| Summary: | 碩士 === 國立陽明大學 === 環境衛生研究所 === 88 === Numerous epidemiological studies have demonstrated significant associations between air pollution, especially particles less than 10 mm in diameter (PM10), and increases in cardiopulmonary mortality and morbidity. In this study, we tested the following hypotheses: (1) On an equal mass basis, the bioactivity of PM will vary depending on region. (2)The bioactivity will be associated with the transition metal and lipopolysaccharide content of PM. (3)On an equal mass basis, fine particles have higher bioactivity than coarse particles.
Ambient particles of PM10 and PM2.5 were collected by Harvard Impactor. Macrophage cell line RAW164.7 cell were exposed to 50mg/ml PM for 16h, and TNF-αproteins in conditioned medium were measured by ELISA.
The results showed that PM from high pollution area had higher bioactivity than low pollution area. Water bath sonication was used to extract particles from the filters, and the efficiency was 55.65 ±10.05% . PM2.5 had higher bioactivity than PM10. The TNF-α cytokine response was associated with the endotoxin content of the particles(R2=0.3944) as measured by Limulus Amebocyte Lysate assay. The TNF-α cytokine response to PM was partly inhibited by polymyxin B and deferoxamine we treatment (71% and 55%), indicating that endoxins and metals were cytokine-inducing moieties in the PM preparation. The correlation of endotoxin content of particle and inhibited TNF-α cytokine was0.56 for PM2.5 and 0.39 for PM10 . Water-soluble fraction and pelleted fraction had similar bioactivity.
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