark dataset containing ~24,000 particles with eight different coarse categories that were highly abundant at a measurement in summer in Central Europe: Elemental Carbon (EC), Organic Carbon and Elemental Carbon (OC-EC), Potassium-rich (K-rich), Calcium-rich (Ca-rich), Iron-rich (Fe-rich), Vanadium-rich (V-rich), Magnesium-rich (Mg-rich) and Sodium-rich (Na-rich). Using the chemical features of particles the performance of the following classical supervised algorithms was tested: K-nearest neighbors, support vector machine, decision tree, random forest and multi-layer perceptron. This work shows that despite the entrenched position of unsupervised clustering algorithms in the field, the use of supervised algorithms has the potential to replace the manual step of clustering algorithms in many applications, where real-time data analysis is essential. For the classification of the eight classes, the prediction accuracy of several supervised algorithms exceeded 97 %. The trained model was used to classify ~49,000 particles from a blind dataset in 0.2 seconds, taking into account also a class of “unclassified” particles. The predictions are highly consistent with the results obtained in a previous study using ART-2a.
URL
Zappi, Alessandro; Padoan, Sara; Tositti, L.; Adam, Thomas. (2023). Chemometrics in environmental chemistry: application of self-organizing maps for the study of Saharan dust events. Colloquium Chemometricum Mediterraneum (11., 2023, Padua).
Abstract
The association between environmental chemistry and chemometrics has deep and consolidated roots. Environment indeed, is characterized by an extreme degree of chemodiversity, with highly expressed time-variability (especially in the fluid phases), huge inhomogeneity over a massive size as compared to the laboratory scale, always claiming large datasets. Therefore, chemometric modeling is a necessary step for both understanding environmental complexity and diagnostic purposes.
The present work proposes the use Self-Organizing Maps (SOM)[1] for diagnostic purposes, i.e. to detect the influence of Saharan dust (SD) events in March 2022 in Munich, Germany, an unusual occurrence for this type of transport at these latitudes. Munich, indeed, besides being a heavily man-impacted city in southern Germany, is located beyond the Alps and is therefore rarely reached by Northern African air masses loaded in Saharan mineral dust, differently from the Mediterranean basin.
These events, however, are increasing in frequency and intensity, sometimes reaching latitudes as high as the UK, as a possible result of climate change. During these events, huge alterations of PM10 concentrations, often exceeding the EU air quality standards as well as of composition are observed leading to increased environmental and health hazard[2].
In this study, particulate matter (PM) was collected daily on quartz fiber filters from March to May 2022, and its metal composition was evaluated by Inductively Coupled Plasma Mass-Spectrometry (ICP-MS). After basic data pre-processing, data was then subjected to SOM with the aim of evaluating the enrichment of metal concentrations due to the presence of SD over Munich. Although Positive Matrix Factorization would have been more appropriate to achieve source apportioning of airborne particulate matter, it requires a huge amount of data to compute reliable models. Though many other multivariate models are usually applied in the case of limited matrices of data, SOM has been proved as a valid and reliable alternative to such methods, due to its simpler and faster computational procedure that can be carried out with any number of samples.
SOM results, also assisted by meteorological data and physical transport-based models, as backtrajectory analysis, successfully demonstrated not only the differences in trace element composition of PM in Munich due to the advent of SD, but even some differences in SD composition according to different source locations as a result of evolving atmospheric dynamics.
References
Licen S, Franzon M, Rodani T, Barbieri P (2021) SOMEnv: An R package for mining environmental monitoring datasets by Self-Organizing Map and k-means algorithms with a graphical user interface, Microchemical Journal, 165, 106181
Tositti L, Brattich E, Cassardo C, Morozzi P, Bracci A, Marinoni A, Di Sabatino S., Porcù F, Zappi A (2022) Development and evolution of an anomalous Asian dust event across Europe in March 2020, Atmospheric Chemistry and Physics, 22, 4047–4073
Passig, Johannes; Schade, Julian; Rosewig, Ellen Iva, Aners, L.; Irsig, Robert; Kröger-Badge, Thomas; Zimmermann, Ralf. (2023). A single-particle perspective on polycyclic aromatic hydrocarbons from different combustion sources and ambient air studies. European Aerosol Conference (2023, Malaga).
Abstract
Czech, Hendryk; Bauer, Martin; Käfer, Uwe; Bendl, Jan; Saraji, M.; Jeong, Seongho; Schade, Julian; Friederici, L.; Schwalb, L.; Rüger, Christopher P.; Gröger, T.; Sklorz, Martin; Streibel, Thorsten; Buchholz, Bert; Zimmermann, Ralf. (2023). Aerosol Emissions from a Marine Engine operated on Fuels with different Levels of Sulphur Compliance: About the Importance of Fuel Composition. European Aerosol Conference (2023, Malaga).
Abstract
Aerosol emissions from marine traffic are known to release substantial amount of air pollutants, such as SO2 and fine particulate matter (PM2.5). In the past two decades, the International Maritime Organisation (IMO) reduced the fuel sulphur content (FSC) to directly lower emissions of SO2 and indirectly of PM2.5. Since 2020, a global FSC cap of 0.5% was set, together with sulphur emission control areas (SECA) with maximum FSC of 0.1%. It was anticipated that ship owners change from heavy fuel oil (HFO) to “cleaner” diesel-like fuels or install open or closed-loop sulphur scrubbers to comply with sulphur regulation. However, compliant hybrid fuels from blending (hydrotreated) residues from the crude oil vacuum distillation with middle distillates, either from straight run gas oil or cycle oil from fluid catalytic cracking, became more established (Ershov et al, 2022).
To investigate the PM2.5 composition from different marine fuels, we analysed emissions from a four-stroke medium-speed marine engine with common rail injection and 80 kW nominal power. The engine was operated over four different loads (25, 50, 75 and 100%) on three SECA-compliant fuels hydrotreated vegetable oil (HVO), marine gas oil (MGO), and ultralow sulphur aromatic-rich HFO (ULS-HFOar); a compliant low-sulphur HFO (LS-HFO) and two non-compliant high sulphur HFOs (HS-HFO, HS-HFOsyn) which may be used combined with sulphur scrubbers (Jeong et al, 2023). Filter samples of PM2.5 were collected and analysed by multi-wavelength thermal optical carbon analysis (Chen et al, 2015) coupled to resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (Diab et al, 2015). Moreover, complementary fuel analysis was carried out to obtain bulk properties and chemical composition.
Optical properties of PM2.5 by means of the Angström Absorption Exponent (AAE) were close to unity for all fuels after weighting according to the IMO engine cycle. Emission factor (EF) of elemental and organic Carbon (EC, OC) revealed significant differences between SECA-compliant fuels and LS-/HS-HFOs, but not among the SECA-compliant fuels (Figure 1). However, the EF of total polycyclic aromatic hydrocarbon (PAH) was similar between the ULS-HFOar and non-SECA-compliant fuels and even more than one order of magnitude higher than for MGO and HVO; estimated toxicity equivalents of carcinogenic PAH (TEQPAH) for ULS-HFOar double the TEQPAH for MGO and HVO. The LS-HFO did not emit less PAH and TEQPAH than the HS-HFO.
The composition of PM2.5 emissions are closely related to the fuel composition because unburned fuel is a major contributor. Therefore, HFOs of different FSC may not be different in PAH emissions and TEQPAH. Moreover, hybrid SECA-compliant fuels from blending with cycle oil may not give the reduction in air pollutant emissions as anticipated from fuel switching to MGO.
This research was funded by the Federal Ministry for Economic Affairs and Climate Action (project SAARUS 03SX483D), dtec.bw-Digitalization (funded by European Union – NextGenerationEU) and Technology Research Center of the Bundeswehr (projects LUKAS and MORE).
Chen, L. W. A.; Chow, J. C.; Wang, X. L. et al. (2015) Atmos. Meas. Techn. 8(1), 451–461.
Diab, J.; Streibel, T.; Cavalli, F.; Lee, S. C. et al. (2015) Atmos. Meas. Techn. 8(8), 3337–3353.
Ershov, M. A.; Savelenko, V.D.; Makhmudova, A.E.; et al. (2022) J. Mar. Sci. Eng. 10, 1828-1866.
Jeong, S., Bendl, J., Saraji-Bozorgzad, M. et al. (2023) Environ. Pollut. 316, 120526-120534.
Passig, Johannes; Schade, Julian; Rosewig, Ellen Iva; Pütz, Michael; Seipenbusch, Martin; Ehlert, Sven; Ruser, Heinrich; Adam, Thomas; Walte, Andreas; Zimmermann, Ralf. (2023). Real-time detection of chemical compounds in dust particles using a single particle mass spectrometer and its potential for safety applications. Proceedings 2023 IEEE Sensors Conference (2023, Vienna).
Abstract
Neukirchen, Carsten; Meiners, T.; Bendl, Jan; Zimmermann, Ralf; Adam, Thomas. (2023). Automated SEM/EDX based imaging of particles in the Munich subway system. European Aerosol Conference (2023, Malaga).
Abstract
Wang, Guanzhong; Ruser, Heinrich; Schade, Julian; Passig, Johannes; Adam, Thomas; Dollinger, Günther; Zimmermann, Ralf. (2023). Robustness Analysis for Classification of Aerosol Particles using Machine Learning with Two Different Single-Particle Mass Spectrometry Datasets. Proceedings 2023 Joint TAP and S&E Conference, Göteborg, Sweden.
Abstract
The chemical composition of aerosol particles in the air is successfully used to determine their origins, e.g., traffic emissions, biomass burning, or ship emissions. Single-Particle Mass Spectrometry (SPMS) is a sensitive measurement technique to analyze the chemical composition in real-time. The current mainstream classification methods in the SPMS community for handling these data require intensive manual post-processing, making an online analysis impossible. A few studies have demonstrated that supervised learning can perform automated classification of SPMS data with high accuracy, enabling selective air quality monitoring in real-time. However, the generalizability and reliability of those algorithms using SPMS data from different sources (e.g., different SPMS instruments, sampling locations, or weather conditions) are still key issues to be solved. This work investigates the classification generalization capacity (or robustness) of a multilayer perceptron network using two different datasets of SPMS data. The results show that the model trained on one dataset is sensitive to the disparate characteristic features of the other dataset, causing its prediction accuracy to decrease significantly. On the contrary, the model trained with data from both datasets performs strong robustness and adaptation to both datasets, with over 96 % correct classifications. The presented results underscore the feasibility and practicability of a uniform approach for automated profiling of data from different sources.
Padoan, Sara; Zappi, Alessandro; Herrmann, Tobias; Mudan, A. P.; Schüller, A.; Bendl, Jan; Tositti, L.; Adam, Thomas. (2023). PM2.5 metallic and ionic composition during Saharan dust events over Munich. European Aerosol Conference (2023, Malaga).
Abstract
Nowadays, the dust coming from the Sahara desert (SD), is widely recognised having a strong impact on the air quality in Europe (Remoundaki, 2011). Whereas in the past, the events of long-range transport of the mineral dust from the African desert mainly reached southern Europe, now, due to climate change, they can also travel to higher latitudes. The presence of this dust in the atmospheric aerosol has several direct effects on the weather and climate as absorbing incoming solar radiation on earth through scattering and absorbing phenomena. It has also some indirect effects as increasing cloud coverage and reducing precipitations throught the cloud condesation nuclei particles´s ability. These events generally alter the normal level of Particulate Matter (PM), even exceeding the limits of the directive for the air quality in Europe, affecting aerosol mass load, its size distribution and its chemical speciation. Moreover, the concentrations of several chemical species are raised, causing potential damages to the environment and human health (Tositti, 2022).
The present study focuses on the evaluation of the elemental and ionic fractions of PM2.5 samples collected during several SD storm events that crossed the city of Munich, Germany. The PM2.5 samples have been daily collected on quartz fiber filters from March to May 2022. The elemental fraction was evaluated by Inductively Coupled Plasma Mass Spectrometry (ICPMS), while the ionic fraction was evaluated by Ion Chromatography (IC). In the first case, samples were extracted by microwave-assisted acid digestion, followed by aqueous dilution. The quantification was performed with an external calibration line. In the second case, samples were extracted in aqueous solution and quantification was performed with an external calibration line.
These results were combined with Optical Particle Sizer (OPS) data, meteorological data, and physical transport-based models as backtrajectory analysis.
The dataset was treated with advanced chemometric techniques, such as Varimax analysis and Self-Organising Maps (SOM) that allows to group daily observations in order to find patterns of samples and variables. SOM was applied to our dataset to fully describe the atmospheric alterations due to SD events. Moreover, SOM was evaluated as a possible alternative to source apportionment methods for a reduced dimension dataset.
First results have shown a general increase in PM concentrations during the SD events of March 2022. In addition, it was also possible to identify some differences in the chemical composition of the two SD events due to a different aerosol enrichment, possibly related to their different paths, as shown in Figure 1. SOM well discriminated the SD events from the normal urban pollution of Munich, indicating the enrichment of some elements (in particular, but not limited to, crustal ones) due to the presence of SD. Correlating SOM results with other data analyses, as meteorological time-series, Varimax, and enrichment factor analysis, made it possible to fully describe the effects of SD on the urban pollution in Munich.
Remoundaki, E. (2011) PM10 composition during an intense Saharan dust transport event over Athens (Greece). Science of the Total Environment.
Tositti, L. (2022) Development and evolution of an anomalous Asian dust event across Europe in March 2020. Atmospheric Chemistry and Physics.
Becker, J.; Di Bucchianico, Sebastiano; Delaval, M.; Hupfer, Andreas; Ihalainen, Mika; Rohkamp, M.; Gründling, B.; Sklorz, Martin; Streibel, Thorsten; Sippula, Olli; Adam, Thomas; Zimmermann, Ralf. (2023). Aircraft engine emissions and aerosol aging health-related effects in airway model systems at the Air-Liquid Interface. European Aerosol Conference (2023, Malaga).
Abstract
Wang, Guanzhong; Ruser, Heinrich; Schade, Julian; Passig, Johannes; Adam, Thomas; Dollinger, Günther; Zimmermann , Ralf. (2023). Deep Learning Approach for Classification of Single-Particle Mass Spectra. European Aerosol Conference (2023, Malaga).
Abstract
Ruser, Heinrich; Wang, Guanzhong; Schade, Julian; Passig, Johannes; Adam, Thomas; Dollinger, Günther; Zimmermann, Ralf. (2023). Real-time Analysis and Classification of Aerosol Particles using Single-Particle Mass Spectrometry and Machine Learning. ASMS Conference on Mass Spectrometry and Allied Topics (71., 2023, Houston, Texas).
Abstract
Streibel, Thorsten; Jeong, Seongho; Bendl, Jan; Saraji-Bozogzad, Mohammad; Sklorz, Martin; Gehm, Christian; Anders, Lukas; Passig, Johannes; Etzien, Uwe; Adam, Thomas; Buchholz, Bert; Schulz-Bull, Detlef; Zimmermann, Ralf. (2023). Effects of sulphur scrubbers on particulate emissions from a marine diesel engine. Joint TAP and S&E Conference (2023, Göteborg).
Abstract
The International Maritime Organization capped the fuel sulfur content of marine fuels outside ECA zones to 0.5 % in 2020. Consequently, either low-sulfur fuels or additional exhaust gas cleaning devices for the reduction in sulfur dioxide (SO2) emissions became mandatory. Although a wet scrubber reduces the amount of SO2 significantly, there is still a need to consider the reduction in particle emissions and organic pollutants. We present data on the particle removal efficiency of a scrubber regarding particle number and mass concentration with different marine fuel types, viz. marine gas oil and two heavy fuel oils (HFOs) with sulphur contents of 1.3 % and 2.4 %, respectively. An open-loop sulfur scrubber was installed in the exhaust line of a marine diesel test engine. Fine particulate matter with diameters below 2.5 µm (PM2.5) was comprehensively characterized in terms of its physical and chemical properties. The wet scrubber led up to a 40% reduction in particle number, whereas a reduction in particle mass emissions was not generally determined, as with HFO 2.4 % sulphur even a slight increase was observed. (Table 1). Furthermore, a shift in size distribution to larger particle diameters occurred after the scrubber when the engine was operated with the HFOs. The behaviour of particle mass concentrations could be related to an increase in sulfate particles with HFO 2.4 %, whereas soot particles did decrease slightly. However, for considerable reduction of respirable particulate matter the sulfur scrubber is not sufficient and one would need an additional filter system. Combining the scrubber with a wet electrostatic precipitator as an additional abatement system indeed showed a reduction in particle number and mass emission factors by >98%. Particles also transport organic pollutants, among them Polycyclic Aromatic Hydrocarbons (PAH), crucial for their carcinogenic and mutagenic potential. Online measurements with the Single Particle Mass Spectrometer revealed for HFO 2.4 % sulfur, that the number of detected soot particles decreased after the scrubber, but the number of PAH containing particles remained constant. With a load of 20 kW, this number even increased. Another important question is the transfer of PAH from the gas/particle phase of the exhaust to the aqueous phase when the exhaust pass the wet scrubber. With a new online instrument using a membrane inlet for extracting organic compounds out of the water into a mass spectrometer, we could clearly detect 2- and 3-ring PAHs in the wash water going out the open-loop scrubber. Concluding, the application of a wet scrubber for the after-treatment of marine fuel oil combustion will reduce SO2 emissions, but it does not substantially affect the number and mass concentration of respirable particulate matter. Complete removal of these particle emissions affords the inclusion of additional abatement systems. Moreover, Polycyclic Aromatic Hydrocarbons are still present in the exhaust after the scrubber and are partially transferred to the wash water, which would be introduced back in the ocean when using a open-loop system. This work was supported by the Federal Ministry for Economic Affairs and Climate Action by the project SAARUS (grant number 03SX483D). The research is also supported by dtec.bw – Digitalization and Technolgy Research Center of the Bundeswehr [project LUKAS and MORE]. Dtec.bw is funded by the European Union – NextGenerationEU. Support by the companies Saacke, RVT, Gea, AVL, and Sult is gratefully acknowledged.
Bendl, Jan; Neukirchen, Carsten; Mudan, A.; Padoan, Sara; Zimmermann, Ralf; Adam, Thomas. (2023). Spatio-temporal dynamics and characterization of subway particulate matter using a self-made mobile system. European Aerosol Conference (2023, Malaga).
Abstract
Schade, Julian; Passig, Johannes; Rosewig, Ellen Iva; Osterholz, Helena; Irsig, Robert; Hovorka, Jan; Schulz-Bull, Detlef; Zimmermann, Ralf; Adam, Thomas. (2023). Remote detection of ship exhaust plumes from different marine fuels on board a research vessel in the Baltic Sea region using single particle mass spectrometry. Joint TAP and S&E Conference (2023, Göteborg, Sweden).
Abstract
Ship emissions are a major cause of global air pollution and have a significant impact on climate and human health. To reduce emissions and improve air quality, a number ofseveral so-called sulphur emission control areas (SECAs) have been established worldwide to further improve air quality in densely populated coastal areas and preserve vulnerable ecosystems. Consequently, ships in SECAs are only authorized to operate on low-sulphur fuels or use exhaust after treatment devices such as exhaust gas scrubbers. To comply with these regulations at sea, sophisticated measurement systems are needed. and present hIn this paperere an approach to remotely detect and characterize ship exhaust plumes through on-board measurements from a research vessel in the Baltic Sea is presented. The ship exhaust plumes are detected by particle number concentration and their size distribution through CPC and SMPS+CPC measurements and qualitatively analysed by on-line single-particle mass spectrometer (SPMS). Passig et al (2020) showed that the ionization method using KrF excimer laser with 248 nm wavelength, also used in this study, exhibits high sensitivity especially for iron but also for other transition metals. In particular, this high sensitivity of the measurement method to health-relevant metals, which are contained in PM from ships with exhaust gas scrubbers and thus serve to distinguish the fuels used, is exploited. The method of SPMS and the device used here are described in more detail in the work of Li et al (2011) and Passig et al (2021). Essentially, single particles in a size range of 0.2 - 2.5 µm can be detected and analysed. In contrast to gas phase measurements, a measurement by SPMS can easily be performed from several kilometres distance in land-based measuring stations, but these measurements are strongly dependent on wind direction (Passig et al, 2021). To overcome the dependency on wind direction, the measurements for this study were performed on board the German research vessel Elisabeth Mann Borgese. The plumes of passing ships could be recorded and analysed from a distance of several kilometres. As an example, a single event is listed in Figure 1, which suggests the use of HFO in conjunction with an exhaust gas scrubber. These measurements show that SPMS can be a powerful tool for ship exhaust monitoring. This project was funded by the DFG (German Research Foundation) – 471841824 and by dtec.bw – Digitilization and Technology Research Center of the Bundeswehr (project LUKAS). dtec.bw is funded by the European Union – NextGenerationEU.
Jeong, Seongho; Bendl, Jan; Saraji-Bozorgzad, Mohammad; Käfer, Uwe; Etzien, Uwe; Schade, Julian; Bauer, Martin; Jakobi, Gert; Orasche, Jürgen; Fisch, Kathrin; Cwierz, Paul; Rüger, Christopher; Czech, Hendryk; Karg, Erwin; Heyen, Gesa; Krausnick, Max; Geissler, Andreas; Geipel, Christian; Streibel, Thorsten; Schnelle-Kreis, Jürgen; Sklorz, Martin; Schuld-Bull, Detlef; Buchholz, Bert; Adam, Thomas; Zimmermann, Ralf. (2023). Aerosol emissions from a marine diesel engine running on different fuels and effects of exhaust gas cleaning measures. Environmental Pollution, Vol. 316, No.1, S.120526.
Abstract
The emissions of marine diesel engines have gained both global and regional attentions because of their impact on human health and climate change. To reduce ship emissions, the International Maritime Organization capped the fuel sulfur content of marine fuels. Consequently, either low-sulfur fuels or additional exhaust gas cleaning devices for the reduction in sulfur dioxide (SO2) emissions became mandatory. Although a wet scrubber reduces the amount of SO2 significantly, there is still a need to consider the reduction in particle emissions directly. We present data on the particle removal efficiency of a scrubber regarding particle number and mass concentration with different marine fuel types, marine gas oil, and two heavy fuel oils (HFOs). An open-loop sulfur scrubber was installed in the exhaust line of a marine diesel test engine. Fine particulate matter was comprehensively characterized in terms of its physical and chemical properties. The wet scrubber led up to a 40% reduction in particle number, whereas a reduction in particle mass emissions was not generally determined. We observed a shift in the size distribution by the scrubber to larger particle diameters when the engine was operated on conventional HFOs. The reduction in particle number concentrations and shift in particle size were caused by the coagulation of soot particles and formation/growing of sulfur-containing particles. Combining the scrubber with a wet electrostatic precipitator as an additional abatement system showed a reduction in particle number and mass emission factors by >98%. Therefore, the application of a wet scrubber for the after-treatment of marine fuel oil combustion will reduce SO2 emissions, but it does not substantially affect the number and mass concentration of respirable particulate matters. To reduce particle emission, the scrubber should be combined with additional abatement systems.
Graphical Abstract
URL
Liu, Xiansheng; Hadiatullah, Hadiatullah; Schnelle-Kreis, Jürgen; Xu, Yanning; Yue, Mingqi; Zhang, Xun; Querol, Xavier; Cao, Xin; Bendl, Jan; Cyrys, Josef; Jakobi, Gert; Philipp, Andreas; Münkel, Christoph; Zimmermann, Ralf; Adam, Thomas. (2023). Levels and drivers of urban black carbon and health risk assessment during pre- and COVID19 lockdown in Augsburg, Germany. Environmental Pollution, Vol. 316, No.1, S.120529.
Abstract
This study aimed to evaluate the levels and phenomenology of equivalent black carbon (eBC) at the city center of Augsburg, Germany (01/2018 to 12/2020). Furthermore, the potential health risk of eBC based on equivalent numbers of passively smoked cigarettes (PSC) was also evaluated, with special emphasis on the impact caused by the COVID19 lockdown restriction measures. As it could be expected, peak concentrations of eBC were commonly recorded in morning (06:00–8:00 LT) and night (19:00–22:00 LT) in all seasons, coinciding with traffic rush hours and atmospheric stagnation. The variability of eBC was highly influenced by diurnal variations in traffic and meteorology (air temperature (T), mixing-layer height (MLH), wind speed (WS)) across days and seasons. Furthermore, a marked “weekend effect” was evidenced, with an average eBC decrease of ∼35% due to lower traffic flow. During the COVID19 lockdown period, an average ∼60% reduction of the traffic flow resulted in ∼30% eBC decrease, as the health risks of eBC exposure was markedly reduced during this period. The implementation of a multilinear regression analysis allowed to explain for 53% of the variability in measured eBC, indicating that the several factors (e.g., traffic and meteorology) may contribute simultaneously to this proportion. Overall, this study will provide valuable input to the policy makers to mitigate eBC pollutant and its adverse effect on environment and human health.
Graphical abstract
Zimmermann, Ralf; Passig, Johannes; Irsig, Robert; Czech, Hendryk; Martens, Patrick; Adam, Thomas; Schade, Julian; Ehlert, Sven. (2023). 150 Keynote: A New Aerosol Mass-Spectrometer for Simultaneous Detection of Health-Relevant Polycyclic Aromatic Hydrocarbons, Soot and Inorganic Components from Individual Airborne Particles. Annals of Work Exposures and Health, Vol. 67, Supplement 1, S.i2-i3.
Abstract
Air pollution by fine particles represents a severe environmental health-risk. The particle’s content of toxic compounds, such as polycyclic aromatic hydrocarbons (PAH), elemental carbon/soot or redox-active transition metals (e.g. Fe), is highly relevant for their toxicity. The particulate matter (PM) composition can be determined by chemical analysis of PM-loaded filter samples but no information on the mixing state of toxicants, i.e. the distribution of toxicants within the particle ensemble, is obtainable by this approach. The mixing state, however, is a crucial parameter to assess health effects as the toxicants may either be equally distributed over many particles (internally mixed) or could be highly concentrated within a small particle sub-population (externally mixed). In the latter case, the few particles with a very high concentration of toxicants can induce stronger cellular effects at the lung-deposition site. A new approach is based on single particle mass spectrometry (SPMS) but introduces a novel, tailored laser ionisation process. Aerosol particles are on-line sampled from the air and size-characterized by laser velocimetry. The organic coating of individual particles is desorbed by intense IR-laser pulses and subsequently the relevant toxicants (transition metals, PAH and soot) are ionized and MS-detected particle-by-particle, using a novel combined UV-laser ionization scheme (Schade et al. Anal., Chem. 2019; Passig et al. ACP 2022). The novel SPMS system offers the characterisation of the most relevant PM-toxicants (soot, metals, PAH) on a sized-resolved, single particle-basis and gives insight into their mixing state. First SPMS-ambient air monitoring results for PAH or metals show that, depending on conditions, the toxicants indeed either are concentrated on a very small fraction of the particle-ensemble or are rather uniformly distributed over all particles. Future application concepts of the new SPMS-technology in air monitoring and environmental health research are discussed.
Wang, Guanzhong; Ruser, Heinrich; Schade, Julian; Passig, Johannes; Adam, Thomas; Dollinger, Günther; Zimmermann, Ralf. (2023). 1D-CNN network based real-time aerosol particle classification with single-particle mass spectrometry. IEEE Sensors Letters, 2023, S.1-4.
Abstract
Single-particle mass spectrometry (SPMS) is a measurement technique that aims to identify the chemical composition of individual airborne aerosol particles (PM 1 or PM 2.5) in real-time. One-dimensional (1D) spectral data of aerosol particles generated by SPMS carry rich information about the chemical composition associated with the sources of the particles, e.g. traffic and ship emissions, biomass burning, etc. Accurate classification of aerosol particles is essential to understand their sources and effects on human health. This paper investigates the application of SPMS and 1D-convolutional neural network (1D-CNN) in aerosol particle classification. The proposed 1D-CNN achieved a mean classification accuracy of 90.4 % with 13 particle classes. According to the experimental results, the combination of SPMS and 1D-CNN enables real-time collection, analysis and classification of airborne aerosol particles, to be used for highly responsive automated air quality monitoring.
Graphical Abstract
DOI
Rohkamp, Marius; Rabl, Alexander; Gündling, Benedikt; Saraji-Bozorgzad, Mohammad Reza; Mull, Christopher; Bendl, Jan; Neukirchen, Carsten; Helcig, Christian; Adam, Thomas; Gümmer, Volker; Hupfer, Andreas. (2023). Detailed Gaseous and Particulate Emissions of an Allison 250-C20B Turboshaft Engine. ASME Turbo Expo (2023, Boston, Mass.), S.1-13.
Abstract
Aviation is known to be one of the most significant contributors to air pollutants. This includes gaseous emissions, like carbon-dioxide (CO2) and nitrogen oxides (NOx), and also particulate matter (PM), especially in the form of soot. This study conducted emission measurements on an Allison 250-C20B turboshaft engine operating on Jet A-1 fuel with a focus on gaseous compounds (e.g. ozone precursors) and PM, regarding their number and mass concentration. The different engine loading points were chosen based on the percentage thrust ratios of the International Civil Aviation Organization (ICAO) Landing and Take-Off-Cycle (LTO-Cycle). A standard FTIR/O2/FID system to measure general combustion compounds e.g. CO2, carbon-monoxide (CO), unburned hydrocarbons (UHC), and NOx, was used for the gaseous measurements. For the investigation of the volatile organic compounds (VOC), which are known to act as ozone precursors, a gas-chromatograph (GC) was applied. Different measurement methods were used to characterize the PM emissions. For the particle size distribution (PSD), we used two types of electrical mobility analyzers (SMPS and DMS500) and an aerodynamic aerosol classifier (AAC). All measurement systems yielded comparable PSD results, indicating reliable results. The particle measurement methods all show increasing aerosol diameter modes (electrical and aerodynamic) with increased engine loading. The aerosol diameter modes were shifting from 29 nm to 65 nm. Furthermore, the size and shape of different individual particles were evaluated with a scanning electron microscope (SEM). In addition, a correlation between the injection system and the particle formation was established. Gaseous turboshaft engine emissions show high CO and UHC values in Ground Idle (GI) level. NOx levels were the highest at Take-Off (TO) conditions. Acetylene and ethylene were the most significant contributors to ozone formation.
URL
https://asmedigitalcollection.asme.org/GT/proceedings-abstract/GT2023/86953/V03AT04A019/1167881
Anders, Lukas; Schade, Julian; Rosewig, Ellen Iva; Kröger-Badge, Thomas; Irsig, Robert; Jeong, Seongho; Bendl, Jan; Saraji-Bozorgzad, Mohammad Reza; Huang, Jhih-Hong; Zhang, Fu-Yi; Wang, Chia C.; Adam, Thomas; Sklorz, Martin; Etzien, Uwe; Buchholz, Bert; Czech, Hendryk; Streibel, Thorsten; Passig, Johannes; Zimmermann, Ralf. (2023). Detection of ship emissions from distillate fuel operation via single-particle profiling of polycyclic aromatic hydrocarbons. Environmental Science: Atmosphere, Vol.3 2023, No.8, S.1127-1244.
Abstract
Using novel ionization technologies in single-particle mass spectrometry (SPMS), we analyzed the polycyclic aromatic hydrocarbons (PAHs) on individual particles from a research ship engine running on marine gasoil (MGO). We found a rather uniform PAH signature on the majority of particles. The PAH pattern is stable for all engine loads and particle sizes and differs from typical signatures of other pyrogenic and petrogenic PAH sources. Based on this observation, we conducted a field experiment and observed that the appearance of this PAH signature is associated with marine air masses. Moreover, we could detect the plume of a single ship passage at 15–20 km distance by the transient appearance of particles with the same distinct PAH profile. Consequently, we suggest the use of the specific PAH pattern as a new marker to detect and monitor ship emissions, independent of the conventional metal signatures that are not applicable for compliant fuels in emission control areas and coastal waters.
Bendl, Jan; Neukirchen, Carsten; Mudan, Ajit; Padoan, Sara; Zimmermann, Ralf; Adam, Thomas. (2023). Personal measurements and sampling of particulate matter in a subway: Identification of hot-spots, spatio-temporal variability and sources of pollutants. Atmospheric Environment, Vol.308 2023, S.119883.
Abstract
A mobile measurement system for complex characterization of particulate matter (PM) was developed together with the proposed methodology and applied in the subway system of Munich, Germany. The main objectives were to observe the spatio-temporal variability of PM, personal exposure, identify hot-spots and pollution sources. Particle mass (PMx) and number (PNC) concentrations, and equivalent black carbon (eBC) were measured at 0.1–1 Hz. On the U5 subway line, PM10, PM2.5 and PM1 concentrations at platforms ranged from 59 to 220, 27–80, and 9–21 μg m−3, respectively. During rides towards downtown, average PM10, PM2.5 and PM1 levels gradually increased from 8 to 220, 2 to 71 and 2–20 μg m−3, respectively, with a similar dynamic of decrease on the return journey. Spatial variability of PM was generally more important than temporal, and significant differences were observed between platforms. During the rides, air exchange between train and tunnel was high in both air-conditioned and old passively ventilated trains. Peak PM concentrations on platforms were associated with arriving/departing trains. Subway PNC were not significantly elevated, but a few cases of intake of traffic-related particles from outside were observed, otherwise air exchange was considered low. Generally, most of the aerosol mass was composed of iron corrosion products from rails and wheels (Fe up to 66 μg m−3 in PM2.5). The effective density of PM2.5 was 2.1 g cm−3. Particles were classified as 75.4% iron oxides, 5.35% metallic Fe, 1.23% aluminosilicates and 17% carbon and oxygen rich particles. The iron oxide particles consisted predominantly of Fe (63.4 ± 8.7 wt%) and O (36.2 ± 8.2 wt%). To effectively monitor subway PM and reduce overall PM exposure, we propose to identify hot-spots using our methodology and focus on improving their ventilation, as well as installing filters in air-conditioned wagons.
Graphical Abstract
Rosewig, Ellen Iva; Schade, Julian; Passig, Johannes; Osterholz, Helena; Irsig, Robert; Smok, Dominik; Gawlitta, Nadine; Schnelle-Kreis, Jürgen; Hovorka, Jan; Schulz-Bull, Detlef; Zimmermann, Ralf; Adam, Thomas. (2023). Remote Detection of Different Marine Fuels in Exhaust Plumes by Onboard Measurements in the Baltic Sea Using Single-Particle Mass Spectrometry. Atmosphere, Vol.14, 2023, No.5, S.849.
Abstract
Ship emissions are a major cause of global air pollution, and in particular, emissions from the combustion of bunker fuels, such as heavy fuel oil (HFO), show strong impacts on the environment and human health. Therefore, sophisticated measurement techniques are needed for monitoring. We present here an approach to remotely investigating ship exhaust plumes through onboard measurements from a research vessel in the Baltic Sea. The ship exhaust plumes were detected from a distance of ~5 km by rapid changes in particle number concentration and a variation in the ambient particle size distribution utilizing a condensation particle counter (CPC) and a scanning mobility particle sizer (SMPS) instrument. Ambient single particles in the size range of 0.2–2.5 μm were qualitatively characterized with respect to their chemical signature by single-particle mass spectrometry (SPMS). In particular, the high sensitivity of the measurement method for transition metals in particulate matter (PM) was used to distinguish between the different marine fuels. Despite the high complexity of the ambient aerosol and the adverse conditions at sea, the exhaust plumes of several ships could be analyzed by means of the online instrumentation.
2022
Käfer, Uwe; Giocastro, Barbara; Gröger, Thomas; Bendl, Jan; Saraji-Bozorgzad, Mohammad; Jeong, Seongho; Etzien, Uwe; Buchholz, Bert; Streibel, Thorsten; Adam, Thomas; Zimmermann, Ralf. (2022). The detailed chemical description of organic particulate matter emitted from ship engines and the effect of fuel chemistry and implementation of scrubber technology studied by comprehensive two-dimensional gas chromatography – high-resolution time-of-flight mass spectrometry. International Aerosol Conference (11., 2022, Athens).
Abstract
Giocastro, Barbara; Gawlitta, Nadine; Zimmermann, Ralf; Adam, Thomas; Gröger, Thomas; Käfer, Uwe. (2022). Quantification In GC×GC: Is It Still An Issue? International GC×GC Symposium (19., 2022, Virtuell)
Abstract
Comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC- MS) is one of the most powerful analytical platforms suitable for the qualitative and quantitative investigation of complex samples. However, while qualitative analysis has been the main area of interest in many GC×GC studies, the focus on quantitative analysis is still less frequently reported. Several quantitative approaches have been proposed, but they often require labour-intensive procedures and the need for constant user supervision. However, the time consumption of those procedures and specific problems are usually not described in detail. Peak integration plays a pivotal role in the reliability of quantitative results. Although many improvements have been made in GC×GC, data handling and data integration are still some of the most challenging and timeconsuming steps during data processing, representing a major source of uncertainty in the results. The development of GC×GC data analysis has already made a lot of progress but is not yet fully mature. Here we provide an overview of the most common quantification approaches currently applied to GC×GC data, with focus on peak integration strategies, as well as on their merits and limitations. Moreover, common challenges regarding peak finding and subsequent integration, such as peak splitting, misassignment, or inconsistent integration, which typically have to be corrected manually, will be discussed. In practice, especially the comparison and analysis of large sample sets demands robust and automated data handling approaches, to avoid time-consuming post-processing. Finally, we introduce the principles of a simplified approach for reliable quantification of polycyclic aromatic hydrocarbons (PAHs) in complex real-world samples, such as atmospheric particulate matter. Acknowledgments This Project is supported by the Federal Ministry for Economic Affairs and Climate Action (BMWK) on the basis of a decision by the German Bundestag (grant ID: KK5037301JO0).
Padoan, Sara; Mudan, Ajit Paul; Bendl, Jan; Saraji-Bozorgzad, Mohammad; Käfer, Uwe; Etzien, Uwe; Streibel, Thorsten; Sklorz, Martin; Buchholz, Bert; Zimmermann, Ralf; Adam, Thomas. (2022). Determination of the metal fraction in marine engine emissions working under different operating conditions. International Aerosol Conference (11., 2022, Athens).
Abstract
Emissions from different types of fuel used in maritime transport are recognised as a major source of pollutant emissions (Sippula et al., 2014). The impact of these emissions has not only been found in harbour cities (Becagli et al., 2012), where the level of pollution is increasing, but also on a global scale, having large effects on the climate (Eyring et al., 2010). The pollution resulting from these emissions has major repercussions not only for the environment, but also for human health (Corbett et al., 2007). The study here presented is part of the broader project Optimization of scrubber exhaust- Gas scrubbing technology to reduce environmentally harmful ship emissions (SAARUS). The general aim of SAARUS is to deal with the current regulation of ship emissions and the subsequent optimisation of scrubber systems, which can control and reduce the environmental risk of these emissions.
The first part of this study focused on the comprehensive physical/chemical characterisation of the emissions of a wide range of ship fuels. Six different fuels, Table 1, which belong to both heavy fuels and distillate fuels have been characterised.
Here, the metal fraction has been determined in the emissions of these different ship fuels which were also working under different operating conditions. A wide range of metals have been determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). For the determination, a pre-analytical treatment, with a microwave acid digestion with HNO3 and H2O2 was used.
The results obtained show the different metallic composition in the emissions of the six different fuels, highlighting common characteristics for some of them. Figure 1, e.g., shows that HVO, MGO and HSLK fuels generally have a lower metal content than the HFO 0.53, HFO 1.34 and HFO 2.4 fuels. This trend was observed during all the different operating conditions of the ship's engine. Aluminium (Al), Calcium (Ca), Copper (Cu), Iron (Fe), Nickel (Ni), Potassium (K), Sodium (Na), Vanadium (V), and Zinc (Zn) are generally the most characteristic metals of the different fuels.
In addition, it has been noticed that the emissions of fuels working under different operating conditions shows a clear trend of change in the metal composition. These first results are significant in order to focus on an overall well-targeted reduction of emissions.
Becagli, S., Sferlazzo, D. M., Pace, G., Di Sarra, A., Bommarito, C., Calzolai, G., … Udisti, R. (2012). Evidence for heavy fuel oil combustion aerosols from chemical analyses at the island of Lampedusa: A possible large role of ships emissions in the Mediterranean. Atmospheric Chemistry and Physics, 12(7), 3479–3492.
Corbett, J. J., Winebrake, J. J., Green, E. H., Kasibhatla, P., Eyring, V., & Lauer, A. (2007). Mortality from ship emissions: A global assessment. Environmental Science and Technology, 41(24), 8512–8518.
Eyring, V., Isaksen, I. S. A., Berntsen, T., Collins, W. J., Corbett, J. J., Endresen, O., … Stevenson, D. S. (2010). Transport impacts on atmosphere and climate: Shipping. Atmospheric Environment, 44(37), 4735–4771.
Sippula, O., Stengel, B., Sklorz, M., Streibel, T., Rabe, R., Orasche, J., … Zimmermann, R. (2014). Particle emissions from a marine engine: Chemical composition and aromatic emission profiles under various operating conditions. Environmental Science and Technology, 48(19), 11721–11729.
Czech, Hendryk; Yli-Pirilä, Pasi; Tiitta, Petri; Ihalainen, Mika; Schneider, Eric; Martens, Patrick; Giocastro, Barbara; Adam, Thomas; Jokiniemi, Jorma; Gröger, Thomas; Rüger, Christopher P.; Sippula, Olli; Zimmermann, Ralf. (2022). Molecular composition of toluene-SOA: effect of “good”, “transient” and “risky” conditions in the oxidation flow reactor “PEAR” and comparison to a smog chamber. International Aerosol Conference (11., 2022, Athens).
Abstract
Oxidation flow reactors (OFR) were demonstrated to fill the gap between oxidation states observed in ambient aerosols and the ones which could be reached in smog chamber experiments. Up to now, several OFRs and operation modes have been proposed to simulate atmospheric chemistry in the laboratory, e.g. to study yields of secondary organic aerosol (SOA) from precursors (Peng & Jimenez, 2020), but also for toxicological exposures (Offer et al., 2022). However, high exposures of OH radicals, high UV light intensity and short OFR residence times has been criticized and proposed to generate aged aerosol being different in chemical composition compared to ambient aerosols.
Peng & Jimenez (2020) developed a model to evaluate the comparability to atmospheric aging conditions involving ratios of atmospheric oxidants OH, O3, O(1D) and O(3P) as well as photolysis for classification of “good”, “transient” and “risky” conditions. However, Peng & Jimenez (2020) state that OFR-generated SOA may differ in properties compared to ambient aerosols.
Experimental and Results
We generated SOA from toluene (tol-SOA) in der OFR “Photochemcial Aging Emission flowtube Reactor” (PEAR) at “good”, “transient” and “risky” conditions (Fig.1 ) as well as in the ILMARI smog chamber at the same OH exposure of 0.9 to 1.2∙1011 s cm-3. The gas phase and particularly the SOA was investigated concerning its molecular composition by a set of state-of-the-art analytical techniques.
Tol-SOAs have similar properties in bulk composition, becoming slightly less oxidized from “good” to risky” conditions, but reveal clear differences in molecular composition (Fig. 2). Furthermore the size mode of SOA particles increased from below 20 nm (a/b) over 55 nm (c) to 200 nm derived from SMPS.
Surprisingly, the chemical composition and properties of chamber-generated tol-SOA were most similar to the one from “risky” OFR conditions. Hence, our study challenges the current concept for assessing OHR chemistry only from gas phase reaction and calls for further research, aiming to harmonize OFR conditions and chemistry in the atmosphere.
This work was supported by the Helmholtz International Laboratory aeroHEALTH (InterLabs-0005).
Ihalainen, M., Tiitta, P., Czech, H., Yli-Pirilä, P., …, Sippula, O. (2019) Aerosol Sci. Technol., 53 (3), 276-294.
Offer, S., Hartner, E., Di Bucchianico, S., …, Zimmermann, R. (2022) Environ. Health Perspect., 130 (2), 27003.
Peng, Z., and Jimenez, J. L. (2020) Chem. Soc. Rev., 49 (9), 2570–2616.
Bendl, Jan; Mudan, Ajit; Neukirchen, Carsten; Adam, Thomas. (2022). Mobile Measurements and Personal Sampling during the Subway Commuting to Analyze Metals, identify Hot-spots and determine the Spatiotemporal Variability of PM. International Aerosol Conference (11., 2022, Athens).
Abstract
Giocastro, Barbara; Braas, Sebastian; Saraji, Mohammed; Gröger, Thomas; Noll-Borchers, Martina; Schnelle-Kreis, Jürgen; Sklorz, Martin; Ehlert, Sven; Eichelberg, Rolf; Zimmermann, Ralf; Adam, Thomas. (2022). Development of an in-situ Measurement System for the Simultaneous Characterization of VOCs and SVOCs in Ambient Aerosols. International Symposium on Chromatography (33., 2022, Budapest).
Abstract
In this poster, we present the concept and the workflow of a novel mobile measuring system for the simultaneous analysis of gaseous and condensed/bound volatile organic compounds (VOCs) and semi volatile organic compounds (SVOCs) in ambient aerosols. The concept allows stand-alone, fully-automated and parallel sampling of the particulate matter (PM) and gaseous phase and its subsequently and successive analysis by thermal desorption combined to gas chromatography coupled to mass spectrometry (GC-MS). Collected PM and gas phase compounds are desorbed on individual units. The PM desorption unit is designed for an on-line derivatization of polar organic compounds before desorption. A PAL based robotic unit is used for handling of collected samples and the instrument is able to operate autonomously and remotely for at least 24 h with up to hourly time resolution. The possibility to automatically exchange between the different modules together with the high-resolution time combined with sensitive analytics make the system a useful tool for long-term field measurements of ambient air.
Jeong, Seongho; Bendl, Jan; Käfer, Uwe; Saraji-Bozorgzad, Mohammad; Pantzke, Jana; Offer, Svenja; Etzien, Uwe; Jakobi, Gert; Bauer, Martin; Czech, Hendryk; Rüger, Christopher; Streibel, Thorsten; Di Bucchianico, Sebastiano; Sklorz, Martin; Buchholz, Bert; Adam, Thomas; Zimmermann, Ralf. (2022). Combustion particles of different marine fuels: genotoxic and mutagenic potential towards human lung cells and evaluation of a wet-scrubber regarding particle removal efficiency. International Aerosol Conference (11., 2022, Athens).
Abstract
Passig, Johannes; Anders, Lukas; Schade, Julian; Rosewig, Ellen Iva; Haubenwallner, Paul; Irsig, Robert; Streibel, Thorsten; Adam, Thomas; Zimmermann, Ralf. (2022). Detection of Ship Plumes using Novel Markers in Single-Particle Mass Spectrometry. International Aerosol Conference (11., 2022, Athens).
Abstract
Adam, Thomas. (2022). Entwicklung eines mobilen Luftschadstoffwarnsystems für den Gesundheits-, Umwelt- & Katastrophenschutz durch Echtzeitüberwachung & -evaluation atmosphärischer Aerosole sowie Ortung der Schadstoffquelle (LUKAS). BMBF-Innovationsforum "Zivile Sicherheit" (2022, Berlin).
Abstract
Giocastro, Barbara; Braas, Sebastian; Saraji-Bozorgzad, Mohammad; Gröger, Thomas; Orasche, Jürgen; Noll-Borchers, Martina; Ehlert, Sven; Schnelle-Kreis, Jürgen; Sklorz, Martin; Walte, Andreas; Eichelberg, Rolf; Zimmermann, Ralf; Adam, Thomas. (2022). Development of an insitu measurement system for the simultaneous characterization of organic compounds in the gas and particulate phase of ambient aerosols. International Aerosol Conference (11., 2022, Athens).
Abstract
Giocastro, Barbara; Hartner, Elena; Käfer, Uwe; Bendl, Jan; Gröger, Thomas; Zimmermann, Ralf; Adam, Thomas. (2022). Investigation of Analytical Artifacts in the Application of Thermodesorption – Comprehensive Two-Dimensional Gas Chromatography - Mass Spectrometry for the Study of Particulate Matter and Atmospheric Processes. International Symposium on Chromatography (33., 2022, Budapest).
Abstract
In this study, thermal desorption (TD) two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) is applied to investigate the chemical composition of the organic fraction of atmospheric particulate matter (PM). The challenges of combining a TD process with GC×GC-TOFMS will be herein addressed with focus directed to the investigation of analytical artifacts. The objective of this study is to demonstrate how the TD process might alter the sample matrix, thus generating uncertain qualitative and quantitative results. Laboratory-generated secondary organic aerosol (SOA) derived from β-pinene oxidation and PM from an urban site (Munich, Germany) were herein investigated. A multistep TD/pyrolysis approach was applied for monitoring thermal decomposition products and oxidations products from TD by varying the maximum desorption/pyrolysis temperature and the temperature gradient ramp. Generally, it has been shown how the thermally labile fraction of the sample matrix will thermally decompose following a trend which is a function of the desorption temperature, the temperature gradient ramp of the heating process, as well as the aerosol chemical composition.
Adam, Thomas. (2022). Ultrafine Particles from Transportation - Health Assessment of Sources. Workshop UFP-Studien 2022.
Abstract
Giocastro, Barbara; Hartner, Elena; Gröger, Thomas; Bendl, Jan; Käfer, Uwe; Orasche, Jürgen; Saraji-Bozorgzad, Mohammad; Czech, Hendryk; Schnelle-Kreis, Jürgen; Sklorz, Martin; Zimmermann, Ralf; Adam, Thomas. (2022). In-depth Investigation of Artefacts from Thermal Desorption of Atmospheric Particulate Matter. International Aerosol Conference (11., 2022, Athens).
Abstract
Adam, Thomas. (2022). Entwicklung eines mobilen Luftschadstoffwarnsystems für den Gesundheits-, Umwelt- & Katastrophenschutz durch Echtzeitüberwachung & -evaluation atmosphärischer Aerosole sowie Ortung der Schadstoffquelle (dtec.bw Projekt LUKAS). Angewandte Forschung für Verteidigung und Sicherheit in Deutschland (2022, Bonn).
Abstract
An der Universität der Bundeswehr München wird derzeit im Rahmen des Zentrums für Digitalisierungs- und Technologieforschung der Bundeswehr (dtec) das Luftschadstoffwarnsystem LUKAS entwickelt. Ziel von LUKAS ist der Aufbau eines innovativen mobilen Mess- und Warnsystems zur Überwachung und Detektion von Schadstoffen in der Atmosphäre. Das System soll in der Lage sein, luftgetragene Feinstäube und Aerosole in Echtzeit auf ihre chemische Zusammensetzung und ihren Schadstoffgehalt im Ultraspurenbereich zu analysieren und mit einer sich kontinuierlich weiterentwickelnden Datenbank abzugleichen. Durch die Echtzeit-Datenanalyse kombiniert mit meteorologischer Modellierung soll zeitgleich eine Ortung der Schadstoffquelle, die Prognose der Schadstoffausbreitung sowie eine prospektive Warnmeldung erfolgen. Die eingesetzte Messtechnik basiert auf einem innovativen Verfahren der Lasermassenspektrometrie zur schnellen chemischen Untersuchung einzelner Partikel im Mikro- und Nanometerbereich. LUKAS soll sich für den Einsatz in der Katastrophenvorbeugung, dem Gesundheits- und Umweltschutz und dem Zivilschutz eignen. Präsentiert werden einige Schlüsselaspekte der Technologie sowie erste Ergebnisse ihrer Anwendung zum Nachweis sicherheitsrelevanter Komponenten. So wird gezeigt, dass Stäube verschiedener gesundheitsrelevanter Stoffe unabhängig von ihrem Dampfdruck charakteristische massenspektrale Signaturen erzeugen, die auch in einem komplexen Aerosolhintergrund identifiziert werden können. Darüber hinaus wird gezeigt, wie Metalle und aromatische organische Schadstoffe mit bisher unerreichter Empfindlichkeit in der Umgebungsluft nachgewiesen werden können.
Cao, Xin; Liu, Xiansheng; Hadiatullah, Hadiatullah; Xu, Yanning; Zhang, Xun; Cyrys, Josef; Zimmermann, Ralf; Adam, Thomas. (2022). Investigation of COVID-19-related lockdowns on the air pollution changes in Augsburg in 2020, Germany. Atmospheric Pollution Research, Vol.13, No. 9, S. 101536.
Abstract
The COVID-19 pandemic in Germany in 2020 brought many regulations to impede its transmission such as lockdown. Hence, in this study, we compared the annual air pollutants (CO, NO, NO2, O3, PM10, PM2.5, and BC) in Augsburg in 2020 to the record data in 2010–2019. The annual air pollutants in 2020 were significantly (p < 0.001) lower than that in 2010–2019 except O3, which was significantly (p = 0.02) higher than that in 2010–2019. In a depth perspective, we explored how lockdown impacted air pollutants in Augsburg. We simulated air pollutants based on the meteorological data, traffic density, and weekday and weekend/holiday by using four different models (i.e. Random Forest, K-nearest Neighbors, Linear Regression, and Lasso Regression). According to the best fitting effects, Random Forest was used to predict air pollutants during two lockdown periods (16/03/2020–19/04/2020, 1st lockdown and 02/11/2020–31/12/2020, 2nd lockdown) to explore how lockdown measures impacted air pollutants. Compared to the predicted values, the measured CO, NO2, and BC significantly reduced 18.21%, 21.75%, and 48.92% in the 1st lockdown as well as 7.67%, 32.28%, and 79.08% in the 2nd lockdown. It could be owing to the reduction of traffic and industrial activities. O3 significantly increased 15.62% in the 1st lockdown but decreased 40.39% in the 2nd lockdown, which may have relations with the fluctuations the NO titration effect and photochemistry effect. PM10 and PM2.5 were significantly increased 18.23% an 10.06% in the 1st lockdown but reduced 34.37% and 30.62% in the 2nd lockdown, which could be owing to their complex generation mechanisms.
Graphical Abstract
URL
https://www.sciencedirect.com/science/article/pii/S1309104222002173?via%3Dihub
Pardo, Michal; Offer, Svenja; Hartner, Elena; Di Bucchianico, Sebastiano; Bisig, Christoph; Bauer, Stephanie; Pantzke, Jana; Zimmermann, Elias J.; Cao, Xin; Binder, Stephanie; Kuhn, Evelyn; Huber, Anja; Jeong, Seongho; Käfer, Uwe; Schneider, Eric; Mesceriakovas, Arunas; Bendl, Jan; Brejcha, Ramona; Buchholz, Angela; Gat, Daniela; Hohaus, Thorsen; Rastak, Narges; Karg, Erwin; Jakobi, Gert; Kalberer, Markus; Kanashova, Tamara; Hu, Yue; Ogris, Christoph; Marsico, Annalisa; Theis, Fabian; Shalit, Tali; Gröger, Thomas; Rüger, Christopher P.; Oeder, Sebastian; Orasche, Jürgen; Paul, Andreas; Ziehm, Till; Zhang, Zhi-Hui; Adam, Thomas; Sippula, Olli; Sklorz, Martin; Schnelle-Kreis, Jürgen; Czech, Hendryk; Kiendler-Scharr, Astrid; Zimmermann, Ralf; Rudich, Yinon. (2022). Exposure to naphthalene and β-pinene-derived secondary organic aerosol induced divergent changes in transcript levels of BEAS-2B cells. Environment International, Vol. 166, S. 107366.
Abstract
The health effects of exposure to secondary organic aerosols (SOAs) are still limited. Here, we investigated and compared the toxicities of soot particles (SP) coated with β-pinene SOA (SOAβPin-SP) and SP coated with naphthalene SOA (SOANap-SP) in a human bronchial epithelial cell line (BEAS-2B) residing at the air–liquid interface. SOAβPin-SP mostly contained oxygenated aliphatic compounds from β-pinene photooxidation, whereas SOANap-SP contained a significant fraction of oxygenated aromatic products under similar conditions. Following exposure, genome-wide transcriptome responses showed an Nrf2 oxidative stress response, particularly for SOANap-SP. Other signaling pathways, such as redox signaling, inflammatory signaling, and the involvement of matrix metalloproteinase, were identified to have a stronger impact following exposure to SOANap-SP. SOANap-SP also induced a stronger genotoxicity response than that of SOAβPin-SP. This study elucidated the mechanisms that govern SOA toxicity and showed that, compared to SOAs derived from a typical biogenic precursor, SOAs from a typical anthropogenic precursor have higher toxicological potency, which was accompanied with the activation of varied cellular mechanisms, such as aryl hydrocarbon receptor. This can be attributed to the difference in chemical composition; specifically, the aromatic compounds in the naphthalene-derived SOA had higher cytotoxic potential than that of the β-pinene-derived SOA.
Graphical Abstract
URL
Cao, Xin; Padoan, Sara; Binder, Stephanie; Bauer, Stefanie; Orasche, Jürgen; Rus, Corina-Marcela; Mudan, Ajit; Huber, Anja; Kuhn, Evelyn; Oeder, Sebastian; Lintelmann, Jutta; Adam, Thomas; Di Bucchianico, Sebastiano; Zimmermann, Ralf. (2022). A comparative study of persistent DNA oxidation and chromosomal instability induced in vitro by oxidizers and reference airborne particles. Mutation Research/Genetic Toxicology and Environmental Mutagenesis, Vol. 874-875, S. 503446.
Abstract
Kösling, Paul; Rüger, Christopher; Schade, Julian; Ehlert, Sven; Etzien, Uwe; Kozhinov, Anton; Tsybin, Yury; Rigler, Martin; Adam, Thomas; Walte, Andreas; Buchholz, Bert; Zimmermann, Ralf. (2022). Real-Time Investigation of Primary Ship Engine Emissions by Vacuum Resonance-Enhanced Multiphoton Ionization High-Resolution Orbitrap Mass Spectrometry. Analytical Chemistry, Vol. 94, No. 48, S. 16855-16863.
Abstract
The comprehensive chemical description of air pollution is a prerequisite for understanding atmospheric transformation processes and effects on climate and environmental health. In this study, a prototype vacuum photoionization Orbitrap mass spectrometer was evaluated for field-suitability by an online on-site investigation of emissions from a ship diesel engine. Despite remote measurements in a challenging environment, the mass spectrometric performance could fully be exploited. Due to the high resolution and mass accuracy in combination with resonance-enhanced multiphoton ionization, the aromatic hydrocarbon profile could selectively and sensitively be analyzed. Limitations from commonly deployed time-of-flight platforms could be overcome, allowing to unraveling the oxygen- and sulfur-containing compounds. Scan-by-scan evaluation of the online data revealed no shift in exact m/z, assignment statistics with root mean square error (RMSE) below 0.2 ppm, continuous high-resolution capabilities, and good isotopic profile matches. Emissions from three different feed fuels were investigated, namely, diesel, heavy fuel oil (HFO), and very low sulfur fuel oil (VLSFO). Regulations mainly concern the fuel sulfur content, and thus, exhaust gas treatment or new emerging fuels, such as the cycle-oil-based VLSFO, can legally be applied. Unfortunately, despite lower CHS-class emissions, a substantial amount of PAHs is emitted by the VLSFO with higher aromaticity compared to the HFO. Hence, legislative measures might need to take further chemical criteria into account.
URL
Schneider, Eric; Giocastro, Barbara; Rüger, Christopher; Adam, Thomas; Zimmermann, Ralf. (2022). Detection of Polycyclic Aromatic Hydrocarbons in High Organic Carbon Ultrafine Particle Extracts by Electrospray Ionization Ultrahigh-Resolution Mass Spectrometry. Journal of the American Society for Mass Spectrometry, Vol. 33, No. 11.
Abstract
The detection of polycyclic aromatic hydrocarbons (PAHs) by electrospray ionization (ESI) without additional reagents or targeted setup changes to the ionization source was observed in ultrafine particle (UFP) extracts, with high organic carbon (OC) concentrations, generated by a combustion aerosol standard (CAST) soot generator. Particulate matter (PM) was collected on filters, extracted with methanol, and analyzed by ESI Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Next to oxygen-containing species, pure hydrocarbons were found to be one of the most abundant compound classes, detected as [M + Na]+ or [M + H]+ in ESI+ and mostly as [M - H]- in ESI-. The assigned hydrocarbon elemental compositions are identified as PAHs due to their high aromaticity index (AI > 0.67) and were additionally confirmed by MS/MS experiments as well as laser desorption ionization (LDI). Thus, despite the relatively low polarity, PAHs have to be considered in the molecular attribution of these model aerosols and/or fresh emissions with low salt content investigated by ESI.
Offer, Svenja; Hartner, Elena; Di Bucchianico, Sebastiano; Bisig, Christoph; Bauer, Stefanie; Pantzke, Jana; Zimmermann, Elias J.; Cao, Xin; Binder, Stefanie; Kuhn, Evelyn; Huber, Anja; Jeong, Seongho; Käfer, Uwe; Martens, Patrick; Mesceriakovas, Arunas; Bendl, Jan; Brejcha, Ramona; Buchholz, Angela; Gat, Daniella; Hohaus, Thorsten; Rastak, Narges; Jakobi, Gert; Kalberer, Markus; Kanashova, Tamara; Hu, Yue; Ogris, Christoph; Marsico, Annalisa; Theis, Fabian; Pardo, Michal; Gröger, Thomas; Oeder, Sebastian; Orasche, Jürgen; Paul, Andreas; Ziehm, Till; Zhang, Zhi-Hui; Adam, Thomas; Sippula, Olli; Sklorz, Martin; Schnelle-Kreis, Jürgen; Czech, Hendryk; Kiendler-Scharr, Astrid; Rudich, Yinon; Zimmermann, Ralf. (2022). Effect of Atmospheric Aging on Soot Particle Toxicity in Lung Cell Models at the Air–Liquid Interface: Differential Toxicological Impacts of Biogenic and Anthropogenic Secondary Organic Aerosols (SOAs). Environmental health perspectives (EHP), Vol. 130, No. 2.
Abstract
Background: Secondary organic aerosols (SOAs) formed from anthropogenic or biogenic gaseous precursors in the atmosphere substantially contribute to the ambient fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)] burden, which has been associated with adverse human health effects. However, there is only limited evidence on their differential toxicological impact. Objectives: We aimed to discriminate toxicological effects of aerosols generated by atmospheric aging on combustion soot particles (SPs) of gaseous biogenic (β-pinene) or anthropogenic (naphthalene) precursors in two different lung cell models exposed at the air–liquid interface (ALI). Methods: Mono- or cocultures of lung epithelial cells (A549) and endothelial cells (EA.hy926) were exposed at the ALI for 4 h to different aerosol concentrations of a photochemically aged mixture of primary combustion SP and β-pinene (SOAβPIN-SP) or naphthalene (SOANAP-SP). The internally mixed soot/SOA particles were comprehensively characterized in terms of their physical and chemical properties. We conducted toxicity tests to determine cytotoxicity, intracellular oxidative stress, primary and secondary genotoxicity, as well as inflammatory and angiogenic effects. Results: We observed considerable toxicity-related outcomes in cells treated with either SOA type. Greater adverse effects were measured for SOANAP-SP compared with SOAβPIN-SP in both cell models, whereas the nano-sized soot cores alone showed only minor effects. At the functional level, we found that SOANAP-SP augmented the secretion of malondialdehyde and interleukin-8 and may have induced the activation of endothelial cells in the coculture system. This activation was confirmed by comet assay, suggesting secondary genotoxicity and greater angiogenic potential. Chemical characterization of PM revealed distinct qualitative differences in the composition of the two secondary aerosol types. Discussion: In this study using A549 and EA.hy926 cells exposed at ALI, SOA compounds had greater toxicity than primary SPs. Photochemical aging of naphthalene was associated with the formation of more oxidized, more aromatic SOAs with a higher oxidative potential and toxicity compared with β-pinene. Thus, we conclude that the influence of atmospheric chemistry on the chemical PM composition plays a crucial role for the adverse health outcome of emissions.
Passig, Johannes; Adam, Thomas; Zimmermann, Ralf. (2022). Unraveling Pollutant Distributions on the Single-Particle Level: A New Aspect in Air Pollution Research. Bunsen-Magazin, Vol. 2, S.56-59.
Abstract
Air pollution accounts for more than 6 million early deaths and 213 million years of healthy life lost worldwide in 2019, and is now listed as the 4th death-leading risk factor behind important chronic diseases including obesity, high cholesterol and malnutrition. Among the different air pollutants, particulate matter (PM) represents the largest risk to human health, which is further increased by the rapid development of global industrial societies and the increasing number of wildfires in the course of climate change.
Passig, Johannes; Schade, Julian; Irsig, Robert; Kröger-Badge, Thomas; Czech, Hendryk; Adam, Thomas; Fallgren, Henrik; Moldanova, Jana; Sklorz, Martin; Streibel, Thorsten; Zimmermann, Ralf. (2022). Single-particle characterization of polycyclic aromatic hydrocarbons in background air in northern Europe. Atmospheric chemistry and physics, Vol. 22, No. 2, S. 1495-1514.
Abstract
We investigated the distribution of polycyclic aromatic hydrocarbons (PAHs) on individual ambient aerosol particles at the Swedish western coast in a pristine environment for 10 d in October 2019. The measurements were carried out using new technology with single-particle mass spectrometry (SPMS) that reveals both the inorganic particle composition as well as the particle-bound PAHs (Schade et al., 2019). More than 290 000 particles were characterized; 4412 of them reveal PAH signatures. Most of the PAH-containing particles were internal mixtures of carbonaceous material, secondary nitrate and metals from distant sources in central and eastern Europe. We characterize the aerosol with respect to the inorganic composition, comparable to conventional SPMS, before we discuss the distribution of PAHs within this particle ensemble. Vice versa, we analyze the single-particle PAH spectra for characteristic patterns and discuss the inorganic composition, origin and atmospheric processing of the respective particles. The study period comprised different meteorological situations: clean air conditions with winds from the North Sea/Kattegat and little terrestrial air pollution, long-range transport from eastern Europe and southern Sweden, and transport of aerosols from central Europe over the sea. For all meteorological conditions, PAHs were detected in particles whose inorganic content indicates traffic emissions, such as combinations of soot, iron and calcium as well as in particles with biomass-burning signatures. However, there were variations in their amounts, dependent on the geographic origin. Because of strong mixing, rapid degradation and speciation limits, e.g., for PAHs of the same nominal mass, the application of diagnostic ratios for source apportionment is limited under the conditions of our study. Nevertheless, the combination with the inorganic content and meteorological data provides unique insights into the particles' origin, aging and mixing state. We exemplarily show how the observation of PAH profiles and inorganic secondary components on a single-particle level can open a new door to investigate aerosol aging processes. To our best knowledge, we herewith present the first comprehensive study on the single-particle distribution of PAHs in ambient air as well as the first set of combined data on PAHs and inorganic composition on a single-particle level.
Graphical Abstract
Zhang, Zhi-Hui; Hartner, Elena; Utinger, Battist; Gfeller, Benjamin; Paul, Andreas; Sklorz, Martin; Czech, Hendryk; Yang, Bin Xia; Su, Xin Yi; Jakobi, Gert; Orasche, Jürgen; Schnelle-Kreis, Jürgen; Jeong, Seongho; Gröger, Thomas; Pardo, Michal; Hohaus, Thorsten; Adam, Thomas; Kiendler-Scharr, Astrid; Rudich, Yinon; Zimmermann, Ralf; Kalberer, Markus. (2022). Are reactive oxygen species (ROS) a suitable metric to predict toxicity of carbonaceous aerosol particles? Atmospheric chemistry and physics, Vol. 22, No. 3, S. 1793-1809.
Abstract
It is being suggested that particle-bound or particle-induced reactive oxygen species (ROS), which significantly contribute to the oxidative potential (OP) of aerosol particles, are a promising metric linking aerosol compositions to toxicity and adverse health effects. However, accurate ROS quantification remains challenging due to the reactive and short-lived nature of many ROS components and the lack of appropriate analytical methods for a reliable quantification. Consequently, it remains difficult to gauge their impact on human health, especially to identify how aerosol particle sources and atmospheric processes drive particle-bound ROS formation in a real-world urban environment. In this study, using a novel online particle-bound ROS instrument (OPROSI), we comprehensively characterized and compared the formation of ROS in secondary organic aerosols (SOAs) generated from organic compounds that represent anthropogenic (naphthalene, SOANAP) and biogenic (β-pinene, SOAβPIN) precursors. The SOA mass was condensed onto soot particles (SP) under varied atmospherically relevant conditions (photochemical aging and humidity) to mimic the SOA formation from a mixing of traffic-related carbonaceous primary aerosols and volatile organic compounds (VOCs). We systematically analyzed the ability of the aqueous extracts of the two aerosol types (SOANAP-SP and SOAβPIN-SP) to induce ROS production and OP. We further investigated cytotoxicity and cellular ROS production after exposing human lung epithelial cell cultures (A549) to extracts of the two aerosols. A significant finding of this study is that more than 90 % of all ROS components in both SOA types have a short lifetime, highlighting the need to develop online instruments for a meaningful quantification of ROS. Our results also show that photochemical aging promotes particle-bound ROS production and enhances the OP of the aerosols. Compared to SOAβPIN-SP, SOANAP-SP elicited a higher acellular and cellular ROS production, a higher OP, and a lower cell viability. These consistent results between chemical-based and biological-based analyses indicate that particle-bound ROS quantification could be a feasible metric to predict aerosol particle toxicity and adverse human effects. Moreover, the cellular ROS production caused by SOA exposure not only depends on aerosol type but is also affected by exposure dose, highlighting a need to mimic the process of particle deposition onto lung cells and their interactions as realistically as possible to avoid unknown biases.
Graphical Abstract
Liu, Xiansheng; Hadiatullah, Hadiatullah; Khedr, Mohamed; Zhang, Xun; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; Adam, Thomas. (2022). Personal exposure to various size fractions of ambient particulate matter during the heating and non-heating periods using mobile monitoring approach: A case study in Augsburg, Germany. Atmospheric Pollution Research, Vol. 13, No. 7.
Abstract
In this study, the exposure to ambient particulate matter metrics (PM1, PM2.5, PM10, black carbon (BC), brown carbon (BrC), ultraviolet particulate matter (UVPM), particle number concentration (PNC), and lung deposited surface area (LDSA)) were measured along a fixed walking route with specific focus on three typical micro-environments (park, central business district (CBD), and traffic) in different time of day during the non-heating (May–Oct.) and heating (Nov.–Apr.2nd year) periods from 2018 to 2020 in the downtown Augsburg, Germany. The spatio-temporal exposure to ambient PM metrics exhibited substantial heterogeneity during the observation period, with park environment having lowest exposure and traffic area having the highest exposure. Generally, the higher LDSA concentrations were found in traffic area and CBD during the observation periods, while the lower concentrations were found in the park, which is similar with other ambient PM metrics (PMX, eUVPM, eBC, and PNC). The correlations between LDSA and other ambient PM metrics were higher during the heating than non-heating period in most of investigated environments, indicating the different PM sources. Overall, this study provides a comprehensive assessment of personal exposure that complements fixed-site ambient PM metrics measurements in the context of health risk assessment and epidemiological studies.
Graphical Abstract
2021
Adam, Thomas. (2021). Traffic-related non-exhaust emission activities at the University of the Bundeswehr München. United Nations Economic Commission for Europe (UNECE) Particle Measurement Programme (PMP) Group.
Abstract
Adam, Thomas. (2021). Aerosolforschung am Institut für Chemie & Umwelttechnik der Universität der Bundeswehr München. Bayerisches Landesamt für Umwelt (LfU).
Abstract
Cao, Xin; Lintelmann, Jutta; Padoan, Sara; Bauer, Stefanie; Huber, Anja; Mudan, Ajit; Oeder Sebastian; Adam, Thomas; Di Bucchianico, Sebastiano; Zimmermann, Ralf. (2021). Adenine derivatization for LC-MS/MS epigenetic DNA modifications studies on monocytic THP-1 cells exposed to reference particulate matter. Analytical Biochemistry, Vol. 618
Abstract
The aim of this study was to explore the impact of three different standard reference particulate matter (ERM-CZ100, SRM-1649, and SRM-2975) on epigenetic DNA modifications including cytosine methylation, cytosine hydroxymethylation, and adenine methylation. For the determination of low levels of adenine methylation, we developed and applied a novel DNA nucleobase chemical derivatization and combined it with liquid chromatography tandem mass spectrometry. The developed method was applied for the analysis of epigenetic modifications in monocytic THP-1 cells exposed to the three different reference particulate matter for 24 h and 48 h. The mass fraction of epigenetic active elements As, Cd, and Cr was analyzed by inductively coupled plasma mass spectrometry. The exposure to fine dust ERM-CZ100 and urban dust SRM-1649 decreased cytosine methylation after 24 h exposure, whereas all 3 p.m. increased cytosine hydoxymethylation following 24 h exposure, and the epigenetic effects induced by SRM-1649 and diesel SRM-2975 were persistent up to 48 h exposure. The road tunnel dust ERM-CZ100 significantly increased adenine methylation following the shorter exposure time. Two-dimensional scatters analysis between different epigenetic DNA modifications were used to depict a significantly negative correlation between cytosine methylation and cytosine hydroxymethylation supporting their possible functional relationship. Metals and polycyclic aromatic hydrocarbons differently shapes epigenetic DNA modifications.
Graphical Abstract
Heide, Jan; Adam, Thomas; Jacobs, Erik; Wolter, Jan-Martin; Ehlert, Sven, Walte, Andreas; Zimmermann, Ralf. (2021). Puff-Resolved Analysis and Selected Quantification of Chemicals in the Gas Phase of E-Cigarettes, Heat-Not-Burn Devices, and Conventional Cigarettes Using Single-Photon Ionization Time-of-Flight Mass Spectrometry (SPI-TOFMS): A Comparative Study. Nicotine and Tobacoo Research, Vol. 23, No. 12, S. 2135-2144.
Abstract
Introduction
A wide array of alternative nicotine delivery devices (ANDD) has been developed and they are often described as less harmful than combustible cigarettes. This work compares the chemical emissions of three ANDD in comparison to cigarette smoke. All the tested ANDD are characterized by not involving combustion of tobacco.
Aims and Methods
Single-photon ionization time-of-flight mass spectrometry (SPI-TOFMS) is coupled to a linear smoking machine, which allows a comprehensive, online analysis of the gaseous phase of the ANDD aerosol and the conventional cigarette (CC) smoke. The following devices were investigated in this study: a tobacco cigarette with a glowing piece of coal as a heating source, an electric device for heating tobacco, and a first-generation electronic cigarette. Data obtained from a standard 2R4F research cigarette are taken as a reference.
Results
The puff-by-puff profile of all products was recorded. The ANDD show a substantial reduction or complete absence of known harmful and potentially harmful substances compared with the CC. In addition, tar substances (i.e. semivolatile and low volatile aromatic and phenolic compounds) are formed to a much lower extent. Nicotine, however, is supplied in comparable amounts except for the investigated electronic cigarette. Conclusions The data show that consumers switching from CC to ANDD are exposed to lower concentrations of harmful and potentially harmful substances. However, toxicological and epidemiological studies must deliver conclusive results if these reduced exposures are beneficial for users. Implications The comparison of puff-resolved profiles of emissions from different tobacco products, traditional and alternative, may help users switch to lower emission products. Puff-resolved comparison overcomes technical changes, use modes between products and may help in their regulation.
Passig, Johannes; Schade, Julian; Irsig, Robert; Li, Lei; Li, Xue; Zhou, Zhen; Adam, Thomas; Zimmermann, Ralf. (2021). Detection of ship plumes from residual fuel operation in emission control areas using single-particle mass spectrometry. Atmospheric Measurement Techniques, Vol. 14, No. 6, S. 4171-4185.
Abstract
Ships are among the main contributors to global air pollution, with substantial impacts on climate and public health. To improve air quality in densely populated coastal areas and to protect sensitive ecosystems, sulfur emission control areas (SECAs) were established in many regions of the world. Ships in SECAs operate with low-sulfur fuels, typically distillate fractions such as marine gas oil (MGO). Alternatively, exhaust gas-cleaning devices (“scrubbers”) can be implemented to remove SO2 from the exhaust, thus allowing the use of cheap high-sulfur residual fuels. Compliance monitoring is established in harbors but is difficult in open water because of high costs and technical limitations. Here we present the first experiments to detect individual ship plumes from distances of several kilometers by single-particle mass spectrometry (SPMS). In contrast to most monitoring approaches that evaluate the gaseous emissions, such as manned or unmanned surveillance flights, sniffer technologies and remote sensing, we analyze the metal content of individual particles which is conserved during atmospheric transport. We optimized SPMS technology for the evaluation of residual fuel emissions and demonstrate their detection in a SECA. Our experiments show that ships with installed scrubbers can emit PM emissions with health-relevant metals in quantities high enough to be detected from more than 10 km distance, emphasizing the importance of novel exhaust-cleaning technologies and cleaner fuels. Because of the unique and stable signatures, the method is not affected by urban background. With this study, we establish a route towards a novel monitoring protocol for ship emissions. Therefore, we present and discuss mass spectral signatures that indicate the particle age and thus the distance to the source. By matching ship transponder data, measured wind data and air mass back trajectories, we show how real-time SPMS data can be evaluated to assign distant ship passages.
Graphical Abstract
Etzien, Uwe. (2021). Analysis of the influence of marine fuels on particle emissions from ships. ETH-Conference on Combustion Generated Nanoparticles (24., 2021, Online).
Abstract
In contrast to the extensive requirements for land-based particulate and fine dust emissions, the maritime sector is still in its infancy and has not yet been able to provide any global limit value regulations. It can be assumed that this topic will become more and more important in the future. With the last tightening of the IMO regulations on January 1st, 2020 (sulfur content in fuel ≤ 0.5% or use of an exhaust gas cleaning system outside of the ECAs), a change in the composition of the fleet emissions is to be expected. In this context, the joint project SAARUS was launched at the University of Rostock, with the aim to investigate ship-based emissions and to reduce them through optimized and expanded exhaust gas cleaning. In addition to reducing SOx emissions,the focus is on separating fine particles that measure smaller than 2.5 μm (PM2.5). In particular, the health-endangering fine dust fractions (aerosols) with particle diameters below 1 μm are only slightly reduced by conventional wet scrubbers. The approach to further decrease the particle load is therefore to use the scrubber as an optimized particle prefilter in order to create the boundary conditions for downstream filter technologies to be tested. In this context, an extensive measurement campaign with six different fuels available on the market took place on a medium-speed single-cylinder research engine, which is representative of the maritime sector and located at the Chair for Piston Engines and Internal Combustion Engines. As part of the investigations, the fuel-based changes in emissions and the combustion behavior of a hydrogenated vegetable oil (HVO), a MGO, a limit-compliant HFO (sulfur content ≤ 0.5%), a standard HFO (sulfur content 2.4%) and two highly aromatic heavy fuel oils (sulfur content 0.06% and 1.3%) are analyzed. The following measurement methods were used to characterize the particle emissions: gravimetric filter analyzes, tapered element oscillating microbalance (TEOM), scanning mobility particle sizer (SMPS), Pegasor particle sensor, online single particle mass spectrometry (SPMS), filter sampling and two-dimensional gas chromatography / mass spectrometry (GCxGC-TOFMS), high-resolution mass spectrometry (HRMS for organic matter) and inductively coupled plasma / mass spectrometry (ICP-MS for elements). The focus of the article is on the presentation of the most important findings of this measurement campaign. In addition to a comparison of the properties of the fuels examined, their effects on the particle load in terms of concentration, size distribution and chemical composition are discussed. In addition, the simulation approach for particle separation in the scrubber and the approaches for separating fine particles measuring smaller than 2.5 μm (PM2.5) as well as the harmful fine dust fractions (aerosols) with particle diameters below 1 μm are presented in an outlook.
2020
Adam, Thomas; Schüler des Ernst-Mach-Gymnasiums Haar. (2020). Die unterschätzte Gefahr: Bremsstaub verschmutzt unsere Atemluft mehr als Abgase. Süddeutsche Zeitung, 28.01.2020.
Zimmermann, Ralf; Adam, Thomas. (2020). Chemische und biologische Charakterisierung von ultrafeinen Partikeln. 60. Jahrestagung der Deutschen Gesellschaft für Arbeitsmedizin und Umweltmedizin (60., 2020, München).
Abstract
Popovicheva, Olga; Padoan, Sara; Schnelle-Kreis, Juergen; Nguyen, Dac-Log; Adam, Thomas; Kistler, Magdalena; Steinkogler, Thomas; Kasper-Giebl, Anneliese; Zimmermann, Ralf; Chubarova, Natalia. (2020). Spring Aerosol in Urban Atmosphere of Megacity: Analytical and Statistical Assessment for Source Impacts. Aerosol and Air Quality Research, Vol. 20, No. 4, S. 702-719.
Abstract
In the complex situation with the plurality of emissions, the important research task of assessing the air quality and potential sources through aerosol composition analyses remains for Moscow’s megacity environment. The light absorption, PM10 mass concentration, aerosol composition, and meteorological parameters in this urban background were measured during spring 2017, a period characterized by significant changes in the air temperature, mass advection, and solar radiation. The organic and elemental carbon (OC and EC) and 76 organic compounds, e.g., alkanes, polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs, hopanes, anhydrosugars, polyols, primary and secondary saccharides, and HULIS, as well as 13 ions, including K+, a marker of biomass burning, have been quantified to determine the carbonaceous and inorganic chemical profiles of the aerosol. The correlation between the absorption Ångström exponent (AAE) and the levoglucosan concentration reveals the relative contributions of agricultural fires and residential biomass burning (BB) nearby to the urban aerosol composition. Combining detailed analytical and statistical approaches, we have identified and analyzed the specific chemical compounds that most accurately represent the variability of the aerosol composition. Principal component analysis (PCA) highlights the main factors for marker species related to gasoline/diesel traffic, BB, biogenic activity, and secondary formation in the atmosphere. Distinguishing the BB-affected periods allows us to evaluate daily changes in the aerosol composition in relation to the transported air masses and detected fires in the areas surrounding Moscow.
Popovicheva, Olga B.; Volpert, Elena; Sitnikov, Nikolay M.; Chichaeva, Marina A.; Padoan, Sara. (2020). Black carbon in spring aerosols of Moscow urban background. Geography, Environment, Sustainability, Vol. 13, No. 1, S. 233-243.
Abstract
Air quality in megacities is recognized as the most important environmental problem. Aerosol pollution by combustion emissions is remaining to be uncertain. Measurements of particulate black carbon (BC) were conducted at the urban background site of Meteorological Observatory (MO) MSU during the spring period of 2017 and 2018. BC mass concentrations ranged from 0.1 to 10 μg m–3, on average 1.5±1.3 and 1.1±0.9 µg/m3 , in 2017 and 2018, respectively. Mean BC concentrations displayed significant diurnal variations with poorly prominent morning peak and minimum at day time. BC mass concentrations are higher at night time due the shallow boundary layer and intensive diesel traffic which results in trapping of pollutants. Wind speed and direction are found to be important meteorological factors affected BC concentrations. BC pollution rose identifies the North as the direction of the preferable pollution. A negative correlation between BC concentrations and wind speed confirms the pollution accumulation preferably in stable weather days. Relation of BC pollution to a number of agriculture fires is distinguishable by air mass transportation from South and South-Est of Russia and Western Europe. Mean season ВС concentrations at rural and remote sites in different world locations are discussed.
URL
Padoan, Sara; Zappi, Alessandro; Adam, Thomas; Melucci, Dora; Gambaro, Andrea; Formenton, Gianni; Popovicheva, Olga; Nguyen, Dac-Loc; Schnelle-Kreis, Jürgen; Zimmermann, Ralf. (2020). Organic molecular markers and source contributions in a polluted municipality of north-east Italy: Extended PCA-PMF statistical approach. Environmental Research, Vol. 186, S. 109587-109598.
Abstract
Exceeding the maximum levels for environmental pollutants creates public and scientific interest for the environmental and human health impact it may have. In Northern Italy, the Po Valley, and in particular the Veneto region, is still a hotspot for air quality improvement. Several monitoring campaigns were carried out in this area to acquire information about sources of pollutants which are considered critical. For the first time, a deep study of the aerosol organic fraction was performed in the town Sernaglia della Battaglia, nearby Treviso. During three seasons of 2017, PM1 and PM2.5 samples were collected simultaneously. Organic molecular markers have been analyzed by in-situ derivatization thermal desorption gas chromatography time-of-flight mass spectrometry (IDTD-GC-TOFMS). Alkanes, polycyclic aromatic hydrocarbons, oxi-polycyclic aromatic hydrocarbons, anhydrous sugars, resins acids, triterpenoids, and acids were considered. The organic chemical composition has been analyzed based on seasonal variation and source contributions. Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) have been combined to deeply investigate the main sources of particulate organic matter. On the one hand, PCA evaluates the correlations between the organic markers and their seasonal distribution. On the other hand, the source contributions to aerosol composition are estimated by PMF. Four main emission sources were found by PMF: solid fuel combustion (coal, wood), combustion of petroleum distillates (gas and fuel oil) and exhaust gases of vehicles, industrial combustion processes, home heating, and forest fires are evaluated as the most important sources for the air quality and pollution in this municipality of Northern Italy.
2019
Padoan, Sara; Popovicheva, Olga; Schnelle-Kreis, Jürgen; Nguyen, Dac-Loc; Kistler, Magda; Kasper-Giebl, Anne; Chubarova, Natalia. (2019). Spring aerosol in urban atmosphere: analytical and statistical assessment for source impacts. 12th International Conference on Carbonaceous Particles in the Atmosphere (ICCPA) (2019, Vienna).
Abstract
High density of population and multi-profile activities in megacities objectively lead to large-scale ecological impact emphasizing the need to assess the sources of air pollution. Spring is the season when complementary impacts of agriculture fires/biomass burning are increasing significantly in accordance to biogenic activity, which can be observed at the same time. In the complex situation of the plurality of anthropogenic emissions, an important research task remains for the megacity environment to identify the contributions of the major sources including biomass burning and biogenic, through aerosol composition analyses.
This study reports the evaluation of air the quality in the urban background of Moscow megacity in spring 2017. This period was characterized by significant changes of air temperature, mass advection, and solar radiation. Synergistic coupling of PM10 mass concentration, light absorbing properties, aerosol composition and meteorological measurements has been performed in urban background at the Meteorological Observatory of the Moscow State University (MSU).
Organic and elemental carbon (OC, EC) as well as 76 organic compounds like alkanes, polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs (o-PAHs), hopans and anhydrosugars, polyols, primary- and secondary saccharides were quantified to describe the carbonaceous particle fraction. Thirteen ions characterize the inorganic composition. Angstrom Absorption Exponent (AAE) parametrization estimates the relative contributions of agriculture fires and domestic biomass burning around the city to urban aerosol composition dominated by fossil fuel combustion.
Combining attentive analytical chemical and statistical approaches, representative chemical compounds are able to describe the highest quantity of variability, evaluated together with the highest analytical validity of the chemical compounds. Comprehensive principal component analyses (PCA) supported by chemical markers, meteorological parameters and air mass transportation analyses is able to highlight the emission sources from fossil fuel combustion, heavy-duty transport, air mass transportation from agriculture fires and domestic activity. Secondary organic and inorganic aerosol formation and photochemical processes occur in the period of increasing biogenic activity.
Schade, Julian; Passig, Johannes; Irsig, Robert; Ehlert, Sven; Sklorz, Martin; Adam, Thomas; Li, Chunlin; Rudich, Yinon; Zimmermann, Ralf. (2019). Spatially Shaped Laser Pulses for the Simultaneous Detection of Polycyclic Aromatic Hydrocarbons as well as Positive and Negative Inorganic Ions in Single Particle Mass Spectrometry. Analytical Chemistry, Vol. 91, S. 10282-10288.
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are toxic organic trace components in atmospheric aerosols that have impacts on climate and human health. They are bound to airborne particles and transported over long distances. Observations of their distribution, transport pathways, and degradation are crucial for risk assessment and mitigation. Such estimates would benefit from online detection of PAHs along with analysis of the carrying particles to identify the source. Typically, laser desorption/ionization (LDI) in a bipolar mass spectrometer reveals the inorganic constituents and provides limited molecular information. In contrast, two-step ionization approaches produce detailed PAH mass spectra from individual particles but without the source-specific inorganic composition. Here we report a new technique that yields the single-particle PAH composition along with both positive and negative inorganic ions via LDI. Thus, the complete particle characterization and source apportionment from conventional bipolar LDI-analysis becomes possible, combined with a detailed PAH spectrum for the same particle. The key idea of the method is spatiotemporal matching of the ionization laser pulse to the transient component distribution in the particle plume after laser desorption. The technique is robust and field-deployable with only slightly higher costs and complexity compared to two-step approaches. We demonstrate its capability to reveal the PAH-distribution on different particle types in combustion aerosols and ambient air.
Graphical Abstract
Liu, Xiansheng; Schnelle-Kreis, Jürgen; Schloter-Hai, Brigitte; Ma, Lili; Tai, Pengfei; Cao, Xin; Yu, Cencen; Adam, Thomas; Zimmermann, Ralf. (2019). Analysis of PAHs Associated with PM10 and PM2.5 from Different Districts in Nanjing. Aerosol and Air Quality Research, Vol. 19, No. 10, S. 2294-2307.
Abstract
Nanjing has areas with different degrees of pollution and is therefore predestined for the analysis of particle phase polycyclic aromatic hydrocarbons (P-PAHs) in different functional areas and their correlation with the latter. The functional sites include a background area (BGA), an industrial area (IDA), a traffic area (TFA), a business area (BNA) and a residential area (RDA), where parameters such as PAH composition, content, carcinogenic and mutagenic potencies were analyzed. The results revealed increasing P-PAH contents (PM2.5, PM10) in the following order: BGA (14.02 ng m–3, 38.45 ng m–3) < BNA (16.33 ng m–3, 44.13 ng m–3) < TFA (17.13 ng m–3, 48.31 ng m–3) < RDA (21.11 ng m–3, 61.03 ng m–3) < IDA (50.00 ng m–3, 93.08 ng m–3). Thereby, the P-PAH content in the industrial area was significantly higher than in the other functional zones (P < 0.01). Furthermore, the gas phase PAH concentrations were also estimated by the G/P partitioning model and the total PAH toxicity was assessed applying toxicity equivalent factors (∑BaPTEF) and mutagenicity equivalent factors (∑BaPMEF). Finally, the incremental lifetime cancer risk (ILCR) value of children and adolescents in Nanjing was higher than that of adults.