Concentration of Heavy Metals in Selected Grasses in Relation to their Soil Content in a Heavily Polluted Area

Abstract

Besides the region of Northern Bohemia where the pollution is widespread, there are some places of point contamination in the Czech Republic. One of them is the alluvium of the Litavka river in the district of Príbram, an area polluted with heavy metals due to metallurgical production. Samples of soils and grasses of generaFestucaandPoawere collected in order to determine content of Cd, Pb and Zn in plant roots and shoots and study to which extent is metal concentration in plants dependent on content of different metal forms in soils and on soil properties. Plant samples were mineralised in a dry mode mineraliser APION, the resulting ash was diluted using 1.5% HNO₃and content of Cd, Pb and Zn in the solution was measured by means of atomic absorption spectrometry (AAS). In soil samples, a kind of sequential extraction with 0.1M Ca(NO₃)₂for exchangeable metals and with 0.05M Na₄P₂O₇(pH 12) for organically bound metals was used. Also, content of metals extractable with cold 2M HNO₃in soils was determined.