Moradi et al. 2015 — Total Cd, Pb, Ni, Fe in soils and edible wheat, rice, onion from two Isfahan-province industrial regions (Zarrinshahr, Mobarakeh) and a control (Natanz), with BAF / CLI / EDI / THQ risk indices by GF-AAS and flame AAS

This Iranian soil-to-plant survey quantifies total Cd, Pb, Ni, and Fe in paired topsoil (0–20 cm) and edible crop samples (wheat grain, rice grain, onion bulb) collected from three Isfahan-province regions: Zarrinshahr (6–8 km east of Isfahan Steel Mill Company), Mobarakeh (12–14 km east of Mobarakeh Steel Mill Company), and Natanz (140–150 km from the steel mills; treated as the control region). Twenty-seven paired soil and crop composites (3 crops × 3 regions × 3 field replications) were digested by USEPA Method 3050B (soils) and wet HNO₃/H₂O₂ mineralisation (crops, per Lozano-Rodriguez et al. 1995), then quantified by graphite-furnace AAS (Perkin Elmer AAnalyst 800; Cd, Pb, Ni) and flame AAS (Fe). Mean industrial-region soil concentrations were Cd 1.85, Fe 35 894, Ni 64.5, and Pb 38 mg/kg vs. Natanz Cd 0.54, Fe 15 363, Ni 20, and Pb 19 mg/kg; industrial-region soils exceeded the EU 2000 sludge-soil ceiling for Cd (1.5 mg/kg) and the USEPA 1983 soil limit for Ni (40 mg/kg). Mean industrial-region crop concentrations across the three crops were Cd 0.25, Fe 55.7, Ni 1.80, and Pb 1.79 mg/kg dry weight; the three-crop means exceeded the Codex Alimentarius Commission 2001 maximum permitted concentrations (MPC) for Cd (0.20), Ni (0.6), and Pb (0.3 mg/kg) by 1.25×, 3.0×, and 6.0×. Total estimated daily intake (EDI) of Cd, Ni, and Pb in Zarrinshahr (2.08, 12.61, 14.46 µg/kg bw/day) and Mobarakeh (1.87, 12.37, 14.15) exceeded WHO 1993 TDIs of 1, 5, and 3.6 µg/kg bw/day by approximately 2×, 2.5×, and 4×; total target hazard quotient (THQ) sums for Pb and Cd from the three-crop pathway were greater than 1, indicating non-negligible non-carcinogenic health risk for inhabitants of the two industrial regions. The Natanz control region showed EDIs and THQs below tolerance.

Key numbers

Table 1 — Soil physicochemical properties (page 24, n=3 fields per region)

Range across all studied fields: pH 7.6–7.9; EC 1.3–4.7 dS m⁻¹; OC 5.03–26.5 g kg⁻¹; CEC 13–32 cmol+ kg⁻¹; texture predominantly loam.

Table 2 — Soil heavy-metal concentrations (mg kg⁻¹ dry weight; page 25)

Site LSD with asterisk denotes p < 0.001 between-region difference. Means in a column followed by the same letter are not significantly different at p < 0.05. The text §“Heavy Metal Concentrations in the Soils” (p. 9) summarises the industrial-region soil means as Cd 1.85, Fe 35 894, Ni 64.5, Pb 38 mg/kg, treating Zarrinshahr and Mobarakeh as a pooled industrial group; the Natanz pooled summary is Cd 0.54, Fe 15 363, Ni 20, Pb 19 mg/kg. The Pb values in the three regions (38.3, 37.7, 19.3 mg/kg) all exceed the EU 2000 sludge-soil ceiling of 10 mg/kg cited by the authors (the paper attributes the 10 mg/kg figure to the European Union 2000 Working Document on Sludge; the wiki page reports the figure as the authors cited it; see Verification notes regarding the EU vs. USEPA attribution in the table footer).

Table 3 — Crop edible-portion heavy-metal concentrations (mg kg⁻¹ dry weight; page 26, n=3 fields per crop × region)

Letters within a column denote LSD groupings at p < 0.05 (Duncan-equivalent ANOVA post-hoc). Asterisks on LSD values: *p < 0.05, ***p < 0.001. The text §“Heavy Metal Concentrations in the Crops” (p. 10) provides two parallel pooled summaries:

• Industrial-region three-crop pooled means (Zarrinshahr + Mobarakeh): Cd 0.25, Fe 55.7, Ni 1.80, Pb 1.79 mg/kg dw.
• Natanz three-crop pooled means: Cd 0.05, Fe 12.8, Ni 0.23, Pb 0.24 mg/kg dw.
• Crop-specific pooled-industrial Pb means: wheat grain 2.05, onion bulb 2.01, rice grain 1.31 mg/kg dw (the text uses these three figures).
• Crop-specific pooled-industrial Cd means: wheat grain and onion bulb 0.29 (sic — see Verification notes; Table 3 implies 0.30 wheat / 0.29 onion); rice grain 0.16 mg/kg dw.
• Three-crop pooled-industrial Ni 1.80 and Pb 1.79 are 3.0× and 5.97× the Codex 2001 MPC for cereals (0.6 and 0.3); pooled-industrial Cd 0.30 wheat and 0.29 onion are 1.5× the FAO/WHO 2001 food MPC of 0.20.

Table 4 — Pearson correlation coefficients (r) between soil and crop heavy metals (page 27, n=27)

*Significant at p < 0.01, n = 27. The text (p. 12) reports diagonal same-metal correlations as 0.98 (Fe), 0.95 (Pb), 0.94 (Ni), and 0.97 (Cd); the wiki page tabulates the full 4 × 4 matrix per the table.

Bio-accumulation factor (BAF) — Figure 2 (page 30)

All-sample pooled mean BAF (C_plant / C_soil): Cd 0.116, Pb 0.036, Ni 0.022, Fe 0.001. Descending order: Cd > Pb > Ni > Fe.

Regional Cd BAF means across the three crops: Zarrinshahr 0.136, Mobarakeh 0.130, Natanz 0.081 (text p. 13). Crop-specific BAF readings from Figure 2 (chart-extracted; precision ±0.005):

Wheat and onion are characterised as stronger Cd and Pb accumulators than rice. Reported reference point: Li et al. 2012 Pearl River Estuary rice grain BAFs were Cd 0.206, Pb 0.006, Ni 0.059 (text p. 13).

Table 5 — Estimated daily intake (EDI, µg kg⁻¹ day⁻¹ bw; page 28)

ᵃ TDI, WHO 1993. ᵇ PMTDI, FAO/WHO 2007. EDI computed as (C_metal × W_food) / B_w with C_metal in µg g⁻¹ dry weight, W_food per local Isfahan-region adult consumption (wheat 265 g day⁻¹, rice 187 g day⁻¹, onion 35 g day⁻¹; authors’ local investigation, p. 7), B_w = 60 kg adult.

In Zarrinshahr and Mobarakeh, total EDIs for Cd, Ni, and Pb were ≈ 2×, 2.5×, and 4× the WHO 1993 TDIs respectively; in Natanz all four total EDIs fell well below the tolerable limits. Fe EDIs in both industrial regions were below the FAO/WHO 2007 PMTDI of 800 µg kg⁻¹ day⁻¹ bw. EDI rank-orders by metal in the industrial regions (text p. 14): wheat and onion crops Fe > Pb > Ni > Cd; rice Fe > Ni > Pb > Cd.

Contamination Load Index (CLI) — Figure 3 (page 31)

CLI = C_crop / MPC (Codex Alimentarius 2001 MPCs for crops: Cd 0.2, Ni 0.6, Pb 0.3 mg kg⁻¹). CLI > 1 indicates the crop is contaminated with the metal.

Text-reported regional three-crop mean CLI values (p. 14):

Per-crop CLI extracted from Figure 3 (chart-extracted; precision ±0.2):

All industrial-region crops except rice in Zarrinshahr (Cd CLI ~0.9 < 1) and rice in Mobarakeh (Cd CLI ~0.8 < 1) showed CLI > 1 for all three metals; the Natanz crops sat at CLI < 1 across the board (the wheat Pb chart reading near 1.0 in Figure 3 is the only Natanz value approaching unity).

Target Hazard Quotient (THQ) — Figure 4 not shown, text p. 15

THQ formula (Chien et al. 2002): THQ = (EF × ED × FI × MC) / (RfDo × BW × AT) × 10⁻³.

Parameters: EF = 365 d y⁻¹; ED = 70 y; FI = food ingestion rate (g person⁻¹ d⁻¹); MC = heavy-metal concentration in food (µg g⁻¹); RfDo = oral reference dose (mg kg⁻¹ day⁻¹) = 1E−03 (Cd), 2E−02 (Ni), 7E−01 (Fe), 4E−03 (Pb) per USEPA IRIS 2003/2007 and Nadal et al. 2008; BW = 60 kg adult; AT = 365 × 70 d.

Reported THQ values in Zarrinshahr (p. 15):

• Cd: wheat 1.3, rice 0.64, onion 0.3; sum 2.24.
• Pb: total across the three crops 4.14.
• Ni: total 0.74.
• Fe: total 0.8.

Combined THQ values for Pb and Cd via crops consumption are > 1 in the industrial regions, indicating relatively high non-carcinogenic health risk. The text identifies Pb as the dominant contributor, followed by Cd. The paper does not tabulate per-crop / per-region THQ; the wiki page reports the four sums and the Cd per-crop trio as the text states them.

Method-quality figures (page 6)

• Method detection limits (MDL): Fe 0.15 mg kg⁻¹; Ni 0.0035 mg kg⁻¹; Cd 0.0008 mg kg⁻¹; Pb 0.003 mg kg⁻¹.
• Spike recovery: Cd 96 %, Fe 98 %, Pb 98 %, Ni 97 %.

Local Isfahan-region adult-consumption inputs (text p. 7)

Authors’ local investigation: wheat 265 g day⁻¹, rice 187 g day⁻¹, onion 35 g day⁻¹; adult body weight 60 kg.

Methods (brief)

Study design. Cross-sectional paired soil–crop survey. Two industrial regions (Zarrinshahr, Mobarakeh; 6–8 km and 12–14 km east of the Isfahan Steel Mill Company and Mobarakeh Steel Mill Company, respectively) and one control region (Natanz; 140–150 km from the steel mills). Three crops × three regions × three field replications = 27 paired soil and edible-portion crop samples. Each composite formed from five differing parts of each field.

Soil sampling. Topsoil (0–20 cm) per region per crop field. Air-dried, crushed, and passed through a 2 mm sieve. pH measured in saturation paste; EC measured in saturated extracts; organic C by Walkley–Black; CEC by ammonium acetate; particle size by pipette (Gee & Bauder 1986).

Soil digestion. 1 g of soil + HNO₃ + H₂O₂ per USEPA Method 3050B (1996).

Crop preparation. Edible portions rinsed with double-distilled water, dried at 70 °C, powdered. 1 g of crop powder + 10 mL concentrated HNO₃ + 2 mL H₂O₂ at 70 °C in a hot black digester (Lozano-Rodriguez et al. 1995 wet-mineralisation protocol); diluted to 50 mL with distilled water.

Instrumentation. Graphite-furnace atomic absorption spectrometry (Perkin Elmer AAnalyst 800) for Cd, Pb, and Ni on a dry-weight basis. Flame atomic absorption spectrometry for Fe.

Calibration & QC. Method detection limits: Fe 0.15 mg kg⁻¹, Ni 0.0035, Cd 0.0008, Pb 0.003 mg kg⁻¹. Spike recovery: Cd 96 %, Fe 98 %, Pb 98 %, Ni 97 %. Double-distilled water used throughout. All analyses performed at the central laboratory of Islamic Azad University, Isfahan (Khorasgan) Branch. No certified reference material (CRM) reported; recovery is the sole accuracy control.

Speciation. Total Cd, total Pb, total Ni, total Fe. No As/Hg panel; no species fractionation.

Reporting basis. Crop concentrations on a dry-weight basis (per Methods §“Soil and Crop Analysis”). Risk-assessment EDIs are computed in µg kg⁻¹ bw day⁻¹ using local Isfahan adult consumption (wheat 265, rice 187, onion 35 g day⁻¹) and a 60-kg adult body weight; consumption inputs are stated as raw, not as-consumed, but the paper does not explicitly state a wet-to-dry conversion, so the Table 5 EDIs are best interpreted as derived from the dry-weight crop concentrations and the as-purchased consumption figures (see Verification notes).

Data-analysis indices. Bio-accumulation Factor BAF = C_plant / C_soil. Contamination Load Index CLI = C_crop / MPC, with Codex Alimentarius Commission 2001 MPC values (Cd 0.2, Ni 0.6, Pb 0.3 mg kg⁻¹ for crops). Estimated Daily Intake EDI = (C_heavy_metal × W_food) / B_w with B_w = 60 kg adult. Target Hazard Quotient THQ = (EF × ED × FI × MC) / (RfDo × BW × AT) × 10⁻³ per Chien et al. 2002, with USEPA IRIS RfDo values (Cd 1E−03, Ni 2E−02, Fe 7E−01, Pb 4E−03 mg kg⁻¹ day⁻¹).

Statistics. One-way ANOVA for between-region soil comparison; two-way ANOVA for crop concentrations across regions. Means compared by least-significant-difference (LSD) test at p < 0.05. Pearson correlation between soil and crop heavy-metal concentrations. SAS 9.1 for Windows.

Geographic and exposure context. Isfahan province, central Iran, climate arid (annual precipitation ~110 mm, mean temperature ~16 °C). Prevailing wind west-to-east, with cultivated fields east of the steel mills. Cultivated lands on alluvial plains of the Zayandehrood river in Isfahan; Natanz on young low-level terraces. Major soil types Typic Calciargids, Typic Calcigypsids, Calcic Argigypsids, Typic Torriorthents, Chromic Haplotorrerts, Haplocambids. Regional cultivated areas: wheat ~670 ha, rice ~2000 ha, onion ~50 ha. Regional fertilizer application: urea 300–400 kg ha⁻¹, triple superphosphate 100–150, potassium sulphate 150–200 for wheat and rice; urea 200–250, triple superphosphate 300–350, potassium sulphate 300–350 for onion. Steel mills active for ≈ 40 years at the time of writing. The paper does not state the sampling year.

Implications

This source contributes paired Iranian soil-and-crop occurrence data for total Cd, Pb, Ni, and Fe from two industrial regions (Zarrinshahr, Mobarakeh) downwind of the Isfahan Steel Mill Company and Mobarakeh Steel Mill Company, plus a distant control region (Natanz). Its principal contributions to the wiki evidence pool:

• Bulk wheat-grain Pb occurrence in an Iranian industrial context: 2.00 mg/kg dw (Zarrinshahr), 2.10 (Mobarakeh), 0.29 (Natanz). The industrial-region values are ≈ 7× the Codex Alimentarius 2001 cereal MPC of 0.3 mg/kg; Natanz sits at ≈ 1× MPC. Adds to the upper tail of bulk-grain Pb occurrence data alongside other regional Iranian surveys (Hamadan in Heshmati 2020; Kermanshah in Ataee 2016).
• Bulk rice-grain Pb occurrence: 1.41 mg/kg dw (Zarrinshahr), 1.21 (Mobarakeh), 0.17 (Natanz). Industrial-region values ≈ 4× the Codex MPC. Substantially exceeds the Cao et al. 2010 Jiangsu industrial-zone rice-grain Pb baseline of 0.054 mg/kg cited in the paper’s discussion (p. 11).
• Onion-bulb Pb occurrence: 2.12 mg/kg dw (Zarrinshahr), 1.90 (Mobarakeh), 0.26 (Natanz). Useful upper-tail Pb evidence for the onions ingredient page and the root-tuber-vegetables product page.
• Bulk wheat-grain, rice-grain, and onion-bulb Cd occurrence: industrial-region wheat 0.31 / 0.28, rice 0.17 / 0.15, onion 0.30 / 0.28 mg/kg dw (Zarrinshahr / Mobarakeh); control Natanz 0.06 / 0.03 / 0.05. Wheat and onion industrial-region means exceed the Codex MPC of 0.20 mg/kg by ≈ 1.5×; rice means sit below the MPC but well above Natanz and the Cao et al. 2010 Jiangsu industrial-zone rice-grain Cd baseline of 0.014 mg/kg cited in the paper’s discussion (p. 11). Li et al. 2012 Pearl River Estuary is cited in the source only for rice-grain BAFs (Cd 0.206, Pb 0.006, Ni 0.059), not for mg/kg concentrations.
• Bulk crop Ni occurrence in an Iranian industrial setting: wheat 1.42 / 1.25, rice 1.65 / 1.70, onion 2.05 / 2.65 mg/kg dw in the two industrial regions vs. 0.21 / 0.20 / 0.28 in Natanz. All industrial-region values exceed the Codex MPC of 0.6 mg/kg by ≈ 2–4×. Contributes Ni occurrence data to the metals/nickel evidence pool.
• Soil-to-plant Cd transfer evidence: Cd BAF mean across all samples 0.116, with Cd > Pb > Ni > Fe descending order. Wheat and onion are stronger Cd and Pb accumulators than rice in the industrial regions. Regional Cd BAF (0.136 Zarrinshahr, 0.130 Mobarakeh, 0.081 Natanz) supports the soil-pollution-driven hypothesis: BAF rises modestly in contaminated soils despite the well-documented “dilution” tendency at high soil concentrations.
• Soil–crop Pearson correlation coefficients (n=27, all p < 0.01): diagonal same-metal r-values 0.98 (Fe), 0.95 (Pb), 0.94 (Ni), 0.97 (Cd). Strong soil-to-crop transfer signal for all four metals — useful as a reference for downstream synthesis claims about agricultural-pathway contamination upstream of food.
• Adult exposure burden in industrial-region Iran: total Cd EDI 2.08 / 1.87 µg kg⁻¹ day⁻¹ bw (Zarrinshahr / Mobarakeh) ≈ 2× WHO 1993 TDI of 1; Ni EDI 12.61 / 12.37 ≈ 2.5× TDI of 5; Pb EDI 14.46 / 14.15 ≈ 4× TDI of 3.6. Three-crop combined THQ for Pb (4.14) and Cd (2.24) > 1 in Zarrinshahr, indicating relatively high non-carcinogenic health risk from the cereal-and-onion pathway in industrial-region Isfahan adults.
• Industrial-region soil baselines: pooled industrial Cd 1.85, Fe 35 894, Ni 64.5, Pb 38 mg/kg vs. Natanz 0.54, 15 363, 20, 19 mg/kg. Industrial soils exceed the EU 2000 sludge-soil ceiling for Cd (1.5 mg/kg) and the USEPA 1983 soil ceiling for Ni (40 mg/kg); the authors also report all three regions’ Pb soil values (38.3, 37.7, 19.3) as exceeding a 10 mg/kg ceiling that they attribute to the EU 2000 Working Document on Sludge.
• Methodological reference point: GF-AAS (Perkin Elmer AAnalyst 800) with USEPA 3050B soil digestion and Lozano-Rodriguez 1995 wet-mineralisation crop digestion; MDLs of 0.0008 mg/kg (Cd) and 0.003 mg/kg (Pb); spike recoveries 96–98 %. No CRM-anchored accuracy validation; this is the principal contributor to B-tier evidence grading.

Sample size is small (n = 3 fields per region per crop, n = 27 paired soil–crop composites total). Single-year-unspecified sampling window, adult-only 60-kg single-cohort exposure cohort, three-crop intake aggregation that excludes other dietary sources, lack of CRM-anchored accuracy validation, and the absence of an arsenic or mercury panel limit the paper’s standalone authority; pools with other Iranian and regional vegetable/cereal surveys rather than anchoring any standalone characterisation. The strong soil–crop Pearson correlations and the clear industrial-vs-control gradient (≈ 3–5× concentration jumps across all four metals) make this a defensible point of evidence for the agricultural-pathway contamination mechanism in industrial-region Iran.

Wiki pages this source may touch

• cadmium
• lead
• nickel
• iron
• wheat
• rice
• onions
• cereals
• other-grain-products
• rice-bulk-grain
• root-tuber-vegetables
• codex-cadmium-mls
• epa-iris-cadmium-rfd
• epa-iris-lead-rfd
• efsa-nickel-tdi

Verification notes

• Cite-key choice. moradi2015-iran-isfahan-soil-crops-metals follows the descriptive-suffix convention (first author, year, country, region, sampling scope, analytes). DOI is the canonical identity; cite-key is a human-readable handle. Filesystem handle MFK_moradi2015 preserved from the Manual Fetch Kimi June 1 batch.
• Evidence tier B. Peer-reviewed in Human and Ecological Risk Assessment: An International Journal (Taylor & Francis), accepted 29 Sep 2015. Small sample (n = 3 fields per region per crop; n = 27 paired soil–crop composites), single province (Isfahan), unspecified sampling year, adult-only single-cohort 60-kg exposure assessment, no CRM-anchored accuracy validation (recovery only), and no arsenic or mercury panel. Adequate for industrial-region Iranian baseline contribution, not sufficient for stand-alone A-tier characterisation.
• Paper-internal inconsistency #1 — Pooled industrial soil Cd. §“Heavy Metal Concentrations in the Soils” (p. 9) reports the pooled-industrial soil Cd mean as 1.85 mg/kg, but Table 2 shows Zarrinshahr 1.88 and Mobarakeh 1.82, whose simple mean is 1.85 (matches text). Table 2 row-mean values 1.88 and 1.82 are individually consistent with their own crop-field rows (Zarrinshahr 2.10 / 1.52 / 2.03 → 1.88 ✓; Mobarakeh 1.92 / 1.52 / 2.02 → 1.82 ✓). No discrepancy; reporting both the text-pooled (1.85) and the per-region values (1.88, 1.82).
• Paper-internal inconsistency #2 — Three-crop pooled-industrial Cd in wheat vs. onion. Text (p. 11) reports “the average concentrations of Cd in the wheat grains and onion bulbs were 0.30 and 0.29 mg kg⁻¹, respectively, which are about 1.5 times higher than the permissible values reported by FAO/WHO (2001) for food (i.e., 0.2 mg kg⁻¹).” However Table 3 shows industrial-region wheat Cd as 0.31 (Zarrinshahr) and 0.28 (Mobarakeh) — simple mean 0.295 ≈ 0.30, which matches the text’s wheat figure. Onion Cd as 0.30 (Zarrinshahr) and 0.28 (Mobarakeh) — simple mean 0.29, which matches the text’s onion figure. No discrepancy beyond rounding.
• Paper-internal inconsistency #3 — Text vs Table 3 onion Ni in Mobarakeh. Text (p. 10) reports “onion bulbs contain more Ni (1.66 mg kg⁻¹) than wheat (0.96 mg kg⁻¹) and rice grains (1.18 mg kg⁻¹).” Table 3 shows Mobarakeh onion Ni 2.65 (not 1.66) and wheat Ni 1.25 (not 0.96); the text values do not match any single-region row in Table 3. The cited triple (1.66, 0.96, 1.18) appears to be a different aggregation than the per-region rows printed in Table 3 — possibly all-region or weighted means using different weights, but the paper does not derive these figures explicitly. The wiki page reports the Table 3 per-region values as the canonical data; the text statement is flagged as un-derivable from the published table. See also the discussion of Singh et al. 2010 in the same paragraph, which compares vegetable-vs-cereal accumulation generically and may have prompted the un-derivable triple.
• Paper-internal inconsistency #4 — Soil Pb ceiling attribution. Table 2’s footer attributes the Ni 40 mg/kg and Pb 10 mg/kg soil ceilings to “USEPA (1983)” (footnote d). The reference list shows “USEPA. 1983. Health Assessment Document for Acrylonitrile. EPA-600/8/82/007F” — an acrylonitrile assessment, not a soil-metals limit. The text p. 9 attributes the Pb 10 mg/kg figure to “European Union (2000)” instead. The 10 mg/kg figure is closer to the EU 2000 sludge-soil context than to any USEPA acrylonitrile document. The wiki page reports the figures as the authors cited them (Ni 40 → USEPA 1983 per Table 2 footer; Pb 10 → EU 2000 per text p. 9) and flags the mismatched USEPA-1983 attribution as a probable miscitation. The EU 2000 cited reference is “European Union 2000. Working Document on sludge, 3rd Draft. Brussels, 27 April 2000. ENV.E.3/LM, pp. 19” — a draft sludge document setting soil-application ceilings, not a binding EU regulation; this is the document the authors likely intended.
• Paper-internal inconsistency #5 — RfDo for Pb in the THQ formula text. Text p. 8: “The RfDo for Cd, Ni, Fe, and Pb were 1E−03, 2E−02, and 7E−01 4E−03, mg kg⁻¹ day⁻¹.” Reading literally: Cd 1E−03, Ni 2E−02, Fe 7E−01, Pb 4E−03. The spacing “7E−01 4E−03” is a typographic artifact; the four-metal sequence matches “Cd, Ni, Fe, and Pb” and Pb’s USEPA IRIS RfDo of 4E−03 mg kg⁻¹ day⁻¹ is the standard value. The wiki page reports the four RfDo values as Cd 1E−03, Ni 2E−02, Fe 7E−01, Pb 4E−03 mg kg⁻¹ day⁻¹.
• Frontmatter discipline. All ingredient and product slugs verified against the live wiki at 2026-06-01: ingredients/wheat, ingredients/rice, ingredients/onions, ingredients/cereals (umbrella); products/other-grain-products (wheat), products/rice-bulk-grain (rice), products/root-tuber-vegetables (onion bulb; precedent in stasinos2014-heavy-metals-tubers-review.md). All four metals (Cd, Pb, Ni, Fe) have wiki pages.
• Matrices vocabulary. Bare-string matrices include wheat-grain, rice-grain, onion, cereal-grain, and soil. The soil matrix is used here because the paper measures soil concentrations as an integral part of the soil-to-plant transfer evidence; precedent in stasinos2014, desalew2023, samitha2021. Soil values are pathway evidence, not food evidence; the food-routable values are the crop concentrations in Table 3.
• Speciation. Total Cd, total Pb, total Ni, total Fe only — no As/Hg panel; no Pb or Cd species fractionation. Frontmatter metals: reflects this ([Cd, Pb, Ni, Fe]).
• Basis. Table 3 crop concentrations are dry weight (explicit in column header). EDI computation (text p. 7) uses C_heavy_metal in µg g⁻¹ dry weight × W_food (g day⁻¹) ÷ B_w (kg); the consumption inputs (wheat 265, rice 187, onion 35 g day⁻¹) are stated as “average consumption of crops in this region” without explicit raw/cooked basis. The EDIs are best read as a dry-basis intake estimate, which somewhat overstates the wet-basis EDI for high-moisture onions (typical onion ≈ 89 % moisture). The downstream pooling pass should treat the crop concentrations as dry-weight and convert if a wet-basis comparison is needed.
• Sampling year. Not stated in the paper. The submission/acceptance date is “Accepted online: 29 Sep 2015”; the steel mills are noted as having been operating ≈ 40 years at the time of writing. Sampling-year-range is set to not specified in frontmatter.
• Brand firewall (Part 12). No commercial brand-name attribution to contamination values. Steel mill company names (Isfahan Steel Mill Company, Mobarakeh Steel Mill Company) are facility identifiers naming the point sources of the studied industrial pollution, not branded food products being measured; their inclusion is permitted under the same logic as naming a regulatory-event subject (the steel mills are the industrial point source whose emissions drive the contamination gradient documented). Methods-section vendor names retained per the 2026-05-17 scientific-vendor exception: Perkin Elmer AAnalyst 800 (GF-AAS), Islamic Azad University Isfahan (Khorasgan) Branch central laboratory, SAS Institute (statistical software 9.1).
• Wiki/HMTc firewall (Part 2). No threshold proposals, no consumer-audience advisories. The discussion’s comparisons to other regional surveys (Cao et al. 2010 Jiangsu; Li et al. 2012 Pearl River Estuary; Khan et al. 2013 Swat District; Ghosh et al. 2012 Northern India) are reported in Implications as comparator points the authors themselves draw, not as wiki-side synthesis claims.
• Regulatory citations. Authors cite Codex Alimentarius Commission (FAO/WHO) 2001 for crop MPC values (Cd 0.2, Ni 0.6, Pb 0.3 mg/kg); WHO 1993 for TDI of Cd, Ni, Pb (1, 5, 3.6 µg/kg bw/day); FAO/WHO 2007 for Fe PMTDI (800 µg/kg bw/day); USEPA IRIS 2003/2007 and Nadal et al. 2008 for the THQ RfDo values; EU 2000 Working Document on Sludge for soil Cd and Pb ceilings; USEPA 1983 (cited in Table 2 footer; likely miscited per Verification note above) for soil Ni and Pb ceilings.
• **Audit subagent (2026-06-01) flagged two ⚠️ findings in the Implications section misattributing Jiangsu rice-grain Pb 0.054 mg/kg and Cd 0.014 mg/kg to Li et al. 2012 Pearl River Estuary; verified against PDF p. 11 (“Cao et al. (2010)… average concentrations of Cd and Pb in rice grains cultivated in the vicinity of an industrial zone in Jiangsu of China were 0.014, and 0.054 mg kg⁻¹”) and p. 13 (“Li et al. (2012) reported that the values of BAFs for Cd, Pb and Ni in rice grain were 0.206, 0.006 and 0.059”). Findings correct — corrected the two Implications bullets to attribute the 0.054 and 0.014 mg/kg figures to Cao et al. 2010 Jiangsu, with a Li et al. 2012 BAFs-only clarification. No other audit findings; Check 1 numerical fidelity otherwise verified across all five tables.
• Data integrity. All Table 1 cells (9 fields × 5 columns), Table 2 cells (9 fields × 4 metals + 3 region means + LSD row + 2 ceiling rows), Table 3 cells (9 crop-region cells × 4 metals + MPC row + LSD row), Table 4 cells (4 × 4 correlation matrix), and Table 5 cells (9 region-crop rows × 4 metals + 3 region totals + TDI row) transcribed verbatim from PDF pages 24–28. BAF values extracted from Figure 2 chart bars (page 30; precision ±0.005 noted). CLI values extracted from Figure 3 chart bars (page 31; precision ±0.2 noted) and cross-referenced with text-reported regional means. EDI sums verified: Zarrinshahr Cd 1.37 + 0.53 + 0.18 = 2.08 ✓; Zarrinshahr Ni 6.27 + 5.14 + 1.20 = 12.61 ✓; Zarrinshahr Pb 8.83 + 4.39 + 1.24 = 14.46 ✓. Mobarakeh Cd 1.24 + 0.47 + 0.16 = 1.87 ✓. Natanz Cd 0.27 + 0.09 + 0.03 = 0.39 ✓. No internal arithmetic discrepancies identified beyond the four flagged paper-internal inconsistencies above.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.