【摘要】 使用质粒DNA评价法研究了2005年12月~2006年10月兰州市区、郊区大气中PM10对质粒DNA的氧化性损伤,并初步探讨了其损伤原因.结果表明,PM10对质粒DNA的氧化性损伤具有冬、夏季相对较高,春、秋季相对较低的特征.市区冬、春、夏、秋季大气PM10全样的TD20平均值分别为17,625,56,260μg/mL,水溶部分的TD20平均值分别为62,840,193,403μg/mL.沙尘暴期间和降雨数天后,PM10对质粒DNA的氧化性损伤相对较小,其全样和水溶部分的TD20值均大于1000μg/mL.PM10全样和水溶部分的TD20值均与样品中12种水溶性微量元素总含量呈明显的负相关关系,表明PM10对质粒DNA的氧化性损伤能力主要来自其水溶性微量元素.更多还原

【Abstract】 An in vitro plasmid DNA assay was employed to study the oxidative damage of airborne PM10 collected in urban and suburban sites of Lanzhou city from December 2005 to October 2006, and the causes of DNA damage induced by PM10 were investigated. The toxicity represented by oxidative damage of the PM10 varied greatly. The oxidative damage caused by PM10 collected in the winter and summer was stronger than those collected in spring and autumn. The average TD20 values (toxic dosages of PM10 causing 20% of plasmid DNA damage) of intact whole PM10 solutions from the urban site in winter, spring, summer and autumn were 17, 625, 56 and 260μg/mL, respectively, and the TD20 values of their corresponding water-soluble fraction were 62, 840, 193 and 403μg/mL, respectively. The PM10 collected during the asian dust storm episodes and after raining showed a low oxidative damage, with TD20 values of both the intact samples and water-soluble fractions being higher than 1000μg/mL. The contents of total analyzed water-soluble trace elements, revealed by ICP-MS, were negatively correlated with the TD20 values of both whole sample and corresponding water-soluble fraction of PM10, which implied that the DNA damage may be attributed to the water-soluble trace elements in PM10.更多还原