Distribution of heavy metals in vegetables and soils collected from Bangalore city region: a case study

Abstract Heavy metal contamination of agricultural products poses a significant threat to public health in rapidly urbanizing regions. This study investigated the concentrations of cadmium (Cd), chromium (Cr), lead (Pb), and nickel (Ni) in agricultural soils and four commonly consumed vegetables (tomato, spinach, carrot, cabbage) from four sites (Hosakote, Nelamangala, Attibele, Malavalli) around Bangalore, India. Samples were digested using nitric acid and analyzed via Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Results revealed that leafy vegetables, particularly spinach, were the highest accumulators of all metals studied. Notably, Cr concentrations in spinach from Nelamangala reached 44.6 mg/kg, and Pb in spinach from Hosakote was 37.75 mg/kg, values that significantly exceed FAO/WHO safety limits. A poor correlation between soil and vegetable metal concentrations suggests that atmospheric deposition and contaminated irrigation water may be more significant contamination pathways than soil uptake alone. These findings highlight a serious, location-specific health risk associated with vegetable consumption in the Bangalore region and underscore the urgent need for source-specific pollution control and targeted food safety monitoring.