The Analysis Of Distribution And Source Profile Of Polycyclic Aromatic Hydrocarbons (PAHs) On Atmospheric Particles In Non-heating Period In Xi'an

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants with carcinogenic and mutagenic activities. The majority of PAHs with serious carcinogen are mainly sorbed on particles, which can be deposited in the respiratory tract, hence, increasing the potential health effects.As the biggest city in northwestern China, Xi'an is significant in history, education, tourism, science and technology throughout the world. However, Xi'an also is a seriously polluted city , The characteristic, distribution, and source profile of PAHs on atmospheric particles in non-heating period in Xi'an is investigated as followed:(1) 16 kinds of PAHs on the particles which were collected in environmental area were analyzed by GCMS. The average concentration of the total PAHs reached to 56.66 ng/m~3 , BaP was 2.56 ng/m3 in non-heating period in Xi'an; For environmentally different zones, the concentrations of particle-associated PAHs in ambient air were arranged in order of heavy industry zone > business zone > cultural zone > residential zone > cleaning zone; 4-6 ring PAHs is predominant in non-heating period in Xi'an; PAHs in south suburb is dominated by the emission of the civilian coal firing, and PAHs in west suburb is dominated by the emission of the heavy industry; Compared with developed countries in the Occident, the pollution of PAHs in Xi'an is more serious.(2) The source profiles of the coke oven, civilian coal firing, the steel and thermo-electric plant, vehicles, cooking in the street of the Hui nationality and the urban dust were obtained. Except the source of vehicles, the concentrations of particle-associated PAHs of the other sources were arranged in order of the coke oven >steel and thermo-electric plant > civilian coal firing > cooking in the street of the Hui nationality >urban dust. The characteristic compounds of the emission of civilian coal firing and cooking in the street of the Hui nationality are Flur, Py, Chry, BbF and DA, the characteristic compounds of the emission of the coke oven and the steel plant and thermo-electric plant are Flur, Py and BbF, the characteristic compounds of the emission of urban industry are Phen, Flur and Py, the characteristic compounds of the emission of vehicle are Na, BP and IN; the distribution characteristics of the PAHs in the source is identical except vehicles. 4 analogical emission sources (the coke oven, civilian coal firing, steel plant and thermo-electric plant and cooking in the street of the Hui nationality) are combined as the source of coal firing, and the characteristic source profile of the PAHs in Xi'an was determined.