English Abstract This report discusses the various factors (Capacity
controlling parameters) which determine the extent of storage of chemicals
and the results of a workshop which dealt with prediction and modelling of
Chemical Time Bombs (CTBs) related to heavy metal contamination.
Combinations of inputs like acidification with deposition of metals from the
atmosphere may cause an effect which is worse than each of them on their
own. Important are those cases where the capacity of the soil/sediment to
retain chemicals changes. Examples are changes in hydrology, changing land
use and civil engineering works. Qualitatively we can predict under these
circumstances thath the pH will change, organic matter content will changes
etc. Also many models are available to predict the effect of single or a
few parameters in heavy metals behaviour, but few if not any to predict the
combined effects. For these dynamic changes we selected changes in
hydrology and changes in land use as topics for the dicussion in the
workshop. The last part of the workshops was devoted to constructing
research proposals to fill in gaps in our knowledge.