Shanghai farm samples had lower reported lead and cadmium concentrations under hydroponic cultivation than conventional soil cultivation. The element-specific summaries combine four vegetables, while commodity-specific means combine lead with cadmium; neither split can be reconstructed into commodity-by-element concentrations from the preserved main paper.
Key numbers
| System | Element | Mean µg/kg | Median | Maximum | EDI µg/kg BW/day | THQ | Detected % | Paper exceedance % |
|---|---|---|---|---|---|---|---|---|
| hydroponic | Pb | 4.77 | 3.6 | 13.4 | 0.0192 | 0.00481 | 68.6 | 0 |
| hydroponic | Cd | 0.91 | 0.65 | 5.1 | 0.00367 | 0.00367 | 46.51 | 0 |
| conventional | Pb | 49.1 | 36.4 | 277 | 0.198 | 0.0495 | 79.12 | 1.1 |
| conventional | Cd | 11.5 | 8.48 | 33 | 0.0464 | 0.0464 | 81.32 | 0 |
Commodity-specific combined Pb+Cd means, conventional/hydroponic (µg/kg): lettuce 80.6/5.7; celery 51.3/3.2; cucumber 58.6/6.4; tomato 47.9/5.6. Soil Pb/Cd: 13.02 ± 4.89 / 0.13 ± 0.02 mg/kg; hydroponic irrigation water: 0.036 ± 0.012 / 0.00017 ± 0.00008 mg/L (§3.3).
Methods (brief)
Fresh produce purchased directly from Shanghai farms in 2022–2023, vacuum freeze-dried for analysis. Pb and Cd measured by ICP-MS (Agilent 7500 CX); details refer to an earlier method. Means exclude results below LOQ (§2.5). Exposure model uses 242 g vegetables/day and 60 kg adult body weight. The preserved main PDF does not explicitly reconcile the reported concentration basis with freeze-dried preparation.
Implications
Supports a local cultivation-system comparison and the soil/irrigation pathway. It does not establish commodity-specific Pb or Cd distributions or universal hydroponic safety. Mixed-contaminant hazard indices include pesticides and phthalates; their interpretation remains source-reported.
Evidence Fitness: EF-2 for qualified comparative occurrence; EF-3 for the exposure model. Preserve summary statistics; require commodity-by-element data and basis clarification before narrower row admission.
Wiki pages this source may touch
- Lettuce
- Celery
- Tomato
- Cucumber
- Leafy / Green Vegetables, Other
- Non-Root Vegetables
- Irrigation water and soil amendments as anthropogenic inputs to cropland
- Lead
- Cadmium
Verification notes
Novel matrix labels vegetables and irrigation-water identify produce and environmental water separately. No speciation inferred. Tables govern the pooled means; §3.3 fold-change statements do not consistently reproduce its displayed combined means. Figure/text overlap on PDF p 10 is not a second observation. Supplement Table S 6 is referenced but absent from this preserved PDF. Source-reported legal comparisons are not verified regulatory instruments.
The preserved Library PDF is identified by RPHMI_5; SHA-256 cefb5b37b00cd83762a899dbc904479c63e57baf682c738ae63dc3ffb7d4001a. The byline, year and publication were verified in the PDF. DOI provenance and any publication-date differences are described above. Original access location: https://europepmc.org/api/getPdf?pmcid=PMC11049364. Source-specific numeric observations, context dispositions, row-fit decisions and remaining gaps are preserved in the structured evidence record. No source value was converted across product, soil, water or experimental matrices during ingest.
Update history
No substantive edit history is available in this build. The full commit record is available in git.