Heavy metals and their bioavailability from soils in the long-term polluted Central Spiš region of SR

The heavy metal contents and their bioavailability were monitored in soils of Central Spiš region of SR. This area belongs to long term contaminated and hygienically loaded areas. Soil contamination by heavy metals is caused especially by ore mining, processing and treatment. Soil samples from the Central Spiš contained higher proportions of mobile forms which corresponded to the following sequence Pb > Zn > Cu, while for mobilizable forms the sequence of investigated metals was as follows: Cu > Zn > Pb. Soil pH is one of the parameters that affect significantly the share of bioavailable forms of metals. Higher proportions of mobile fractions of metals were detected in samples taken from soils with acidic pH. Statistical processing confirmed a relationship between the percentage share of lead and zinc in the mobile form and the level of pH/KCl, which was significant for Zn: r = –0.53. The relationships for lead and copper were insignificant.