Rice finding 2682
Source evidence and comparison details for the Rice profile.
Polished rice · Methylmercury (MeHg) · 6 household rice samples.
Selected finding and reference
6 household rice samples. Basis: unspecified.
no non-detects reported
HMI baseline position
Limited data · HMI uncooked-grain MeHg reference · 2 sampling families. Geometric mean as reported: 7.18 µg/kg. HMI median 1.05–6.15 (bounded); Q1 ≤2.2; Q3 2.2–10 (bounded) µg/kg. 2 families. Reporting bounds prevent a rating.
Reporting bounds or insufficient reference spread prevent a stable Low / Moderate / High classification.
This is an external comparison; the finding does not set the reference.
Sensitivity to weighting
Equal subgroup weight within each family: Limited data. The position remains unresolved under this alternative. This check does not address all sampling, rounding or analytical uncertainty.
Sensitivity to source selection
- Without WHO GEMS/Food: High.
- Without Sarah et al. 2021: Limited data.
These checks show dependence on each sampling family; they are not confidence intervals.
Collection period
2019–2020
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Rice (Wanshan households)
Sampling site within one study.
Sampling, analysis and reporting limits
THg: HNO3 digestion and CVAFS (EPA 1631E), also DMA-80; MeHg: KOH-methanol digestion, solvent extraction, aqueous ethylation GC-CVAFS (EPA 1630); isotopes by MC-ICP-MS.
no non-detects reported
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 |
|---|---|---|
| geometric_mean | 8.57 4.84 7.18 | none |
Table 1, row Rice, MeHg Geomean; p.4.
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 MeHg reference · 2 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 | ≤2.2 | 1.05–6.15 (bounded) | 2.2–10 (bounded) |
| Alternative weighting | ≤2.2 | 1.05–6.15 (bounded) | 2.2–10 (bounded) |
6 reference units; 2 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| WHO GEMS/Food | 1 | 50% |
| Sarah et al. 2021 | 5 | 50% |
Methods
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
Reference version and interpretation
Frozen evidence selection: 2026-10-22. Method: hmi-pooled-reference-v2.
hmi-pooled-reference-v2:rice-native-MeHg:5554533eb7eb
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.