Rice finding 342

Source evidence and comparison details for the Rice profile.

K. et al. 2017

Packed rice as sold (milling form not stated) · Total arsenic (tAs) · 30 rice samples (triplicate analyses).

Selected finding and reference

93 µg/kg (mean ± 9 SD)Mean.

30 rice samples (triplicate analyses). Basis: unspecified; samples oven-dried (80 C 2 h, then 105 C 6 h) before dry ashing for Cd/Pb, so values are likely dry-weight but the paper does not state the reporting basis.

No non-detects reported; LOD Cd 1, Pb 7, As 10 ug/kg; treatment of values below LOD not described

HMI baseline position

Low · HMI uncooked-grain tAs reference · 16 sampling families. Mean as reported: 93 µg/kg. HMI median 139–140 (bounded); Q1 110; Q3 230 µg/kg. 16 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: Low. The position is unchanged under this alternative. This check does not address all sampling, rounding or analytical uncertainty.

Sensitivity to source selection

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

Mazandaran

Reported growing area.

Sampling, analysis and reporting limits

Dry ashing (550 C) and HNO3 for Cd/Pb by graphite-furnace AAS (Varian AA-1275); HNO3 wet digestion for As by hydride-generation AAS.

No non-detects reported; LOD Cd 1, Pb 7, As 10 ug/kg; treatment of values below LOD not described

Source inconsistency noted (does not affect this value): Table 1 EDIs back-calculated give As Mazandaran 92, Gilan 101, Pakistani 187, Indian 136 ug/kg; text says the maximum was Indian 0.188 mg/kg, but Table 1 implies the 0.188 value belongs to Pakistani rice (possible label swap). Gilan and Pakistani As means are printed only as Figure 3 bars.

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
meanand Mazandaran rice 0.093±0.009 mg/kg, respectivelymg/kg x 1000

Original SD: 0.009 mg/kg.

Results 'Arsenic' paragraph, p.252; Figure 3.

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 uncooked-grain tAs reference · 16 sampling families. Uncooked grain as analysed (native or unstated moisture), µg/kg. Distribution of subgroup median concentration values.

Reference (µg/kg)Q1MedianQ3
Primary HMI reference110139–140 (bounded)230
Alternative weighting110139–140 (bounded)230

102 reference units; 16 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing familyReference unitsWeight
Alrashdi et al. (2024)66%
WHO GEMS/Food496%
Authors 201636%
Clair-Caliot et al. 202116%
EFSA 200926%
Gama et al. 202516%
Implications 2023116%
Limmer et al. 202616%
Liu et al. 202226%
Lockwood et al. 2023116%
A.A. et al. 200856%
Moreda-Pineiro et al. 202036%
Sim et al. 202416%
U.S. 202126%
Zavala et al. 200836%
Wheat et al. 202416%

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-native-tAs:1784506f9277

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.