Rice finding 88

Source evidence and comparison details for the Rice profile.

Rahman et al. 2007

Brown rice, non-parboiled (lab-dehulled) · Total arsenic (tAs) · 3 field sampling points (3 per variety, each 2 m2; text says three points in each of two locations, reported n=3).

Selected finding and reference

800 µg/kg (mean ± 100 SD)Mean.

3 field sampling points (3 per variety, each 2 m2; text says three points in each of two locations, reported n=3). Basis: dry weight.

none; all samples above instrumental LOD (stated)

HMI baseline position

High · HMI dry-grain tAs reference · 8 sampling families. Mean as reported: 800 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 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.

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

BRRI dhan28

Rice variety or type within one study.

Sampling, analysis and reporting limits

HNO3 + HClO4 heating-block digestion (0.5 g); total As by flow-injection HG-AAS (Perkin-Elmer AAnalyst 100, FIAS 100) with matrix-matched standards.

none; all samples above instrumental LOD (stated)

Source inconsistency noted (does not affect this value): the Abstract (lines 37-39) states 'parboiled and non-parboiled brown rice of BRRI dhan28 were 0.8±0.1 and 0.5±0.0 ... respectively', the reverse assignment; the Results text and the authors' conclusion (non-parboiled higher) support non-parboiled = 0.8. Also brown rice (0.8) exceeds raw rice with hu

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
meanbrown rice of non-parboiled and parboiled of the rice variety contained 0.8±0.1 and 0.5±0.0 mg of As kg-1 dry weight, respectively (n=3) (Table 4)mg/kg x 1000

Original SD: 0.1 mg kg-1 dry weight.

Results 'Arsenic distribution in fractions of rice grain', manuscript lines 220-222 (Table 4).

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)Q1MedianQ3
Primary HMI reference140186210
Alternative weighting140186210

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

Contributing familyReference unitsWeight
FDA rice survey (2013)813%
Myat Soe et al. (2023)513%
WHO GEMS/Food213%
Meharg et al. 20091012%
TatahMentan et al. 2020313%
Welna et al. 2018113%
Williams et al. 2007213%
Xie et al. 2026113%

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.