Coghlan et al. 2015 - Heavy Metals in Traditional Chinese Medicine Products
Coghlan et al. combined DNA sequencing, toxicological screening, and heavy-metal screening to audit 26 traditional Chinese medicine products. The heavy-metal component screened 25 products for arsenic, lead, and cadmium by sector-field ICP-MS and compared estimated daily exposures from package dosage directions against Australian TGA medicine limits. The paper is direct finished-product evidence for dietary-supplement/herbal-remedy contamination, not for brewed herbal tea or botanical infusions.
Key numbers
| Finding | Source-reported value |
|---|---|
| Products audited | 26 TCM products |
| Products screened for heavy metals | 25; one aqueous product could not be analyzed by SF-ICP-MS |
| Metals emphasized | Arsenic, lead, cadmium |
| Products with at least one of As/Pb/Cd | 20 of 25 screened products |
| Products with all three As/Pb/Cd | 11 products |
| Regulatory comparison | TGA daily intake limits for a 60 kg person: arsenic 1.2 ug/day, lead 2.2 ug/day, cadmium 0.22 ug/day |
| Highest qualitative flag | One non-listed TCM sample was marked “much greater than 10 times” the arsenic daily limit |
| Overall audit result | 92% of examined TCMs had some form of contamination and/or substitution across DNA, toxicology, and heavy-metal screening |
Table 3 reports heavy-metal results as exceedance bands rather than exact concentrations in the article body: + at or below two times the TGA limit, ++ greater than two times, +++ greater than ten times, and ++++ much greater than ten times. The source states that raw SF-ICP-MS ppm results are in supplementary Table S4; those exact values were not present in the extracted article body.
Methods (brief)
Sixteen heavy metals were determined under ultra-trace clean conditions using sector-field ICP-MS (Thermo Fisher Scientific ELEMENT XR). Samples were mixed with an indium internal standard and introduced by autosampler under metal-free conditions. Instrumental blanks, full procedural blanks, replicates, and quality-control standards were run throughout. Heavy-metal non-compliance was evaluated against TGA threshold daily intake values for lead, cadmium, and arsenic using product dosage instructions.
Implications
For the dietary-supplements product page, this source provides high-relevance evidence that traditional Chinese medicine products can contain arsenic, lead, and cadmium at levels exceeding medicine daily-intake limits. It should not be routed as brewed herbal infusion occurrence evidence unless a later source identifies the exact product form as an infusion. The article body supports qualitative and regulatory-exceedance claims; exact concentration extraction requires the supplementary Table S4 raw ppm data.
For brand-firewall purposes, the source’s TCM sample numbers are sufficient. The wiki should not reproduce consumer product names from the audited medicines.
Wiki pages this source may touch
Verification notes
- Batch 1 auto-fetched ingest, 2026-05-25. The wishlist query targeted herbal/botanical infusions, but the actual PDF is a traditional Chinese medicine product audit. Ingested under the actual paper scope and routed to dietary supplements rather than tea/infusion product rows.
- Evidence fitness: direct finished-product supplement evidence, but the article body reports exceedance bands for Table 3. Exact concentration values are pending supplementary-table extraction.
- Brand firewall: TCM product identifiers are kept as numbered samples only.
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.