Preliminary Assessment of Toxic Metals in Cookware, Moulding Materials and Soils from Manufacturing Sites in Southwest Nigeria, with Evaluation of Cookware Leaching Potential

Abstract Informally manufactured cookware is often associated with elevated levels of toxic metals due to poor quality control and unregulated use of moulding materials. In this study, a preliminary assessment of toxic metal levels in cookware, associated moulding materials, and soils collected from informal cookware manufacturing sites in Saki, southwest Nigeria, with evaluation of cookware leaching potential, was conducted. Samples were acid-digested and analyzed for Mn, Pb,Cr, Cd and Ni using flame atomic absorption spectrophotometry. Cookware leaching potential was evaluated by boiling tap water in pots for 1, 2, and 3 hours, followed by metal analysis of the leachates. Metal concentrations (mg/kg) in cookware samples ranged as follows: Mn (94.0–1,064), Pb (18.4–439), Cr (10.4–60.2), Cd (0.300–5.45), and Ni (33.3–578). Moulding materials showed: Mn (79.2–185,388), Pb (8.35–1,004), Cr (5.78–58.5), Cd (<0.001–11.7), and Ni (0.0250–48.5). Soil samples contained: Mn (257–1,306), Pb (10.7–177), Cr (30.0–95.0), Cd (0.0250–3.88), and Ni (9.90–58.0). Metal concentrations in cookware generally exceeded accepted safety limits. Manganese was particularly predominant in soil and moulding materials, while Pb and Cd were present at levels of concern. However, metal concentrations in all leachate samples were below detection limits, indicating minimal immediate risk of metal release under normal cooking conditions. Despite the negligible leaching observed, the high total metal concentrations in cookware highlights potential long-term risks to public health. These findings underscore the need for regulatory oversight, improved manufacturing practices, and sustainable quality control measures in informal cookware manufacturing to prevent toxic metal exposure and contamination.