Assessment of Heavy Metal Contamination in Green Leafy Vegetables Grown in Bangalore Urban District of Karnataka

Abstract

Randomly collected waste water, soil and green leafy vegetable samples were from five stations of Bangalore urban district were analysed for the heavy metals namely Cu, Zn, Pb, Cr, Cd and Mn using Atomic absorption spectrophotometer. Present study explains the extent of heavy metal contamination in two leafy vegetables viz., palak (Beta vulgaris) and coriander (Coriandrum sativum). Results showed that, palak leaves contain Cu, Zn, Pb, Cr and Mn in all the sampling points. Cr at S₁, S₂ and S₅ stations crossed safe value limit recommended by FAO/WHO. In coriander leaves Cu, Zn and Mn found in all stations. Pb concentration was exceedingly high in palak (28.43ppm to 149.50ppm) and coriander (54.69ppm to 75.50ppm) in all sampling stations. Cd was detected only at two stations in S₂ (0.81ppm) and S₄ (1.50ppm). Cr was detected at S₁, S₂ and S₃ stations and at S₂ station, Cr content in palak (70.79ppm) and coriander (127.27ppm) was alarmingly exceeding the allowable limit. Cytological studies indicated the formation of anaphase bridge, irregular metaphase, chromosome stickiness, precocious chromosome at anaphase and vagrant chromosomes. Soil samples do not revealed any appreciable increase in the concentration of heavy metals and found within the permissible limits but values were higher than control that shows contamination was mainly due to automobile exhaust, pesticides and industrial exhaust. Pb was detected in all the waste water samples and in S₁ (<0.05PPM) and S₂ (<0.05ppm) traces of Cd was detected. Physico-chemical parameters of waste water were also determined and factors such as pH, EC, TDS and DO found to exceed the drinking and irrigation water standards.

Key Words: Heavy metals, leafy vegetables, palak, coriander, waste water, soil, chromosome.