Many materials, commonly found indoors have the potential to emit organic and/or inorganic compounds. In addition to primary emissions, diffusion with regard to indirect contributions from materials, sorption on sinks, and secondary generation by chemical processes are essential parameters. Secondary organic aerosols (SOAs), is formed as a result of reactions between ozone and unsaturated Volatile Organic Compounds (VOCs) like tepenes. So far, the primary pollutants have been studied within the context of many researches worldwide. Besides ozone generating consumer products, the major source of indoor ozone is transportation of outdoor air into the indoors by ventilation/infiltration. Terpenes are emitted from most of the consumer products, commonly found in most of the indoors. Reactions between the primary emissions of terpenes from the indoor sources and ozone transported from outdoors to indoors (i.e. ozonolysis reaction) result in generation of SOAs in nanometer scale and carbonyls as well as hydroxyl radical. As the size of the particle decreases, its adverse health impact increases. Also, it's known that carcinogenicity of some of the aldehydes (e.g. formaldehdye) are crucial. A controlled, 1m3 emission test chamber was used in this study to find out the mechanism of ozone initiated reactions with the presence of terpenes. Also, a custom-made constructed test-room (V = 9.6 m3), covered with wallpaper and carpet and also including furniture, was designed to estimate the mechanism of SOAs formation together with the VOCs and aldehydes.  The levels of ozone, VOCs, aldehydes, fine particles (i.e. PM2.5), and nanoparticles (i.e. >6 nm) were measuered. Ozone decay rate in the chamber was calculated (R2 = 0.992). Righ after the ozone dosing, terpene levels clearly decreased. Moreover, levels of aldehydes (especially formaldehyde and acetaldehyde) and SOAs sharply increased after ozone dosing. Formations of SOAs and aldehydes were found to be associated with both ozone and terpene presences.

Generation mechanism of secondary organic aerosols (SOAs) and aldehydes from ozone-initiated reactions in test chambers, close to typical room conditions

248th National Meeting (2014)

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