Soils were characterized for common chemical parameters and for heavy metal
contents (Table 1) according to standard soil science procedures.Soil samples were digested in concentrated HNO3 and H2O2 and the heavy metals, Cd, Cr, Cu, Ni, Zn, and Pb were determined by inductively coupled plasma-optical emission spectrometry A certified standard reference material from the National Centre for Standard Materials was used in the digestion and
analysis. Average recovery was 92 4% for all the metals determined