1. Ambient Measurements. All the studies used the chemical measurements of elements (17-36 elements from Na to U). Studies in Beijing (Zhang Y.H. et al., 2004; Zheng et al., 2005; Song et al., 2006a, 2006b), Jinan (Feng et al., 2004), Hong Kong PM2.5 (Ho et al., 2006), and Chongqing (Tao et al., 2006) also used chemical measurements of water-soluble ions (chloride [Cl], nitrate [NO3], sulfate [SO42−], ammonium [NH4+], and sometimes sodium [Na+], potassium [K+], calcium [Ca2+]), and carbon (organic [OC] and elemental carbon [EC]). Studies in Xi’an (Zhang X.Y. et al., 2001), and Hong Kong PM10 (Lee et al., 1999) used the measurements of elements and ions.

  2. Source Measurements and Profiles. No area-specific source profile measurements were taken in studies of Beijing (Zhang Y.H. et al., 2004; Song et al., 2006a, 2006b), Yantai (Xu et al., 2001), Xining (Wang W., 2006), and Hong Kong (Lee et al., 1999; Ho et al., 2006). Only dust aerosol or dustfall samples from source-dominated microenvironments were taken in studies of Beijing (Zheng et al., 2005), Xi’an (Zhang X.Y. et al., 2001), Jinan (Feng et al., 2004), Yinchuan (Sang et al., 2005), Nanjing (Hang et al., 2000), and Chongqing (Tao et al., 2006). Other profiles like diesel engine exhaust, gasoline-powered vehicle exhaust were taken from earlier tests in the study area or similar areas (Feng et al., 2004; Zheng et al., 2005).

  3. Source Contribution Estimates. The major sources including coal combustion dust, fugitive dust (soil dust), and construction dust accounted for 58 percent at Xi’an (Zhang X.Y. et al., 2001), 77 percent in Jinan (Feng et al., 2004), 67 percent in Yantai (Xu et al., 2001), 79.4 percent in Xining (Wang, 2006), 84.7 in Nanjing (Hang et al., 2000) for TSP fraction. They accounted for 72 percent in Jinan (Feng et al., 2004), 80 percent in Yinchuan (Sang et al., 2005), only 6.1 percent in Hong Kong (Lee et al., 1999) for PM10 fraction. Their percentage is 37.8 percent in Beijing (Zhang Y.H. et al., 2004), and 6-30 percent in Hong Kong (Ho et al., 2006) for PM2.5 fraction. Coal is the dominant energy source and construction activities are serious in most of cities in north China. Strong wind and dry weather results in the large fugitive dust (soil dust) in TSP in these cities. These three sources are also dominant sources contributed to PM10 in cities in north China, but not in Hong Kong. Hong Kong is a developed city without intensive construction activities and coal utilization and coastal area with frequent precipitations, which lead to the small contribution from these three sources. In PM2.5 fraction, their contribution decreased because the increasing contribution from secondary sources and vehicular exhaust in Beijing and Hong Kong.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement