Rice finding 498
Source evidence and comparison details for the Rice profile.
Paddy rice · Total arsenic (tAs) · Sample count unreported.
Selected finding and reference
Sample count unreported. Basis: unspecified.
no non-detects reported for this cell; source does not describe non-detect handling
HMI baseline position
Moderate · HMI uncooked-grain tAs reference · 1 sampling family. Individual sample as reported: 230 µg/kg. HMI median 245; Q1 220; Q3 270 µg/kg. 1 family. 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.
Collection period
2019
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Punta de Bombom district
Sampling site within one study.
Sampling, analysis and reporting limits
Grinding to flour, microwave-assisted HNO3 digestion (CEM MARS6), HR-ICP-MS (Thermo ELEMENT2) for Cd114, Sn118, Pb208 (medium resolution) and As75 (high resolution, total As); total Hg by CVAAS (EPA SW 846 7471B).
no non-detects reported for this cell; source does not describe non-detect handling
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 |
|---|---|---|
| sample_value | (0.23 +/- 0.03) mg kg-1 | mg/kg x 1000 |
Original SD: 0.03 mg kg-1.
Section 3.3, p.6 (Fig. 4 text).
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 tAs reference · 1 sampling family. 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 | 220 | 245 | 270 |
| Alternative weighting | 220 | 245 | 270 |
4 reference units; 1 sampling family. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| Román-Ochoa et al. 2021 | 4 | 100% |
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. This is the only compatible family for this scope in the completed rice ledger; a single-family reference cannot represent other markets. 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-paddy-rice-grain-with-hull-tAs:e538e172d8f6
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.