Identification of heavy metal sources in the reclaimed farmland soils of the pearl river estuary in China using a multivariate geostatistical approach.

Heavy metals in the reclaimed farmland soils of the Pearl River Estuary in China have attracted much attention because of the health risk posed to local residents. The identification of heavy metal sources in these soils is necessary to reduce their health risk. Reclaimed farmland soil samples were collected from 144 sites in the Pearl River Estuary and the contents of heavy metals (Cd, Pb, Cr, Ni, Cu, and Zn) were determined. All these heavy metals showed concentrations substantially higher than their background values, indicating possible anthropogenic pollution. The results of a multivariate geostatistical method demonstrate that grouped Cd, Cr, and Cu were mainly controlled by chemical fertilizers. Grouped Pb and Zn were the most severely impacted by atmospheric deposition from Guangzhou and Foshan, and Ni was primarily impacted by electroplating factories' wastewater discharge.