Cadmium and Lead Bioaccumulation During Growth Stages Alters Sugar and Vitamin C Content in Dietary Vegetables

Abstract

A field experiment was designed to investigate the effects of cadmium and lead on biomass production, sugar and vitamin C content of dietary vegetables. At seedling stage the reduction magnitudes in biomass production with added cadmium up to 50 mg kg−1 soils were 49–51 % in fenugreek root and 32.2–39.6 % in spinach leaf; while at 40 days after sowing (vegetative growth stage); they were observed as 36.1–47.2 % in spinach root and 17.8–20 % in coriander leaf. Cadmium caused maximum reduction in sugar content (62 %) in radish leaf and vitamin C content (56.4 %) in coriander leaf at seedling stage; whereas, maximum reduction in sugar content (66.7 %) and vitamin C content (59.4 %) was observed in spinach leaf and coriander leaf, respectively, under the combined treatment (Cd 50 mg kg−1 + Pb 500 mg kg−1) at vegetative growth stage. The dietary vegetables enhance their antioxidant activity against metal stress when applied below the critical level, however, dosage of Cd higher than critical level (≥25 mg kg−1 soil in treatments II, III and IX) drastically alters plant growth (stunted), reduced yield as well as dietary contents (sugar and vitamin C) of these important vegetables especially it’s antioxidant content; and the hazardous effect was more visible at higher bioaccumulation of heavy metals during vegetative growth stage. It is concluded that dietary vegetables should be utilized for human consumption before the vegetative growth stage especially in the soils polluted with cadmium and lead in order to minimize the intake of pollutants.