Overview
Ahmad and colleagues measured eight elements by flame AAS in raw milk from five livestock species in District Karak, Khyber Pakhtunkhwa, and grouped the species by cluster and principal component analysis. Table 2 gives one mean ± SD per species and element in mg/kg. Lead was below the detection limit in every species.
Key numbers
- Camel milk: cadmium 0.102 ± 0.007 mg/kg, chromium 0.024 ± 0.013 mg/kg, nickel 0.220 ± 0.001 mg/kg, lead BDL (Table 2).
- Buffalo milk had the highest cadmium, 0.117 ± 0.086 mg/kg; goat milk nickel and chromium are both printed as 1.152 ± 0.045 mg/kg (Table 2).
- Camel milk zinc 5.150 ± 0.021 mg/kg and iron 1.580 ± 0.530 mg/kg were the highest among species (Table 2).
Methods (brief)
Ten mL of milk was digested with hydrogen peroxide and nitric acid on a hot plate and read by flame AAS (PerkinElmer PinAAcle 900T) against a three-point calibration. No detection limits, reference material or recoveries are reported.
Evidence Fitness
Direct but weak evidence for raw camel milk. Per-species sample size is unclear, the lead detection limit is not stated, and there is no analytical quality control. The paper has internal inconsistencies: sheep cadmium is 0.001 mg/kg in the text but 0.01 mg/kg in Table 2 (flagged), goat nickel and chromium are identical, and the text says all values met WHO limits although iron means and goat nickel exceed the limits printed in Table 1 (Cd 0.58, nickel (Ni) 0.43, Fe 0.5 mg/kg). Cadmium near 0.1 mg/kg by flame AAS is high for milk and should be read with caution.