Magnetic properties and heavy metal pollution of soils in the vicinity of a cement plant, Xuzhou (China)

• Self-organizing map was applied to metal data for ‘correlation hunting’.
• Cd enriched significantly while Pb, Cu, Ni and Zn accumulated moderately in soils.
• Soils were dominated by SP + MD ferrimagnetic minerals.
• Only Cu showed a significant correlation with χ, χARM and SIRM.

This study characterized the magnetic property and levels of heavy metals of the topsoils near a cement plant. The concentrations of five selected heavy metals (Pb, Cu, Zn and Cd) were measured on 32 topsoil samples (0–20 cm) collected near a cement plant via inductively coupled plasma/mass spectroscopy (ICP-MS). The orders of enrichment factors (EF), on average, were Cd (7.3) > Cu (3) > Zn (2.9) > Pb (2.1), respectively. A self-organizing map (SOM) was applied to the concentrations of heavy metals for “correlation hunting”. Mineral magnetic concentration parameters, such as the specific magnetic susceptibility (χ), susceptibility of anhysteretic remanent magnetization (χARM), saturation isothermal remanent magnetization (SIRM), together with interparametric ratios (such as IRM− 100mT/SIRM, SIRM/χ, χARM/SIRM) show that ferrimagnetic, superparamagnetic (SP) and multi-domain (MD) minerals dominated the soils. The results of correlation analysis indicate that copper showed a significant correlation with χ, χARM and SIRM but such a relationship with χ, χARM and SIRM was only weakly identified for Zn, Cd and Pb.