| Summary: | 碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 88 === Numerous of epidemologic studies have demonstrated a consistent association between urban air pollution and increasing morbidity and mortality in the US. Among the mixtures of air pollution, particulate matter (PM) and ozone (O3) are two major air pollutants responsible for such adverse health effects. However, these pollutants’ toxic mechanisms are still not clear. Cellular inflammation in respiratory system is believed to an important biological mechanism for air pollutant’s toxicity. In this study, we select the A549 cell line, a type Ⅱ cell of alveoli, and IL-8 (interleukin-8) as a cytotoxicity marker to conduct an in-vitro experiment on PM and O3. PM Samples with seven cut-off sizes by MOUDITM and elemental analysis by X-Ray Fluorescence (XRF) are used to test the contribution of size and components to cytotoxicity. Water-soluble components in PM analyzed also by IC are used to evaluate the cytotoxicity between different soluble components of PM. The result shows that PM with a size less than 1.0 um has a significant increase in IL-8 expression than PM with a size greater than 1.0 um under exposed 4 hours to 20 mg/ml PM (p = 0.03, t-test). No PM content is significantly associated with increase in IL-8 expression except sulfur. Since sulfur content is strongly associated with size and sulfates in soluble portion of PM are not associated with IL-8 expression. In addition, an additional IL-8 expression is also detected for PM exposure after A549 cells have been exposure to O3 first, compare to ozone alone (p = 0.06,Wilcoxon Rank-Sum test). Therefore, fine PM showed produce more cytotoxicity for A549 cells than coarse PM. Also, there is an addition effect of cytoxicity between O3 and PM exposure.
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