Winter and Summer PM^sub 2.5^ Chemical Compositions in Fourteen Chinese Cities

• Published in: Journal of the Air & Waste Management Association (1995) 2012-10, Vol.62 (10), p.1214
• Main Authors: Cao, Jun-Ji, Shen, Zhen-Xing, Chow, Judith C, Watson, John G, Lee, Shun-Cheng, Tie, Xue-Xi, Ho, Kin-Fai, Wang, Ge-Hui, Han, Yong-Ming
• Format: Article
• Language: English
• Subjects: Coal; Dust; Geology; Motor vehicle fleets; Nitrates; VOCs; Volatile organic compounds
• ISSN: 1096-2247; 2162-2906

PM^sub 2.5^ in 14 of China's large cities achieves high concentrations in both winter and summer with averages >100 µg m^sup -3^ being common occurrences. A grand average of 115 µg m^sup -3^ was found for all cities, with a minimum of 27 g m 3 measured at Qingdao during summer and a maximum of 356 µg m^sup -3^ at Xi'an during winter. Both primary and secondary PM^sub 2.5^ are important contributors at all of the cities and during both winter and summer. While ammonium sulfate is a large contributor during both seasons, ammonium nitrate contributions are much larger during winter. Lead levels are still high in several cities, reaching an average of 1.68 µg m^sup -3^ in Xi'an. High correlations of lead with arsenic and sulfate concentrations indicate that much of it derives from coal combustion, rather than leaded fuels, which were phased out by calendar year 2000. Although limited fugitive dust markers were available, scaling of iron by its ratios in source profiles shows ~20% of PM^sub 2.5^ deriving from fugitive dust in most of the cities. Multipollutant control strategies will be needed that address incomplete combustion of coal and biomass, engine exhaust, and fugitive dust, as well as sulfur dioxide, oxides of nitrogen, and ammonia gaseous precursors for ammonium sulfate and ammonium nitrate. [PUBLICATION ABSTRACT]