Rice finding 1550

Source evidence and comparison details for the Rice profile.

Mahmood et al. 2015

Rice grain unspecified (packed retail rice, milling degree not stated) · Lead (Pb) · 5 rice samples (~250 g), five per brand/type, 10 types; Section 2.1 also says 210 packed rice samples (15-20 kg) were selected from markets.

Selected finding and reference

760 µg/kg (mean ± 190 SD)Mean.

5 rice samples (~250 g), five per brand/type, 10 types; Section 2.1 also says 210 packed rice samples (15-20 kg) were selected from markets. Basis: dry weight.

no non-detects reported; LOD not reported

HMI baseline position

High · HMI dry-grain Pb reference · 3 sampling families. Mean as reported: 760 µg/kg. HMI median ≤5; Q1 ≤2.5; Q3 32 µg/kg. 3 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

2013

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

Geographic scope

Imported Thailand

Rice variety or type within one study.

Sampling, analysis and reporting limits

AOAC 999.11 dry ashing at 450 °C after drying at 105 °C 48 h, 6M HCl, residue in 0.1 M HNO3; flame and graphite furnace AAS (Shimadzu AA-680); triplicate digestion, three readings each.

no non-detects reported; LOD not reported

Source inconsistency noted (does not affect this value): Table 4 EWI rows for Thailand and Abdossalam duplicate the Maryam and Abdossaeid rows exactly, so EWIs for these two types are not derivable from Table 3.

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
mean0.76±0.19Bµg/g x 1000

Original SD: 0.19 µg/g dry weight.

Table 3, row Imported Thailand, column Pb.

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 Pb reference · 3 sampling families. Dry-weight grain, µg/kg dry weight. Distribution of subgroup median concentration values.

Reference (µg/kg)Q1MedianQ3
Primary HMI reference≤2.5≤532
Alternative weighting≤2.5≤532

7 reference units; 3 sampling families. Counts describe evidence units, not independent studies or certainty.

Contributing familyReference unitsWeight
WHO GEMS/Food433%
Cantoral et al. 2024133%
TatahMentan et al. 2020233%

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-dry-Pb:6c0ebd5619fe

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.