Palmieri et al. 2020 - mercury in rice
This paper reports mercury measurements in 29 rice samples from Thailand, India, China, and the United States. The source frames the exposure concern as methylmercury in rice, but the analytical method description visible in the paper is ICP-MS with results reported as Hg in ng element/g sample, without a separate chromatographic speciation method. This source page therefore routes the occurrence data as total mercury (tHg) and documents the source’s methylmercury wording as a limitation.
Key numbers
Rice Hg results (Table 1 and results text; ng element/g sample):
| Result | Value |
|---|---|
| Overall range | 0.18-6.01 |
| Highest sample | 6.01, China, “other” rice color |
| Highest Thailand samples in top ten | 4.47, 4.10, 3.73, 3.16, 2.99, 2.98, 2.95 |
| United States control samples in top ten | 3.71 and 2.84 |
| Lowest sample | 0.18, China, “other” rice color |
The authors state that seven of the top ten samples were from Thailand, two were from the United States control set, and none were from India. Eight of the top ten were white rice, one was brown, and one was “other” color.
Methods (brief)
The paper states that 29 rice samples were analyzed for mercury using ICP-MS and concentrations were quantified as ng element/g sample. It does not provide a detailed digestion protocol, LOD/LOQ, certified-reference-material recovery, or chromatographic separation for mercury species in the extracted text. The results table labels the measured analyte as Hg.
Implications
Standards work: This source is a small, exploratory rice Hg occurrence dataset. It is useful as a signal that rice can carry measurable mercury, but it is not strong enough for threshold synthesis without corroborating rice-Hg sources that report method validation and species-specific MeHg data.
Courses: Useful for illustrating the difference between a paper’s exposure narrative and the analytical endpoint actually reported. A source can discuss methylmercury while still only supporting total-Hg routing if it does not document speciation.
App: Route as total mercury in rice grain only. Do not use this source as finished-product evidence for rice-containing baby foods; the paper discusses baby rice foods as exposure context but measured bulk rice samples.
Microbiome: Not addressed directly, though the paper references rice methylmercury literature tied to paddy biogeochemistry.
Wiki pages this source may touch
Verification notes
- Fresh auto-fetch ingest 2026-05-19 from the gap-driven rice-containing mixed-meal total-Hg wishlist. The actual measured matrix is rice grain, so this page routes to rice-bulk-grain rather than mixed meals.
- Speciation discipline: the source repeatedly discusses methylmercury, but the visible method and table support total Hg only. This page uses
tHgand notes the limitation. - The paper provides limited method-validation detail; evidence tier set to B.
- Strict brand firewall: no commercial rice brands are reported in this source page.
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.