Shearston et al. 2024 — Metal(loid)s in tampons
Shearston et al. measured 16 metal(loid)s in disposable tampons using microwave-acid digestion and ICP-MS. The study tested duplicate subsamples from 30 tampons representing 24 brand-product line-absorbency combinations. All assessed metals were detected in at least one sample, and several HMTc-relevant analytes were detected in every tampon sample.
Key numbers
Table 2 reports tampon concentrations in ng/g. Lead was detected above the method detection limit in 60/60 samples, with a median of 173 ng/g, 25th to 75th percentile range of 50.8 to 215 ng/g, maximum of 468 ng/g, geometric mean of 120 ng/g, and geometric standard deviation of 2.24.
Cadmium was detected in 60/60 samples, with a median of 9.63 ng/g, 25th to 75th percentile range of 2.48 to 15.1 ng/g, maximum of 56.1 ng/g, geometric mean of 6.74 ng/g, and geometric standard deviation of 2.67.
Arsenic was detected above the method detection limit in 57/60 samples, with a median of 2.30 ng/g, 25th to 75th percentile range of 1.69 to 3.70 ng/g, maximum of 14.1 ng/g, geometric mean of 2.56 ng/g, and geometric standard deviation of 2.02. The paper reports total arsenic, not inorganic arsenic.
Other reported medians were 75.6 ng/g for Ni, less than the detection limit for Cr because only 6/60 samples exceeded the MDL, less than the detection limit for Hg because only 5/60 samples exceeded the MDL, 71.3 ng/g for Cu, 2,100 ng/g for Fe, 369 ng/g for Mn, 11.5 ng/g for Se, and 65,000 ng/g for Zn.
The authors report higher lead concentrations in non-organic tampons than organic tampons and lower Cd, Co, and Pb concentrations in EU/UK-purchased tampons than US-purchased tampons. They did not identify a product category with consistently lower concentrations across all or most metals.
Methods (brief)
The study digested approximately 0.2 to 0.3 g from each tampon and measured As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr, V, and Zn by ICP-MS. Duplicate subsamples were prepared from each tampon. Concentrations below the MDL were handled with machine-read values for descriptive statistics. Speciation was not performed, so arsenic is total arsenic and mercury is total mercury.
Implications
Certification: This is direct occurrence evidence for the menstrual-tampon product category. The values are product-as-sold concentrations in ng/g, equivalent to µg/kg, and should not be converted into exposure without a separate leaching or absorption model.
Courses: The source is useful for explaining why product-presence data and bioavailability data are different evidence layers.
App: The source supports a tampon category evidence card for Pb, Cd, tAs, Ni, Cr, and tHg, with clear flags that Cr and Hg were mostly below detection and that As/Hg are total species.
Microbiome: Not applicable.
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Verification notes
The PDF is an author manuscript of the final Environment International article. The DOI, authors, journal, and year are visible on the first page. The source names brands in Table 1, but this page intentionally reports only category-level and study-level statistics under the brand firewall. The source does not speciate arsenic or mercury.
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 |
|---|---|---|
| 4039d20 | 2026-06-10 | scope: broaden ingest to the full upstream+downstream literature (marine, atmospheric, attribution, exposure, toxicology) — inclusion is the default |