Health risk assessment of heavy metals in pesticide-treated local and hybrid maize using neutron activation analysis

Abstract

This study evaluated the concentration and potential health risks of selected heavy metals in pesticide-treated local and hybrid maize samples using Neutron Activation Analysis (NAA). Elemental concentrations were determined, and health risk indices including Estimated Daily Intake (EDI), Hazard Quotient (HQ), and Hazard Index (HI) were computed to assess non-carcinogenic risks associated with maize consumption. The results revealed the presence of essential and trace elements such as Zn (21.2 ± 3.90 - 45.3 ± 3.90) ppm, Cr (BDL - 0.36 ± 0) ppm, and as (0.024 ± 0 - 0.063 ± 0.012) ppm with varying concentrations across the samples. The EDI (0.000034 - 5.392) (mgkg ^-1day^-1) values of toxic elements were significantly lower than their respective oral reference doses (0.0003 – 1.5). The HQ values for all analyzed elements were less than unity, indicating no significant non-carcinogenic health risk. Similarly, the cumulative Hazard Index (HI) (0.042- 3.5) remained below one, suggesting that combined exposure to multiple metals does not pose a health concern. Although pesticide application slightly influenced elemental concentrations, the values remained within permissible limits recommended by international standards such as the World Health Organization and Food and Agriculture Organization. The findings indicate that consumption of both local and hybrid maize is safe with respect to heavy metal contamination; however, continuous monitoring is recommended to prevent long-term accumulation.