Assessment of Concentration and Potential Health Risks of Heavy Metals in Vegetable Samples Cultivated in Toro Mining Site, Bauchi State Nigeria

Abstract

Study’s Novelty/Excerpt This study evaluates heavy metal contamination in leafy vegetables from a long-term mining area in Toro, Bauchi State, Nigeria, highlighting significant public health risks. The research identifies lead (Pb) concentrations exceeding maximum allowable limits, while other heavy metals remain within safe thresholds. By assessing the non-carcinogenic and carcinogenic risks through Target Hazard Quotient (THQ), Health Risk Index (HRI), and Incremental Lifetime Cancer Risk (ILCR), this study provides critical insights into the potential disease burden from prolonged exposure, emphasizing the need for stringent control measures. Full Abstract Heavy metals are dense metallic elements with significant environmental and health impacts. The risk of exposure to the population from heavy metals in an area that had witnessed long-term mining activities was evaluated in the current study. Leafy vegetable samples from Toro Local Government Area, Bauchi State, Nigeria, were evaluated for the presence of heavy metals using Atomic Absorption Spectrophotometry. The health risks of the evaluated heavy metals in the samples 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). Pb concentration in the samples falls above the Maximum Allowable Concentrations (MAC) of 2.680mg/kg, 0.220mg/kg, 3.670mg/kg, 4.900mg/kg, and 4.280mg/kg for Amaranthus, Onion, Cabbage, Pepper, and Tomato respectively, while Cu, Cr, Co, Fe, Mn, Ni, and Cd were within the permissible values. The results of the Target Hazard Quotient (THQ) associated with the evaluated heavy metals exposure through consumption of vegetables for adults and children were all lower than 1. The combined health risks for all the metals in the sample for the adults and children population represented as HRI were also below 1.0. The result of the Incremental Life Cancer Risk (ILCR) for both the adult and children population revealed that the heavy metals were beyond the threshold safety limit for cancer risk. The consumption of vegetables poses a health risk concern regarding Pb because of its high concentration, and this may contribute to disease burden in the population upon long time exposure, necessitating control measures.