Heavy metals in food databaseRice, grains and beansChecked 2026.10.03
Wheat: cadmium, arsenic, lead
In a MAFF survey (2012–14 crops, 1,800 samples), cadmium in domestic wheat averaged 0.05 and peaked at 0.50 mg/kg. About 17% of the cadmium taken in from agricultural products is estimated to come from wheat (rice is about 46%). Total arsenic and lead were mostly below the limit of quantification.
Levels measured in Japanese government surveys and studies
| Metal | Form / state | Mean | Range / max | Samples | Survey |
|---|---|---|---|---|---|
| Cadmium | Total cadmium, wheat grain (domestic) | 0.05 (median 0.03) | max 0.50 | 1,800 samples | MAFF, 2012–14 crops |
| Arsenic | Total arsenic, wheat (domestic) | 0.009 | max 0.04 | 363 samples (86% below the limit of quantification) | MAFF, fiscal 2003–05 |
| Lead | Total lead, raw wheat (harvested grain) | 0.00–0.02 | max 0.05 | 300 samples (238 below the limit of quantification) | MAFF, fiscal 2003–05 |
| Lead | Total lead, wheat flour | 0.00–0.01 | max 0.01 | 220 samples (219 below the limit of quantification) | MAFF, fiscal 2018–19 |
Units are mg/kg (= ppm). A range such as “0.00–0.02” runs from the mean with samples below the limit of quantification counted as 0 to the mean with them counted at the limit of quantification. Arsenic is total arsenic; no Japanese public survey values were found for inorganic arsenic.
Limits (Japan, international, EU)
| Set by | Limit | Note |
|---|---|---|
| Japan (Food Sanitation Act) | No standard for cadmium, arsenic, or lead | The cadmium standard covers only rice and mineral waters. The Consumer Affairs Agency says that “for foods other than rice, setting a standard would have little reducing effect,” and that it responds with measures at the production stage and surveys of actual levels |
| Codex (international standards) | Cadmium, wheat 0.2 / lead, cereals 0.2 | The cadmium limit for cereals (other than rice and wheat) is 0.1 |
| EU (Regulation 2023/915) | Cadmium, cereals 0.10 (barley and rye 0.050, durum wheat 0.18, wheat germ 0.20) / lead, cereals 0.20 | — |
Good to know
- Cadmium in domestic wheat averages 0.05, with a median of 0.03, a 95th percentile of 0.12, and a maximum of 0.50 mg/kg. MAFF writes that 1.3% exceeded the Codex standard of 0.2. Because Japan has no standard, this is a reference using another country’s yardstick.
- MAFF’s estimate (2016) is that about 46% of the cadmium taken in from agricultural products comes from rice, 17% from wheat, and 11% from soybeans; these three together with potatoes, spinach, onions, and carrots, seven items in all, account for about 90%.
- Total arsenic in wheat averages 0.009 mg/kg, and 86% of samples were below the limit of quantification (0.01). These values are an order of magnitude lower than for rice or seaweed.
- For lead as well, 238 of 300 samples of raw wheat and 219 of 220 samples of wheat flour were below the limit of quantification.
- What was surveyed is domestic wheat. No public survey values were found for heavy metals in imported wheat, and no Japanese public test values showing changes during milling or processing were found.
- For wheat and health (such as the relation to cancer), see the article on wheat flour, which brings together papers and national data. The figures here concern heavy metals only.
Related explainers
Pages for each metal
Sources
- MAFF, “Survey of cadmium in domestic agricultural products (fiscal 2009–14)”
- MAFF, cadmium survey data (attachment, agricultural products, Table 3.3)
- MAFF, “Survey of arsenic contained in food”
- MAFF, “Survey of lead contained in agricultural products”
- Consumer Affairs Agency, “Q&A on cadmium in food”
- MAFF, “International standards for cadmium in food” (Codex)
- EU Regulation 2023/915 (maximum levels for contaminants in food)
Last checked 2026.10.03 (against the original government documents and papers, collected and cross-checked in Gemini Notebook).
Heavy metals occur naturally in soil and the sea, and every food contains small amounts. This page lists facts from government surveys, limits and assessments and from published papers; it does not judge any food as good or bad. Where there is official advice — such as on eating fish during pregnancy — follow it.