Rice finding 482
Source evidence and comparison details for the Rice profile.
Rice and rice products (Chongqing monitoring category '大米及其制品'; rice grain not separated from rice products) · Total arsenic (tAs) · 464 food samples (rice and rice products category; 4,900 samples all foods).
Selected finding and reference
464 food samples (rice and rice products category; 4,900 samples all foods). Basis: unspecified (as sold; paper does not state wet/dry basis).
Results <LOD substituted by 1/2 LOD (median bound, MB) and LOD (upper bound, UB) per WHO/EFSA; detection rate for this category 89.87%; LODs across food categories 0.0006-0.0400 mg/kg (not given per category); this value is the median-bound (1/2 LOD substitution) estimate
HMI baseline position
Limited data · HMI uncooked-grain tAs reference · 1 sampling family. Mean as reported: 98.1 µg/kg. HMI median 107; Q1 107; Q3 107 µg/kg. 1 family. Too few reference units.
Only 2 reference unit is available; at least four are required by this descriptive display rule.
This finding’s sampling family contributes to the fixed reference.
Sensitivity to weighting
Equal subgroup weight within each family: Limited data. The position remains unresolved under this alternative. This check does not address all sampling, rounding or analytical uncertainty.
Collection period
2018–2023
No year-by-year sample register is reconstructed from this summary.
Geographic scope
Rice and rice products
All samples in the study.
Sampling, analysis and reporting limits
Total As by hydride-generation AFS (GB 5009.11-2014) or ICP-MS (GB 5009.268-2016); iAs not measured (exposure modelled via iAs:tAs ratios).
Results <LOD substituted by 1/2 LOD (median bound, MB) and LOD (upper bound, UB) per WHO/EFSA; detection rate for this category 89.87%; LODs across food categories 0.0006-0.0400 mg/kg (not given per category); this value is the median-bound (1/2 LOD substitution) estimate
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 | 0.0981 (MB) | mg/kg x 1000 |
Table 2 (Total arsenic levels in food products sold in Chongqing in 2018-2023), row 'Rice and rice products', column mean MB; p.4 of journal PDF.
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 tAs reference · 1 sampling family. Uncooked grain as analysed (native or unstated moisture), µg/kg. Distribution of subgroup median concentration values.
| Reference (µg/kg) | Q1 | Median | Q3 |
|---|---|---|---|
| Primary HMI reference | 107 | 107 | 107 |
| Alternative weighting | 107 | 107 | 107 |
2 reference units; 1 sampling family. Counts describe evidence units, not independent studies or certainty.
| Contributing family | Reference units | Weight |
|---|---|---|
| Dai et al. 2024 | 2 | 100% |
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. This is the only compatible family for this scope in the completed rice ledger; a single-family reference cannot represent other markets. 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-mixed-rice-grain-and-rice-products-tAs:6a84aa38d15e
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.