Chemical characterization of aerosols at the summit of Mountain Tai in Central East China
- ISSN: 16807316
- DOI: 10.5194/acp-11-7319-2011
PM2.5 and TSP samples were collected at the summit of Mountain Tai (MT)\n(1534 m a.s.l.) in spring 2006/2007 and summer 2006 to investigate the\ncharacteristics of aerosols over central eastern China. For comparison,\naerosol samples were also collected at Tazhong, Urumqi, and Tianchi in\nXinjiang in northwestern China, Duolun and Yulin in northern China, and\ntwo urban sites in the megacities, Beijing and Shanghai, in 2007. Daily\nmass concentrations of TSP and PM2.5 ranged from 39.6-287.6 mu g m(-3)\nand 17.2-235.7 mu g m(-3) respectively at the summit of MT. Averaged\nconcentrations of PM2.5 showed a pronounced seasonal variation with\nhigher concentration in summer than spring. 17 water-soluble ions\n(SO42-, NO3-, Cl-, F-, PO43-, NO2-, CH3COO-, CH2C2O42-, C2H4C2O42-,\nHCOO-, MSA, C2O42-, NH4+, Ca2+, K+, Mg2+, Na+), and 19 elements of all\nsamples were measured. SO42-, NO3-, and NH4+ were the major\nwater-soluble species in PM2.5, accounting for 61.50% and 72.65% of\nthe total measured ions in spring and summer, respectively. The average\nratio of PM2.5/TSP was 0.37(2006) and 0.49(2007) in spring, while up to\n0.91 in summer, suggesting that aerosol particles were primarily\ncomprised of fine particles in summer and of considerable coarse\nparticles in spring. Crustal elements (e. g., Ca, Mg, Al, Fe, etc.)\nshowed higher concentration in spring than summer, while most of the\npollution species (SO42-, NO3-, K+, NO2-, NH4+, Cl-, organic acids, Pb,\nZn, Cd, and Cr) from local/regional anthropogenic emissions or secondary\nformation presented higher concentration in summer. The ratio of Ca/Al\nsuggested the impact of Asian dust from the western deserts on the air\nquality in this region. The high concentration of K+ in PM2.5 (4.41 mu g\nm(-3)) and its good correlation with black carbon (r = 0.90) and oxalic\nacid (r = 0.87) suggested the severe pollution from biomass burning,\nwhich was proved to be a main source of fine particles over central\neastern China in summer. The contribution of biomass burning to the fine\nparticle at MT accounted for 7.56% in spring and 36.71% in summer, and\neven reached to 81.58% on a day. As and Pb were two of the most\nenriched elements. The long-range transport of aerosols spread the heavy\npollution from coal-mining/coal-ash to everywhere over China.\nAnthropogenic air-pollution was evidently rather severe at MT, though it\nhas been declared by UNESCO to be a World Heritage site.