Rice finding 63

Source evidence and comparison details for the Rice profile.

Meharg et al. 2009

Polished (white) rice, market · Total arsenic (tAs) · 110 rice samples (63 speciated).

Selected finding and reference

40 µg/kg (median)Median.

110 rice samples (63 speciated). Basis: dry weight.

not reported; no non-detect handling described

HMI baseline position

Low · HMI dry-grain tAs reference · 8 sampling families. Median as reported: 40 µg/kg. HMI median 186; Q1 140; Q3 210 µg/kg. 8 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: Low. The position is unchanged under this alternative. This check does not address all sampling, rounding or analytical uncertainty.

Sensitivity to source selection

Without FDA rice survey (2013): Low.
Without Myat Soe et al. (2023): Low.
Without WHO GEMS/Food: Low.
Without Meharg et al. 2009: Low.
Without TatahMentan et al. 2020: Low.
Without Welna et al. 2018: Low.
Without Williams et al. 2007: Low.
Without Xie et al. 2026: Low.

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

Egypt

Reported growing area.

Sampling, analysis and reporting limits

Total As by ICP-MS; speciation by HPLC-ICP-MS (methods of Williams et al.).

not reported; no non-detect handling described

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
median	N 110; mean 0.05; median 0.04; min 0.01; max 0.58	mg/kg x 1000

Table 1, row 'Egypt', total As columns; p. 1613.

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 tAs reference · 8 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.

Reference (µg/kg)	Q1	Median	Q3
Primary HMI reference	140	186	210
Alternative weighting	140	186	210

32 reference units; 8 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing family	Reference units	Weight
FDA rice survey (2013)	8	13%
Myat Soe et al. (2023)	5	13%
WHO GEMS/Food	2	13%
Meharg et al. 2009	10	12%
TatahMentan et al. 2020	3	13%
Welna et al. 2018	1	13%
Williams et al. 2007	2	13%
Xie et al. 2026	1	13%

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-tAs:d4f75b6c7078

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.