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Objective To investigate and compare PM2.5pollution levels in Taiyuan and Beijing and to study the DNA damage induced by PM2.5.Methods PM2.5pollution levels in Taiyuan with coal smoke pollution and in Beijing with mixing air pollution typed by coal smoke and automobil exhaust were monitored,and the DNA damage induced by PM2.5was detected by single cell gel-electrophoresis(SCGE)(Comet assay)using human alveolar epithelial cell line A549(A549cells).Results The PM2.5pollution levels in Taiyuan and Beijing during winter were0.132-0.681mg /m 3 and0.028-0.436mg /m 3 respective-ly.PM2.5could induce DNA damage in A549cells after exposure to doses of5,50and200?g /ml for12h and24h-incuba-tion.Compared with the negative control group,there were significant differences(P
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Objective To evaluate the removal effectiveness of air pollutants by photocatalytic nanocomposite coating. Methods TiO2-coated glass board was exposed to UV light of 365 nm in chamber with volume of 4 m3. The purification efficiencies of TiO2 nanocomposite coating for SO2?NO2 and formaldehyde were determined at light intensity of 107-271 ?W/cm2 and wind velocity of 0.3-1.5 m/s. Results The purification efficiencies of TiO2-coated glass board treated under this experimental condition for 30 min were 97%?90%, 69% for SO2?NO2 and formaldehyde in indoor air respectively, and only 48% for SO2 without exposure to UV light. Conclusion This method provided basic data for establishing an evaluation method for purification effectiveness of photocatalytic nanocomposite coating for indoor air pollutants. Further approach was needed for exploring the effects of various environmental influential factors on the purification effectiveness of TiO2 nanocomposite coating.