Overview
This greenhouse study characterized arsenic uptake and accumulation in two contrasting vegetable types — a fruit vegetable (bean, Phaseolus vulgaris) and a leafy vegetable (lettuce, Lactuca sativa) — across multiple developmental stages when irrigated with water containing 0.1, 0.25, and 0.5 mg As/L. Lettuce edible parts accumulated As concentrations of 0.30, 0.61, and 1.21 mg/kg DW at the three irrigation treatments respectively, substantially higher than bean fruits (0.008, 0.005, and 0.022 mg/kg DW), and the study found that health risks from As consumption were significant at all applied concentrations in lettuce.
Key numbers
Edible-part As concentrations (mg/kg DW) at irrigation levels of 0.1, 0.25, and 0.5 mg As/L respectively:
- Lettuce (mature): 0.30, 0.61, 1.21
- Bean fruit: 0.008, 0.005, 0.022
Transfer factor (TF = edible part / root):
- Lettuce young stage: 0.09–0.19 (control and 0.1 mg/L treatments)
- Bean flowering stage: 0.09–0.41 (all treatments)
Developmental stage effects:
- Lettuce As accumulation order: young > mature
- Bean As accumulation order: fruiting > young > flowering
The irrigation water threshold for comparison: WHO drinking water guideline 10 µg/L; FAO irrigation water threshold 100 µg/L; Hungarian groundwater geogenic As up to 220 µg/L.
Methods (brief)
Controlled growth chamber experiment (25–27 °C day / 17 °C night; 16 h lighting at 500 µmol/m²/s). Sodium arsenate (Na₂HAsO₄·7H₂O) dissolved in irrigation water. Plant samples digested with HNO₃ and H₂O₂; total As quantified by ICP-MS (Analytik Jena). Certified reference material NIST 1573a (tomato leaf) used for accuracy verification. All As measurements are total As (tAs); no speciation between inorganic and organic As was performed.
Implications
Certification: Lettuce is a high-risk vegetable for As accumulation from contaminated irrigation water; concentrations far exceed safe dietary intake thresholds under typical contaminated-irrigation scenarios. Relevant to supply-chain sourcing requirements for leafy vegetable ingredients.
Courses: Strong illustration of how irrigation water quality drives food-chain As exposure; the fruit-vs-leaf distinction is useful for teaching differential accumulation.
App: Lettuce contamination profile should note irrigation-water-source dependency; bean As is low even under high contamination scenarios.
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Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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 | Change | Description |
|---|---|---|---|
| a8052bb | 2026-08-09 | major | 6 sections added; narrative text revised |