Comparison of inorganic chemical compositions of atmospheric TSP, PM10 and PM2.5 in northern and southern Chinese coastal cities.

To compare the inorganic chemical compositions of TSP (total suspended particulate), PM10 (particulate matter with an aerodynamic diameter less than 10μm) and PM2.5 (particulate matter with an aerodynamic diameter less than 2.5μm) in southern and northern cities in China, atmospheric particles were synchronously collected in Dalian (the northern city) and Xiamen (the southern city) in spring and autumn of 2004. The mass concentrations, twenty-three elements and nine soluble ions were assessed. The results show that in Dalian, the mass concentrations of Mg, Al, Ca, Mn and Fe in spring were 4.0-10.1, 2.6-8.0, 4.1-12, 1.2-3.6 and 2.9-7.9 times higher, respectively, than those in Xiamen. The dust storm influence is more obvious in Dalian in spring. However, in Xiamen, heavy metals accounted for 13.9%-17.9% of TSP, while heavy metals contributed to 5.5%-9.3% of TSP in Dalian. These concentrations suggest that heavy metal pollution in Xiamen was more serious. In addition, the concentrations of Na+, Cl-, Ca2+ and Mg2+ were higher in Dalian due to the influence of marine aerosol, construction activities and soil dust. The NO3-/SO42- ratios in Dalian (0.25-0.49) were lower than those in Xiamen (0.51-0.62), indicating that the contributions of vehicle emission to particles in Xiamen were higher. Coefficient of divergence values was higher than 0.40, implying that the inorganic chemical composition profiles for the particles of Dalian and Xiamen were quite different from each other.