Salahel din et al. 2025 — Multi-matrix heavy metals in Egyptian foods, Qena

This study quantified Pb, Cd, Cr, and total As in 54 food and beverage samples from five categories (beverages, processed cereals, milk and dairy products, fish and meat products, and table salt) collected during 2022 from local markets in Qena Governorate, southern Egypt. Pb dominated the overall heavy-metals burden at 72% of detected mass, with the highest mean concentration in canned fish and meat products (221.5 ± 39.9 µg/kg). Health-risk metrics (hazard quotient, hazard index, and carcinogenic risk) computed against EFSA, USEPA, and JECFA reference values stayed within acceptable ranges, but Pb exceeded the EFSA 10 µg/kg limit in 79% of carbonated and energy drinks, the 20 µg/kg limit in 50% of milk and dairy samples, and the 100 µg/kg limit in 100% of canned beef and luncheon samples; Cd exceeded the 10 µg/kg limit in 29% of carbonated and energy drinks and the 50 µg/kg limit in 100% of luncheon samples; and tAs exceeded the 10 µg/kg limit in 50% of luncheon samples.

Key numbers

All concentrations µg/kg (= ppb), wet weight, mean ± SD with min–max range, from Table 1 (p. 3). The “Maximum permissible limits” column in Table 1 cites EFSA references [15,34,35,53].

Beverages (n=20):

• Carbonated soft drinks (n=12): Pb 18.7 ± 9.7 (range 8–41); Cd 9.3 ± 8.5 (1–30); Cr 7.7 ± 5.8 (2–21); tAs 1.5 ± 0.8 (ND–6).
• Energy drinks (n=2): Pb 21.5 ± 5.5 (16–27); Cd 8.5 ± 4.5 (4–13); Cr 11 ± 5 (6–16); tAs 1.6 ± 1.0 (ND–3).
• Tea (n=3): Pb 33.0 ± 9.4 (21–44); Cd 15.0 ± 3.7 (10–19); Cr 8.7 ± 0.5 (8–9); tAs 5.0 ± 0.8 (4–6).
• Instant coffee (n=3): Pb 14.0 ± 4.1 (9–19); Cd 8.0 ± 0.8 (7–9); Cr 5.3 ± 0.5 (5–6); tAs 2.7 ± 1.2 (1–4).
• All beverages combined (n=20): Pb 20.4 ± 10.3 (8–44); Cd 9.9 ± 7.2 (1–30); Cr 7.8 ± 5.0 (2–21); tAs 4.1 ± 1.4 (ND–6).

Processed cereals (n=18):

• Wheat flour (n=5): Pb 68.0 ± 21.3 (34–96); Cd 6 ± 2 (3–9); Cr 6.8 ± 0.8 (5–9); tAs 4.0 ± 1.7 (3–8).
• Bread (n=3): Pb 43.7 ± 16.3 (24–64); Cd 5.7 ± 1.7 (4–8); Cr 2.7 ± 1.2 (1–4); tAs 3.3 ± 1.2 (2–5).
• Macaroni (n=2): Pb 45 ± 5 (40–50); Cd 5.5 ± 1.5 (4–7); Cr 3.0 ± 0.7 (3–3); tAs 2 ± 1 (1–3).
• Instant noodles (n=5): Pb 97.0 ± 21.4 (70–124); Cd 7.0 ± 1.4 (5–9); Cr 8.2 ± 0.7 (7–9); tAs 6.8 ± 1.6 (5–9).
• Corn products (n=3): Pb 24.3 ± 6.8 (19–34); Cd 7.3 ± 1.7 (5–9); Cr 4.0 ± 0.8 (3–5); tAs 3.7 ± 1.2 (3–5).
• All cereals combined (n=18): Pb 62.2 ± 31.4 (19–124); Cd 6.4 ± 1.8 (3–9); Cr 5.6 ± 2.4 (1–9); tAs 5 ± 2.4 (1–9).

Milk and dairy products (n=6):

• Milk (n=4): Pb 20.8 ± 6.6 (12–30); Cd 6.3 ± 2.8 (3–9); Cr 5.3 ± 1.9 (3–8); tAs 1.8 ± 0.4 (1–2).
• Dairy milk (cheese and yogurt) (n=2): Pb 25 ± 15 (10–40); Cd 6.5 ± 1.5 (5–8); Cr 4.0 ± 0.8 (3–5); tAs 4.0 ± 0.5 (range reported as “4” in Table 1).
• All milk/dairy combined (n=6): Pb 22.2 ± 10.4 (10–40); Cd 6.3 ± 2.4 (3–9); Cr 5.3 ± 1.6 (3–8); tAs 2.5 ± 1.1 (1–4).

Fish and meat products (n=6):

• Canned fish (n=2): Pb 206 ± 28 (178–234); Cd 9.5 ± 1.5 (8–11); Cr 7.5 ± 1.5 (6–9); tAs 8 ± 1 (7–9).
• Canned beef (n=2): Pb 194 ± 4 (190–198); Cd 8.5 ± 0.5 (8–9); Cr 6.5 ± 0.5 (6–7); tAs 7 ± 1 (6–8).
• Luncheon (n=2): Pb 264.5 ± 33.5 (231–298); Cd 119.5 ± 14.5 (105–134); Cr 94.5 ± 4.5 (90–99); tAs 10.5 ± 1.5 (9–12).
• All fish/meat combined (n=6): Pb 221.5 ± 39.9 (190–298); Cd 45.8 ± 52.8 (8–134); Cr 36.2 ± 41.3 (6–99); tAs 8.5 ± 1.8 (6–12).

Table salt (n=4): Pb 174.0 ± 38.5 (111–211); Cd 8.3 ± 1.5 (6–10); Cr 10.0 ± 4.1 (6–17); tAs 7.8 ± 0.8 (7–9). Reported as “processed and natural” in Table 1.

Overall (n=54): total detected mass = 5118 µg/kg; Pb 3685 (72.0%); Cd 659 (12.9%); Cr 546 (10.7%); tAs 228 (4.5%) (p. 3, Table 1; p. 5 narrative).

Regulatory permissible limits cited in Table 1 (EFSA references, µg/kg): Pb 10 (CSD), 500 (tea), 200 (cereals), 20 (milk), 300 (canned fish), 100 (canned meat, luncheon), 2000 (table salt); Cd 10 (CSD, energy drinks), 100 (cereals), 10 (milk), 50 (canned fish, canned meat), 500 (table salt); Cr 50 (CSD), 200 (cereals), 150 (milk), 100 (canned fish, canned meat); tAs 10 (CSD, energy drinks), 10–100 (cereals), 10 (milk), 100 (canned fish, canned meat, luncheon).

Exceedance counts reported in the text (p. 5): Pb exceeded the 10 µg/kg EFSA limit in 79% of carbonated and energy drink samples, the 20 µg/kg limit in 50% of milk and dairy samples, and the 100 µg/kg limit in 100% of canned beef and luncheon samples. Cd exceeded the 10 µg/kg limit in 29% of carbonated and energy drink samples and the 50 µg/kg limit in 100% of luncheon samples. tAs exceeded the 10 µg/kg limit in 50% of luncheon samples.

Method performance (p. 2): recovery 85–96%; replicate analysis (n=3) RSD <10%. LOD/LOQ in µg/kg: Pb LOD 0.1–0.5, LOQ 0.3–1.5; Cd LOD 0.05–0.1, LOQ 0.15–0.3; Cr LOD 0.2–0.5, LOQ 0.6–1.5; As LOD 0.1–0.5, LOQ 0.3–1.5.

Dietary intake and risk (Table 3, p. 6; Table 4, p. 6):

• Total estimated daily intake (EDI), µg/kg b.w./day, across all foods: Pb 6.88×10⁻¹; Cd 1.12×10⁻¹; Cr 9.91×10⁻²; tAs 5.11×10⁻². Ratio of EDI to EFSA health-based guidance values (HBGV) across categories: Pb 0.06–52.4%; Cd 0.02–8.1%; Cr 0.03–11%. HBGVs cited: Pb 0.63, Cd 0.36, Cr 0.30 µg/kg b.w./day; no safe level for As.
• Highest individual food-category Pb EDI: wheat flour 3.30×10⁻¹ µg/kg b.w./day (consumption rate 0.340 kg/day).
• Highest individual food-category Cd EDI: wheat flour 2.91×10⁻². Highest Cd EDI from luncheon meat 2.49×10⁻².
• Hazard quotient (HQ) ranges (Table 4): Pb 7.25×10⁻⁵ to 1.33×10⁻¹; Cd 6.11×10⁻⁵ to 4.37×10⁻²; Cr 2.37×10⁻⁵ to 1.46×10⁻²; tAs 9.39×10⁻⁵ to 9.71×10⁻². All HQ and total HI <1.
• Carcinogenic risk (CR): 2.16×10⁻⁹ to 4.37×10⁻⁵; all within USEPA acceptable lifetime range (10⁻⁶ to 10⁻⁴). Pb 2.16×10⁻⁹ to 3.96×10⁻⁶; Cd 2.32×10⁻⁸ to 1.66×10⁻⁵; Cr 3.56×10⁻⁸ to 2.18×10⁻⁵; tAs 4.23×10⁻⁸ to 4.37×10⁻⁵.
• Relative contributions to total HQ across all foods: Pb 38.9%; tAs 32.7%; Cd 21.8%; Cr 6.6% (p. 8).
• Processed cereals contributed the largest food-category share: HI 3.45×10⁻¹ (67.5%); ΣCR 1.09×10⁻⁴ (62.5%).

Biomarker estimates (Table 5, p. 9):

• Pb-attributable systolic blood pressure increase summed across all food categories: 5.29×10⁻¹ mmHg, based on the JECFA model of 1 mmHg increase per 1.3 µg/kg b.w./day Pb intake.
• Cd-attributable urinary cadmium (UCd) summed across all categories: 1.06 µg/g creatinine; well below the JECFA UCd safety limit of 5.24 µg/g creatinine and the EFSA renal-injury threshold of 5 µg/g creatinine.

Methods (brief)

Analytical method: atomic absorption spectroscopy (AAS, AAnalyst 400, PerkinElmer, USA) at the National Research Centre, Cairo. Sample prep: 0.5 mL liquid or 0.5 g solid digested with 10 mL concentrated 98% H₂SO₄, evaporated on a hot plate with 98% HClO₄ added until organic matter was destroyed and the sample turned white; cooled, filtered, and diluted to 50 mL with deionized water. Blank samples processed identically with deionized water in place of bio-sample and subtracted from sample values. Calibration: certified 1000 mg/L standards diluted to four points; recovery 85–96% across analytes; replicate analysis n=3 with RSD <10%. Speciation: total arsenic only (no inorganic/organic separation reported); total chromium only (no Cr-VI/Cr-III speciation). Basis: wet weight; results expressed as µg/kg. Geographic scope: Qena Governorate, southern Egypt. Sampling period: January–December 2022.

Risk-assessment parameters: EDI computed against an average adult body weight of 70 kg using national dietary consumption statistics (Statista 2023, cited as ref [22]); HQ used RfDs from USEPA IRIS and EFSA (Pb 0.0035, Cd 0.001, Cr 0.003, tAs 0.0003 mg/kg/day); CR used CSFs from USEPA (Pb 0.0085, Cd 0.38, Cr 0.5, tAs 1.5 mg/kg/day); exposure duration 70 years, frequency 365 days/year, averaging time = ED × 365. Limitations explicitly stated by the authors (pp. 4, 9–10): EDI reflects average adult exposure and may not adequately capture variation in vulnerable groups (children, pregnant women, individuals with different eating habits); uncertainty not quantified (no confidence intervals or probabilistic risk assessment); biomarker correlations rely on international reference values without Egypt-specific epidemiological data.

Implications

Certification (HMTc): Contributes occurrence and EDI data for Pb, Cd, Cr, and tAs across carbonated and energy beverages, tea and coffee, wheat flour, bread, pasta/macaroni, instant noodles, corn-based products, milk, cheese/yogurt, canned fish, canned beef, luncheon meat, and table salt sampled in southern Egypt during 2022. Documents Pb exceedances above the category-specific EFSA limits (100 µg/kg) in 100% of canned beef and luncheon samples, Cd exceedances above the 50 µg/kg limit in 100% of luncheon samples, and tAs exceedances above 10 µg/kg in 50% of luncheon samples for the studied locale.

Courses: Suitable case material for regulatory affairs and brand QA audiences covering health-risk assessment methodology (EDI, HQ, HI, CR), the use of JECFA blood-pressure and UCd biomarker models for downstream interpretation of Pb and Cd intake, and the application of EFSA HBGVs to multi-category market surveys in lower-regulation markets.

App: Adds occurrence data points for the following ingredient-metal pairs in Egyptian retail product matrices: wheat (Pb, Cd, Cr, tAs), bread (Pb, Cd, Cr, tAs), pasta (Pb, Cd, Cr, tAs), maize (Pb, Cd, Cr, tAs), tea (Pb, Cd, Cr, tAs), coffee (Pb, Cd, Cr, tAs), whole-milk (Pb, Cd, Cr, tAs), milk-and-dairy (Pb, Cd, Cr, tAs), fish (Pb, Cd, Cr, tAs), beef (Pb, Cd, Cr, tAs), meat (Pb, Cd, Cr, tAs). Adds product-form occurrence data for carbonated soft drinks, energy drinks, instant coffee, wheat flour, instant noodles, corn products, canned fish, canned beef, processed luncheon meat, and table salt.

Wiki pages this source may touch

• lead
• cadmium
• chromium
• arsenic
• arsenic-total
• wheat
• bread
• pasta
• maize
• tea
• coffee
• whole-milk
• milk-and-dairy
• fish
• beef
• meat
• soft-drinks-carbonated-beverages
• sports-energy-drinks
• tea
• coffee
• flour-non-rice
• bread-and-baked-goods
• pasta-wheat-based
• other-grain-products
• canned-fish
• processed-meats
• beef-product
• salt

Verification notes

• “Energy drinks” in this paper are non-alcoholic caffeinated beverages (Red Bull-class) rather than electrolyte sports drinks; routed to products/sports-energy-drinks as the closest taxonomy match, which currently spans both. Flag if a finer split exists in a future snapshot.
• Instant noodles category was routed to products/pasta-wheat-based; the paper does not specify rice-based vs wheat-based noodle composition, but the discussion of Egyptian noodles alongside macaroni implies wheat-based product form.
• “Luncheon” in Egyptian retail context is canned/cured processed luncheon meat; routed to both products/processed-meats (primary) and products/beef-product (since composition is typically bovine-based).
• Total mass percentages in Table 1’s “Overall heavy metals content” row are computed across all 54 samples; Pb 72% + Cd 12.9% + Cr 10.7% + tAs 4.5% = 100.1% (rounding artifact in source).
• Arsenic is reported as total As only; no inorganic speciation, so tAs used throughout. Chromium total only; no Cr-VI speciation.
• LOQ of As applied where As was undetected in HQ/CR calculations (Tables 3 and 4 footnote).
• Audit subagent (2026-06-03) flagged the abstract paragraph and exceedance recap as misattributing the 10 µg/kg threshold to all three Pb categories; verified against PDF p. 5 — the threshold is category-specific (Pb 10 µg/kg in CSD/ED, 20 µg/kg in milk/dairy, 100 µg/kg in canned beef/luncheon; Cd 10 µg/kg in CSD/ED, 50 µg/kg in luncheon; tAs 10 µg/kg in luncheon). Corrected.
• Audit subagent flagged a Cr/As metal mix-up: the page originally stated “Cr above the 50 µg/kg limit in 100% of luncheon samples.” PDF p. 5 actually says “As exceeded limits (10 µg/kg) in 50% of luncheon samples.” Corrected.
• Audit subagent flagged dairy-milk tAs range “3.5–4.5” as fabricated; verified Table 1 reports range as “4” only. Corrected.

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