Overview
Issa and colleagues bought raw and pasteurized milk, white cheese, yellow cheese and yoghurt from supermarkets in three regions of Alexandria in 2015 and measured aluminum, selenium, zinc, cadmium, copper and lead by ICP-MS. Table 1 gives minimum, maximum and mean ± SD for each product and region. Reported lead means of about 1.8 to 4.4 mg/kg are very high for dairy foods.
Key numbers
- Raw milk lead, Eastern Alexandria: 1.850 ± 1.557 mg/kg, range 0.018 to 6.754 mg/kg (Table 1).
- Yellow cheese lead, Eastern and Western Alexandria: 4.404 ± 1.607 mg/kg (Table 1).
- Pasteurized milk cadmium, Western Alexandria: 0.291 ± 0.184 mg/kg, maximum 0.673 mg/kg (Table 1).
- Pooled means across all samples: lead 3.541 and cadmium 0.212 ppm (Table 2).
Methods (brief)
Closed-vessel microwave digestion with nitric acid and hydrogen peroxide, then ICP-MS. No limit of detection, blank, certified reference material or recovery data are reported. The basis is not stated, and the abstract (powdered samples) and methods (2.0 mL aliquots) disagree.
Evidence Fitness
Weak analytical quality. No quality-control data are given, several Table 1 cells repeat identical values across regions, seven cells have a mean outside their own range or a maximum below the minimum, and the lead levels are implausibly high for milk. Sample counts per product are unclear. For the thin pages it was pulled for (fromage frais, custard, cheese pizza, ranch dressing, reduced-fat milk), this is only a dairy ingredient proxy; none of those foods was measured.