Rice finding 2645

Source evidence and comparison details for the Rice profile.

Liu et al. 2022

Brown rice (husked), field-collected late-season rice, sun-dried · Dimethylarsinic acid (DMA) · 125 cultivars (4 plants pooled per cultivar from one paddy).

Selected finding and reference

20 µg/kg (median)Median.

125 cultivars (4 plants pooled per cultivar from one paddy). Basis: sun-dried brown rice powder; moisture basis not stated (effectively air-dried/dry weight).

No non-detects for tAs/iAs/DMA (detection rate 100%); LOD not reported.

HMI baseline position

Moderate · HMI uncooked-grain DMA reference · 4 sampling families. Median as reported: 20 µg/kg. HMI median 58.6; Q1 20; Q3 100 µg/kg. 4 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 finding’s sampling family contributes to the fixed 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

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

Reference, contributing evidence and methods

Collection period

2020

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

Geographic scope

Hybrid rice

Rice variety or type within one study.

Sampling, analysis and reporting limits

HNO3/H2O2 digestion, ICP-MS (Agilent 7700x) for Cd and tAs; As species by 1% HNO3 extraction and HPLC-ICP-MS (PRP-X100 anion exchange).

No non-detects for tAs/iAs/DMA (detection rate 100%); LOD not reported.

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
medianAverage 0.02 ± 0.02a; Median 0.02mg/kg x 1000

Table 2 (Descriptive statistics of As species in brown rice); p.5.

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 DMA reference · 4 sampling families. Uncooked grain as analysed (native or unstated moisture), µg/kg. Distribution of subgroup median concentration values.

Reference (µg/kg)Q1MedianQ3
Primary HMI reference2058.6100
Alternative weighting2058.6100

11 reference units; 4 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing familyReference unitsWeight
WHO GEMS/Food525%
Liu et al. 2022225%
Sim et al. 2024125%
Zavala et al. 2008325%

Methods

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-DMA:72c9b8f9eec4

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.