Magnetic susceptibility (MS) and 7 heavy metals of 112 topsoil samples from four profiles QS, SQ, DXH and HN, Wuhan city, Hubei Province, were measured, and the SEM was used to identify magnetic fractions in the extraction from the representative samples. The results revealed that the magnetic properties of the QS profile which is located near a heavy industrial district and SQ profile which is in the center of the Wuhan city are controlled dominantly by human activity magnetic inputs and have the highest MS values; and in the DXH which is located west suburb, pedogenic factors dominate to magnetic characteristic of topsoil; the HN is located in the downwind direction of winter monsoon of Wuhan and MS is influenced by both human and natural factors. The SEM photos and the energy spectra of the extractions revealed that the main magnetic materials with spherules in the topsoil are iron oxides. The correlation between MS and heavy metals indicate that MS correlated well with Pb and Cu for the SQ profile. As magnetic minerals within soil in QS profile was destructed in the waterlogged soil, which is ubiquitous around the profile, so, no correlation between MS and heavy metals was observed. In the suburb profile, there are no essential association relations between MS and heavy metals.
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