Publications by authors named "K M DALLENBACH"
Particulate Matter (PM) is the most toxic component in polluted air causing over 6 million deaths per year worldwide according to World Health Organisation estimates. Due to the highly complex composition of PM in the atmosphere, with thousands of inorganic and especially organic components, it is unknown which particle sources are responsible for their toxicity. In recent years it emerged that overall oxidising particle properties might directly link particle composition with health effects.
View Article and Find Full Text PDFArticle Synopsis
- Fine particulate matter (PM) significantly contributes to global premature deaths, but oxidative potential (OP) serves as a more accurate measure of its health impacts.
- This study presents the first online measurements of PM OP in Beijing during winter, revealing that primary PM and oxygenated organic aerosol (OOA) are the key contributors to OP.
- The research indicates that pollution events like fireworks and dust storms affect OP differently, emphasizing the importance of understanding both PM levels and chemical composition to address health risks associated with air pollution.
Detailed knowledge of the physical and chemical properties and sources of particles that form clouds is especially important in pristine areas like the Arctic, where particle concentrations are often low and observations are sparse. Here, we present in situ cloud and aerosol measurements from the central Arctic Ocean in August-September 2018 combined with air parcel source analysis. We provide direct experimental evidence that Aitken mode particles (particles with diameters ≲70 nm) significantly contribute to cloud condensation nuclei (CCN) or cloud droplet residuals, especially after the freeze-up of the sea ice in the transition toward fall.
View Article and Find Full Text PDFAtmospheric aerosols have significant effects on the climate and on human health. New particle formation (NPF) is globally an important source of aerosols but its relevance especially towards aerosol mass loadings in highly polluted regions is still controversial. In addition, uncertainties remain regarding the processes leading to severe pollution episodes, concerning the role of atmospheric transport.
View Article and Find Full Text PDFArticle Synopsis
- - Understanding the formation of secondary organic aerosols (SOA) at a molecular level is challenging due to unclear mechanisms and inadequate analytical methods, particularly in developing countries where haze impacts climate and health significantly.
- - This study includes simultaneous measurements of volatile organic compounds (VOCs), oxygenated organic molecules (OOMs), and SOA particles in Beijing, revealing that OOMs are responsible for 26-39% of organic aerosol mass growth.
- - The findings indicate that the contribution of OOMs to SOA increases during severe haze episodes, establishing a clear link from emissions to the formation of haze through condensable organic oxidation products.