[Source Apportionment of Heavy Metals in Farmland Soils Around Mining Area Based on UNMIX Model].

Forty-two farmland soil samples were collected from the mining area of Huize City, Yunnan Province, to identify the sources of metals in the farmland soils, and 14 selected elements in farmland soils were detected. The UNMIX model was applied to identify the sources of the metals. The inverse distance weighted interpolation method of statistical analysis in ArcGIS was used to develop a spatial distribution map of the six severely polluted metals to validate the source apportionment results of the UNMIX model. The results indicated that:① the metals, Pb, Zn, and Cd, in the studied farmland soils were seriously polluted according to the soil background values of Yunnan Province and the Chinese environmental quality standard; ② there were three potential sources of metals according to UNMIX model:source 1 was the anthropogenic sources caused by industrial activities with a source contribution rate of 16.32%; source 2 was the anthropogenic sources caused by coal combustion and fertilization with a source contribution rate of 68.26%; and source 3 was the combined sources caused by mining related activities and soil parent materials with a source contribution rate of 15.42%; and ③ the spatial distribution of selected metals was in accordance with the local land-use and the results of the UNMIX model. Therefore, the UNMIX model can be effectively applied to the source apportionment of heavy metals in farmland soils around the mining area.