Size Distributions and Cytotoxicity of Ambient Aerosols Collected Near a Semiconductor Plant

• Main Authors: Tzu-Min Wu, 吳慈敏
• Other Authors: Shui-Jen Chen
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/45715067978685890933

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 100 === In this study, PS-1, Dichot, MOUDIs and Nano-MOUDIs were used to collect TSP, PM2.5-10, PM2.5, PM0.01-10 (as PM10 thereafter), PM0.01-2.5 (as PM2.5), PM0.01-1 (as PM1.0), PM0.01-0.1 (as PM0.1) and PM0.01-0.056 (as PM0.056) samples on the rooftops of a semiconductor plant and a wastewater treatment plant (48.9 and 16 m high, respectively) (from March to September, 2011) in a Southern Taiwan Science Park to characterize the size distributions of sampled particles and the cytotoxicity of particle extracts. In addition to the analyses of particulate water-soluble ions, carbon, and PAHs, human male single cells (U937) and the method MTT(3- (4, 5dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide) were utilized to test the cytotoxicity of particle extracts obtained via water and organic-solvent extractions. The results showed that the atmospheric PM2.5/PM10 values of semiconductor plant was lower during air pollution episode days and general sunny days (0.67 and 0.63, respectively), while the corresponding ratio was higher on sunny days after raining (0.74). Although the PM10 concentration on sunny days after raining was about 0.57 time that on general sunny days, the PM0.1 and PM0.056 concentrations after raining increased by 1.20 and 1.34 times, respectively, when compared with that on general sunny days. Moreover, the ratios of PM0.1/PM10 and PM0.056/PM10 on sunny days after raining were 2.2 and 2.7 times those on general sunny days. The atmospheric particles were approximately bi-modal distributed, with a main peak in fine mode (0.32–1 µm) and a secondary peak in coarse mode (2.5–5.6 µm). About 30–50% of PM2.5 and 29–39% of PM2.5-10 were water-soluble ions. The primary species of water-soluble ions were secondary aerosols, such as SO42-, NO3- and NH4+ (more than 80%). In PM2.5, the concentration and content of SO42- were the highest, while in PM2.5-10, NO3- had the highest concentration and content. About 33–40% of atmospheric TSP in the park was contributed by carbon species, and the OC/EC value was 1.89–2.23. About more than 97% (96.9−98.5%) of total metallic concentrations in PM0.056, PM0.1, PM1, PM2.5 and PM2.5-10 were contributed by Na, Mg, Al, K, Ca, Fe, Ni, and Zn. The at emiconductor plant exhibited the highest average concentration of PAHs in atmospheric TSP during air pollution episode days. On both general sunny days and sunny days after raining, the PAHs in PM10 mainly distributed in fine particles (PM2.5). For the samples taken on the roof of semiconductor plant, the cytotoxicity of water-soluble extracts from differently sized atmospheric particles was higher on general sunny days than on sunny days after raining. Such cytotoxicity was higher in PM0.32-1.8 (particles with the size ranges 0.32–0.56, 0.56–1.0, and 1.0–1.8 μm). Moreover, the cytotoxicity of particle organic-solvent extract was higher for PM2.5 than for PM2.5-10. The cytotoxicity of water extract of TSP collected in different periods was in order episode days > general sunny days > sunny days after raining.