Rice finding 2393
Source evidence and comparison details for the Rice profile.
Rice grain unspecified (market rice, crushed to powder before digestion) · Inorganic arsenic (iAs) · 2720 rice samples.
Selected finding and reference
2720 rice samples. Basis: unspecified (no drying or moisture correction stated).
Source substitutes LOD/2 for results below LOD (section 2.4); LOD values are not reported. Statistics include those substituted values; minima (and medians/percentiles where the detection rate is below 50%) equal the substitution value, not a measurement.
HMI baseline position
Moderate · HMI uncooked-grain iAs reference · 10 sampling families. Median as reported: 110 µg/kg. HMI median 110; Q1 82.5–84 (bounded); Q3 150 µg/kg. 10 families. Not a safety grade.
Low is below Q1; Moderate includes Q1 through Q3; High is above Q3. Reporting bounds must give the same category throughout.
This finding’s sampling family contributes to the fixed reference.
Sensitivity to weighting
Equal subgroup weight within each family: Moderate. The position is unchanged under this alternative. This check does not address all sampling, rounding or analytical uncertainty.
Sensitivity to source selection
- Without Alrashdi et al. (2024): Moderate.
- Without WHO GEMS/Food: Moderate.
- Without EFSA et al. 2021: Moderate.
- Without Limmer et al. 2026: Moderate.
- Without Liu et al. 2022: Moderate.
- Without Moreda-Pineiro et al. 2020: Moderate.
- Without Sim et al. 2024: Moderate.
- Without Tian et al. 2024: Moderate.
- Without Yan et al. (2025): Moderate.
- Without Zavala et al. 2008: Moderate.
These checks show dependence on each sampling family; they are not confidence intervals.
Collection period
2020–2022
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Rural
Sampling site within one study.
Sampling, analysis and reporting limits
ICP-MS after microwave digestion of 0.3 g powder in 7 mL HNO3 (section 2.2); no arsenic speciation step described.
Source substitutes LOD/2 for results below LOD (section 2.4); LOD values are not reported. Statistics include those substituted values; minima (and medians/percentiles where the detection rate is below 50%) equal the substitution value, not a measurement.
Source inconsistency noted (does not affect this value): species identity (iAs vs total As) is not verifiable from the reported method.
Shared samples and study overlap
Subgroup rows, statistics of the same subgroup and the study total share samples; they are not independent results.
Each table row describes a food/analyte result. Repeated rows do not add independent samples or datasets. No cross-study trend is calculated in this comparison mode.
Reported values, conversion and source locator
| Source statistic | Original result | Displayed unit conversion |
|---|---|---|
| median | Median 0.110 | mg/kg x 1000 |
Table 3 (levels of heavy metals in rice in urban and rural areas of Henan, mg/kg), Rural rows, column As; page 5.
No moisture, cooking-yield or species conversion is applied to the original finding above. Any basis conversion used for its HMI comparison is stated separately with the numerical target.
Open the primary publication · HMI source record
Reference and scope
HMI uncooked-grain iAs reference · 10 sampling families. Uncooked grain as analysed (native or unstated moisture), µg/kg. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 82.5–84 (bounded) | 110 | 150 |
| Alternative weighting | 82.5–84 (bounded) | 110 | 150 |
87 reference units; 10 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| Alrashdi et al. (2024) | 6 | 10% |
| WHO GEMS/Food | 54 | 10% |
| EFSA et al. 2021 | 10 | 10% |
| Limmer et al. 2026 | 1 | 10% |
| Liu et al. 2022 | 2 | 10% |
| Moreda-Pineiro et al. 2020 | 2 | 10% |
| Sim et al. 2024 | 1 | 10% |
| Tian et al. 2024 | 1 | 10% |
| Yan et al. (2025) | 7 | 10% |
| Zavala et al. 2008 | 3 | 10% |
Methods
HMI calculates a pooled distribution of subgroup medians across the admitted sampling families. HMI pools subgroup medians from every compatible rice sampling family in the evidence ledger for this analyte, material and basis: published subgroup medians, medians HMI calculates from printed per-sample values and WHO GEMS/Food region-by-year medians (random sampling only). Each family has equal total weight; subgroups have equal weight within a family. Non-detects stay as zero-to-limit intervals, so quartiles carry lower and upper bounds. Means, ranges and maxima never enter as observations. Dry-weight, native-moisture and cooked results are kept in separate references; no moisture conversion is assumed.
Inverse weighted empirical CDF; midpoint at exact cumulative-weight boundaries. At least four reference units and a definitely positive Q1–Q3 spread are required. This is a display eligibility rule, not statistical validation.
Limitations
An evidence-library reference, not a probability sample of the world rice market. Sampling families differ in frame (retail, farm, contaminated sites, monitoring) and period; GEMS/Food regions are reporting regions, not growing origins. Many submissions are non-detects with differing limits, which widens the bounds. A position is descriptive concentration, not a safety or compliance judgment.
Admitted source families
- Alrashdi et al. (2024)
- WHO GEMS/Food
- EFSA et al. 2021
- Limmer et al. 2026
- Liu et al. 2022
- Moreda-Pineiro et al. 2020
- Sim et al. 2024
- Tian et al. 2024
- Yan et al. (2025)
- Zavala et al. 2008
Reference version and interpretation
Frozen evidence selection: 2026-10-22. Method: hmi-pooled-reference-v2.
hmi-pooled-reference-v2:rice-native-iAs:ac23d7340743
The reference is computed by HMI from admitted evidence, not copied from a study baseline. It describes the evidence currently in this scope; it is not a worldwide or current-lot benchmark. Source, year and region filters do not change it. Different HMI scopes are not one common ranking.