Assessment of Lead and Cadmium Residues in Assorted Vegetables Collected from Markets in Monrovia, Liberia

Abstract

Vegetables are considered as important dietary components because they often contain essential vitamins, minerals, and fibers that are protective against chronic diseases. Despite the nutritional importance of vegetables, they are quite susceptible to heavy metals contamination. Vegetable contamination by heavy metals can result into bioaccumulation of these toxic contaminants in body tissues of consumers. The current study, therefore, sought to investigate the levels of some toxic heavy metals (lead and cadmium) in edible vegetables sold in major markets in Monrovia, Liberia. A total of thirty-six vegetable samples belonging to six plant species were randomly sampled from the markets. After sample preparation, flame atomic absorption spectroscopy (FAAS) was used for the determination of heavy metal concentrations. The concentrations of the heavy metals (mg kg-1) ranged as follows: lead (Pb) 0.093-0.470 and cadmium (Cd) 0.042-0.131. The metal levels in the vegetable samples were generally below the FAO/WHO maximum permissible limits, indicating that, at the moment, the tested vegetable samples are safe for human consumption with respect to levels of Pb and Cd. However, considerable attention should be paid to the potential health risk of heavy metals via other exposure pathways and other regions of Liberia.