Omosigho et al. 2025 - Toothpaste heavy metals in Nigeria

Omosigho and colleagues measured cadmium, copper, zinc, manganese, and lead in five toothpaste products sold in Warri, Nigeria. This is direct product-occurrence evidence for toothpaste, with source-reported concentrations in mg/kg and accompanying pH and moisture checks.

Key numbers

Table 2 reports the following heavy-metal concentrations in mg/kg:

The abstract summarizes source-reported ranges as Cd 2.470-2.952 mg/kg, Cu 0.096-5.165 mg/kg, Zn 13.396-24.164 mg/kg, Mn 1.700-3.402 mg/kg, and Pb 4.917-6.113 mg/kg. Table 2 prints sample Q zinc as 12.396 mg/kg, so the table value is preserved here and the abstract range discrepancy is noted.

Table 1 reports pH values of 6.59-7.03 and moisture/volatile content of 3.1-7.4 across the five toothpaste samples.

Methods (brief)

Five toothpaste samples coded M through Q were purchased in Warri, Delta State. pH was measured with a pH meter, moisture and volatile content were determined by the authors’ stated recommended method, and heavy metals were measured by atomic absorption spectrometry after sample preparation described in the methods section.

Implications

Certification: This is direct toothpaste occurrence evidence and can support product-level contamination tracking for personal-care items.

Courses: Useful introductory case for showing that routine consumer personal-care products can carry measurable Pb and Cd burdens even when basic quality parameters such as pH fall within recommended ranges.

App: Context only unless and until the toothpaste product evidence layer is being synthesized.

Wiki pages this source may touch

• toothpaste
• cadmium
• copper
• zinc
• manganese
• lead

Verification notes

Recovered from skip:incomplete-metadata during the 2026-06-11 recovery fire. DOI was not present in the extracted PDF text, but the paper contains direct heavy-metal measurements and is in-scope lane a1 product occurrence evidence.

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.