Polycyclic Aromatic Hydrocarbons in Background Air – A Single-particle Study on Their Sources and Atmospheric Processing in Northern Europe
JOHANNES PASSIG, Julian Schade, Robert Irsig, Thomas Kröger-Badge, Hendryk Czech, Henrik Fallgren, Jana Moldanova, Martin Sklorz, Thorsten Streibel, Andreas Walte, Ralf Zimmermann,
Helmholtz Zentrum München and University of Rostock Abstract Number: 244
Working Group: Source Apportionment
AbstractInhalation of Polycyclic Aromatic Hydrocarbons (PAHs) is a well-known cause of morbidity and mortality (Holme et al., 2019). Furthermore, PAHs have important climate effects, e.g. via direct absorption, photooxidation and cloud condensation. However, distribution pathways and atmospheric interactions of PAHs are not fully understood (Keyte et al. 2013). We recently introduced ionization methods for single-partice mass spectrometry (SPMS) that combine different ionization pathways and produce mass spectra from traces of PAHs – in addition to the particle’s inorganic composition (Schade et al. 2019). This approach is combined with resonant ionzation of iron, a further health-relevant aerosol compound with strong effects on marine ecosystems (Passig et al., 2020).
Here we present results from the first ambient air study on the single-particle resolved distribution and sources of PAHs (Passig et al. 2022). At at the Swedish west coast, we detected long-range transported particles from traffic emissions, residential heating, biomass burning and even individual ship plumes. The combined single-particle information from PAHs and inorganics allows novel source apportionment and provides unprecedented insight into complex aerosols. We show, how PAHs might be harnessed as a molecular sensor for atmospheric processing. Therefore, we demonstrate that different ageing effects e.g. PAH degradation, oligomerization and secondary aerosol formation can be unravelled from the combined data of PAHs, inorganic source markers and secondary material. Finally, our study gives an estimate on the number fraction and origin of PAH-containig particles in the accumulation and coarse mode during autumn in northern Europe.
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