Heavy metal contamination and health risks from consumption of 'Kokonte' flour produced by mechanical processing

Heavy metal contamination in foods is a global concern as mechanized processing increasingly replaces traditional methods. This study assessed the contribution of mechanical disk grinding process to heavy metal contamination in kokonte flour, a cassava-based staple in Navrongo, Ghana, and evaluated the associated chronic non-carcinogenic health risks. Flours produced using mortar and pestle (control) and mechanical disk grinders were analyzed for Fe, Zn, Mn, Cu, Pb, and Ni using flame atomic absorption spectrophotometry after aqua regia digestion. Process-related heavy metal enrichment was evaluated using the contamination factor (CF) and pollution load index (PLI), while chronic non-carcinogenic risk was assessed using the hazard quotient (HQ) and hazard index (HI). Concentrations of Fe, Zn, Mn, Cu, Pb, and Ni were higher (P < 0.05) in mechanically ground samples (0.00752-50.63 mg/kg) compared with control (0.003935-37.17 mg/kg). CF values (1.36-1.91) indicated moderate contamination, and a PLI of 1.6 confirmed cumulative effects from disk grinding. All HQ values and the overall HI (0.380) were below 1, suggesting no significant chronic non-carcinogenic health risk. Findings show that the mechanical disk grinding process moderately increases heavy metal levels in kokonte flour and highlight the need for food-grade grinder components, proper maintenance, and monitoring to enhance food safety.