Atmospheric Pb levels over Mount Qomolangma region

The Pb spectral concentration of atmospheric aerosol samples observed over Mount Qomolangma site (28 degrees 11'33N, 86 degrees 49'59E, 4950 m ASL) in 2002 was 13.3 ng/m(3). about 4.5 times higher than that in 2000. The Pb spectral distribution showed three peaks, located at <0.25 mu m, 0.5-1 mu m, and 4-8 mu m in diameters. The peaks for <0.25 mu m and 0.25-0.5 mu m may be due to long-distant transport, while that for 4-8 mu m probably results from local floating dust. The atmospheric Pb concentration over Mount Qomolangma was lower than that of South Pole, most of the urban areas, and desert areas in the northern hemisphere. The enrichment factors for fine and coarse particles of atmospheric Pb in 2002 over Mount Qomolangma were 413.2 and 62.6. respectively, in support of the slight atmospheric pollution with Pb over the Qinghai-Tibetan Plateau. (C) 2008 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.