Mean levels (dry matter weight) of Pb, Cd and Ni in lettuce were 23, 4.5 and 2.7 ppm, respectively (Beavington 1975). In two districts of West Bengal, India, the mean concentration of Cu was within the safe value recommended by FAO/ WHO but of Pb in all the samples and of Cd & Cr in some of the samples exceed the allowable limit. The study highlighted how there is an increased risk of taking fresh fruits and vegetables (Banerjee et al., 2010).