Sixteen soil samples from agriculturally used soils flooded in August 2002 were taken because new information about the state of soil contamination was required. The area in the Vltava river basin from Pragueto Mělník and in the Laberiver basin from Neratovice to Děčín was investigated. The samples were taken in September 2002 and analysed for the contents of potentially risky elements and persistent organic pollutants, including persistent dibenzodioxins and dibenzofurans. The results were compared with the data from the project Labe 1992. The findings show a low soil load of potentially risky elements and a slight reduction of their contents in soil in comparison with the state in 1992 (except for vanadium). The same situation was observed in the case of persistent organic pollutants. Only the content of DDT was increased in the soils of most localities after floods in August 2002. This finding needs further observations on a larger collection of samples. The dreads resulting from expected soil contamination by dibenzodioxins from Spolana Neratovice factory were not confirmed and their contents in the soils of observed localities meet the requirements for plant production without any reduction.

The efficiency of the application of organic and inorganic additives on the reduction of mobility and transfer of As, Cd, Pb and Zn from the soil into the plants was observed. The dung, compost, acid peat and muck presented organic additives. Synthetic zeolite type P c of cubic structure, loamy shale and dolomite limestone presented inorganic additives. Five soil types were used during the testing (arenic regosol, typic cambisol, dystric cambisol, typic chernozem and typic fluvisol). The changeover of the mobility of As, Cd, Pb a Zn in the soil (the ratio of mobile and total contents, sequential analysis) and the transfer of the elements from the soil into the plants (the vegetables, cereals and fodder plants) were investigated. The results showed the primary importance of the soil pH value on the behaviour of potentially toxic elements and their intake by the plants. The efficiency of the use of organic additives strongly depended on the quality of the organic matter. Inorganic additives on the base of the sorbents worked in the case of mobile hazardous elements (Cd, Zn). The efficiency of the soil additives was strongly influenced by the soil type.