Charles et al. 2017 — Metals and PAHs in instant noodles from Port Harcourt
Charles and colleagues measured Pb, As, Ni, Hg, Cu, Cd, Al, and Cr in six instant-noodle brands commonly consumed in Port Harcourt, Nigeria, and also measured PAHs. The paper reports coded brand identifiers; this page reports aggregate ranges and coded-brand counts rather than pairing identifiers with values. Pb, Ni, Cu, Al, and Cr were detected, while As, Hg, and Cd were not detected in the noodle samples. Arsenic, mercury, and chromium are reported only as total analytes, with no iAs, MeHg, or Cr-VI speciation.
Key numbers
Table 2 reports heavy metal concentrations in selected noodle samples (mg/kg, mean ± SD, n = 3):
| Metal/species | Detection summary | Aggregate range, mg/kg | Source comparator |
|---|---|---|---|
| Pb | Detected in 4 of 6 coded brands | ND to 3.163 ± 0.21; detected values ranged 0.043 ± 0.15 to 3.163 ± 0.21 | WHO standard 0.025 |
| tAs | Not detected in all 6 coded brands | ND | WHO standard 0.015 |
| Ni | Detected in 3 of 6 coded brands | ND to 0.354 ± 0.20 | WHO standard 1.00 |
| tHg | Not detected in all 6 coded brands | ND | WHO standard 0.005 |
| Cu | Detected in all 6 coded brands | 0.021 ± 0.01 to 0.119 ± 0.10 | NA |
| Cd | Not detected in all 6 coded brands | ND | WHO standard 0.003 |
| Al | Detected in all 6 coded brands | 0.014 ± 0.11 to 0.237 ± 0.11 | WHO standard 0.237 |
| Cr | Detected in 4 of 6 coded brands | ND to 2.421 ± 0.71; detected values ranged 0.041 ± 0.11 to 2.421 ± 0.71 | WHO standard 0.050 |
Additional source-reported values:
- Table 3 reports Pb THQ values above 1 in two coded brands: 4.91 and 1.59.
- Table 4 reports HI values above 1 in the same two coded brands: 5.004 and 1.680.
- Table 5 reports one coded brand with Cr carcinogenic risk
66E-3, marked as above the permissible range. - Table 6 reports total PAHs ranging from 0.564 ± 0.61 to 7.889 ± 0.73 mg/kg and carcinogenic PAHs ranging from 0.564 ± 0.61 to 5.615 ± 0.93 mg/kg.
- The risk model used adult noodle intake of 0.310 kg/person/day, exposure frequency of 365 days/year, exposure duration of 70 years, average African adult body weight of 60 kg, and a 70-year averaging time for carcinogenic effects.
Methods (brief)
The authors selected six high-growth instant-noodle brands that together represented over 70% share of noodles sold in Nigeria, then purchased samples from retail shops across Port Harcourt metropolis. Noodle samples were dried at 105 degrees C for 24 hours, ground to powder, and 5 g portions were dry-ashed in crucibles with concentrated nitric acid as ashing aid in a muffle furnace up to 550 degrees C for 4 hours. Ash was cooled, rinsed with 1 M nitric acid, filtered, diluted to 25 mL, and analyzed by Varian AA 280 atomic absorption spectrophotometry. PAHs were extracted with dichloromethane and analyzed by gas chromatography. The paper reports total elements only.
Implications
This source contributes Nigeria-market instant-noodle occurrence evidence for Pb, total Cr, Cu, Ni, Al, and non-detect context for total As, total Hg, and Cd. It is useful for processed non-rice grain and wheat-based noodle routing, especially because the source reports both concentration and risk-screening tables. The coded-brand structure and the public nature of noodle brands require brand-firewalled reporting; later extraction should preserve sample coding only if internal systems need it, not as public brand ranking. Total As, total Hg, and total Cr should not be used as iAs, MeHg, or Cr-VI evidence.
Wiki pages this source may touch
- noodles
- wheat
- pasta-wheat-based
- other-grain-products
- lead
- arsenic-total
- nickel
- mercury-total
- copper
- cadmium
- aluminum
- chromium
Verification notes
- PDF text extracted with
pdftotext -layout; the extracted text contained the title/DOI page, methods, Tables 1-6, discussion, conclusion, and open-access license statement. - DOI verified from the PDF title page and metadata as
10.1007/s11356-017-0583-0; DOI, raw-handle, and cite-key checks found no existing source page before creation. - Table 2 concentration ranges, Table 3 THQ values, Table 4 HI values, Table 5 carcinogenic-risk flag, and Table 6 PAH ranges were checked against the extracted text. Units are preserved as
mg/kgandkg/person/day; no conversions were performed. - Speciation: arsenic is total As, mercury is total Hg, and chromium is total Cr. The source does not report iAs, MeHg, or Cr-VI.
- Brand firewall: the source uses coded brand identifiers, but this page reports aggregate ranges and coded-brand counts only. No public brand names are paired with contamination values.
- 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.
| Commit | Date | Description |
|---|---|---|
| 0e2ae2d | 2026-06-08 | STOPPED EARLY — no claimable auto-fetched PDFs |