HR: 15:30h
AN: NS43A-06    [Abstracts]
TI: Degree And Extension Of Soil Pollution Around Polish Iron Factories And Main Roads As Indicated By Magnetometric Studies
AU: * Nawrocki, J
EM: jerzy.nawrocki@pgi.gov.pl
AF: Polish Geological Institute, Rakowiecka 4, Warsaw, 00-975, Poland
AU: Polechonska, O
EM: olga.polechonska@pgi.gov.pl
AF: Polish Geological Institute, Rakowiecka 4, Warsaw, 00-975, Poland
AB: Magnetic iron minerals, whose presence in soils can easily be detected by magnetic susceptibility measurements, are components of numerous industrial dusts. There is a linear dependence between magnetic particles content and content of heavy metals like: Cu, Fe, Pb and Zn (in urban dusts). A similar dependence was observed in atmospheric dusts (for Pb, Cu, Zn, and Cd). If the origin of magnetic particles and a considerable part of heavy metals permeating into soils as a result of industrial emission or imission is the same, the application of magnetic susceptibility measurements for the detection of potential high risk-areas is possible. Several roads and ironworks are surrounded by the cereal and other plants cultivation fields. Cultivated soils are often polluted by heavy metals. Two Polish ironworks and several sectors of roads were chosen for the case study. Lateral and vertical extension of soils pollution are studied and compared with several parameters like type of soil and directions of prevailing winds. Maps of magnetic susceptibility were prepared basing on measurements collected directly in the field, using Bartington device. Extents of increased values are explicitly visible on maps. Their directions correspond with prevailing wind directions, and increased concentrations of heavy metals are expected at a distance up to 1.5 km from the ironworks and up to 80 m from the roads. Several soils profiles were taken from the polluted areas. Vertical migration of heavy metals were determined by further petromagnetic and geochemical analysis of profile samples, taken with 5cm step. In the soils from ironworks areas magnetic susceptibility decreases rapidly from the top level to 15 cm where it stabilizes at the level characteristic for natural podzols and sands. It is confirmed by geochemical analysis, showing decrease of Fe as well as Zn and Pb content at the same depth distance. SEM images shows that there are numerous Fe spherules in top samples of studied profiles. They have miscellaneous structures, usually with empty space inside. Some titanomagnetites appears at subsoils of profile from ironworks area causing abovementioned increased values of magnetic susceptibility. Those minerals are visible at SEM images as irregular grains, sometimes with Al, Ca, Si jacket.
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly