Overview
This Scientific Reports study measured As, Cd, Hg, Pb, Cr, and Ni in 100 breast milk samples from western Iran and estimated infant health risks. Mean concentrations followed Cr > Ni > Pb > As > Cd > Hg. The occurrence data are routeable to human-milk and infant-exposure context; As and Hg are total/source-reported values, not inorganic arsenic or methylmercury.
Key numbers
Table 1 reports breast-milk concentrations in ug/L:
| Metal | Mean | SD | Min | Max | Source threshold | Samples over threshold |
|---|---|---|---|---|---|---|
| tAs | 1.96 | 2.04 | 0.06 | 11.76 | 0.3 | 75% |
| Cd | 0.72 | 0.42 | 0.07 | 2.11 | 0.4 | 74% |
| tHg | 0.31 | 0.26 | 0.05 | 1.12 | 0.7 | 9% |
| Pb | 11.5 | 4.48 | 4.11 | 21.74 | 3.6 | 100% |
| Cr | 41.07 | 23.19 | 11.02 | 128.72 | 0.9 | 100% |
| Ni | 19.25 | 11.81 | 0.10 | 66.98 | 12 | 72% |
The paper reports that 40% of breast milk samples had Cr, Pb, Cd, As, and Ni all above the source’s WHO tolerable-daily-intake comparison values. THQ exceeded 1 for As only in selected age/sex groups, while Cr-related THQ exceeded 1 across all age and gender groups.
Methods (brief)
Breast milk samples were collected in acid-washed containers. As, Cd, Cr, Hg, Ni, and Pb were measured by ICP-MS (Agilent 7900), with reported recoveries of 97-102% for the measured elements. Risk assessment used point and uncertainty analysis for THQ, TTHQ, ILCR, and TCR.
Implications
The source supports human-milk occurrence evidence for western Iran and health-risk context for breastfed infants. It should remain separate from infant formula or commercial infant-food benchmark pools, and total As/tHg should not be substituted for iAs/MeHg standards.
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Verification notes
The PDF contains full DOI, author, journal, and year metadata. Product routing is limited to infant-exposure context because breast milk is not a commercial product row. The source’s As and Hg methods do not provide speciation.
Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.