Heavy metal levels in leafy vegetables from selected markets in Guyana.

Abstract

Leafy vegetables (Brassica oleracea, Brassica chinensis, Basella alba, and Lactuca sativa) from market sites of Regions 3 and 4 in Guyana were tested for Cd, Pb, Cu, Zn, Co, Ni, Mn, and Fe. Results indicate significant differences in elemental concentrations among the vegetables analyzed, with Cd, Co, and Mn exceeding the safe limits in all vegetables, and Pb and Fe exceeding this limit in some vegetables. Cu and Zn did not exceed the safe limits in any of the vegetables. B. chinensis contained higher levels of Cd, Pb, and Co than the other vegetables while B. alba contained the lowest levels of these elements. Concentrations of the other elements varied in the vegetables so that no specific trend was established. A high concentration of some metals in the vegetables analyzed may be attributable to their concentrations in the soils irrigated with mineral-rich water and fertilized with metal-rich compounds. A risk factor exists for consumption of the leafy vegetables.