Heavy Metals Uptake And Translocation In Root Vegetables Harvested At Mjindi Area Located In Jozini, Kwazulu Natal, South Africa

This study, was conducted to evaluate the uptake of heavy metal from the soil by root vegetables and their translocation within different plant parts. The analysis was conducted using inductive coupled plasma optical emission spectroscopy after nitric acid digestion with microwave assisted method. Sweet potato roots had high uptake of heavy metals with arsenic (22.2 µg g-1), cadmium (19.2 µg g-1) and lead (21.6 µg g-1) compared to other vegetables studied, however carrot roots had higher chromium uptake of 30.8 µg g-1. The total concentrations of the toxic metals (arsenic, cadmium, cobalt, chromium, lead) were found to be higher than permissible limits in soil and edible parts. All nutritious metals (cupper, iron, manganese, nickel, zinc) were detectable in all samples and within permissible limits. Zinc concentration ranged between 20.9 to 40.7 µg g-1 in edible parts of all vegetables studied, with the highest concentration in sweet potatoes and lowest in potatoes. Among all heavy metals studied, cadmium showed high bioaccumulation factor rate which was highest in carrots (0.97) and lowest in sweet potatoes (0.61). Iron showed the lowest bioaccumulation factor rate <0.01 in all root vegetables studied. The presence of these metals in vegetables reveals their potential consumption by humans and thus health effects, thus their continuous assessment is of importance, also prevention measures need to be considered.

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