Cluster Analysis of Atmospheric Aerosol in Beijing Based on Chemical Compositional Data

From September 2005 to September 2006, 166 samples of total suspended particles(TSP) were collected in Beijing at three sites in north suburb Changping, downtown, and south suburb Liangxiang, respectively. Lead and other 28 elements were measured using inductively coupled plasma-mass spectrometry(ICP-MS) and atomic emission spectroscopy(ICP-AES). Cluster analysis based on elemental compositions presented five classes as clean and polluted aerosol samples. Clean samples account for 48.8% of the total, being mainly from north suburb site; while polluted samples account for 51.2%, being largely from downtown and south suburb sites. Four classes of polluted samples had different chemical compositions, featured respectively by soil mineral dusts with high aluminium, iron and rare earth elements contents, and construction dust with high calcium and magnesium contents from manufactories and application sites, and sulphate dominating particles from coal combustion and other combustion processes, and particles with high lead and zinc contents most likely from non-ferrous industry emissions. Cluster analysis results are compatible with those of previous studies on aerosol source identification and apportionment. This kind of information is needed for Beijing air quality management and air pollution control. It will facilitate efficient air pollution control and management and effective environmental investment.