Rice finding 1465

Source evidence and comparison details for the Rice profile.

Mari et al. 2016

Rice grain (form not stated; commercially available, produced in Iran) · Lead (Pb) · 1 one rice sample per market (3 markets), each analysed in triplicate.

Selected finding and reference

314 µg/kg (individual sample ± 25.4 SD)Individual sample.

1 one rice sample per market (3 markets), each analysed in triplicate. Basis: as analysed after washing and oven-drying at 50 C for 2 h (paper does not label results dry or fresh weight).

no non-detect for rice; n.d. used elsewhere in Table 4 without a numeric bound

HMI baseline position

High · HMI uncooked-grain Pb reference · 10 sampling families. Individual sample as reported: 314 µg/kg. HMI median 25; Q1 10–15.5 (bounded); Q3 54.5–64.5 (bounded) µg/kg. 10 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: 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

Local market no. 3

Purchase or reporting market; growing origin not identified.

Sampling, analysis and reporting limits

dry ashing at 500 C, HNO3/H2O2 dissolution, DLLME-SFO with DDTP, GFAAS (Analytik Jena novAA 400).

no non-detect for rice; n.d. used elsewhere in Table 4 without a numeric bound

Source inconsistency noted (does not affect this value): reported sample concentrations (55-320 ug/kg) exceed the stated linear calibration range of 0.1-50 ug/kg and no dilution step is described; value is the mean +/- SD of triplicate analyses of a single market sample, not a between-sample statistic.

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
sample_value314 ± 25.4none (reported in ug/kg)

Original SD: 25.4 ug/kg.

Table 4, local market 3, Rice, Pb, Added '-', pp. 279-280.

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 Pb reference · 10 sampling families. Uncooked grain as analysed (native or unstated moisture), µg/kg. Distribution of subgroup median concentration values.

Reference (µg/kg)Q1MedianQ3
Primary HMI reference10–15.5 (bounded)2554.5–64.5 (bounded)
Alternative weighting10–15.5 (bounded)2554.5–64.5 (bounded)

82 reference units; 10 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing familyReference unitsWeight
Myat Soe et al. (2023)510%
Alrashdi et al. (2024)610%
WHO GEMS/Food4110%
Mari et al. 2016310%
Authors 2016310%
Bazie et al. 2022510%
Gama et al. 2025110%
Ibrahim et al. 2024110%
Lockwood et al. 20231110%
Yan et al. (2025)610%

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-Pb:4a9266cf68b5

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.