Health Risk Assessment of Heavy Metals in a Vegetable Cultivated in a Conflict Zone

Abstract

The health risk to the population from exposure to heavy metals in an area that have witnessed a surge in illegal mining activities, cattle rustling and banditry were evaluated in the current study. Sorel (Hibiscus sabdariffa) leaves sample from Gadirge village, Jibia local Government area, Katsina State, Nigeria was evaluated for the presence of heavy metals using Atomic Absorption Spectrophotometry. The health risks of the evaluated heavy metals in the sample to the population were assessed using the Target Hazard Quotient (THQ) and Health Risk Index (HRI)) to assess the possible non-carcinogenic effect and the Incremental Lifetime Cancer Risk (ILCR) for the cancer risks. The result of the mean concentration values of the evaluated heavy metals Fe, and Pb from the sample falls above the Maximum Allowable Concentrations (MAC) of heavy metals in leafy vegetables. The concentrations of the other metals including Cu, Zn, Ni, Mn and Cd evaluated in the sample were within the permissible values The result of the Target Hazard Quotient (THQ) associated with the evaluated heavy metals exposure through consumption of the sample for adults and children all were below 1, with exception of the THQ for the heavy metal Fe in the adults and children population and for Mn in the children population that were above 1. The combined health risks for all the metals in the sample for the adults and children population represented as the HRI were above 1, the result of the Incremental Lifetime Cancer Risk (ILCR) for both the adult and children population shows that the heavy metal Ni is beyond the threshold of the safety limit for cancer risk. There is a health risk concern from consumption of the vegetable sample as it may add to the disease burden of the population.