贵州主要城市PM2.5的氧化性损伤评价

对贵州省主要城市(贵阳、安顺、遵义、都匀)按季节进行PM_2.5样品的采集,应用质粒DNA评价法研究了贵州省主要城市PM_2.5氧化性损伤能力,并与PM_2.5质量浓度、微量元素含量做相关性分析。结果表明,PM_2.5全样TD₂₀值均小于其相应的水溶样TD₂₀值;四个城市PM_2.5氧化性损伤能力均表现为冬季>秋季>春、夏季;城区PM_2.5氧化性损伤能力强于背景区;研究区内PM_2.5样品的氧化性损伤能力表现为都匀市最强,安顺市最弱;PM_2.5全样和水溶样的TD₂₀值与质量浓度之间无明显相关关系;PM_2.5水溶样的TD₂₀值与相应的12种微量元素的浓度总和呈负相关关系(P<0.05);全样Al、Mn、Cd、Pb的含量与PM_2.5全样TD₂₀值呈明显负相关关系,水溶样Cd、Pb、Cu的含量与PM_2.5水溶样TD₂₀值呈明显负相关关系,表明研究区PM_2.5氧化性损伤可能与样品中水溶性元素Cd、Pb、Cu等的含量有关。

Evaluation of Oxidative Damage of PM2.5 in Main Cities of Guizhou Province

PM_2.5 samples were collected seasonally in four main cities (Guiyang, Anshun, Zunyi, and Duyun) in Guizhou Province to study the oxidative damage capacity of PM_2.5 by in vitro plasmid DNA assay. The correlation between the toxicity represented by oxidative damage capacity and the contents of trace elements and mass concentrations were investigated. The results showed that, the TD₂₀ values of the whole samples were less than the corresponding TD₂₀ values of the water-soluble fractions. In the four cities, PM_2.5oxidative capacity was the strongest in winter, followed by autumn and weak in spring and summer. PM_2.5 oxidative damage capacity in urban areas is stronger than in suburban areas. The oxidative damage capacity of PM_2.5 was strongest in Duyun and weakest in Anshun. Correlation analysis showed there was no obvious correlation between the TD₂₀ value and mass concentrations of PM_2.5. The TD₂₀ value of water-soluble fraction showed a general (P<0.05) negative correlation with the sum of 12 trace element concentrations in PM_2.5. The content of aluminum, manganese, cadmium, and lead is significantly negatively correlated with the TD₂₀ value of whole sample. The content of cadmium, lead, and copper has a significant negative correlation with the TD₂₀ value of water-soluble samples. It shows that the oxidative damage capacity of PM_2.5 in the major cities of Guizhou probably relates with the contents of water soluble cadmium, lead, and copper in samples.