Abstract:  The asbestos composition and distribution, spatial migration and transformation of involved heavy metals, and their effects on microbial community structure and biodiversity in the soil surroundings in the Xiaobabao asbestos tailings ponds in Qilian County, Qinghai Province were investigated in this study, aiming at understanding the risk of asbestos pollution to soil environment and providing technical support for further treatment and mitigation of asbestos pollution. The results of investigations showed that the major mineral components in the field soil include quartz, clinochlore, serpentine, ferropargasite and albite and so on. Serpentine was identified as the representative mineral of asbestos. The results indicated that different spatial distribution of variouslysourced heavy metals along both vertical and longitudinal profiles across the site; The distribution trend of CaO was closely related to the serpentine minerals along these typical profiles. The spatial distribution of Cr showed a similar pattern with asbestos; The mass fraction of Cr exceeded the risk control value for soil contamination of construction land (78 mg/kg), especially in the asbestos tailings slag where the mass fraction of Cr greatly exceeded the risk control level. The asbestos stress reduced biodiversity of the local soil, leading to a great impact on soil microbial community structure. 

Key words: soil, asbestos, mineral, heavy metals, migration and transformation, distribution