Monitoring and Health Risk Assessment of Heavy Metal Contamination in Food

Mansour SA

doi:10.1002/9781118474563.ch13

Mansour 2014 — Monitoring and health risk assessment of heavy metals in food (Wiley book chapter)

Chapter 13 of Practical Food Safety: Contemporary Issues and Future Directions (Bhat & Gómez-López, eds., Wiley-Blackwell 2014) by Sameeh A. Mansour of Egypt’s National Research Centre. The chapter has two halves: §13.2 surveys the analytical-method toolbox for heavy metals in food (colorimetric, FAAS, GFAAS, ICP-AES, ICP-MS, XRF screening) with detection-limit characteristics, and §§13.3–13.5 compile contamination occurrence and dietary-health-risk-assessment results from a broad international literature (with the author’s own Egyptian cucumber and potato farming-system work as the most extensively reported primary data). Quantitative anchors include Tables 13.1–13.4 plus Figures 13.1–13.5: Egyptian-market medicinal-plant concentrations of 10 metals (Abou-Arab et al. 1999), seasonal heavy-metal content in cucumber from conventional/greenhouse/organic Egyptian farms (Mansour et al. 2009a), the same for potato tubers (Mansour et al. 2009b), Egyptian Pb and Cd dietary intakes from 20 vegetables and fruits (Soliman et al. 1997), and HRI bars for Cd and Pb in 10 Indian foodstuffs from wastewater-irrigated sites (Singh et al. 2010). The framework half lays out DIM, DDI, HQ, HRI, PTWI/RfD/ADI methodology with the standard equations.

Key numbers

Analytical-method detection limits and characteristics (§13.2)

Colorimetric methods (AHPA 2009 white paper): detection limit 10–20 ppm range across responding metals (Pb, Hg, Bi, As, Sb, Sn, Cd, Ag, Cu, Mo). Inadequate for modern food safety limits; mercury not recovered at all by the standard sulfide colorimetric procedure.
FAAS: oldest of the instrumental methods; relies on light absorption at element-specific wavelengths.
GFAAS: graphite tube atomization retains sample in light path for extended period; significantly lower detection limits than FAAS.
ICP-AES: ICP atomization at 5,500–8,000 K (plasma up to 10,000 K) followed by emission detection; multi-element.
ICP-MS: ICP atomization followed by mass spectrometric detection; lowest detection limits among the routine instrumental methods; multi-element.
XRF: x-ray fluorescence as a screening tool — fast, inexpensive, minimal sample prep, multi-element, but only moderately sensitive (positioned as field-screening complement to ICP-MS, not a replacement).
Standard sample-prep for FAAS/GFAAS/ICP-AES/ICP-MS: digestion in concentrated HNO₃ and/or HCl, with H₂O₂ assistance as needed.

Table 13.1 — Heavy metals in 5 Egyptian-market medicinal plants (Abou-Arab et al. 1999; mg/kg dry weight; ND = not detected)

Peppermint (Mentha piperita): Pb 0.081, Cd 0.306, Cr 0.096, Ni ND, Co ND, Zn 38.8, Mn 38.8, Cu 6.90, Fe 84.8, Sn ND
Chamomile (Matricaria chamomilla): Pb 0.308, Cd 0.211, Cr 0.069, Ni ND, Co ND, Zn 122.0, Mn 28.8, Cu 10.40, Fe 125.0, Sn ND
Anise (Pimpinella anisum): Pb 0.224, Cd 0.081, Cr 0.088, Ni 0.106, Co 0.042, Zn 61.8, Mn 36.6, Cu 4.10, Fe 36.6, Sn ND
Caraway (Carum carvi): Pb 0.214, Cd 0.226, Cr 0.050, Ni 0.814, Co 0.162, Zn 38.0, Mn 28.4, Cu 1.38, Fe 66.4, Sn 0.040
Tilio (Lindin blossom): Pb 0.121, Cd 0.141, Cr 0.096, Ni ND, Co 0.064, Zn 60.4, Mn 36.4, Cu 4.90, Fe 49.4, Sn ND
1986 ZEBS regulation cutoffs referenced for comparison: Pb 0.25 mg/kg; Cd 0.10 mg/kg. Only chamomile exceeded the ZEBS Pb cutoff (0.308 vs 0.25 mg/kg). All five samples exceeded the ZEBS Cd cutoff (0.081–0.306 vs 0.10 mg/kg). Highest Pb/Zn/Cu/Fe in chamomile; highest Cd/Cr/Mn in peppermint; highest Ni/Co/Sn in caraway.

Table 13.2 — Total heavy metal content in cucumber by farming system (Mansour et al. 2009a, Egyptian markets; mg/kg)

Conventional cucumber: total 6.25 mg/kg → Fe 48.43%, Zn 22.35%, Cu 8.51%, Pb 4.04%, Cd 1.10%
Greenhouse cucumber: total 4.97 mg/kg → Fe 41.98%, Zn 28.67%, Cu 8.28%, Pb 5.76%, Cd 0.67%
Organic cucumber: total 5.35 mg/kg → Fe 42.27%, Zn 26.29%, Cu 6.40%, Pb 5.81%, Cd 0.91%

Cucumber seasonal totals (Figure 13.3 readings, mg/kg)

Conventional: summer 7.71, fall 4.52, winter 5.08, spring 7.68 — order summer > spring > winter > fall.
Greenhouse: summer 5.49, fall 4.26, winter 5.79, spring 4.33 — order winter > summer > spring > fall.
Organic: summer 5.55, fall 4.33, winter 5.01, spring 6.51 — order spring > summer > winter > fall.

Table 13.3 — Total heavy metal content in potato tubers by farming system (Mansour et al. 2009b, Egyptian markets; mg/kg)

Conventional potato: total 34.84 mg/kg → Fe 83.60%, Zn 7.79%, Cu 2.70%, Mn 1.95%, Cr 2.45%, Pb 1.19%, Cd 0.10%
Organic potato: total 17.59 mg/kg → Fe 68.48%, Zn 16.83%, Cu 4.50%, Mn 4.14%, Cr 3.01%, Pb 1.99%, Cd 0.30%
Conventional potato heavy-metal load was nearly 2× that of organic potato.

Potato seasonal totals (Figure 13.4 readings, mg/kg)

Conventional: summer 19.87, fall 44.7, winter 33.64, spring 41.14 — order fall > spring > winter > summer.
Organic: summer 10.99, fall 7.76, winter 32.96, spring 18.46 — order winter > spring > summer > fall.

Table 13.4 — Estimated Pb and Cd dietary intake from 20 Egyptian vegetables and fruits (Soliman et al. 1997; µg/day per 182 g vegetables and 236 g fruits per day)

Vegetables (Pb µg/day; Cd µg/day):

Spinach 54.60; 2.184
Chard 27.30; 0.364
Garden rocket 32.76; 7.644
Dill 32.76; 0.364
Coriander 27.30; 0.346
Lettuce 20.02; 0.546
Spearmint 32.66; 0.182
Green onion 49.14; 0.182
Tomatoes 27.30; 0.708
Mallow 67.34; 0.182
Radish 61.88; 0.728
Leek 56.42; 3.094
Parsley 32.76; 1.456
Celery 47.32; 0.546
Kale 29.12; 1.092
Molokhia 118.30; 1.638
Potato tuber 25.48; 0.910

Fruits (Pb µg/day; Cd µg/day):

Peach 128.85; 6.136
Strawberry 103.60; 11.564
Cantaloupe 21.24; 0.708

Range summaries reported in §13.6: Pb intake from vegetables 20.02–118.30 µg/day; Pb intake from fruits 21.24–128.85 µg/day; Cd from vegetables 0.182–7.644 µg/day; Cd from fruits 0.708–11.564 µg/day. The author notes Egyptian Pb intakes are higher than global-diet reference levels (cited as 9.0–12.0 µg Pb/day for vegetables and fruits), and that Egyptian Cd intakes are generally lower than the global 1.0–2.0 µg Cd/day reference, except in spinach, garden rocket, leek, strawberry, and peach.

Figure 13.1 — Heavy metal content in wastewater-irrigated Indian vegetables (Arora et al. 2008; mg/kg dry weight; ranges)

Fe 116–378, Mn 12–69, Cu 5.2–16.8, Zn 22–46 mg/kg across the eight vegetables.
Highest Fe in mint, lowest in radish. Highest Zn in carrot, lowest in radish and brinjal.
All values were reported as below recommended maximum tolerable levels.

Figure 13.2 — Heavy metals in Chongqing-market vegetables (Yang et al. 2011; mg/kg dry weight)

Pb highest on dry-weight basis in mustard (14.9 mg/kg), then spinach (12.8 mg/kg); Pb in garlic leaf (10.4 mg/kg) > stem (9.72 mg/kg). Bar chart depicts Pb/Cd/Cu/Zn across 11 vegetables (potato, lettuce, cucumber, mustard, cabbage, spinach, asparagus stem/leaf, garlic stem/leaf, leek); per-metal numeric ranges are not given in the chapter text.
Measured Pb and Cd exceeded FAO/WHO and Chinese regulatory limits — flagged as serious contamination.

Figure 13.5 — Health Risk Index (HRI) for Cd and Pb in 10 Indian wastewater-irrigated foodstuffs (Singh et al. 2010)

Approximate HRI readings (HRI ≥ 1 indicates risk):

Palak: Cd ≈ 4.7, Pb ≈ 3.0
Cabbage: Cd ≈ 10.1, Pb ≈ 1.8
Cauliflower: Cd ≈ 3.9, Pb ≈ 7.5
Lady’s finger: Cd ≈ 5.1, Pb ≈ 1.6
Brinjal: Cd ≈ 1.5, Pb ≈ 1.3
Tomato: Cd ≈ 0.5, Pb ≈ 0.7
Pumpkin: Cd ≈ 1.0, Pb ≈ 1.1
Radish: Cd ≈ 0.6, Pb ≈ 0.5
Wheat: Cd ≈ 5.9, Pb ≈ 6.8
Rice: Cd ≈ 9.1, Pb ≈ 6.8

Other quantitative anchors cited in §13.3 (selected; numerical attribution to the cited primary studies)

Radwan & Salama 2006 (Egyptian market basket): Pb 0.01–0.87, Cd 0.01–0.15, Cu 0.83–18.3, Zn 1.36–20.9 mg/kg in unspecified Egyptian fruits and vegetables. Highest mean Pb in strawberries, Cd in cucumber, Cu in date, Zn in spinach. Reported as below FAO/WHO 1999 tolerable levels.
Tufuor et al. 2011 (Abura-Asebu-Kwamankese District, Ghana): As, Pb, Cr, Ni, Cu, Zn, Fe measured in oranges, limes, lemons. Lime juice highest in trace metals (attributed to acidity and chelation by citric/tartaric/malic acids; acidity lime > lemon > orange). Mean trace-metal order As < Cu < Pb < Zn < Fe. All metal levels below dietary reference values (UK Department of Health; US EPA).
Arora et al. 2008 (wastewater-irrigated Indian vegetables; see Figure 13.1 above for ranges) — values reported as below recommended maximum tolerable levels.
Yang et al. 2011 (Chongqing market vegetables): Pb 14.9 mg/kg in mustard; Pb 12.8 mg/kg in spinach; Pb 10.4 mg/kg in garlic leaf; Pb 9.72 mg/kg in garlic stem (all dry weight). Pb and Cd exceeded FAO/WHO and Chinese regulatory limits.
Subramanian et al. 2012 (15 Indian medicinal plants used in curries): Pb 0.478–9.890 mg/kg, Zn 6.94–49.76 mg/kg, Cd 0.684–2.751 mg/kg, Cu 11.51–94.05 mg/kg dry weight. All below FAO/WHO recommended levels.
Obi et al. 2006 (25 random Nigerian traditional herbal products): 100% of samples contained elevated Cd, Cu, Fe, Ni, Se, Zn, Pb, and Hg.
Cuadrado et al. 2000 (FAO European Co-operative Research Network, Madrid cereals diet): pasta highest in Cd 50.4 ± 0.4 µg/kg dw, Mo 308 ± 6 µg/kg dw, Ni 383 ± 5 µg/kg dw, Se 110 ± 3 µg/kg dw, Cu 3.81 ± 0.09 mg/kg dw; whole bread highest in Pb 59.2 ± 8.0 µg/kg dw, Zn 18.4 ± 0.1 mg/kg dw, Mn 17.1 ± 0.3 mg/kg dw. Cereal-group contributions to PTWI under 15% of permissible international standards for all elements.
Bermudez et al. 2011 (Cordoba wheat grains): air-pollution-source associations; topsoil Ba, Co, Cr, Zn exceeded international thresholds; Cd associated with cement-plant proximity and industrial waste incinerator. Total Hazard Index = 3.311 for wheat-grain consumption.
Sen et al. 2011 (Yamuna fish, India; ICP-OES): Si, Pb, Fe showed high concentrations relative to other measured elements; Ca/K/Mg/Na/P above WHO limits.
Roychowdhury et al. 2003 (West Bengal arsenic-affected food composites): As 20.9 and 21.3 µg/kg (vegetables, Jalangi/Domkal); 130.0 and 179.0 µg/kg (cereals and bakery); 133 and 202 µg/kg (spices). Se 495 and 365 µg/kg in spices.
Fu et al. 2008 (rice, southeast China E-waste recycling region): geometric mean Cd, Cu, Hg in soils 4.0, 2.0, 1.1 mg/kg; Pb in polished rice 3.5× higher than the Chinese MAC; 31% of rice samples exceeded national Cd MAC. Pb daily intake via local rice exceeded FAO TDI.
Cao et al. 2010 (rice and garden vegetables, southeast China): Cr/Cu/Zn/Cd/Hg/Pb averages 0.75/2.64/12.00/0.014/0.006/0.054 mg/kg dw in rice; 0.67/1.18/4.34/0.011/0.002/0.058 mg/kg fw in garden vegetables. Daily intakes Cr/Cu/Zn/Cd/Hg/Pb 5.66/16.90/74.21/0.10/0.04/0.43 µg/kg/day. Combined Hazard Index ≈ 1 for self-planted rice and vegetables.
Song et al. 2009 (Beijing, 416 vegetable samples, 100 varieties): mean As/Cd/Cr/Cu/Ni/Pb/Zn 0.013/0.010/0.023/0.51/0.053/0.046/2.55 µg/g fw. Pb 17.3%, As 12.6%, Ni 2.62%, Cr 0.96%, Cd 0.58% of samples surpassed Chinese national standards.
Amundsen et al. 1997 (Norway/Russia border freshwater fish): Cd, Cu, Hg, Ni, Zn in muscle/liver/gills of whitefish, perch, pike, brown trout, burbot, vendace; Cd and Ni in fish liver rose with smelter proximity. Hg was the only metal where species differences appeared to track biomagnification.
Whyte et al. 2009 (NZ greenshell mussel Perna canaliculus): Cd 0.75 mg/kg and As 2.97 mg/kg highest at Urapukapuka; all below FSANZ MLs. Average diet PTWI not exceeded except potentially for Cd in Māori/Pacific-Islander/Asian consumers with higher shellfish intake.
Zhuang et al. 2009 (Dabaoshan mine, south China): Fandong-village paddy soil Cu 703, Zn 1100, Pb 386, Cd 5.5 mg/kg. Rice grain Cd/Pb/Zn concentrations in vegetables exceeded Chinese permissible concentrations. THQ ranges across four villages: Cu 0.66–0.89, Zn 0.48–0.60, Pb 1.43–1.99, Cd 2.61–6.25. Bioaccumulation order Cd > Zn > Cu > Pb.
Maleki & Zarasvand 2008 (Sanandaj, Iran): mean Pb/Cu/Cr/Cd in various vegetables (examples named: leek Allium ampeloprasum, sweet basil Ocimum basilicum, parsley Petroselinum crispum, garden cress Lepidium sativum, tarragon Artemisia dracunculus) 13.60 ± 2.27, 11.50 ± 2.16, 7.90 ± 1.05, 0.31 ± 0.17 mg/kg respectively. Dietary intakes Pb/Cu/Cr/Cd 2.96/2.50/1.72/0.07 mg/day. Vegetables flagged as a health hazard.
Zheng et al. 2007 (Huludao industrial city, China): per-metal THQ < 1 for single foodstuffs, but HIs for all-foodstuff intake > 1 for adults and children. Relative HI contributions Hg/Pb/Cd/Zn/Cu were 1.7%/11.7%/24.0%/23.4%/39.6% in adults and 1.5%/11.7%/21.8%/26.1%/38.8% in children.
Raghunath et al. 2006 (Mumbai duplicate-diet, 250 samples): vegetarian and non-vegetarian Na/K/Ca/Cu/Zn/Fe/Mn/Mg/Pb/Cd/Co/Ni daily intakes reported; Pb/Cd/Co/Ni daily intakes reported in the chapter as 32.3/2.2/2.2/108 mg/day respectively. The chapter prints “mg” — likely a typographic error for µg propagated from the cited primary source, since 108 mg/day Ni is roughly 30× a typical adult Ni TDI and the same paragraph states “the intake of toxic metals such as Pb, Cd, and Ni is much lower than the tolerable daily intake derived from PTWI given by FAO/WHO.” The wiki preserves the printed unit; downstream synthesis should consult the Raghunath 2006 primary paper before using these values.

Dietary HRA framework equations (§13.5; reproduced verbatim from the chapter)

Exposure (mg/kg bw/day) = Consumption (mg/kg bw/day) × Residue (mg/kg)
DDI (Daily Dietary Index) = X × Y × Z / B, where X = metal concentration in vegetable (mg/kg), Y = dry weight of the vegetable (mg), Z = approximate daily intake of vegetable (mg/day), B = average body mass (kg)
DIM (Daily Intake of Metals) = C_metal × C_factor × D_intake / B, where C_factor converts fresh weight to dry weight (Rattan et al. 2005)
HQ (Hazard Quotient) = W_plant × M_plant / (RfD × B), with risk at HQ ≥ 1
HRI (Health Risk Index) = DIM / RfD; HRI < 1 indicates safe exposure (IRIS 2003)
MPI (Metal Pollution Index) = (Cf₁ × Cf₂ × … × Cfₙ)^(1/n) — geometric mean of concentrations across food items (Usero et al. 1997, Singh et al. 2010)
Reference oral doses cited: Cu 4 × 10⁻², Zn 0.3, Cd 1 × 10⁻³ mg/kg/day (USEPA 2002); Pb 0.004, Ni 0.02, Cr 1.5 × 10⁻³ mg/kg/day (USEPA 1997).
PTDI examples cited from Mohammad & Ahmed 2006: 100 g/person/day potato consumption → 1 µg Pb, 2 µg Cd, 0.08 mg Cu, 0.72 mg Zn daily; 116.7 g/person/day vegetables → 30, 4.67, 0.45, 1.58 mg/day for Pb, Cd, Cu, Zn against Egyptian PTDI safe limits of 214, 60, 3, 60 mg/day for Pb, Cd, Cu, Zn (WHO/FAO).

Methods (brief)

Book chapter (review-with-incorporated-primary-data hybrid). Chapter 13 (pp. 235–255) of Practical Food Safety: Contemporary Issues and Future Directions, First Edition, edited by Rajeev Bhat and Vicente M. Gómez-López, John Wiley & Sons 2014 (DOI 10.1002/9781118474563.ch13). Author affiliation: Environmental Toxicology Research Unit (ETRU), Pesticide Chemistry Department, National Research Centre, Cairo, Egypt.

The §13.2 analytical-methods survey is referenced primarily against the AHPA (2009) Heavy Metal Analysis and Interim Recommended Limits for Botanical Dietary Supplements white paper; the chapter does not redescribe instrument-specific operating parameters in original detail.

The §§13.3–13.5 occurrence and HRA sections are a narrative compilation of approximately 40 cited primary studies (1992–2012) plus the author’s own Egyptian primary work — Mansour et al. 2009a (cucumber from conventional/greenhouse/organic farming systems, Chemosphere 75:601–609), Mansour et al. 2009b (conventional vs organic potato tubers, Food Chemistry and Toxicology 47:615–624) — and earlier Egyptian-market dietary-intake estimates by colleagues at the National Nutrition Institute (Soliman et al. 1997, Bulletin of National Nutrition Institute of Cairo) and the National Research Centre (Abou-Arab et al. 1999 medicinal plants; Mohammad & Ahmed 2006; Radwan & Salama 2006). Specific analytical instruments and digestion protocols for the author’s Egyptian primary data are not redescribed in the chapter; reference to the original Mansour et al. 2009a,b Chemosphere and Food Chemistry and Toxicology papers is needed for method-level fidelity.

Limitations relevant to wiki use:

Narrative-review compilation; no PRISMA, no formal quality appraisal, no meta-analysis. Evidence_tier B.
The chapter cites approximate Figure-13.3, 13.4, 13.5 values from bar-chart readings (the author’s own re-presentation of Mansour et al. 2009a,b and Singh et al. 2010); for HMTc workbench use the chapter’s bar-chart numbers should be replaced by the original Mansour 2009a,b and Singh 2010 tabulated values when those are routed in.
Speciation: no speciation work reported in the chapter. As is reported as total (tAs), Hg as total (tHg), Cr as total (Cr). The wiki frontmatter reflects this — no iAs, no MeHg, no Cr-VI claim.
Cr presented in two registers: (i) Roychowdhury et al. 2003 spice/cereal “As” composites and Cr in Mansour et al. 2009b potato tables are total chromium; (ii) the chapter mentions chromium in 8-metal HI calculations without speciation. No Cr(VI) determinations are reported.
Sn appears in Table 13.1 medicinal-plant data (ND for four of five plants; 0.040 mg/kg in caraway only) and in Sen et al. 2011 Yamuna fish (qualitative mention). The wiki frontmatter retains Sn given Table 13.1’s quantification.
Al appears in the chapter’s reference DDI/RfD framework via the Mansour et al. 2009b potato study (which measured Al alongside Fe in some tabulations) and via DEFRA 1999 European Total Diet Study citation, but Al concentrations are not separately tabulated in this chapter. Al retained in frontmatter as the chapter explicitly invokes Aluminium in the European Total Diet Study reference list and the §13.4 GM-crop heavy-metal discussion.
Fe, Mn, Cu, Zn, Co are quantified extensively (Table 13.1 and reference studies) but are not in the HMTc 10-analyte vocabulary; they are noted in Key numbers but not added to metals: frontmatter.
The 1986 ZEBS regulation cited as benchmark for Table 13.1 is West-German pre-EU; current EU thresholds for medicinal/herbal materials (EMA Q3D, EU Pharmacopoeia) are not compared in the chapter.
Table 13.4 reports estimated intake values for spinach (Pb 54.60, Cd 2.184), garden rocket (Pb 32.76, Cd 7.644), and others “in mg per day” in the chapter narrative — the table header itself is µg day⁻¹ and the narrative context confirms µg/day is correct; the chapter’s body sentence describing “0.182–7.644 mg day⁻¹” Cd intake in vegetables is a verbal slip the table-header unit corrects. Wiki preserves µg/day per the table header.

Implications

Certification. The chapter’s most certification-relevant primary data are the Egyptian farming-system comparison for cucumber (Mansour et al. 2009a) and potato (Mansour et al. 2009b): conventional production carries ≈1.3× (cucumber) to 2× (potato) the total-heavy-metal load of organic production for the same commodity at the same Egyptian market. The metal-composition breakdown (Table 13.2 and 13.3) shows the bulk of total heavy-metal mass is Fe in both farming systems and both commodities, with Zn second; HMTc-tracked analytes (Pb 1.2–5.8%, Cd 0.1–1.1%) are a small fraction of total mass but the absolute Pb load in conventional cucumber (≈ 0.25–0.45 mg/kg estimated from total × Pb%) is in the same order of magnitude as commodity-level Pb benchmarks. Table 13.1 medicinal-plant Pb (0.081–0.308 mg/kg) and Cd (0.081–0.306 mg/kg) provides occurrence anchors for any Egyptian-sourced herbal-botanical category. Table 13.4 dietary-intake estimates from Soliman et al. 1997 are usable as Egyptian-population exposure context (highest Pb-intake vegetables: molokhia 118.30, peach 128.85, strawberry 103.60 µg/day; highest Cd-intake vegetables: strawberry 11.564, garden rocket 7.644, peach 6.136 µg/day).

Courses. The §13.2 method-progression survey (colorimetric → FAAS → GFAAS → ICP-AES → ICP-MS, with XRF as a field-screening complement) is the cleanest teaching anchor: each step’s sensitivity gain is described in plain language, the colorimetric detection-limit ceiling (10–20 ppm) is identified as the historical reason modern food-safety limits could not be enforced before instrumental methods, and the AHPA 2009 white paper is named as the underlying reference. The §13.5 HRA-framework equations (Exposure, DDI, DIM, HQ, HRI, MPI) and their associated RfD values are a self-contained derivation suitable for a worked-example module on dietary-risk-index calculation, and the Singh et al. 2010 HRI bar chart (Figure 13.5) gives an immediate visual of how HRI ≥ 1 cases (cabbage Cd ≈ 10.1, cauliflower Pb ≈ 7.5, rice Cd ≈ 9.1, wheat Pb ≈ 6.8) sit against safe-range commodities (tomato, radish, brinjal).

App. Provides Egyptian-market occurrence data for cucumber, potato, spinach, strawberry, peach, leek, parsley, celery, kale, molokhia, garden rocket, radish, mallow, chamomile, peppermint, anise, caraway, tilio that can populate ingredient-level Egyptian regional sub-fields if/when the app exposes country-of-origin priors. The bulk of the chapter’s content, however, is review-of-cited-studies and would more appropriately route through the cited primary papers (Soliman et al. 1997; Mansour et al. 2009a,b; Abou-Arab et al. 1999; Singh et al. 2010; Yang et al. 2011; Cao et al. 2010; Fu et al. 2008) than through this chapter when those primary studies are individually ingested.

Microbiome. Not applicable; the chapter does not discuss gut-microbiome interactions.

Wiki pages this source may touch

Verification notes

Merge-enhanced 2026-05-18 from the prior 2026-05-14 page. The prior page’s central claim “No primary occurrence data are reported in the extracted text” was factually wrong: the chapter contains Tables 13.1, 13.2, 13.3, 13.4 with quantitative primary data plus Figures 13.1–13.5, all of which were missing from the prior page. Defects corrected against the source PDF (pp. 235–255):

raw_handle: papers-cube placeholder → canonical PCMF_mansour2014 (per established PCMF handling, cf. PCMF_islam2007, PCMF_khan2015, PCMF_hussein2024).
doi corrected from null to 10.1002/9781118474563.ch13 (Wiley book-chapter DOI for the Practical Food Safety edited volume); no_doi_assigned flipped to false; access_url populated with the DOI resolver.
Added raw_sha256: 553247af22939503338593b8c3eb49973cf5587bce04f225a66f23f4c6fa6b55.
metals corrected from [Pb, Cd, tHg, tAs, Cr] to [Pb, Cd, tHg, tAs, Cr, Ni, Sn, Al]. Ni added (caraway 0.814, anise 0.106 mg/kg in Table 13.1; Mumbai Ni intake 108 mg/day in Raghunath et al. 2006; Ni in Cu PDT discussions). Sn added (caraway 0.040 mg/kg in Table 13.1; Sn in Sen et al. 2011 Yamuna fish ICP-OES). Al retained per DEFRA 1999 European Total Diet Study reference and GM-crop discussion. tHg retained per Hg discussions across multiple cited studies (Roychowdhury et al. 2003; Cao et al. 2010; Whyte et al. 2009). tAs retained per Roychowdhury et al. 2003 (West Bengal As composites), Tufuor et al. 2011 (Ghana citrus), Sen et al. 2011 (Yamuna fish). Cr retained per Table 13.1 (0.050–0.096 mg/kg in 5 medicinal plants) and Mansour et al. 2009b potato Cr fraction (2.45% conventional, 3.01% organic). No iAs claim — the chapter does not speciate arsenic anywhere. No MeHg claim — the chapter does not speciate mercury. No Cr-VI claim — total chromium throughout.
ingredients corrected from [[ingredients/vegetables]], [[ingredients/rice]], [[ingredients/wheat]] to add fruit, cucumber, potatoes, herbal-botanicals, fish. The prior list omitted the chapter’s most extensively reported primary commodities (Egyptian cucumber and potato from Mansour 2009a,b; Egyptian medicinal plants from Abou-Arab 1999) and the fish content (§13.3.4). All eight slugs verified against the current ingredients taxonomy snapshot.
matrices corrected from [food, vegetables, cereals, dietary-intake] to add fruit, fish, medicinal-plants, analytical-method. The chapter explicitly covers fruit (Table 13.4), fish (§13.3.4 multiple Norway/Russia/India/NZ studies), medicinal plants (Table 13.1; Subramanian et al. 2012; Obi et al. 2006), and analytical-method framework (§13.2). All matrix bare-strings verified against the corpus-established matrices vocabulary (grep -h '^matrices:' wiki/sources/*.md).
jurisdictions corrected from [EG] to [EG, CN, IN, GH, IR, NG, AR, RO, NZ, NO, RU]. The chapter compiles studies from each of these jurisdictions. Egypt remains the primary jurisdiction (author’s own data) but the chapter’s narrative scope is global.
sample_population rewritten from one-sentence summary to identify the cited primary studies (Mansour 2009a,b; Soliman 1997; Abou-Arab 1999) and the chapter’s global narrative-review scope.
publication corrected from “Practical Food Safety: Contemporary Issues and Future Directions (Wiley)” to “Practical Food Safety: Contemporary Issues and Future Directions (Wiley-Blackwell)” per the title-page imprint.
Body — Opening prose rewritten from “central limitation noted is that colorimetric methods have detection limits in the 10–20 ppm range” to a complete chapter overview identifying both halves (analytical-methods survey + occurrence/HRA compilation) and naming the principal primary-data sources.
Body — ## Key numbers rebuilt from “No primary occurrence data are reported” to full coverage of Tables 13.1, 13.2, 13.3, 13.4 plus Figures 13.1, 13.2, 13.3, 13.4, 13.5 plus selected quantitative anchors from cited studies plus the §13.5 dietary-HRA framework equations and RfD values.
Body — ## Methods (brief) expanded to identify the chapter’s two halves, the AHPA 2009 white paper as the analytical-methods reference, the author’s primary Egyptian studies (Mansour 2009a,b), and the limitations relevant to wiki use (narrative-review status, bar-chart reading approximations, no speciation, ZEBS 1986 regulation vintage, Fe/Mn/Cu/Zn/Co quantified but outside HMTc 10-analyte scope).
Body — ## Implications rewritten to surface the certification-relevant Egyptian farming-system comparison (cucumber 1.3× and potato 2× total-heavy-metal load conventional vs organic) and the courses-relevant method-progression survey, replacing the prior vague “useful reference for the analytical methods section of HMT&C auditor guidance” language with concrete numerical anchors.
Body — replaced legacy ## Wiki pages updated on ingest heading with current ## Wiki pages this source may touch form.
Body — kept Part 2 wiki/HMTc firewall: no threshold proposals; the Implications section describes what the chapter contributes to threshold work without advocating any HMTc certification level.
Body — kept Part 12 brand firewall: the chapter does not name commercial brands attached to contamination values; no brand stripping was needed. The reference-material/instrument-vendor exception was not invoked (the chapter does not name vendors).
Body — preserved unit fidelity (mg/kg dry weight specified where dw applies; µg/day for Table 13.4 dietary intake) and noted the chapter’s own internal unit slip (narrative “mg day⁻¹” vs table header “µg day⁻¹” for Table 13.4 — table header is authoritative).

Post-audit corrections (subagent audit, 2026-05-18)

Three definite errors flagged by the fresh-context audit subagent and verified against the PDF on re-read:

Figure 13.2 (Yang 2011) misattribution corrected. The prior wiki revision attributed the ranges Cd 0.478–9.890 / Cu 6.94–49.76 / Zn 0.684–2.751 / Pb 11.51–94.05 mg/kg to Figure 13.2 / Yang 2011 / Chongqing-market vegetables. Verified against PDF p. 239: those ranges belong to Subramanian et al. 2012 (15 Indian medicinal plants used in curries) as Pb/Zn/Cd/Cu respectively, not to Yang 2011. The Yang 2011 / Figure 13.2 section in the chapter provides only qualitative Pb maxima (mustard 14.9, spinach 12.8, garlic leaf 10.4, garlic stem 9.72 mg/kg dw) plus the bar-chart depiction across 11 vegetables; no per-metal range is given in the chapter text. Figure 13.2 bullet rewritten; the Subramanian bullet (which already had the correct attribution) preserved. Audit subagent finding verified correct and applied.
Maleki & Zarasvand 2008 “6 vegetables” corrected. Verified against PDF p. 251: the chapter writes “various vegetables – for example, leek (Allium ampeloprasum), sweet basil (Ocimum basilicum), parsley (Petroselinum crispum), garden cress (Lepidium sativum) and tarragon (Artemisia dracunculus)” — five named examples under “various vegetables”, not six. Rewritten to name the five examples explicitly and drop the count. Audit subagent finding verified correct and applied.
bivalve-molluscs ingredient slug added. Verified against PDF p. 250: §13.3.4 Fish-and-seafood includes Whyte et al. 2009 greenshell mussel (Perna canaliculus) Cd 0.75 / As 2.97 mg/kg from Bay of Islands, NZ. Added [[ingredients/bivalve-molluscs]] to ingredients: frontmatter and to the wiki-pages-this-source-may-touch list. Audit subagent finding verified correct and applied.
Raghunath 2006 “mg” unit anomaly flagged in body. The Raghunath bullet under §13.5 expanded to note the unit discrepancy (108 mg/day Ni is ~30× a typical adult Ni TDI; the chapter’s own sentence “the intake of toxic metals such as Pb, Cd, and Ni is much lower than the tolerable daily intake” is incompatible with the printed “mg” attribution). Wiki preserves the chapter’s printed unit per audit fidelity but warns downstream synthesis to consult the Raghunath 2006 primary paper. Audit subagent ⚠ concern verified and addressed by adding the cross-check note (no edit to the numeric value itself).

No false positives in this round. All other audit checks returned ✅.

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.

Commit	Date	Description
b0f3d38	2026-06-12	batch \| corpus rescreen b04 old terminal skips

Heavy Metal Index

Index