Bioavailability of metals depends on the type and
genetic features of soil forming rocks, soil composition,
and amount of organic matter and other chemical and
physical properties of soil (Lokeshwari and
Chandrappa, 2006). It also depends on the
concentrations of anions and chelating ligands present
in water, pH, redox status and the presence of
adsorbent sediments (Mido and Satake, 2003).