Concentration and chemical composition of PM2.5 in Shanghai for a 1-year period

Weekly PM2.5 samples were collected in Shanghai, China at two sites, Tongji University and Hainan Road. Sampling started in March 1999 and was conducted for 1 year. The ambient mass concentration and chemical composition of the PM2.5 were determined. Chemical analyses included elemental composition, water-soluble ions, and organic and elemental carbon. Weekly PM2.5 mass concentrations ranged from 21 to 147 μg/m3, with annual average concentrations of 57.9 and 61.4 μg/m3 at the two sites, respectively. Seasonal variation of PM2.5 concentrations was significant, with the highest concentrations observed from mid-November through December and the lowest from June through September. Ammonium sulfate and nitrate accounted for 41.6% of the PM2.5 mass with sulfate alone accounting for 23.4% of the PM2.5 mass. Carbonaceous material accounted for 41.4% of the PM2.5 mass, with 73% of that mass being organic, as defined by the TOR analysis method. Crustal components averaged 9.6% of the PM2.5 mass. Potassium, which was 95% water soluble, accounted for 2.7% of the PM2.5 mass.