YANG Yushuang, TAO Yun, LI Jinjuan, GUO Xingqiang, LI Chen, SHI Wei

(The College of Resources and Environmental Engineering , Key Laboratory of Karst Georesources and Environment , Ministry of Education , Guizhou University , Guiyang 550025, China)

Abstract:PM2.5 samples were collected seasonally in Guiyang, Anshun, Zunyi, and Duyun. An in vitro plasmid DNA assay was used to study the oxidative capacity of PM2.5, and the inductively coupled plasma mass spectrometry was used to analyze the contents of 12 trace elements in PM2.5. The correlation between the toxicity represented by oxidative 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, PM2.5 oxidative capacity was the strongest in winter, followed by autumn and weak in spring and summer. PM2.5 oxidative capacity in urban areas is stronger than in suburban areas. The oxidative capacity of PM2.5 was the strongest in Duyun and the weakest in Anshun. Correlation analysis showed no obvious correlation between the TD20 value and mass concentrations of PM2.5, showing that the method of evaluating the health impact of atmospheric particulate matter only by the mass concentration did not truly reflect its degree of harm to human health. The TD20 value of water-soluble fraction showed a general(P<0.05) negative correlation with the sum of 12 trace element concentrations, indicating that the oxidative capacity of PM2.5 comes from the interaction of water-soluble elements and non-water-soluble elements. 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 toxidative capacity of PM2.5 in the major cities of Guizhou probably relates with the contents of water soluble cadmium, lead, and copper in samples.

Key words: PM2.5; plasmid DNA assay; oxidative capacity; trace element; toxicology

EARTH AND ENVIRONMENT Vol.49, No.1, Tot No.344, 2021, Page717-725