Analysis of Heavy Metals Contents of Green Leafy Vegetables Collected from Selected Sites of National Capital Region, India

The study assesses the presence of heavy metal contamination in green leafy vegetables collected from two polluted areas in the Delhi NCR Region.

For the examination of heavy metals such as Lead, Arsenic, Cadmium and Mercury in vegetables like Onion leaves (Allium cepa L.), mustard leaves (Brassica juncea), and fenugreek leaves (Trigonella foenum-graceum L.), the sample was taken from these places. The analysis was done using a standard method called ICP-MS. Calculations were made to determine the ADI (Average Daily Index), Hazard Quotient (HQ) and Hazard Index (HI).

The average concentration ranges of heavy metals detected in onion, mustard and fenugreek leaves were 1.2 to 24.4, 1.6 to 3.9, 0.002 to 0.979 mg/kg for Lead (Pb), Arsenic (As), Cadmium (Cd) respectively. The outcome reveals that the order of the abundance of metallic elements in onion, fenugreek, and mustard leaves was Pb>As>Cd>Hg. Also, it was found that onion leaves had a higher level of ADI and HQ when compared with mustard and fenugreek leaves. The findings of this study shows that heavy metal levels in vegetables exceeded those permitted by FAO/WHO guidelines.

Therefore, consuming a large number of heavy metals may pose a health risk and disrupt biological processes and biological activities in human being. In order to prevent a significant increase in heavy metal content that may eventually cause a major non-cancer health risk to the consumer of the vegetables, it is advised that the soil and vegetable crop of the research location be periodically monitored.