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| Titel |
The role of long-lived reactive oxygen intermediates in the reaction of ozone with aerosol particles |
| VerfasserIn |
Manabu Shiraiwa, Aurélie Rouvière, Yulia Sosedova, Hong Yang, Yingyi Zhang, Jonathan Abbatt, Markus Ammann, Ulrich Pöschl |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250049756
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| Zusammenfassung |
| Heterogeneous reactions of ozone with aerosol particles have been studied extensively, but
the molecular mechanism and kinetics remained unresolved. Among the organic aerosol
components readily reacting with ozone, polycyclic aromatic hydrocarbons (PAHs) are one of
the most prominent groups related to health effects. Chemical transformation can change the
toxicity of PAHs and modify the hygroscopic properties and climate effects of combustion
aerosol particles. Several studies have shown that ozone can also promote the nitration of
protein molecules contained in primary biological aerosol particles like pollen and fungal
spores [1]. This posttranslational modification can enhance the allergenic potential of
proteins. It provides a molecular rationale for the enhancement of allergic diseases
by traffic-related air pollution in urban and rural environments, which has been
observed in epidemiological studies but remains to be elucidated on a molecular level
[2].
Based on new experimental data and model calculations, here we show that
long-lived reactive oxygen intermediates (ROIs) are formed upon oxidation of PAH and
nitration of protein [3]. The chemical lifetime of these intermediates exceeds 102 s,
which is much longer than the surface residence time of molecular O3 (~10-9 s).
The ROIs explain and resolve apparent discrepancies between earlier quantum
mechanical calculations and kinetic experiments. They play a key role in the chemical
transformation and adverse health effects of toxic and allergenic air particulate
matter, such as soot, polycyclic aromatic hydrocarbons and proteins. Moreover,
ROIs may contribute to the coupling of atmospheric and biospheric multiphase
processes.
Apart from chemical aging of air particulate matter, long-lived ROIs might also
participate in the formation and growth of secondary organic aerosols. In particular, surface
interactions of long-lived ROIs may lead to the formation of multifunctional organic
substances (acids, nitrates, sulfates, dimers/oligomers, etc.) with high molecular mass and
low vapor pressure that are required for the nucleation and growth of new particles and may
also influence their phase state [4]. The experimental and theoretical information currently
available suggests that long-lived ozone-generated ROIs play a central role in the multiphase
chemistry of atmospheric aerosols.
Acknowledgements.
This work was funded by the Max Planck Society (MPG), the Swiss National
Science Foundation (grant no. 130175), and the European Integrated Project on
Aerosol, Cloud, Climate and Air Quality Interactions (No 036833-2 EUCAARI). We
thank M. Birrer, T. Bartels-Rausch and M. Kerbrat for support. The staffs of the PSI
accelerator facilities are acknowledged for providing stable proton beams used to produce
13N.
References.
[1] Franze, T., et al„ Protein nitration by polluted air. Environ. Sci. Technol., 39(6): p.
1673-1678, 2005.
[2] Gruijthuijsen, Y.K., et al., Nitration enhances the allergenic potential of proteins. Int.
Arch. Allergy Immunol, 141(3): p. 265-275, 2006.
[3] Shiraiwa, M., et al., The role of long-lived reactive oxygen intermediates in the
reaction of ozone with aerosol particles, Nature Chemistry, accepted.
[4] Virtanen, A., et al., An amorphous solid state of biogenic secondary organic aerosol
particles. Nature, 467: p. 824-827, 2010. |
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