Yakubu and Yola 2020 - Kano aluminium-utensil foundry metals

Yakubu and Yola measured Zn, Mn, Cd, Cr, and Pb in soil and nearby borehole water around local aluminium-utensil production in Bachirawa, Kano. This is not utensil migration or finished-product occurrence evidence: it is source-attribution evidence for environmental metal loading around informal aluminium-utensil foundry activity.

Key numbers

The study collected three soil samples labeled A, B, and C from local aluminium-utensil production sites and two borehole-water samples labeled D and E from boreholes 50 m away from the project site.

Table 1 reports site A soil at 18 cm depth, in mg/kg:

Table 2 reports site B soil at 18 cm depth, in mg/kg:

Table 3 reports site C soil at 18 cm depth, in mg/kg:

Table 4 reports water-sample concentrations in mg/l and the WHO guideline values printed by the authors:

The abstract summarizes soil ranges as Zn 1158.13-11117.80 mg/kg, Mn 285.719-1809.672 mg/kg, Cd 0.026-0.540 mg/kg, Cr 0.498-0.832 mg/kg, and Pb 42.54-285.53 mg/kg. The table value for site A Pb is 285.59 mg/kg, so the table value is used in the table above and the abstract range is treated as rounded or mistyped.

The conclusion states that foundry activities are sources of environmental pollution in Bachirawa foundry market, with soil metal concentrations decreasing in the order Zn > Mn > Pb > Cd > Cr. The authors also state that Cd and Mn in both water samples and Pb in site E water were above the cited permissible limits.

Methods (brief)

Soil samples were dried, ground, sieved through 2 mm mesh, and digested with concentrated HNO3 and 70% HClO4 on a hot plate until the digest turned white. Water samples were acidified with nitric, hydrochloric, and perchloric acid, digested on a hot plate, filtered, and transferred to 100 ml plastic bottles. Metals were measured by atomic absorption spectrophotometer, model AAS 240 FSAA. Pollution index was calculated as the ratio of metal concentration in the site soil to metal concentration in a control soil.

Implications

Certification: Do not use these soil or borehole-water values as metal-utensil product occurrence or migration data. They document the environmental burden around local utensil-production activity, not consumer exposure from a finished utensil.

Courses: Strong source-attribution case for informal metal-product manufacturing. The paper connects a consumer-product supply-chain activity with local soil and water contamination signals.

App: Context only. The source can support shared-liability/source-attribution narrative for metal loading around local aluminium-utensil production, but it cannot rank utensils or estimate metal release into food.

Wiki pages this source may touch

• source-attribution-environmental-burden-apportionment
• atmospheric-deposition
• lead
• cadmium
• chromium
• manganese
• zinc

Verification notes

Recovered from skip:not-food-occurrence under the 2026-06-10 inclusion-by-default rule. The old skip treated the paper as out of scope because it lacked utensil-product migration data. On reading, it is in-scope a3 source-attribution evidence because it measures environmental metals around local aluminium-utensil production.

Numbers were checked against the extracted PDF text, especially the abstract, soil/water sampling methods, Tables 1-5, discussion, and conclusion. Chromium is total Cr; no Cr(VI) is reported. The paper does not measure aluminium despite its aluminium-utensil production setting, and no finished utensil or food-contact values are inferred.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.