Abdelnaby et al. 2022 — Lead and cadmium in Egyptian milk with natural adsorbent remediation

Abdelnaby et al. measured lead (Pb) and cadmium (Cd) in 35 Egyptian cow milk samples from farms, independent farmers, and dairy shops in El-Qalyubia governorate, then tested bentonite clay, date pit powder, and chitosan nanoparticles as adsorbents for contaminated milk. The paper is routeable as Egyptian dairy occurrence evidence and as mitigation-method context, with concentrations reported in mg/kg wet-weight milk.

Key numbers

Milk occurrence concentrations, Table 1, wet-weight basis:

• Pb: 33/35 positive samples (94.3%); total mean 0.237 +/- 0.179 mg/kg, range 0.008-0.644 mg/kg.
• Pb in raw milk: 14/15 positive samples; mean 0.270 +/- 0.18 mg/kg, range 0.010-0.557 mg/kg.
• Pb in pasteurized milk: 19/20 positive samples; mean 0.212 +/- 0.18 mg/kg, range 0.008-0.644 mg/kg.
• Cd: 25/35 positive samples (71.4%); total mean 0.041 +/- 0.036 mg/kg, range 0.001-0.095 mg/kg.
• Cd in raw milk: 7/15 positive samples; mean 0.015 +/- 0.02 mg/kg, range 0.001-0.067 mg/kg.
• Cd in pasteurized milk: 18/20 positive samples; mean 0.06 +/- 0.03 mg/kg, range 0.015-0.095 mg/kg.

Exceedance counts, Table 2:

• Pb: 29/35 samples (82.8%) exceeded both the Egyptian and Codex 0.02 mg/kg limit cited by the authors.
• Cd: 15/35 samples (42.8%) exceeded the Egyptian 0.05 mg/kg limit cited by the authors; 24/35 samples (68.5%) exceeded the Codex 0.0026 mg/kg limit cited by the authors.

Adsorption efficacy in contaminated milk, Table 4, N=20:

• No-adsorbent control: Pb 0.363 +/- 0.12 mg/kg; Cd 0.065 +/- 0.03 mg/kg.
• Bentonite clay: Pb 0.059 +/- 0.04 mg/kg after treatment (84% removal); Cd 0.008 +/- 0.007 mg/kg after treatment (88% removal).
• Date pit powder: Pb 0.012 +/- 0.01 mg/kg after treatment (97% removal); Cd 0.005 +/- 0.003 mg/kg after treatment (93% removal).
• Chitosan nanoparticles: Pb 0.065 +/- 0.06 mg/kg after treatment (82% removal); Cd 0.001 +/- 0.001 mg/kg after treatment (98% removal).

Methods (brief)

The authors collected 15 raw cow milk and 20 pasteurized cow milk samples in nitric-acid-washed polyethylene containers, stored them frozen, digested 10 mL aliquots with hydrogen peroxide and nitric acid, and measured Pb and Cd by graphite-furnace atomic absorption spectrophotometry using AOAC procedures. Adsorption tests treated contaminated milk with bentonite clay, roasted date pit powder, or chitosan nanoparticles and remeasured residual Pb and Cd by graphite-furnace AAS. The paper reports total Pb and total Cd only; it does not provide sample-level records or a US-market benchmark pool.

Implications

Certification: Egyptian milk Pb values averaged 237 ppb and Cd values averaged 41 ppb in this limited El-Qalyubia sample set. These results are useful for dairy sourcing risk and cross-market context, but they should not be silently pooled into a US dairy benchmark.

Courses: Good case study demonstrating jurisdiction-specific dairy contamination and a mitigation experiment that reduces measured Pb and Cd without materially changing measured fat, protein, or lactose.

App: Contributes geographically tagged dairy/milk context. Values should be retained as Egypt-specific, not global default dairy concentrations.

Microbiome: Not applicable.

Wiki pages this source may touch

• milk-and-dairy
• lead
• cadmium
• milk-and-dairy
• egypt-food-standards

Verification notes

An auto-fetched duplicate PDF at raw/manual-fetch/seasonal-geographic-variance/auto-fetched/ing-chitosan-cd_2022_10-1007-s12011-022-03353-w.pdf was matched to this canonical DOI on 2026-06-04. The canonical page metadata was corrected from the PDF byline and journal page: title, authors, publication, and Table 1/Table 4 values were updated. The source reports total Pb and total Cd in milk; it does not report inorganic arsenic, methylmercury, or sample-level values.

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