北京市PM2.5对DNA的氧化性损伤规律分析

运用质粒DNA损伤评价法,在北京市2010年6月至2011年6月全年的大气PM2.5样品中,选取每月的2个样品(包括正常和雾霾天气),共24个样品进行实验,分析其氧化性损伤能力的变化规律及其与采样条件的相互关系.结果表明,北京市大气颗粒物全样的氧化性损伤能力等于或略大于相应的水溶组分,说明颗粒物氧化性损伤能力多来自于水溶组分,大气颗粒物对DNA损伤率呈现在50,100,150, 200mg/mL剂量水平下依次递增的规律,即随剂量的增加而增加;雾霾天气下DNA损伤率出现高值;4月和6月的DNA损伤率在全年中较高.其他月份正常天气条件下损伤率均较低,在200mg/mL剂量下损伤率基本低于50%;损伤率与环境平均温度和湿度呈正相关,与平均大气压强和日平均风速呈负相关,相关性大小顺序为:环境平均温度>平均大气压强>平均湿度>日平均风速.

Analysis of oxidative capacity of PM2.5 in Beijing

An in vitro plasmid scission assay was employed to study the variation of the oxidative capacity of a yearly PM2.5 samples in a residential area of Beijing. A total of 24 PM2.5 samples including 2samples per month (normal weather, fog and haze included) were collected from June 2010 to June 2011.The experimental results showed that toxicity of the whole sample solutions of the PM2.5 samples was approximately equal to or slightly greater than that of the corresponding water soluble fractions, confirming that the toxicity of the particles was mainly sourced from their water soluble fractions. The damage rate of samples to supercoiled DNA increased with their experimental dose levels such as 50, 100, 150, and 200μg/mL. For the different weather conditions, the damage rate of the samples was high in the fog and the haze days; and for the monthly variation, the damage rate of the samples in April and June was the highest while the other months were characterized by a low oxidative capacity with the DNA damage under 200μg/mL dose being below 50%. The damage rate had a positive correlation with average temperature and humidity, and had a negative correlation with the average atmospheric pressure and daily wind speed.