The Study On Inhalable Particles Distributed Characteristic In Urban City

Atmosphere particles have been the primary air pollutants of the cities in recent years. Particles in different sizes do harm to the human health and the atmospheric quality are not the same. The research for the distribution characteristics of PM₁₀, which were continuous sampled in Beijing for long-term could propose the scientific basis for the national standards for air quality revision and correct control strategy put forward.The PM₁₀ which were sampled around hangtian bridge, xisanhuan, Beijing during March to December, 2009 were studied. The mass concentration, Micro-morphology and chemical composition of the PM₁₀ had been measured by DustTrak, Scanning Electronic Microscopy, X-ray Energy Dispersive Spectrometer, Ionic Chromatogram and Inductively Coupled Plasma-Mass Spectrum. And the distribution of particle sizes and seasons were analysed. The source apportionment of PM₁₀ was made at the last part.The result showed: the mass concentration of PM₁₀ in winter and spring was much higher than summer and autumn. The annual average of PM_2.5/PM₁₀ and PM_1.0/PM₁₀ were 82.6% and 70.3%, respectively. The pertinences between PM₁₀ and PM_2.5, PM₁₀ and PM_1.0 were up to 0.896 and 0.912; The mass concentration of water-solubility SO42- in PM₁₀ was higher in summer and winter than autumn and spring. The rangeability of mass concentration of NO3- was modest in the year. The concentrations of water-solubility SO42- and NO3-in the 0.43-2.1μm PM were high, and accounted for 68.3% and 57.6% of PM₁₀, respectively. NO₃^-/SO₄^2-was 65.9% which suggested that the larger part of pollutants in Beijing belonged to stationary source, but the proportion of moving source had been rising; the PM₁₀ were sorted into 9 classes like fly ash from coal combustion, gypsum particles and so on. The irregular shape partcles were more than the regular, which were occupied a lot by the fly ash and gypsum particles. The comparatively mass percentages of Hg, Zn and Pb were high. The content of S was account for 87% of the PM₁₀; The concentrations of metal elements in PM₁₀ were higher in winter and spring than summer and autumn. As the particle size diminished, the concentrations of lithosphere elements like Mg, Ca, Fe were decreased and the heavy metal elements like Pb, Zn, Ni were increased. The PM₁₀ were contributed by three factors: dust from architecture and nature, dust from cars and vehicles, dust from living and industry.