Aziz et al. 2021 - Heavy metals in Bangladesh Gracilaria seaweed
Aziz et al. analyzed the nutritional composition and selected heavy metals in Gracilaria tenuistipitata var. liui grown at Nuniachara, Cox’s Bazar, Bangladesh. The paper directly reports Pb, total As, Cr, and Cd on a dry-weight basis for an edible red seaweed consumed locally and considered as a food supplement. All four reported heavy-metal concentrations were below the source’s cited tolerance levels.
Key numbers
| Finding | Source-reported value |
|---|---|
| Matrix | Dried Gracilaria tenuistipitata var. liui |
| Lead | 0.031 mg/kg dry wt. |
| Total arsenic | 0.01 mg/kg dry wt. |
| Chromium | 0.06 mg/kg dry wt. |
| Cadmium | 0.02 mg/kg dry wt. |
| Source-cited tolerance comparators | Pb 0.1 to 0.3 mg/kg; As 0.12 mg/kg; Cr 0.1 mg/kg; Cd 0.2 mg/kg |
| Protein | 25.55 +/- 0.18 percent dry wt. |
| Fiber | 5.65 +/- 0.13 percent dry wt. |
| Lipid | 0.16 +/- 0.03 percent dry wt. |
| Carbohydrate | 45.93 +/- 1.53 percent dry wt. |
| Ash | 10.61 +/- 0.69 percent dry wt. |
Methods (brief)
The authors analyzed sundried Gracilaria grown under an adaptive seaweed cultivation project in coastal Bangladesh. Nutrients, minerals, amino acids, beta-carotene, vitamin C, and heavy metals were measured using standard laboratory methods. The paper reports heavy metals as Pb, As, Cr, and Cd in mg/kg dry weight, without arsenic speciation.
Implications
For seaweed and algae-based supplement pages, this is direct occurrence evidence for a Bangladesh-grown edible red seaweed. It contributes low reported Pb, total As, Cr, and Cd values, but those values are specific to one species and location.
For standards work, the dry-weight basis is explicit. The arsenic value is total arsenic and must not be substituted for inorganic arsenic.
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Verification notes
The abstract and Table IV provide the heavy-metal values. The paper describes the organism as consumed by local communities and evaluated as seafood/food supplement, supporting food/supplement routing rather than environmental-only routing.
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 |
|---|---|---|
| c1aef38 | 2026-06-02 | audit-queue: hamid2021-bacterial-plant-biostimulants-review → audited-promote |