Taghavi et al. 2023 - trace elements in saffron-cultivation soils
Taghavi and colleagues measured trace elements in agricultural soils used for saffron cultivation in Gonabad County, Iran. This is upstream supply-chain evidence: it reports the soil reservoir and soil-exposure indices that can inform saffron-origin contamination context, but it does not measure saffron stigmas or finished spice. The page therefore treats the values as soil-to-crop pathway context, not as saffron occurrence data.
Key numbers
The study sampled 16 saffron farmlands and reported trace-element concentrations in mg/kg dry weight. Table 3 gives average soil concentrations of Cd 0.102 mg/kg, Co 6.968 mg/kg, Cr 22.550 mg/kg, Cu 29.263 mg/kg, Mn 457.281 mg/kg, Ni 34.234 mg/kg, Pb 13.617 mg/kg, Zn 54.482 mg/kg, and Fe 19,683.6 mg/kg.
Table 3 gives observed ranges of Cd 0.072-0.14 mg/kg, Co 6.194-8.185 mg/kg, Cr 20.25-25.91 mg/kg, Cu 24.325-35.895 mg/kg, Mn 371.441-516.136 mg/kg, Ni 32.027-37.743 mg/kg, Pb 11.628-15.527 mg/kg, Zn 35.469-99.827 mg/kg, and Fe 14,254.5-24,005.2 mg/kg. The local Gonabad background values used for pollution-index calculations were Cd 0.409 mg/kg, Co 9.13 mg/kg, Cr 41.88 mg/kg, Cu 40.34 mg/kg, Mn 546.704 mg/kg, Ni 20.3 mg/kg, Pb 20.08 mg/kg, Zn 92.99 mg/kg, and Fe 17,963.1 mg/kg.
The authors report soil pH values ranging from 7.2 to 7.9, described as neutral to sub-alkaline. They compared soil results with FAO/WHO and Iranian agricultural-soil standards and concluded that the sampled soils were safe for agricultural purposes in terms of the measured trace elements.
For non-carcinogenic soil-exposure risk, Table 6 reports summed hazard indices of 6.97E-02 for adults and 4.38E-01 for children, both below 1. The route contribution order was ingestion > inhalation > skin contact for both subpopulations.
For carcinogenic soil-exposure risk, Table 7 reports adult total cancer risk values of Cd 6.90E-10, Cr 1.66E-05, Pb 1.65E-07, and Ni 9.14E-05. Child total cancer risk values were Cd 5.42E-09, Cr 1.52E-04, Pb 1.54E-06, and Ni 5.82E-05.
For soil pollution indices, mean contamination-factor values decreased in the order Ni 1.68, Mn 0.83, Co 0.76, Fe 0.73, Cu 0.72, Pb 0.67, Zn 0.58, Cr 0.53, Cd 0.24. The authors state that CF values for Ni and Zn exceeded 1 in 100% and 6.25% of the farmlands, respectively. Mean enrichment-factor values were Cd 0.34, Co 1.04, Cr 0.74, Cu 1, Mn 1.15, Ni 2.32, Pb 0.93, Zn 0.80, and Fe 1.
Methods (brief)
Composite soil samples were collected from 16 saffron farms in Gonabad County, with background samples from three control sites with no farming or human activity. Soil was air-dried, oven-dried at 80 degrees C for 72 h, ground, homogenized, sieved through 2 mm mesh, and digested with HNO3/HCl at 1/3 before filtration through 0.45 µm cellulose acetate. Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe were measured by ICP-OES. The reported LOQs were Cd 0.001 mg/kg, Co 0.007 mg/kg, Cr 0.001 mg/kg, Cu 0.005 mg/kg, Mn 0.001 mg/kg, Ni 0.05 mg/kg, Pb 0.07 mg/kg, Zn 0.003 mg/kg, and Fe 0.003 mg/kg; recovery values were Cd 94.5%, Co 93.5%, Cr 95.4%, Cu 109.8%, Mn 98.5%, Ni 97.5%, Pb 79.8%, and Zn 98.1%.
Implications
Certification: This source does not contribute saffron, spice, infant-formula, or other product occurrence values. It contributes upstream soil context for saffron supply-chain assessment, especially Ni enrichment and multi-element soil-exposure indices in an Iranian saffron-growing area.
Courses: This is a useful case study for supplier and sourcing audiences because the auto-fetched filename suggested infant formula, while the PDF actually reports saffron-cultivation soils. It demonstrates why recovery ingest must read the PDF and route by actual matrix rather than query label.
App: Context only. The soil values should not populate a saffron or spice contamination profile without crop-transfer or measured saffron data.
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Verification notes
Recovered from skip:not-food-occurrence under the 2026-06-10 inclusion-by-default rule. The old skip reason was too narrow because the paper measures agricultural soil used for a consumable crop’s cultivation; it is in scope as a3 supply-chain source/pathway evidence.
All key numbers were checked against the extracted PDF text, especially Tables 3, 6, and 7 and the pollution-index prose. The paper reports soil values only; no saffron stigma, spice, infant-formula, or finished-product concentrations were found in extracted text. Products and ingredients are intentionally empty, and the soil numbers must not enter HMTc occurrence or threshold pools.
The extracted prose contains an apparent typo saying lead concentrations had median 34.234 mg/kg; Table 3 shows the Pb average as 13.617 mg/kg and 34.234 mg/kg as the Ni average. This page follows Table 3.
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.