Li et al. 2017 — Cadmium transfer from Jiangsu soils into rice
Li and colleagues studied cadmium transfer through a soil-rice-human chain in southern Jiangsu Province, China. The authors collected 70 paired Indica rice-grain and surface-soil samples, measured Cd and Zn by ICP-MS, and used RIVM in vitro digestion to estimate bioaccessible Cd in rice grain. The source is a supply-chain occurrence paper: rice-grain Cd is the product-facing evidence, while soil chemistry and extractable Cd/Zn are context for predicting rice Cd and bioaccessible rice Cd.
Key numbers
| Finding | Source-reported value |
|---|---|
| Paired samples | 70 rice-grain/soil pairs, 14 from each of five southern Jiangsu areas |
| Rice type | All rice samples were Indica rice |
| Rice-grain Cd rank by area | DS > YF > EH > TC > WT |
| Rice samples above the source-cited 0.2 mg kg-1 staple-rice criterion | DS 100%, YF 42.86%, EH 14.29%, TC 7.14%, WT 0% |
| Total soil Cd range | 0.17 to 10.50 mg kg-1 |
| Mean soil Cd across studied areas | 1.45 mg kg-1 |
| CaCl2-Cd fraction of total soil Cd | 0.40-26.92%, with mean value 9.06% |
| Soil-to-rice transfer fraction | About 14.89% of total Cd concentration in soils transferred from soil to rice grain |
| Soil-to-human bioaccessible fraction via rice | Cd Bio in rice accounted for about 3.19% of total Cd concentration in soil |
| Total rice Cd prediction model | Cd rice grains = 0.167 + 2.547·CaCl2-Cd -0.532·CaCl2-Zn; R2=0.862 |
| Total rice Cd simple model | Y = -0.033 + 2.245X1; R2=0.785, where X1 is CaCl2 extracted Cd concentration in soil |
| Total rice Cd vs bioaccessible rice Cd | Y = 0.13X - 0.0015; R2 = 0.82, p<0.05, where X is total Cd and Y is Cd Bio in rice |
| Bioaccessible rice Cd MLR model 1 | Y = 0.011 + 0.086X1; R2=0.307 |
| Bioaccessible rice Cd MLR model 2 | Y = -0.035 + 0.083X1 - 6.580-5X2; R2=0.511 |
| Bioaccessible rice Cd curve models | Quadratic R2=0.862; cubic R2=0.892; the authors chose the cubic model as best fit |
| Rice-grain concentration table availability | Exact rice-grain Cd concentrations by sample or area were not reported as a readable numeric table in the extracted text |
The rice-grain exceedance percentages are product-facing occurrence evidence for rice-bulk-grain. Soil Cd, CaCl2-extractable Cd/Zn, and regression equations are retained as supply-chain context and should not be entered as product concentration values.
Methods (brief)
The authors collected paired rice grains and 0-15 cm soils from Yifeng, Dingshu, Ehu, Wangting, and Taicang in southern Jiangsu Province. Soil samples were air-dried, ground, and sieved; rice grains were oven-dried at 105 deg C for 1 h and then at 70 deg C to constant weight, ground, and sieved. Rice samples were digested with HClO4 and HNO3 for 6 hours, and Cd/Zn concentrations were determined by ICP-MS (XSERIES, Thermo Electron). CaCl2-extractable Cd and Zn were obtained with 0.01 M CaCl2 shaken for 16 hours at a 10:1 solution-to-soil ratio. Cd bioaccessibility in rice grain was measured with the RIVM in vitro digestion model. QA/QC used certified reference materials GBW10010 for rice plants and GBW07442, GBW07443, GBW07402, GBW07403, GBW07404, and GBW07406 for soils; recoveries were 93-105% for GSB-1 and 95-105% for the soil CRMs, with replicate relative difference below 5%.
Implications
This source supports rice-bulk-grain cadmium routing for a Chinese contaminated-soil supply-chain setting. It provides an unusually explicit bridge between soil phytoavailable Cd, total rice-grain Cd, and bioaccessible rice Cd, but the source page should keep those compartments separate: soil numbers describe the field environment, rice exceedance percentages describe the edible product, and RIVM outputs describe digestive bioaccessibility. Because the extracted text does not provide a clean sample-level or area-level numeric rice Cd table, downstream pooling should use this paper cautiously unless the formatted final article or figure data are retrieved.
Verification notes
- PDF text extracted with
pdftotext -layout; the accepted-manuscript text, methods, soil Table 1, regression Tables 2-4, and Results prose were readable. - DOI verified from the accepted-manuscript cover and running headers as
10.1039/C6EM00631K; DOI, raw handleMFK_li2017, and cite-key checks found no existing source page before creation. - All numbers above were checked against the extracted abstract, sampling/methods text, Results sections 3.1-3.5, and Tables 1-4.
- Units are preserved as reported (
mg kg-1, percentages, R2 values); no dry-weight to wet-weight or food-basis conversion was performed. - Speciation: cadmium is reported as Cd; no arsenic, mercury, or chromium speciation issue applies.
- Rice occurrence vs soil context: soil Cd and CaCl2-extractable values are not product concentration values. This page routes to rice because the source reports rice-grain Cd exceedance percentages and rice-grain Cd models from paired soil/rice sampling.
- Exact sample-level or area-mean rice Cd concentrations were not cleanly available in the extracted text; the page therefore does not invent or visually estimate them from figures.
- Frontmatter product and ingredient slugs were checked against
docs/gpt-collaboration/taxonomy-snapshot.md; no new product or ingredient slug was invented.
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 |
|---|---|---|
| e038a80 | 2026-07-02 | feat(index): category SECTION pages + lean directory (Examine hierarchy) |