Heavy metals and microbial contamination of certain leafy vegetables grown in abattoir effluent disposal province of Saharanpur (Uttar Pradesh), India

Abstract

The present investigation was carried out to study the heavy metals and microbial contamination of four selected leafy vegetables viz., cabbage, lettuce, coriander and spinach grown in abattoir effluent irrigated soil. The results revealed that the values of various parameters of abattoir effluent viz., TDS (2840 mg L^-1), BOD (2480.50 mg L^-1), COD (2890.00 mg L^-1), total N (195.80 mg L^-1), Fe (18.48 mg L^-1), Mn (2.88 mg L^-1), total bacteria (6.97×10⁸ CFU ml ^-1), coliform bacteria (3.24×10⁴ MPN 100 ml ^-1) and total fungi (7.78×10⁵ CFU ml ^-1) were found beyond the prescribed limit of Indian irrigation standards. The abattoir effluent irrigation significantly (p<0.05/p<0.01) increased the EC, total N, available P, OC, Ca, Mg, K, Na, Fe, Cd, Cr, Cu, Mn, Zn, total bacteria, coliform bacteria of the soil used for the cultivation of cabbage, lettuce, coriander and spinach in comparison to their respective controls. The most numbers of bacteria (8.67×10⁸ CFU ml^-1), coliform bacteria (7.80×10⁵ MPN 100 ml^-1) and total fungi (9.85×105 CFU ml^-1) were noted in the lettuce after abattoir effluent irrigation. Therefore, the higher contents of heavy metals and microbial population in cabbage, lettuce, coriander and spinach might be related to their contents in the soils irrigated with abattoir effluent. Therefore, the agronomical practices with abattoir effluent should be regularly monitored to avert environmental problems and attendant health hazards.