Rice finding 1834
Source evidence and comparison details for the Rice profile.
Polished white rice · Inorganic arsenic (iAs) · 1180 rice samples.
Selected finding and reference
Basis: Freeze-dried grain. Reported ranges include results below detection. Abstract reports <2 µg/kg while methods give LOD 3 µg/kg; retain that discrepancy.
Source-reported range: <2–399 µg/kg; censoring is retained as reported.
HMI baseline position
Low · HMI dry-grain iAs reference · 8 sampling families. Median as reported: 66 µg/kg. HMI median 96; Q1 70; Q3 106 µg/kg. 8 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: Low. The position is unchanged under this alternative. This check does not address all sampling, rounding or analytical uncertainty.
Sensitivity to source selection
- Without FDA rice survey (2013): Low.
- Without Carey et al. (2020): Low.
- Without WHO GEMS/Food: Low.
- Without Houlihan et al. 2025: Low.
- Without Meharg et al. 2009: Low.
- Without Navaretnam et al. 2025: Low.
- Without Signes-Pastor et al. 2016: Low.
- Without Welna et al. 2018: Low.
These checks show dependence on each sampling family; they are not confidence intervals.
Collection period
Collection period not reported
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Global · 29 sampling zones
Locally produced market rice.
Sampling, analysis and reporting limits
IC-ICP-MS; NIST 1568b rice-flour CRM.
Reported ranges include results below detection. Abstract reports <2 µg/kg while methods give LOD 3 µg/kg; retain that discrepancy.
Accessible retailers and unequal regional sampling; historical survey, without population weighting. Recovered regional medians enter the HMI summary layer; the withdrawn atmospheric column is excluded. Regional counts differ from the reported overall total.
Shared samples and study overlap
Possible shared sampling with Shi 2020; separate analytes do not create independent grain samples.
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 | 66 µg/kg (median) | No conversion |
Abstract; Rice Sample Collection; Sample Preparation; Chemical Analysis; Results; January 2020 correction.
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 dry-grain iAs reference · 8 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 70 | 96 | 106 |
| Alternative weighting | 70 | 96 | 106 |
74 reference units; 8 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| FDA rice survey (2013) | 8 | 13% |
| Carey et al. (2020) | 29 | 12% |
| WHO GEMS/Food | 2 | 13% |
| Houlihan et al. 2025 | 16 | 13% |
| Meharg et al. 2009 | 4 | 13% |
| Navaretnam et al. 2025 | 1 | 13% |
| Signes-Pastor et al. 2016 | 13 | 12% |
| Welna et al. 2018 | 1 | 13% |
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
- FDA rice survey (2013)
- Carey et al. (2020)
- WHO GEMS/Food
- Houlihan et al. 2025
- Meharg et al. 2009
- Navaretnam et al. 2025
- Signes-Pastor et al. 2016
- Welna et al. 2018
Reference version and interpretation
Frozen evidence selection: 2026-10-22. Method: hmi-pooled-reference-v2.
hmi-pooled-reference-v2:rice-dry-iAs:f14ec1f869e4
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.