Exposure to particulate matter (PM) in school environments has been associated with respiratory illnesses among children. Although using air cleaners was reported to reduce PM exposure and improve residents' health in homes, their effects in classrooms are not well understood. We examined how the use of air cleaners in classrooms and school/classroom characteristics affect the levels of indoor PM. Our environmental study included 102 classrooms from 34 elementary schools located on the mainland peninsula and an island in Korea. Indoor and outdoor PM were monitored simultaneously with portable aerosol spectrometers, and indoor gravimetric PM levels were measured with low volume, size-selective samplers during the class hours. Correlations among PM measurements were computed and final multiple regression models for indoor PM were constructed with a model building procedure. Correlation between indoor and outdoor PM 2.5 (PM < 2.5 μm in aerodynamic diameter) was higher (r = 0.78, p < 0.01) than that of PM 10 (PM < 10 μm) (r = 0.49, p < 0.01). School location, classroom occupant density, and ambient PM levels significantly (p-values<0.05) affected classroom PM concentrations. The adjusted PM levels in classrooms using air cleaners were significantly (p-values<0.01) lower by approximately 35% than in classrooms not using them. However, air cleaners appeared to remove PM 2.5 more effectively than PM 10 , perhaps because coarse particles settle more rapidly than fine particles on surfaces, or their resuspension and generation rate by occupants exceeds the removal rate by air cleaners. Our

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An experimental and modeling study was conducted to assess the ground-level atmospheric ozone impacts of several types of consumer product compounds Environmental chamber experiments were carried out for the representative amines 2-amino-2-methyl-1-propanol (AMP), ethanolamine, isopropyl amine and t-butyl amine and also for d-limonene. AMP and t-butyl amine were found to inhibit ozone formation, but the others enhanced ozone, and most were found to significantly enhance formation of secondary particle matter (PM). Methods to estimate mechanisms for amines that were qualitatively consistent with the chamber data were developed. However, the amine chamber data were not useful for quantitative valuation because the amount of amine available for gas-phase reaction could not be measured, and appeared to be significantly less than the amount injected. Estimates of atmospheric ozone impacts for the amines are also very uncertain because the amount of amines removed by reaction with HNO 3 in the atmosphere cannot be predicted. The chamber data obtained for d-limonene were well simulated by the existing d-limonene mechanism.Representations of the atmospheric reactions of for 15 amines and 30 other types of consumer product VOCs were added to the SAPRC-07 mechanism and its MIR and other reactivity scale tabulations, which are included with this report.iii