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Iyabo et al. 2015 — Zn, Cu, Cd, and Pb in staple foods consumed by Ekiti students

Iyabo and colleagues measured zinc, copper, cadmium, and lead in staple foods commonly consumed by university students in Ekiti State, southwest Nigeria. The foods were grouped as cereal/cereal products, legume products, and tuber products, with concentrations reported in mg/kg. The paper reports no arsenic, mercury, chromium, or nickel data.

Key numbers

Table 1 reports heavy metal concentrations in food items in mg/kg:

Food itemZnCuCdPb
Spaghetti3.632.800.160.13
Jollof rice10.05.000.10LT DL
Rice with stew10.94.000.47LT DL
Rice with beans & fish14.712.40.500.30
Palp with milk (Solid)23.03.300.400.20
Wheat with soup39.53.400.200.22
Semovita with soup18.06.900.300.03
Indomine29.45.500.25LT DL
Ordinary palp0.432.400.20LT DL
Semovita11.01.300.200.10
Beans (White)3.481.050.010.01
Beans with plantain25.46.000.280.15
Akara ball34.94.500.070.16
White bean with rice & fish11.04.70LT DL0.20
Moinmoin8.679.480.350.01
Beans with garri13.83.46LT DL0.25
Melon18.92.340.010.10
White beans, rice with palm oil7.224.500.05LT DL
Groundnut14.017.60.260.05
Sweet Beans (Red)23.02.01not reported in tableLT DL
Yam9.254.500.010.03
Pounded Yam With Melon18.18.130.050.05
Amala (Cassava Flour)11.33.840.030.14
Amala (Yam Flour)9.202.15LT DL 0.020.30
Eba With Melon6.103.450.030.30
Fried Cassava (Garri)5.211.07LT DL 0.020.30
Yam With Oil11.52.950.050.30
Yam With Egg16.06.43LT DL0.30
Potato13.00.82not reported in table0.30
Fufu6.261.32not reported in table0.15

Detection limits printed below Table 1:

MetalDetection limit
Cu0.02
Zn0.04
Cd0.0009
Pb0.005

Table 2 reports average levels in mg/kg by food group:

Food groupZn mean +/- SD (range)Cu mean +/- SD (range)Cd mean +/- SD (range)Pb mean +/- SD (range)
Cereals Products (A)16.6 +/- 11.9 (0.43-39.5)4.70 +/- 2.99 (1.30-12.20)0.28 +/- 0.23 (0.06-0.50)0.10 +/- 0.15 (LTDL-0.30)
Legumes products with others (B)16.1 +/- 10.5 (3.48-34.9)5.60 +/- 5.10 (1.05-17.60)0.10 +/- 0.10 (LTDL-0.50)0.10 +/- 0.10 (LTDL-0.25)
Tubers product with others (C)11.1 +/- 5.34 (6.26-18.1)3.70 +/- 3.30 (0.82-8.13)0.02 +/- 0.02 (LTDL-0. 50)0.22 +/- 0.17 (0.03-0.30)

Additional source-reported values:

  • The text states overall Table 1 ranges as Zn 0.43-39.5, Cu 0.82-17.6, Cd LTDL-0.50, and Pb LDTL-0.30 mg/kg.
  • Highest individual-item levels were Zn 39.5 mg/kg in wheat, Cu 17.6 mg/kg in groundnut, and Cd 0.50 mg/kg in rice with beans & fish.
  • The paper states lead was significantly high in yam, Amala (yam and cassava flour), Garri (fried cassava), and potato; Table 1 lists several of those foods at Pb 0.30 mg/kg.
  • Recommended permissible limits printed by the source were Zn 99.0 mg/kg, Cu 40.0 mg/kg, Pb 0.30 mg/kg, and Cd 0.20 mg/kg as set by FAO/WHO (2001).
  • Percentage recoveries were Zn 92.2%, Cu 94.3%, Cd 96.0%, and Pb 98.2%.

Methods (brief)

A questionnaire was administered to 200 volunteered Ekiti State University students to identify commonly consumed staple foods. The identified foods were purchased from food vendors in the research locations, categorized into cereals, legumes, and tubers, air-dried for about 2-3 days, oven-dried at 105 °C for 24 h, and pulverized. One gram of each solid staple food was digested by dry ashing. Zinc, copper, lead, and cadmium were measured by atomic absorption spectrophotometer (AAS, Perkin Elmer Model 2130), and data were compared with FAO/WHO food-standard guideline values.

Implications

This source contributes Nigeria-market occurrence evidence for Zn, Cu, Cd, and Pb in prepared staple-food forms, including rice-containing mixed meals, wheat/noodle products, legume meals, peanut/groundnut, and tuber-based foods. The values are reported as food-item concentrations in mg/kg; the paper does not give a wet/dry basis beyond the stated sample drying protocol, so downstream normalization should preserve this uncertainty. Several entries are mixed meals rather than single ingredients and should be routed by product form rather than silently assigned to one ingredient.

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Verification notes

  • PDF text extracted with pdftotext -layout; Table 1 and Table 2 pages were also rendered from the PDF because several non-detect cells were visually crowded in the text layer.
  • DOI verified from the first page as 10.5539/ijc.v7n1p155; DOI, raw-handle, and cite-key checks found no existing source page before creation.
  • Table 1 values above were checked against the rendered page 157. Units are copied as mg/kg; no conversion was made.
  • LT DL/LTDL is preserved as the source’s less-than-detection-limit label. Blank Cd cells for Sweet Beans (Red), Potato, and Fufu are recorded as not reported in table rather than filled.
  • The source reports Zn, Cu, Cd, and Pb only. It does not report arsenic, mercury, chromium, nickel, inorganic arsenic, methylmercury, or Cr(VI).
  • Frontmatter product and ingredient slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; no new slug was invented.

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.

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97920102026-06-08ingest: garrity1990-mt1-tissue-specific-promoter fresh from MFK/heavy_metals_peptides