Dokht Khatibi et al. 2024 — Lead and Cadmium in Infant Formula and Baby Food, Zahedan, Iran
This 2024 paper from Zahedan University of Medical Sciences measured Pb and Cd in 18 brands of powdered infant milk formula and 7 brands of baby cereals collected in 2020 from the Zahedan market in southeastern Iran. Analytical method was graphite-furnace atomic absorption spectroscopy (AAS). Estimated daily intake (EDI) and health risk index (HRI) were computed for two age groups (0–6 months and 6–12 months).
Key numbers
All concentrations are wet-weight (as-sampled dry powder, µg/kg):
Lead (Pb):
- Infant milk formula: mean 14.7 ± 0.98 µg/kg; detected in 100% of samples (n = 18)
- Infant cereals: mean 13.77 ± 1.51 µg/kg; detected in 100% of samples (n = 7)
- Individual outliers in infant formula: sample no. 2 = 49.73 ± 0.85 µg/kg; sample no. 9 = 45.27 ± 3.27 µg/kg (both significantly above mean, p < 0.05)
- All other formula samples ranged 5.92–16.78 µg/kg; cereal samples ranged 8.51–18.16 µg/kg
Cadmium (Cd):
- Infant milk formula: mean 0.097 ± 0.016 µg/kg; detected in 22% of samples (4/18 brands); range in positive samples: 0.11–1.19 µg/kg (sample no. 4 highest at 1.19 µg/kg)
- Infant cereals: mean 0.705 ± 0.12 µg/kg; detected in 57% of samples (4/7 brands); highest 1.80 µg/kg (sample no. 5)
Exposure and risk:
- Highest EDI for Pb: 0.226 µg/kg·day·bw for infant formula (age 0–6 months) — below Codex TDI of 1.8 µg/kg·day·bw
- HRI for Pb and Cd in all samples and both age groups was below 1.0, indicating low non-carcinogenic risk at mean exposure
- EDI for Cd in infant formula (0–6 months): 0.001 µg/kg·day·bw; in infant cereals: 0.010 µg/kg·day·bw — both well below Codex TDI
Regulatory standards applied:
- Codex and Iranian standard for Pb in infant formula: 10 µg/kg; in baby food: 20 µg/kg
- Codex standard for Cd: 0 (zero tolerance cited by authors); American Public Health Association standard: 10 µg/g (note: this appears to be a mis-cited or non-standard reference; the Codex limit for Cd in infant formula as of CXS 193-2009 is 0.010 mg/kg)
- LOD: Pb = 0.008 mg/kg; Cd = 0.0096 mg/kg
Methods (brief)
Ashing at 500 °C for 8 hours (dry-ashing in kiln), dissolution in 6 M HCl then 0.1 M HNO3, measurement by graphite-furnace AAS (Perkin Elmer Analyst 700). LOD = 3 × SD of six blank runs. Matrix-spike recovery: 95.5–104.6%. Calibration: five-point, r² = 0.998–0.9996. Only Pb and Cd measured; no speciation, no As, Hg, or other metals.
Implications
Certification: Mean Pb in Iranian infant formula (14.7 µg/kg) and cereals (13.77 µg/kg) exceeds the Codex/Iranian permissible level for infant formula (10 µg/kg) on a mean basis, driven by two outlier formula brands at ~45–50 µg/kg. No regulatory exceedance was reported by the authors, who compared mean EDI to TDI rather than comparing measured concentrations to the 10 µg/kg product limit directly; this discrepancy between the product-level standard and the mean concentration merits attention. HMT&C comparison should note that even excluding outliers, most formula brands fall 5.9–16.8 µg/kg for Pb, straddling or exceeding the 10 µg/kg product limit. Cd values are low and consistent with other infant formula literature.
Courses: Illustrates regional variation in infant formula Pb contamination. Iranian market context suggests raw milk contamination (local traffic/industrial Pb loading) and possible equipment contamination as drivers. The desiccation-concentration effect noted in the discussion is relevant to understanding dry-powder concentration vs. liquid-equivalent.
App: Pb signal in Iranian infant formula is notably higher than EU/US benchmarks. Cd is low. Geographic origin matters; sourcing from Sistan and Baluchestan should be flagged as a higher-Pb region.