Magnetic susceptibility as proxy for heavy metal pollution: a site study

A magnetic susceptibility field survey was undertaken at a former industrial iron production and processing site, measuring samples from different depths. The aim was to investigate the suitability of such field measurements for indicating heavy metal pollution. Geochemical analysis of soil samples showed close correlation of concentrations between Fe, Cu, Mn, and Ni. In addition, Fe concentrations correlated with magnetic susceptibility field measurements, particularly when taken after removing the turf layer. An important finding of this study is that best correlation is obtained for magnetic susceptibility values higher than a site-specific threshold. These results demonstrate the potential of magnetic susceptibility field mapping for fast preliminary site assessment, greatly reducing the scale of subsequent geochemical sampling and analysis.