Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Yinchuan City in Northwest China
2005 年 40 巻 3 号 p. 129-135
詳細
2005 年 40 巻 3 号 p. 129-135
monitoring program for PAHs was conducted for three periods January, April, and July & October (these represent, respectively, the heating period for homes from November to March, the spring-sandstorm period from March to May and the non-heating period for homes from June to October in Yinchuan). The monitoring program for PAHs started in January 1989 and was carried out in 7 specific areas including urban residential, industrial, commercial, cultural & educational, public parks, suburban, and heavy traffic roads in Yinchuan, the capital city of the Ningxia Hui Autonomous Region. The aim of the study was to determine temporal variations of PAHs and their distribution in specific areas and the concentration of particle size-segregated PAHs. A total of 210 samples were collected and 6 PAHs species were identified, they are Phenanthrene (PHEN), Pyrene (PYR), Chrysene (CHR), Perylene (PER), Benzo [a] pyrene (Bap) and Benzfluorence (BFLU).
It is documented that the concentration of PAHs is the highest in January, the PAHs mainly come from coal burning for heating and vehicle emissions. The concentration of PAHs of the 7 specific areas are arranged in decreasing order: suburbs, heavy traffic roads, urban residential areas, commercial centers, public parks, cultural & educational areas and industrial areas. Bap concentration is ranged from 6.05-29.55 ng/m3 in January, 3.23-13.70ng/m3 in April, which is the spring-sandstorm period, and 0.30-8.70ng/m3 from July to October, which is the non-heating period. Bap has been detected in the specific areas, except for the suburbs in the July through October period. The PHEN, PYR, BFLU and PER are higher in January and have been detected in each specific area. PHEN, PYR and CHR were not detected in the cultural & educational areas nor in the parks in the July & October Period. More than 50% of the PAHs are absorbed in particles less than 2.5μm in diameter with few exceptions.
Concentration of PAHs is higher in Yinchuan than that in other places concerned in this paper, so great efforts should be made to improve air quality in this region.
