Unveiling the threat of lead, cadmium, and nickel toxicity in salient commercially grown vegetables in Kolkata, India.

Abstract

Heavy metal (HM) contamination in agricultural crops, particularly vegetables, is a matter of global concern due to its potential health risks to humans. Commercially growing vegetable samples were analyzed for heavy metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for leafy greens and fruit vegetables collected during winter from highly susceptible zones, in the vicinity of Kolkata. ICP-MS is advantageous over Atomic Absorption Spectrometry (AAS) for unparalleled accuracy, efficiency, faster turnaround time, cost-effectiveness, etc. The results revealed that Saturia (Pb, 0.1-0.3 mg/Kg; Cd, 0.1 mg//kg; Ni, 0.1-0.2 mg/Kg) and Dhapa (Pb, 0.2-1.3 mg/Kg; Cd, 0.07-0.2 mg/Kg; Ni, 0.1-0.3 mg/Kg) have shown significantly higher heavy metal accumulation in the edible part of the vegetables. Leafy vegetables such as red spinach, bathua, and coriander have shown much higher accumulation (Pb, 0.1-1.3 mg/Kg; Cd, 0.07-0.2 mg/Kg; Ni, 0.1-0.2) than fruit vegetables in the edible parts, except capsicum from Chelegualia (Pb, 0.11 mg/Kg; Cd, 0.135 mg/Kg; 0.18 mg/Kg). Translocation factor (< 1.5) and bioaccumulation factor (< 1.2) are observed to have lower values for Dhapa, Saturia, Jirangachi, Raghunathpur, and Kulti compared to Chelegualia, Gabtala, and Vogalirampur. The health-risk effect Hazard Index is greatest in Dhapa, Saturia, and Chelegualia regions. Pb in red spinach and mustard in Dhapa had a higher hazard quotient. The study highlights the need for monitoring the regulation of HM contamination in commercially growing belts near Kolkata to ensure food safety and protection of human health. Putative remedial strategies like phytoremediation involving hyperaccumulators, soil amendments like biochar, and microbial mechanisms for diminishing the translocation of HMs to edible commodities are being explored presently.