Heavy Metals and Pathogens in Green Leafy Vegetables

Abstract

Presence of heavy metal and bacterial pathogen in randomly collected samples of green leafy vegetables from agricultural field in and around Rajpura and Patiala city was detected. In palak (Beta vulgaris L), Coriander (Coriandrum sativum) and yellow sarsoo (Brassica campestris) heavy metals Fe, Zn, Cd, Cr and Pb were analyzed by tri-acid digestion method and total bacteria and coliforms were enumerated on TSA (Tryptone Soya Agar) and VRBA (Violet Red Bile Agar) media respectively. The presence of heavy metals was in the order of Fe>Zn>Pb>Cu>Cd. Nearly 16% of samples of palak were showing higher levels of Cd than the permissible limit of 1.5 mg/kg as per Indian Standard of Food Adulteration Act (PFA), 1954. All the samples including palak, coriander and bathua (grown in different plots) and samples of palak, cabbage and yellow sarsoo purchased from the market had Cd within the safe limits. Among all these green leafy vegetables nearly all these were high in Zn, Pb and Fe having crossed the permissible limits of PFA. The safe limits recommended for Pb is 2.5 mg/kg whereas for Zn is 2.5 mg/kg and none of the vegetable samples were in this range. The metal content in vegetables from agricultural areas indicates high levels of soil contamination and there is a potential danger of heavy metal accumulation particularly Pb and Cd in vegetables grown in vicinity of Village Bhappal, Kami-kalan and Bahadurgarh.The result indicates that the consumers are purchasing vegetables with high level of heavy metals (HMs). The total bacterial count in randomly collected samples of palak ranged from 45±17.3 cfu/g to 2.68±0.9l Log cfu/g, in cabbage from 12.7±1.2 cfu/g to 1.05±0.3 Log cfu/g whereas in case of brassica was 26.8±6.4 cfu/g to 1.2±0.08 Log cfu/g which is an indication of improper pre-harvest and post harvest handling.