Yazdanian Ghahfarokhi et al. 2025 — Heavy metals in raw camel milk from Iran
This study collected 115 raw camel milk samples from Chaharmahal Bakhtiari province, Iran, and analyzed 49 samples (randomly selected) for Pb, Cd, and As by atomic absorption spectrophotometry (AAS). The paper’s primary focus was microbial safety (S. aureus and E. coli prevalence and virulence genes), with the heavy metal analysis as a secondary component; results indicated that concentrations of all three metals were generally low and below applicable maximum allowable concentrations (MACs). The data provide a baseline occurrence dataset for heavy metals in raw camel milk from rural Iran, a geographic region and food matrix with very limited prior published data.
Key numbers
All concentrations in ppm (mg/L), which for milk is equivalent to mg/kg (ppb × 1000). Method: AAS (Shimadzu AA-670), LODs: As 0.000698 ppm, Cd 0.000665 ppm, Pb 0.00342 ppm.
From Table 3 (sub-grouped by microbial contamination status — note heavy metals measured in the 49 microbiologically positive samples):
27 samples containing S. aureus:
- Pb: mean 0.0053 ± 0.011 ppm, range 0.0013–0.055 ppm (13–55 µg/kg)
- Cd: mean 0.0031 ± 0.001 ppm, range 0.0012–0.0059 ppm (1.2–5.9 µg/kg)
- As: mean 0.0020 ± 0.008 ppm, range 0.001–0.0041 ppm (1.0–4.1 µg/kg)
22 samples containing E. coli:
- Pb: mean 0.0039 ± 0.006 ppm, range 0.001–0.034 ppm (1.0–34 µg/kg)
- Cd: mean 0.0032 ± 0.002 ppm, range 0.0015–0.0043 ppm (1.5–4.3 µg/kg)
- As: mean 0.0024 ± 0.001 ppm, range 0.0012–0.0067 ppm (1.2–6.7 µg/kg)
Summary: Pb max observed 55 µg/kg; Cd max 5.9 µg/kg; As max 6.7 µg/kg. All metals reported as totals (tAs; speciation not performed). All values described as below applicable MACs. Note: this subset represents microbiologically positive samples only; the 66 microbiologically negative samples were not tested for heavy metals — a sampling limitation that means these are not fully representative of the full 115-sample dataset.
Methods (brief)
AAS (Shimadzu AA-670) with specific cathode lamps per element. Calibration with certified standards; standard curves for quantification. Pb detected at 288.3 nm, Cd at 288.8 nm, As at 193.7 nm. No speciation performed for arsenic or chromium. Sample preparation not fully described in available text. n=49 of 115 total samples analyzed for metals (randomly selected from those testing positive for either E. coli or S. aureus).
Implications
Certification: Camel milk is not an HMT&C-certified product category as of 2026, but the data establish background levels in this specialty dairy matrix for use in ingredient and product-category assessments if camel milk products enter the program.
Courses: Illustrates multi-hazard food safety assessment combining microbial and chemical contamination monitoring; demonstrates that heavy metal contamination can be below regulatory levels even in artisanal/nomadic raw milk.
App: Camel milk ingredient profile — Pb, Cd, and As at low ppb levels in this Iranian dataset; note that the sampling limitation (only microbially positive samples tested) means these values may not represent the full market distribution.