Rice finding 2628
Source evidence and comparison details for the Rice profile.
Market rice (type not separated) · Dimethylarsinic acid (DMA) · 3 market rice samples (788 white) in the database, excluding field survey samples; field survey n per Table 3.5; speciation n=45.
Selected finding and reference
3 market rice samples (788 white) in the database, excluding field survey samples; field survey n per Table 3.5; speciation n=45. Basis: unspecified (market rice as purchased; Aberdeen database tables state no dry/fresh basis).
No non-detects in this row.
HMI baseline position
Moderate · HMI uncooked-grain DMA reference · 4 sampling families. Mean as reported: 70 µg/kg. HMI median 58.6; Q1 20; Q3 100 µg/kg. 4 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 is an external comparison; the finding does not set the 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 WHO GEMS/Food: Moderate.
- Without Liu et al. 2022: Moderate.
- Without Sim et al. 2024: High.
- Without Zavala et al. 2008: 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
purchased UK, origin Italy
Purchase or reporting market; growing origin not identified.
Sampling, analysis and reporting limits
Total arsenic per Williams et al. procedures (not described in this report) with NIST 1568a rice flour CRM; speciation by HPLC-ICP-MS after TFA extraction (Figure 3.4 caption; inorganic = arsenate + arsenite).
No non-detects in this row.
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 |
|---|---|---|
| mean | average 0.07 | mg/kg x 1000 |
Table 3.7, p.21.
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 DMA reference · 4 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 | 20 | 58.6 | 100 |
| Alternative weighting | 20 | 58.6 | 100 |
11 reference units; 4 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| WHO GEMS/Food | 5 | 25% |
| Liu et al. 2022 | 2 | 25% |
| Sim et al. 2024 | 1 | 25% |
| Zavala et al. 2008 | 3 | 25% |
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-DMA:72c9b8f9eec4
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.