SUITMA 2005 Cairo - Vertical distribution of heavy metals in air over heavily polluted industrial soils in the Ruhr area, Germany
SUITMA 2005 Cairo
| This abstract is about one of the papers of the Industrials, traffic, and mining pollution theme of the SUITMA 2005 symposium. |
| Silke Hoeke.i |
- i - Department of Soil Technology, University Duisburg-Essen, Essen, Germany.
Investigations the agricultural wind erosion processes over farmlands show that normally a rolling particle share between 5-25 %, a saltating share between 50-75 % , and a suspending share between 3-40 % exist. Furthermore, soil-born dusts are mainly transported (ca. 90 mass-%) into a height of 30 cm above the surface.
When polluted soils are available from which dust can be released, it depends on the vertical pollutant concentration distribution and the vertical pollutant mass distribution, if health risks exist and/or surrounding soil can be contaminated.
As a rule, only suspended soil particles (< 63 µm) cause relevant risks. Only these particles can be raised in upper air layers and can be inhaled or transported over longer distances. The smaller soil particles (clay minerals, humus, and sesquioxides) are normally the main pollutant carriers.
On a highly polluted, vegetationless plain fallow land of a former factory site with 100 m diameter, on 10 sites altitude profiles of the dust flux (BSNE) were measured over several months. Measurements took place in the luff and center of the erosion plain, in different distances to the fringe of the erosion plain (3 m, 25 m,100 m) and in measuring heights of 15, 35 and 100 cm above the surface. Beside the dust flux masses, Cd-, Pb- and Ba- contents in the dust were measured.
Depending on the weathering conditions (especially squalls), the distance to the fringe, the ground vegetation close to the dust traps (wind field) and the Cd-, Pb- and Ba- contents in the soils subject to the particle sizes in the ambience of the dust traps, very different distributions of the metals regarding their contents in the dust and their concentrations in the air were found. The vertical distributions of the dust flux, the metal contents in the dust und the metal fluxes were presented and discussed exemplarily.
