Levels of Heavy Metals in Some Vegetables and Human Health Risk Assessment in Loumbila Area, Burkina Faso

Contamination by heavy metals of soil, water and agricultural products is currently a major problem of environmental pollution in the world. The consumption of plants contaminated with heavy metals can be the cause of diseases such as cancers, the number of cases of which is only growing. The objective of this study was to determine the concentration of copper (Cu), chromium (Cr), zinc (Zn), lead (Pb), nickel (Ni), and cadmium (Cd) in plants from the vegetable farm of LOUMBILA and the assessment of health risks linked to the consumption of plants. In this paper, the concentration of heavy metal in vegetable was measured using the model AANALYST 200 flame atomic absorption spectrometer from PERKIN ELMER. The level of Zn in the vegetables from Loumbila vegetable farms ranged between 42.95 mg/kg and 78 mg/kg. The concentrations of Zn in the studies vegetables were higher than the permissible levels set by FAO/WHO (20 mg/kg). The concentration Pb in vegetables varied from 1.73 mg/kg to 27.02 mg/kg. All concentrations of Pb in vegetable were higher than the permissible levels set by FAO/WHO (0.3 mg/kg). Daily intake of Ni, Cr and Pb was higher than the MTDI, so consumption of vegetables from Loumbila vegetable farms can lead to health problems related to Ni, Cr and Pb. In vegetables from LOUMBILA, the estimated daily intake decreased in the following order: Zn > Cu > Pb > Ni > Cr. The Hazard index values for carrot, onion, lettuce, green bean and onion leaves were greater than (>) one (1) which indicates that there might be a potential health risk to those consuming these vegetables. The Target Cancer Risk (TCR) analysis also revealed the potential cancer risk induced by Cu, Ni, Zn, Cr and Pb due to the consumption of carrot, onion leaves, onion, lettuce, green bean, and bell pepper because their TCR values were above the threshold.