ABSTRACT
In this study the crops cultivated on the application of sewage sludge were investigated. The crops grown included lady finger [okra], round gourd, smooth luffa, spinach, pumpkin, red pepper, green pepper and the fruits [pomegranate, mango, lemon, java plum, guava, banana, melon]. Results showed that sewage irrigation significantly increased total heavy metal contents in different organs [leaf, peel and pulp] of the crops in comparison to river water. The sewage water carried a very high load of Pb, Fe, Cu, Zn, Mg, Ca and other heavy elements. Maximum concentration in lady's fmger was for Mg followed by Zn, Cu, Ca, Fe, Pb and Co. There was significant increase in Mg concentration in leaf at 73.20 mg ke. Concentrations of Zn, Cu, Ca, Fe, Pb and Co were lower varying from 0.30 to 1.0 in leaf, 0.50 to 1.60 in peel and 0.70 to 1.70 in pulp. The accumulation of heavy metals by other vegetables was similar except spinach which showed high content of Fe at 39.0 mg kg-' in leaf. Plants fed on sewage water produced fruits showing heavy metals accumulation. It appeared that the metals accumulated and distributed between tissues in nearly the same proportion as in the vegetables. The river water fed vegetables and fruits, however, showed lesser accumulation of the heavy metals