Rice finding 659
Source evidence and comparison details for the Rice profile.
Polished (white) market rice · Cadmium (Cd) · 10 rice samples.
Selected finding and reference
10 rice samples. Basis: freeze-dried grain (dry weight).
Values below the LoD (9.8 ug/kg) were assigned 1/2 LoD = 4.9 ug/kg by the source; earlier-survey values below 4.9 were also set to 4.9. A printed 4.9 is therefore a non-detect bounded 0-9.8 ug/kg, not a measured value.
HMI baseline position
Moderate · HMI dry-grain Cd reference · 9 sampling families. Median as reported: 23.1 µg/kg. HMI median 71; Q1 4.7–9 (bounded); Q3 149 µg/kg. 9 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 Myat Soe et al. (2023): Moderate.
- Without Shi et al. (2020): Moderate.
- Without WHO GEMS/Food: Moderate.
- Without Huang 2023: Moderate.
- Without Li et al. 2022: Moderate.
- Without Qin et al. 2026: Moderate.
- Without Signes-Pastor et al. 2016: Moderate.
- Without TatahMentan et al. 2020: Moderate.
- Without Xie et al. 2026: Moderate.
These checks show dependence on each sampling family; they are not confidence intervals.
Collection period
Collection date unreported
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Bolivia
Purchase or reporting market; growing origin not identified.
Sampling, analysis and reporting limits
Freeze-dried, milled; HNO3/H2O2 microwave digestion (CEM MARS 6); Cd by ICP-MS (Thermo iCAP-Q), Rh internal standard (new batch). Earlier surveys per Williams et al. 2007 and Meharg et al. 2013..
Values below the LoD (9.8 ug/kg) were assigned 1/2 LoD = 4.9 ug/kg by the source; earlier-survey values below 4.9 were also set to 4.9. A printed 4.9 is therefore a non-detect bounded 0-9.8 ug/kg, not a measured value.
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 | Amer. Bolivia n=10 Min 4.9 25% 4.9 Med 23.05 75% 80.95 Max 123.4 Range 118.5 | none |
Table 1, Bolivia row, Med column; p.871.
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 Cd reference · 9 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 4.7–9 (bounded) | 71 | 149 |
| Alternative weighting | 4.7–9 (bounded) | 71 | 149 |
65 reference units; 9 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| Myat Soe et al. (2023) | 5 | 11% |
| Shi et al. (2020) | 32 | 11% |
| WHO GEMS/Food | 1 | 11% |
| Huang 2023 | 3 | 11% |
| Li et al. 2022 | 5 | 11% |
| Qin et al. 2026 | 5 | 11% |
| Signes-Pastor et al. 2016 | 9 | 11% |
| TatahMentan et al. 2020 | 3 | 11% |
| Xie et al. 2026 | 2 | 11% |
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
- Myat Soe et al. (2023)
- Shi et al. (2020)
- WHO GEMS/Food
- Huang 2023
- Li et al. 2022
- Qin et al. 2026
- Signes-Pastor et al. 2016
- TatahMentan et al. 2020
- Xie et al. 2026
Reference version and interpretation
Frozen evidence selection: 2026-10-22. Method: hmi-pooled-reference-v2.
hmi-pooled-reference-v2:rice-dry-Cd:59d3645f9f4f
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.