THE ORIGIN OF ARSENIC IN SOILS AND GROUNDWATER OF THE PANNONIAN PART OF CROATIA

Arsenic content in surface layer (0-25 cm) varies from 0.9 mg/kg soil to almost implausible 490 mg/kg. The reason for the highest content in hydromorphic soils should probably be sought in recent history. It is less probable that the reason for the increased arsenic content in hydromorphic soils is the geological origin of rocks in river valleys. It is more probable that the reason for the increased arsenic content is river flooding and changes in river flows in the recent past. Based on 208 groundwater samples from 12 locations of Koprivnica-križevci county during 2009-2012, the range of arsenic concentration from <0.1 μg/l to 25.4 μg/l was determined. The concentrations are, generally, very low (