Rice finding 1727
Source evidence and comparison details for the Rice profile.
Rice grain, edible portion (form not stated) · Nickel (Ni) · 9 field composites (3 rice fields per region x 3 regions; each composite from 5 parts of a field).
Selected finding and reference
9 field composites (3 rice fields per region x 3 regions; each composite from 5 parts of a field). Basis: dry weight.
none reported
HMI baseline position
High · HMI dry-grain Ni reference · 1 sampling family. Mean as reported: 1180 µg/kg. HMI median 349; Q1 305; Q3 376 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: High. 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
Rice grains, all three regions
All samples in the study.
Sampling, analysis and reporting limits
Rinsed with double-distilled water, dried at 70 C, powdered; HNO3/H2O2 wet mineralization at 70 C (Lozano-Rodriguez 1995); Cd, Pb, Ni by GF-AAS (Perkin Elmer AAnalyst 800); Fe by flame AAS.
none reported
Source inconsistency noted (does not affect this value): the sentence is placed after an industrial-region Pb/Cd sentence, but the value matches the all-region mean (the paired Fe figure 37.3 is explicitly 'in all regions'). Wheat Ni 0.96 in the same sentence also equals the all-region mean.
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 | onion bulbs contain more Ni (1.66 mg kg-1) than wheat (0.96 mg kg-1) and rice grains (1.18 mg kg -1) | mg/kg x 1000 |
Results, 'Heavy Metal Concentrations in the Crops', pp.10-11.
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 Ni 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 | 305 | 349 | 376 |
| Alternative weighting | 305 | 349 | 376 |
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-Ni:e91fb60d7d27
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.