Abdulrasheed et al. 2026 — Toxic metals in informally manufactured Nigerian cookware

Abdulrasheed and colleagues measured Mn, Pb, Cr, Cd, and Ni in informally manufactured cookware from Saki, southwest Nigeria, along with moulding inputs and site soils. The paper is direct product evidence for metal-alloy cookware composition and supply-chain evidence for informal manufacturing inputs. Its leaching test found no detectable metals in boiled-water leachates, so the total cookware concentrations should not be treated as the amount transferred to food.

Key numbers

• Four cookware samples had mean metal concentrations of Mn 375 +/- 461 mg/kg, Cr 26.9 +/- 23.9 mg/kg, Cd 1.70 +/- 2.50 mg/kg, Pb 136 +/- 201 mg/kg, and Ni 181 +/- 265 mg/kg.
• Sample-level cookware Pb ranged from 18.4 +/- 0.9 to 439 +/- 12 mg/kg. Cd ranged from 0.30 +/- 0.01 to 5.45 +/- 0.15 mg/kg. Ni ranged from 33.3 +/- 1.5 to 578 +/- 18 mg/kg.
• The highest cookware sample also had Mn 1064 +/- 32 mg/kg, Cr 62.2 +/- 1.8 mg/kg, Cd 5.45 +/- 0.15 mg/kg, Pb 439 +/- 12 mg/kg, and Ni 578 +/- 18 mg/kg.
• In the neutral-water leaching test, 500 mL distilled water was boiled in cookware for 1, 2, and 3 h; Mn, Cr, Cd, Ni, and Pb were all below the analytical detection limit of 0.01 mg/L, so the paper did not tabulate leachate concentrations.
• Moulding materials showed a wide range of metals: battery material contained Mn 185,388 mg/kg, Cd 11.5 mg/kg, Pb 1004 mg/kg, and Ni 48.5 mg/kg. Clay, sand, ash, and charcoal had lower but detectable Pb values from 6.58 to 28.1 mg/kg.
• Manufacturing-site soils contained Mn 257-1306 mg/kg, Pb 10.7-177 mg/kg, Cr 30.0-95.0 mg/kg, Cd 0.0250-3.88 mg/kg, and Ni 9.90-58.0 mg/kg.

Methods (brief)

The authors clipped cookware fragments, air-dried and sieved soil and moulding materials, digested samples using US EPA Method 3050B, and analyzed Mn, Pb, Cr, Cd, and Ni by flame atomic absorption spectrophotometry. Leaching potential was tested by boiling distilled water in cookware for up to 3 h and analyzing cooled leachates by flame AAS. Chromium was measured as total chromium, not Cr-VI.

Implications

Certification: The source supports a cookware-metal-alloy evidence surface for total product content and informal-manufacturing risk. The below-detection neutral-water leachates mean these data should not be converted directly into food exposure without separate acidic, salty, or food-matrix migration data.

Courses: Useful for supply-chain modules on recycled inputs, lead-acid battery contamination, informal casting, and the difference between total composition and leaching under a specific use condition.

App: Can support product-context warnings that informally manufactured metal cookware may contain elevated Pb, Cd, Ni, and Cr even when short neutral-water boiling tests do not detect leaching.

Wiki pages this source may touch

• cookware-metal-alloy
• lead
• cadmium
• nickel
• chromium
• atomic-absorption-spectroscopy

Verification notes

• DOI, title, authors, year, journal, and license were read from the PDF title page.
• The auto-fetch row labelled this as nonstick-coated cookware, but the source describes informally manufactured iron cookware; routing uses the broader cookware-metal-alloy page.
• Leachates were below detection only for distilled-water boiling. The authors explicitly note that acidic or salty foods could increase metal mobility, so the negative leachate result should not be generalized to all cooking conditions.
• Chromium is total Cr by flame AAS; no Cr-VI value is inferred.

Page history

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