Source apportionment of heavy metals in farmland soil with application of APCS-MLR model: A pilot study for restoration of farmland in Shaoxing City Zhejiang, China

The conditions of the sources of heavy metals are essential to assess its potential threats to human health. The identification of the origin of heavy metals is essential for planning effective measures to control long-term accumulation of heavy metals. In this study, analysis of pollution sources was performed on 100 soil samples with geostatistics and absolute principal component score-multiple linear regression (APCS-MLR) receptor model. The descriptive statistics revealed that concentrations of heavy metals (Pb, Zn, Cu, Ni) have exceeded the background value of Zhejiang Province. The coefficient of variation is Pb > Cd > Cu > Zn > Ni > Cr. The APCS-MLR and geo statistical analysis showed that sources of pollution: PC1 was Ni, Cr, Cu, Zn because of soil parent material. The contribution rates were 89.42%, 87.19%, 29.64%, and 33.58%, respectively. The PC2 was Pb, Zn and Cu which were mainly caused by anthropogenic mining activities. The contribution rates were 95.92%, 24.81%, and 40.62%, respectively. The PC3 was Cd, Zn and Cu which was mainly caused by agricultural inputs, and their contribution rates were 91.96%, 41.61%, and 30.14% respectively. According to Nemero Synthesis Index evaluation method, the Shaoxing City Zhejiang, China is heavily polluted with heavy metals.