Fine particulate matter (PM2.5) as an atmospheric pollutant is strongly related to increased mortality and morbidity. The empirically established link between aerosol concentration and human health compels increased efforts to reduce the atmospheric concentrations of fine particles. Organic material accounts for about 20-60% of the total PM2.5 and contains substances of known toxicity. It has been shown that in some areas secondary organic aerosol (SOA) accounts for 20% of the total organic aerosol throughout the year but can contribute up to 70% in smog episodes. The estimation of the sources and concentrations of organic aerosol is therefore crucial to the proper assessment of related health effects
Part of this work attempts a critical review of the literature on SOA. The goal is to describe formation mechanisms, to identify likely precursor gases, and to estimate the SOA contribution to PM2.5. SOA forms by oxidation of volatile organic compounds (VOC). The aerosol yield varies significantly among different VOC species as well as source sectors and the contribution of SOA to the total particulate organic material is dependent on the time of the day and the season. The consequences of these findings for reduction strategies are discussed.
The knowledge gained in the literature review is further used to exemplify a possible procedure to assess and compare the aerosol formation potential of some source sectors used in the RAINS model. It is found that traffic and solvent use in the printing industry and paint are important sectors for SOA production
