Rice finding 1207

Source evidence and comparison details for the Rice profile.

Rittirong et al. 2018

Raw white rice grain (milled), three brands grown in central Thailand · Total chromium (Cr) · 3 rice brands (3); 20 cooking combinations.

Selected finding and reference

270 µg/kg (mean ± 30 SD)Mean.

3 rice brands (3); 20 cooking combinations. Basis: dry weight (raw grain oven-dried at 65 C for 48 h, then milled).

No non-detects reported; instrument detection limit 20 ng/L in digest solution (900 ng/L Fe), not converted to a mass-basis LOD by the source.

HMI baseline position

High · HMI dry-grain Cr reference · 1 sampling family. Mean as reported: 270 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: High. The position is unchanged under this alternative. This check does not address all sampling, rounding or analytical uncertainty.

Reference, contributing evidence and methods

Collection period

Collection date unreported

No year-by-year sample register is reconstructed from this summary.

Geographic scope

Raw Rice

Purchase or reporting market; growing origin not identified.

Sampling, analysis and reporting limits

HNO3 hot-plate digestion (95 C); ICP-MS (Agilent 7500a/7500c).

No non-detects reported; instrument detection limit 20 ng/L in digest solution (900 ng/L Fe), not converted to a mass-basis LOD by the source.

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 statisticOriginal resultDisplayed unit conversion
meanRaw Rice ... 0.27±0.03 (Cr)mg/kg x 1000

Original SD: 0.03 mg/kg.

Table 4, row 'Raw Rice'; p.377.

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)Q1MedianQ3
Primary HMI reference345567
Alternative weighting345567

5 reference units; 1 sampling family. Counts describe evidence units, not independent studies or certainty.

Contributing familyReference unitsWeight
Myat Soe et al. (2023)5100%

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.