Health risk assessment of instant noodles commonly consumed in Port Harcourt, Nigeria

Overview

Charles and colleagues measured lead (Pb), arsenic (As), nickel (Ni), mercury (Hg), Cu, cadmium (Cd), aluminum (Al), and chromium (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 inorganic arsenic (iAs), methylmercury (MeHg), or hexavalent chromium (Cr-VI) speciation.

Key numbers

Table 2 reports heavy metal concentrations in selected noodle samples (mg/kg, mean ± SD, n = 3):

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.

Related evidence

• Noodles
• Wheat
• Pasta (wheat-based)
• Other grain products (oat, millet, quinoa, barley)
• Lead
• Arsenic, Total
• Nickel
• Mercury, Total
• Copper
• Cadmium
• Aluminum
• Chromium

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git.