Summary
This study assessed exposure to cadmium, lead, total arsenic, and inorganic arsenic from rice collected from the 30 largest rice-producing provinces of Indonesia, using data from the national Total Diet Study framework. As the world’s fourth-largest rice consumer by volume (annual consumption approximately 125 kg per capita in 2023), Indonesia faces particular concern about rice as a source of cadmium, arsenic, and lead intake. The study measured concentrations in raw and cooked rice and estimated dietary exposure for five age groups (infants 0 to 59 months, children 5 to 12 years, adolescents 13 to 18 years, adults 19 to 55 years, and adults over 55 years). Cooking with bottled water reduced cadmium content by 76% and increased lead levels by 1403%, while arsenic levels were unchanged. The margin of exposure (MOE) for lead was below 10,000 for inorganic arsenic, indicating a possible health risk per EFSA CONTAM Panel criteria.
Key numbers
| Measure | Value | Units | Matrix | Source location |
|---|---|---|---|---|
| cadmium (Cd) concentration range | 0 to 136 | µg/kg | Raw rice, all provinces | Abstract |
| lead (Pb) concentration range | 0 to 684 | µg/kg | Raw rice, all provinces | Abstract |
| Total arsenic (As) concentration range | 0 to 609 | µg/kg | Raw rice, all provinces | Abstract |
| inorganic arsenic (iAs) concentration range | 0 to 267 | µg/kg | Raw rice (estimated) | Abstract |
| Codex CXS_193e ML, cadmium (Cd) in rice | 100 | µg/kg | Reference | p. 2 |
| Indonesia SNI ML, cadmium (Cd) in rice | 100 | µg/kg | Reference | p. 2 |
| Indonesia SNI ML, lead (Pb) in rice | 200 | µg/kg | Reference | p. 2 |
| Codex/Indonesia ML, inorganic arsenic (iAs) | 200 | µg/kg | Reference | p. 2 |
| EDI cadmium (Cd) range (all age groups) | 0.134 to 0.248 | µg/kg body weight per day | All age groups | Abstract |
| EDI lead (Pb) range (all age groups) | 0.258 to 0.475 | µg/kg body weight per day | All age groups | Abstract |
| EDI total arsenic (As) range (all age groups) | 0.348 to 0.642 | µg/kg body weight per day | All age groups | Abstract |
| EDI inorganic arsenic (iAs) range (all age groups) | 0.236 to 0.435 | µg/kg body weight per day | All age groups | Abstract |
| lead (Pb) IQ reduction estimate, toddlers | up to 2.59 ± 0.95 | IQ points | Toddlers | Abstract |
| lead (Pb) IQ reduction estimate, children | up to 5.27 ± 1.93 | IQ points | Children | Abstract |
| Effect of cooking on cadmium (Cd) | -76% | percentage reduction | Cooked vs. raw | Abstract |
| Effect of cooking on lead (Pb) | +1403% | percentage increase | Cooked vs. raw | Abstract |
| LOD: cadmium (Cd) | 0.024 | mg/kg | Analytical | p. 5 |
| LOD: lead (Pb) | 0.021 | mg/kg | Analytical | p. 5 |
| LOD: arsenic (As) | 0.03 | mg/kg | Analytical | p. 5 |
| LOQ: cadmium (Cd) | 0.08 | mg/kg | Analytical | p. 5 |
| LOQ: lead (Pb) | 0.07 | mg/kg | Analytical | p. 5 |
| LOQ: arsenic (As) | 0.1 | mg/kg | Analytical | p. 5 |
Methods (brief)
Samples taken from the 30 largest rice-producing provinces in Indonesia (based on 2022 BPS production data). Two cities per province; 1 kg from each location. ICP-MS analysis (Thermo ICAP RQ) with microwave digestion (Milestone Ethos Up). Inorganic arsenic estimated using a linear regression model derived from 13 published paired total arsenic (tAs)/inorganic arsenic (iAs) observations from Asian countries. Cooking method: rice cooker and aluminum steamer, using bottled drinking water. Exposure calculated using Individual Food Consumption Survey data from Ministry of Health Indonesia (SKMI 2014). JECFA PTMI for cadmium: 25 µg/kg body weight per month.
Evidence fitness
This is a national-scale Indonesian study with strong methodological rigor (ICP-MS, national Total Diet Study framework, multi-province sampling from all major producing regions). The cooking experiment finding, that lead increases by 1403% upon cooking with bottled water and cadmium decreases by 76%, is a methodologically important result with direct food safety implications for exposure assessment based on raw rice data alone. The iAs MOE below 10,000 indicates a potential carcinogenic risk signal. The IQ-loss estimates for lead are derived from established dose-response relationships and are relevant to child nutrition policy in high-rice-consumption countries.
Limitations
iAs concentrations estimated from tAs using a regression model, not directly measured; this introduces uncertainty in the iAs exposure estimates. Cooking experiment conducted on only 10 samples from 10 randomly selected provinces. Bottled water used in cooking experiment may not represent typical tap water conditions in Indonesia.
Related evidence
- Dietary heavy-metal exposure
- Rice
- Cadmium
- metals/inorganic-arsenic
- Lead
Update history
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