Assessment of Heavy Metal Concentration and Evaluation of Health Risk of Some Vegetables Cultivated in Loumbila Farmland, Burkina Faso

Abstract

Vegetables such as spinach, African eggplant, cabbage, eggplant, okra, chili peppers and tomatoes are found in our everyday foods and are the most important dietary source of nutrient. But, it becomes deleterious to human as well as animals as it accumulates toxic metals in their tissue when grown in contaminated soil. The mostly consumed vegetables like spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato were collected from Loumbila market gardening. Heavy metals copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), cadmium (Cd) and zinc (Zn) were measured using atomic absorption spectrophotometer (AAS) model AANALYST 200 from PERKIN ELMER. The results of this study showed that the concentrations of lead (0.49 to 8.59 mg/kg) and zinc (20.73 to 71.29 mg/kg) in spinach, African eggplant (fruit and leaves), Corchorus olitorius leaf, Amaranthus hybridus leaf, cabbage, eggplant, okra, pepper and tomato exceeded the permissible level of FAO and WHO standard. The daily plant metal intake for Cd (0.001 - 0.015 mg/kg), Pb (0.041 - 0.730 mg/kg), and Cu (0.703 - 1.543 mg/kg) is higher than the recommended daily intake of metals but does not exceed the tolerable limit. The calculated values of the health risk indices show high values for Cd, Pb, Zn, Ni and Cu while low values are observed for Cr. Except for Cr, the IRS evaluated for all the studied metals were greater than one (IRS > 1). This implies that exposed populations are susceptible to developing diseases linked to the following metals: Cd, Pb, Zn, Ni and Cu.