Rice finding 2458
Source evidence and comparison details for the Rice profile.
Polished (white) rice · Dimethylarsinic acid (DMA) · 10 rice samples (Table 1 per-zone 'No. of values' sum to 1093).
Selected finding and reference
10 rice samples (Table 1 per-zone 'No. of values' sum to 1093). Basis: dry weight (freeze-dried grain).
Source states LoD 3 ug/kg for iAs and DMA (Methods) and '< 2' in Abstract/Results; Table 1 prints numeric values for low results without flagging non-detects.
HMI baseline position
Moderate · HMI dry-grain DMA reference · 3 sampling families. Median as reported: 66 µg/kg. HMI median 55; Q1 31; Q3 84 µg/kg. 3 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 FDA rice survey (2013): Moderate.
- Without Carey et al. (2020): Moderate.
- Without Signes-Pastor et al. 2016: 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
C. Brazil
Reported growing area.
Sampling, analysis and reporting limits
Freeze-dried, ball-milled grain; 1% HNO3 microwave extraction (CEM MARS 6, 95 C), H2O2 oxidation of arsenite to arsenate; IC (Thermo IC5000, AS7 column) coupled to ICP-MS (Thermo iCAP Q, m/z 75, He collision mode).
Source states LoD 3 ug/kg for iAs and DMA (Methods) and '< 2' in Abstract/Results; Table 1 prints numeric values for low results without flagging non-detects.
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 | C. Brazil | DMA | No. of values 10 | Median (ug/kg): 66 | none |
Table 1, C. Brazil, DMA, Median (ug/kg); pp.713-715.
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 DMA reference · 3 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 31 | 55 | 84 |
| Alternative weighting | 31 | 55 | 84 |
46 reference units; 3 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| FDA rice survey (2013) | 8 | 33% |
| Carey et al. (2020) | 29 | 33% |
| Signes-Pastor et al. 2016 | 9 | 33% |
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
Reference version and interpretation
Frozen evidence selection: 2026-10-22. Method: hmi-pooled-reference-v2.
hmi-pooled-reference-v2:rice-dry-DMA:6cd4368d3cb7
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.