Airborne heavy metal pollution in the environment of a danish steel plant

A survey of heavy metal deposition was carried out in the vicinity of a Danish steel plant. Bulk precipitation and transplanted lichen (Hypogymnia physodes (L.) Nyl.) were sampled at 12 stations in the environment before and after the production had been converted from open-hearth furnaces to electric-arc furnaces.

The samples were analyzed for Cd, Cr, Cu, Fe, Mn, Pb and Zn.The results show that heavy metal pollution from the steelworks still is severe and that it follows a decreasing power curve when the distance to the steelworks is increased. However, a reduction in the deposition of heavy metals close to the steelworks has been observed, pointing to the conclusion that the change from a situation of emission through a 46 m stack without any filter to emission from the electric arc furnaces equipped with bag-filters has lead to changes in the emission.

At the sampling stations with the highest deposition levels measured in bulk precipitation the corresponding concentrations in the lichens were relatively lower indicating a change in particle size distribution. Within each station there was a direct proportionality of metal concentrations in lichens and atmospheric fallout measured in bulk precipitation.