Literature review and health risks assessment of heavy metal contamination in human milk

Overview

Sushila et al. (2024) conducted a PRISMA-guided systematic review of 22 primary studies reporting metal concentrations in human breast milk across multiple countries, supplementing the literature survey with estimated daily intake (EDI), hazard quotient (HQ), and cancer risk (CR) calculations. This source is quarantined for country-specific Cd outlier use: the Cd section reports Iraq as having the highest Cd concentration (Ci=57.33 mg/L), but assigns the matching EDI/HQ/CR values (EDI=4.7 mg/kg/day, HQ=4.7, CR=3.62) to Iran, and then states that Lebanon, Cyprus, and Iraq exceeded the recommended allowance. Other clearly labeled values can be used cautiously as source-reported review values, but the Cd outlier should not be used for downstream synthesis until the figures or underlying study data are manually checked.

Key numbers

Number of primary sources included: 22. Approximately 380 records were retrieved, 107 duplicates removed, 181 excluded at initial screening, 92 full texts reviewed, and 70 excluded for insufficient or insignificant data. Countries represented include Iran, Cyprus, Pakistan, China, India, Turkey, Nigeria, Poland, Italy, Sweden, Spain, South Africa, Brazil, Egypt, Ghana, Lebanon, Saudi Arabia, South Korea, Iraq, and Australia. Arsenic was not speciated in the review-level extraction; concentrations cited here should be treated as total arsenic unless an underlying primary study specifies otherwise. The Cd outlier is internally inconsistent in the source text and should not be generalized to any country until manually reconciled.

Methods (brief)

Systematic review following PRISMA guidelines. Studies were collected from ScienceDirect, PubMed, and Google Scholar for 2013-2023 using trace-metal/heavy-metal/toxic-metal/trace-element terms combined with mothers’ milk, human milk, and breast milk. Included studies were English full-text articles reporting mean metal concentrations in breast milk; duplicate articles, books, review articles, and papers lacking mean values were excluded. Reported units were converted to mg/L, and country means were averaged when more than one study was available. EDI used Ci x 0.67 L/day divided by infant body weight 8.15 kg; HQ used EDI/RfD with a 10^-3 conversion factor; CR used exposure frequency, duration, average time, EDI, and cancer slope factor.

Implications

Certification: This source is not suitable for HMT&C threshold setting or country-specific Cd claims until the Cd country-label contradiction is resolved. It remains useful as a cautionary biomonitoring review showing that breast-milk metal risk estimates are highly sensitive to geography, study selection, and unit harmonization.

Courses: Useful for teaching how EDI, HQ, and CR are calculated from review-level concentration data, and for showing why country labels, unit harmonization, and source-level limitations must be checked before using outlier values.

App: Breast milk is a biomonitoring and health-context matrix rather than a certification product benchmark. Do not promote the Cd outlier into app-facing data unless manually reconciled.

Wiki pages this source may touch

• Breastmilk
• Cadmium
• Lead
• Arsenic, Total
• Mercury, Total
• Nickel
• Chromium
• Aluminum

Verification notes

• Corrected author metadata to match the PDF title page.
• Corrected source type to review and frontmatter metal speciation to total arsenic/total mercury.
• Corrected the Cyprus Pb unit from mg/kg to mg/L, matching the source figure caption for reported mean concentrations.
• Quarantined the page because the Cd outlier is internally inconsistent in the source text (Iraq Ci vs Iran EDI/HQ/CR assignment).
• Removed a missing health wikilink and routed only to existing ingredient/metal pages.
• Strict Part 12 brand-firewall recheck found no sampled-product brand names in the source-page content.

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.