关键词: PIXE;气溶胶;长城站;南极

Abstract:

Atmospheric pollution is not only directly harmful to human health at source region but it also be transported through the atmosphere over great distances. Atmospheric particles, especially submicron aerosol particles which have long atmospheric residence times have led to the contamination of many non-urban areas. Baseline atmosphericumcasure-ments should help us make clear the source, dispersion, concentrations, degree of transportation and enrichment factors of these pollutants. The Antarctica area offers one of the best locations on the Earth for studing the composition of the background aerosol since it is isolated both geographically and meteorologically from the major souices of anthropo-gentric emission. The aerosol samples were collected by cascade impactors designed and constructed by our Res. Center. Each sample provided eight particle size fractions in the normal aerody namic diameters (μm) ranges. From first stage to the 7th stage Mylar film in 3μm thickness was used, Nuclepore film with 0.40μm of pore diameter was used in the last stage. The samples were collected at flow of two liters per minute. The samples were analysed by Proton Induced X-ray Emission (PIXE) method. The X-ray spectra were analysed by computer, with small peaks being checked by manual integration to obtained the final con centrations. The data are given in μg per standard cubic meter. In order to learn the enrichment factors of various elements the results were separated to two groups: coarse and fine particles. Coarse mode (>10μm) concentrations were compared with the composition of the earth's crust. The fine mode of elements show large relative enrichments. Authors have compared to those recently measured results at some other locations. It was also showed the aerosol results measured in Antarctica by a part of authors. It can be concluded that the Antarctica is a good background area on the Earth. The measurements of atmospheric chemical composition, are valuable in order to establish concentration baselines with which polluted air may be compared. They also give an opportunity to investigate the physical and chemical characteristics of the atmosphere withont complicating anthropological influences.