[Analysis of Heavy Metal Sources in Soil in Ping'an Basin Based on APCS-MLR and PMF Models].

values of Pb and Zn were less than 40, and there was no ecological risk. Cr and Cu had a small number of moderate ecological risk points, and the ecological risk was low. Hg, Cd, and As had medium and high ecological risk points, and there was a certain risk, with Hg>Cd>As characteristics. The RI value of ecological risk in the study area was 102, indicating low risk overall. ③ The APCS-MLR and PMF models complemented and verified each other and jointly resolved the four main heavy metal sources in the study area. That is, sulfide-dominated natural sources, mantle material-dominated natural sources, epigenetically modified natural sources, and human activity interference sources. This study provides technical support for the selection of heavy metal risk prevention and ecological treatment projects in the study area and has guiding significance for the study of heavy metal evolution and ecological effects in typical areas of the Qinghai-Xizang Plateau.