Rice finding 1555
Source evidence and comparison details for the Rice profile.
Champa rice after harvesting and husking (described as raw white rice in Section 2.3); washed with double-distilled water before analysis · Lead (Pb) · Sample count unreported.
Selected finding and reference
Sample count unreported. 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: 1130 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
- Without WHO GEMS/Food: Limited data.
- Without Cantoral et al. 2024: High.
- Without TatahMentan et al. 2020: Limited data.
These checks show dependence on each sampling family; they are not confidence intervals.
Collection period
2021
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Lordegan
Reported growing area.
Sampling, analysis and reporting limits
Washed, oven-dried 110-120 °C, ashed at 151 °C (as printed), 1 g extracted with 4 M HNO3 at 95 °C; Varian 710-ES ICP atomic emission (ICP-OES).
No non-detects reported; LOD not reported
Source inconsistency noted (does not affect this value): reported mean 1.1265 mg/kg lies far outside the reported min-max 0.0200-0.2100 mg/kg, and the CV 0.501 is inconsistent with SD 0.0634/mean 1.1265 (0.056); the text says Lordegan Pb is about 7 times the 0.15 mg/kg Iranian limit (~1.05), which matches the mean but not the range. Either the mean or the
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 |
|---|---|---|
| mean | Pb Lordegan Mean 1.1265 Std. Deviation 0.0634 | mg/kg x 1000 |
Original SD: 0.0634 mg/kg.
Table 1, p.581.
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) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | ≤2.5 | ≤5 | 32 |
| Alternative weighting | ≤2.5 | ≤5 | 32 |
7 reference units; 3 sampling families. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| WHO GEMS/Food | 4 | 33% |
| Cantoral et al. 2024 | 1 | 33% |
| TatahMentan et al. 2020 | 2 | 33% |
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.