The organic top horizons of forest soils in the vicinity of industrial centers in Upper Silesia, Poland, are characterized by remarkably high magnetic susceptibility. The unusually strong soil susceptibility does not result from weathering or pedogenesis or from deposition of natural detrital ferrimagnetic minerals but is due rather to the influx of anthropogenic magnetic particles contained in industrial dusts and fly ashes. The magnetic particles are iron oxide spherules which originate during the combustion of fossil fuels (brown and hard coals) and during iron or steel production. Heavy metals, such as zinc, lead, or cadmium which stem from the same pollution sources, are often associated with the magnetic and other dust particles and cause soil contamination, which is potentially hazardous for plants, animals, and humans. Because the regional magnetic susceptibility distribution pattern is closely correlated to measured dust fall and largely parallels the distribution of heavy metals, measurements of magnetic susceptibility, which can be conducted easily both in the laboratory and in the field, can be used as a fast and sensitive tool to trace and monitor soil contamination in industrialized regions. ¿ 1998 American Geophysical Union