GEOCHEMICAL CHARACTERISTICS AND EVALUATION OF HEAVY METALS IN NEAR-SURFACE ATMOSPHERIC DUST, PANZHIHUA MINE AREA, SICHUAN PROVINCE, CHINA.

Panzhihua is a very large iron mining center in China famous for its production of vanadium-rich titanium magnetite. Panzhihua City, rich in mineral resources including vanadium titanium magnetite, coal and limestone, is a typical mining town. A large amount of heavy metal is generated by the mining and associated activities and metal that escapes from the industrial process stream could have a significant impact on the environment. Many researchers have carried out studies on the soils and stream sediments in Panzhihua but no work has been done on the atmospheric dust. In this study, we characterize the mineralogy, particle size, and heavy metal content of the near surface atmospheric dust and attempt to quantify the potential eco-logical risk of these dust emissions. Our studies showed that the near-surface atmospheric dust particles are small and the dust occurs in two size categories, 10-50 m and 5-20 m. Mineralogically the dust is basically quartz, with some feldspar, gypsum, and carbonate minerals. In the dust samples collected, the level of heavy metal is high and the V and Ti contents are very high. The potential ecological risk index evaluation shows that the near-surface atmospheric dust in Panzhihua is an intermediate to strong ecological hazard and the hazards posed by Cd and V are the most significant. [ABSTRACT FROM AUTHOR]