Rice finding 1191
Source evidence and comparison details for the Rice profile.
Unpolished rice · Total chromium (Cr) · 9 rice samples (each analysed in triplicate).
Selected finding and reference
9 rice samples (each analysed in triplicate). Basis: dry weight (sun-dried, oven-dried 60 °C 2 days; paper refers to mg/kg dry weight).
No non-detects reported; analyte-specific LOD/LOQ only in Table S2 (not in text copy); overall LOD 0.09-35.75 µg/kg, LOQ 0.023-42 µg/kg
HMI baseline position
Moderate · HMI dry-grain Cr reference · 1 sampling family. Mean as reported: 52 µg/kg. HMI median 55; Q1 34; Q3 67 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 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.
Collection period
Collection date unreported
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Pka Am Pun rice (Surin province)
Rice variety or type within one study.
Sampling, analysis and reporting limits
Microwave digestion (HNO3/H2O2, 160 °C) and ICP-MS (Agilent 7900); total As only.
No non-detects reported; analyte-specific LOD/LOQ only in Table S2 (not in text copy); overall LOD 0.09-35.75 µg/kg, LOQ 0.023-42 µg/kg
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 | Cr B 0.052 0.023 (Table 1: Element, Rice variety, Mean (mg kg-1), SD) | mg/kg x 1000 |
Original SD: 0.023 mg/kg.
Table 1 'Concentrations of heavy metals in Thai local rice', p. 31 (manuscript).
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 Cr reference · 1 sampling family. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 34 | 55 | 67 |
| Alternative weighting | 34 | 55 | 67 |
5 reference units; 1 sampling family. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| Myat Soe et al. (2023) | 5 | 100% |
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. 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-dry-Cr:2a59881cf8c5
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.