Overview
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.
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Verification notes
An auto-fetched duplicate PDF at the archived source file 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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