Sewage contained on an average 1.20 mg·Kg−1 Cd, over
8 times the permissible level by the EU standards (0.2
mg·Kg−1); Cu concentrations were 29.07 mg·Kg−1, which
is little higher than EU Standard (20 mg·Kg−1); concentrations
of Pb were 6.77 mg·Kg−1, over 22 times the permissible
levels allowed by both EU standards and UK
guidelines (0.3 mg·Kg−1); Zn concentrations were 221
mg·Kg−1, over 4 times the guideline value (50 mg·Kg−1).