Screening and monitoring of metal contamination in soils of environmental disaster areas: available techniques and needs

The monitoring of metals in the environment is well advanced technically and analytically, though the sustainable development requirements induce the need of new methods of metal assessment in the terrestrial and aquatic environment. The current metal monitoring in soil is based on the total content that does not allow for assessment of their environmental mobility and bioavailability. The new techniques should enable metal partitioning with respect to susceptibility to migrate and exert the toxic effect on the target organisms. This statement is exemplified in the screening survey for metals of the area impacted by the catastrophic flood of 1997 in the Odra River valley in Poland. Metals enrichment of soils due to river sediments deposition, as well as their mobility in soils of the affected area were assessed in view of potential risk to the receptors. Sampling cells positioning by GPS and the assessment of the post-flood changes in metal spatial distribution with use of the Geographical Information System (GIS) were most helpful, while the sequential extraction analytical procedure for evaluation of binding strength and major chemical forms of metals was conducted manually and thus was very laborious. Automation of metal partitioning, and bioavailable forms assessment by DGT technique would have given the most valuable information and reduce the time needed for the manual analysis.