Overview
This field study measured cadmium, lead, copper, manganese, nickel, zinc, iron, and chromium in leaves, stems, and roots of Brassica juncea grown on an agricultural farm in Brunei Darussalam, alongside soil concentrations before and after harvest. The authors calculated health risk indices (HRI) for adults and children consuming the vegetable. Soil cadmium was 1.3 mg/kg (pre-harvest), near the Canadian Council of Ministers of the Environment guideline of 1.4 mg/kg but below the USEPA ceiling of 3.0 mg/kg, indicating moderately elevated (not severely contaminated) agricultural soil.
Key numbers
Plant tissue concentrations (dry weight, mg/kg), Table 4:
- Cadmium: leaves 4.1 ± 1.7, stems 4.4 ± 0.9, roots 4.2 ± 0.4
- Lead: leaves 4.8 ± 1.9, stems 4.8 ± 1.0, roots 4.4 ± 0.1
- Nickel: leaves 1.3 ± 0.4, stems 1.5 ± 0.2, roots 1.6 ± 0.1
- Copper: leaves 1-3 mg/kg range; Mn and Zn higher in stems
Both cadmium and lead in leaves and stems exceeded FAO/WHO permissible limits for vegetables (Cd 0.1 mg/kg, lead (Pb) 0.3 mg/kg dry weight) by roughly 40-fold and 16-fold respectively.
Health risk index (HRI = estimated daily intake / oral reference dose):
- Cadmium: HRI adults 3.294, children 5.180 (both above 1 - health risk signal)
- Lead: HRI adults 0.279, children 0.439 (below 1 at stated consumption assumptions)
Bioaccumulation factors (BAF = plant/soil) were above 1 for cadmium (Cd) and Pb in leaves and stems, confirming soil-to-plant transfer.
Methods
ICP-OES; n = 15 plant samples per plant part; soil sampled before and after harvest; HRI calculated from consumption assumptions for Brunei adults and children.
Implications
This is a field study from non-severely contaminated agricultural soil producing B. juncea with Cd and Pb far exceeding FAO/WHO vegetable limits. The soil Cd concentration (~1.3 mg/kg) is a moderately elevated background rather than an acute industrial spill. The HRI values above 1 for cadmium reflect high bioaccumulation from this moderately elevated soil, not extreme industrial pollution. These values inform the pathways section of the mustard ingredient page (soil-to-plant transfer under non-industrial agricultural conditions) and demonstrate that even sub-USEPA soil Cd concentrations can produce plant tissue above regulatory thresholds.
Certification: not in HMT&C threshold pools (field study, single-site, non-retail sampling). Mechanism evidence for soil-to-plant Cd and Pb transfer; routes to Cadmium, Lead, Soil-to-plant transfer of heavy metals.
App: No contamination_profile blocks are touched.
Microbiome: Not a focus of this source.
Update history
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