The enrichment for the three elements may be attributed to their downward migration due to dissolution of zircon and thorite by humus acid and adsorption by montmorillonite and amorphous iron oxides.
We found that the enrichment factors of pollution elements in Taiyuan were much higher than that in Beijing, through analyzing the enrichment factor of pollutants elements. Beijing is in the downward wind direction, therefore the atmosphere pollution would transport to Beijing from Shanxi.