Combined Determination of the Chemical Composition and of Health Effects of Secondary Organic Aerosols: The POLYSOA Project

Epidemiological studies show a clear link between increased mortality and enhanced concentrations of ambient aerosols. The chemical and physical properties of aerosol particles causing these health effects remain unclear. A major fraction of the ambient aerosol particle mass is composed of secondary organic aerosol (SOA). Recent studies showed that a significant amount of SOA consists of high molecular weight compounds (oligomers), which are chemically not well characterized. Within the POLYSOA project a large variety of state-of-the-art analytical chemical methods were used to characterize the chemical composition of SOA particles with emphasis on the oligomeric mass fraction. Mass spectrometric results showed that SOA oligomers are highly oxidized compounds and that hydroperoxides are formed, which is consistent with NMR results. This high molecular weight fraction accounts for up to 23% of the total organic carbon in SOA particles. These well-characterized SOA particles were deposited on three lung cel...