Overview
This peer-reviewed narrative review from Nanjing Agricultural University synthesises the contamination status of arsenic (As), cadmium (Cd), and lead (Pb) across 25+ food categories, drawing on Total Diet Study data from Australia, Brazil, France, Japan, New Zealand, Singapore, and 19 European countries, and assesses dietary intake relative to health-based guidance values. The central finding is that for the general population dietary intake remains generally below JECFA/EFSA guidance values, but vulnerable populations — infants, children, and pregnant women — are at or above those values for iAs and Cd. Mitigation strategies at the agronomic, processing, and supply-chain level are catalogued.
Key numbers
Arsenic — total As in food (Table 1, TDS-aggregated national means):
- Seafood: dried seaweeds 0.114–236 mg/kg tAs (n=953); fish 0.10–62 mg/kg (n=1,409); shellfish/molluscs 0.09–66 mg/kg (n=171)
- Rice 0.002–1.83 mg/kg tAs (n=1,693)
- Cereals (excluding rice) 0.007–0.43 mg/kg (n=410)
- Vegetables 0.001–1.27 mg/kg (n=2,503)
- Mushrooms 0.011–5.79 mg/kg (n=302)
Arsenic — iAs in rice (29-country global survey, 1,180 polished rice samples):
- iAs range: <0.002–0.39 mg/kg
- 0.4% of samples exceeded the EU/Codex maximum level for iAs in polished rice (0.2 mg/kg)
- For infant rice products: 17.6% of the same global survey exceeded the 0.1 mg/kg limit for infants
- South American rice showed relatively high iAs; North American and European rice showed higher DMA proportions than Asian rice
- US rice median tAs 0.25 mg/kg; France 0.28 mg/kg; Egypt 0.04 mg/kg (901 polished samples, 10 countries)
- Hijiki seaweed (Hizikia fusiforme): tAs mean 110 mg/kg, iAs mean 77 mg/kg — a notable iAs outlier in seafood
Cadmium (Table 1, national mean ranges across 19+ countries):
- Shellfish/molluscs: 0.01–4.8 mg/kg (n=7,403) — highest Cd food category
- Cocoa, tea, coffee: 0.0001–1.8 mg/kg (n=3,505)
- Offal (liver/kidney): 0.03–0.5 mg/kg (n=1,406); poultry offal 0.006–0.5 mg/kg (n=1,224)
- Nuts/oilseeds: 0.02–0.1 mg/kg (n=350)
- Vegetables: 0.006–0.1 mg/kg (n=18,183); leafy vegetables accumulate more than root/legume types
- Rice: national means 0.004–0.02 mg/kg (n=2,295); below EU (0.15 mg/kg) and FAO/WHO (0.4 mg/kg) limits at the national mean level, but wide within-country variance (India: 0.005–1.005 mg/kg; China: <0.001–0.74 mg/kg with 2.2% above 0.2 mg/kg)
- Cereals (excluding rice): ND–0.02 mg/kg (n=12,637); wheat 0.009–0.04 mg/kg (n=1,503)
Lead (Table 1, national mean ranges):
- Coffee/tea/cocoa: ND–1.03 mg/kg (n=764) — highest Pb category reported
- Vegetables: ND–0.4 mg/kg (n=13,402)
- Alcoholic beverages: ND–0.38 mg/kg (n=2,304)
- Rice: ND–0.004 mg/kg (n=85) at national means; global survey of 782 market rice (13 countries) found Pb 0.001–0.33 mg/kg; Chinese survey (712 milled rice) found Pb <0.005–0.4 mg/kg with 0.84% above 0.2 mg/kg
- Cereals: ND–0.029 mg/kg (n=5,027)
- Mining-impacted areas of Hunan, China: rice grain median Pb 0.05–0.78 mg/kg (11 sites); e-waste recycling area southeast China: mean rice Pb up to 2.04 mg/kg
Dietary intake (Fig. 2, cross-country summaries):
- Total As dietary intake: 9 µg/day (US) to 258.4 µg/day (Norway); grain-based products contribute 23% of iAs intake in Europe
- Dietary Cd intake: 4.6 µg/day (US) to 34.6 µg/day (Bangladesh); Bangladesh exceeds EFSA TWI of 21.4 µg/day; cereals contribute 26.6–65.4% of Cd intake in Asia vs Europe
- Dietary Pb intake: varies from 1.8 to 35.4 µg/day across countries
Health-based guidance values (Table 2):
- iAs: JECFA BMDL05 3 µg/kg bw/day; EFSA BMDL01 0.3–8 µg/kg bw/day
- Cd: JECFA PTMI 25 µg/kg bw/month; EFSA TWI 2.5 µg/kg bw/week
- Pb: JECFA PTWI withdrawn (no threshold); EFSA BMDL01 0.50 µg/kg bw/day (neurotoxicity); BMDL10 0.63 µg/kg bw/day (chronic kidney disease)
Methods (brief)
Narrative review. Occurrence data in Table 1 are sourced from two large cross-national datasets (references 143 and 144 in the paper, identified as EFSA SCENIHR / GEMS Food databases). iAs data for the 29-country rice survey sourced from Meharg et al. (ref. 36). Dietary intake estimates compiled from national Total Diet Study publications. No primary analytical work; all values are re-analysed secondary data.
Implications
Certification: The review’s Table 1 provides a defensible multinational baseline for As, Cd, and Pb in 25+ food matrices against which HMT&C threshold-setting can be anchored. Key reference points: cocoa Cd to 1.8 mg/kg (raw cocoa bean end); shellfish Cd to 4.8 mg/kg; offal Cd 0.03–0.5 mg/kg; rice iAs 17.6% of global samples exceed the 0.1 mg/kg infant limit. These are literature-reported maximums/ranges, not distributions; they establish ceiling context rather than percentile distributions.
Courses: The iAs/tAs distinction is illustrated concretely: despite seafood having the highest tAs of any category (up to 236 mg/kg in seaweed), it poses lower iAs risk than rice because organoarsenicals dominate. DMMTA emergence in rice (converted to DMA by standard acid extraction, masking its greater cytotoxicity) is flagged as a future analytical concern. Hijiki seaweed is named as an iAs outlier (mean 77 mg/kg iAs) warranting category-specific risk assessment rather than reliance on total As alone.
App: The occurrence table supports per-ingredient risk tier assignments. Cocoa, offal, and shellfish rank highest for Cd; rice and seaweed rank highest for iAs; tea and cocoa contribute the highest Pb among commonly consumed ingredients. The global iAs exceedance rates for rice (0.4% of polished rice above 0.2 mg/kg; 17.6% above 0.1 mg/kg infant threshold) provide app-level probability anchors for rice-derived ingredients in infant products.
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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 |