北京西北城区一次重污染过程中PM_(10)的氧化损伤能力研究

Oxidative capacity of PM_(10) during a heavy polluted weather in northwest Beijing

为评估大气重污染期间北京市可吸入颗粒物(PM_(10))的毒性,采集2016年3月份一次大气重污染过程中北京市大气PM_(10)样品,应用质粒DNA损伤评价法来研究其氧化损伤能力。结果表明,雾霾期间PM_(10)对DNA的损伤率高于雾霾逐渐消退时期,远高于雾霾前期清洁天,颗粒物对DNA损伤率随剂量的增加而增加。雾霾前后PM_(10)水溶样品的平均TD_(20)值表现为雾霾前清洁天(788.01μg/mL)>雾霾消退后期(470.40μg/mL)>雾霾期间(55.78μg/mL),说明氧化能力雾霾期间>雾霾消退后期>雾霾前清洁天。另外通过雾霾前后数据对比得到,暴露毒性指数TI大小顺序为雾霾期间(13 245.06)>雾霾消退后期(1 658.87)>雾霾前清洁天(254.08),说明雾霾期间PM_(10)对人体危害更大。

In order to evaluate the toxicity of the airborne particles in Beijing during the pollution process, the authors collected the PM_（10）(particulate matter with aerodynamic diameters of less than 10 μm） in the urban area of Beijing in 2016 and analyzed the oxidative capacity of the particles by plasmid scission assay. The results indicated that the oxidative capacity of PM（10） during the haze was higher than that after haze, and both were higher than that before the haze. In addition, the damage rate of supercoiled DNA by the samples increased with increasing experimental dose levels. The TD（20） values of the PM samples before, during, and after the haze displayed a descending order of before haze(788. 01 μg/mL） 〉 after haze(470. 40 μg/mL） 〉 during haze(55. 78 μg/mL）, which indicated a descending order of the PM oxidative capacity of during haze 〉after haze〉 before haze. The TI value during haze was higher than that after haze, both were higher than that before haze, suggesting that the PM（10） during haze was more harmful to human health.