Rice finding 526

Source evidence and comparison details for the Rice profile.

Anahita et al. 2015

Rice grain, edible portion (form not stated; rinsed, oven-dried 70 C, powdered) · Cadmium (Cd) · 3 field composites (3 rice fields per region x 3 regions; each composite from 5 parts of a field).

Selected finding and reference

30 µg/kg (mean)Mean.

3 field composites (3 rice fields per region x 3 regions; each composite from 5 parts of a field). Basis: dry weight.

No non-detects reported; all means above MDL

HMI baseline position

Moderate · HMI dry-grain Cd reference · 9 sampling families. Mean as reported: 30 µg/kg. HMI median 71; Q1 4.7–9 (bounded); Q3 149 µg/kg. 9 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 Myat Soe et al. (2023): Moderate.
Without Shi et al. (2020): Moderate.
Without WHO GEMS/Food: Moderate.
Without Huang 2023: Moderate.
Without Li et al. 2022: Moderate.
Without Qin et al. 2026: Moderate.
Without Signes-Pastor et al. 2016: Moderate.
Without TatahMentan et al. 2020: Moderate.
Without Xie et al. 2026: Moderate.

These checks show dependence on each sampling family; they are not confidence intervals.

Reference, contributing evidence and methods

Collection period

Collection date unreported

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

Geographic scope

Rice of Natanz

Sampling site within one 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.

No non-detects reported; all means above MDL

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	Rice of Natanz Cd 0.03 e	mg/kg x 1000

Table 3, 'Rice of' block, p.26.

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 Cd reference · 9 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.

Reference (µg/kg)	Q1	Median	Q3
Primary HMI reference	4.7–9 (bounded)	71	149
Alternative weighting	4.7–9 (bounded)	71	149

65 reference units; 9 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing family	Reference units	Weight
Myat Soe et al. (2023)	5	11%
Shi et al. (2020)	32	11%
WHO GEMS/Food	1	11%
Huang 2023	3	11%
Li et al. 2022	5	11%
Qin et al. 2026	5	11%
Signes-Pastor et al. 2016	9	11%
TatahMentan et al. 2020	3	11%
Xie et al. 2026	2	11%

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-Cd:59d3645f9f4f

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.