Alinezhad et al. 2024 — Heavy metals in pasteurized and sterilized milk: systematic review

This PRISMA-compliant systematic review included 48 studies with data on 981 pasteurized and sterilized milk samples from 17 countries. The review found that Cu, Cd, Zn, and Pb were the metals most commonly exceeding regulatory maximum permissible limits (MPLs), with exceedance proportions of 94%, 67%, 62%, and 46% of milk samples, respectively. Risk calculations in the review identified moderate-to-high carcinogenic risk in 33 studies (68.75%) and moderate-to-high non-carcinogenic risk in 7 studies (14.5%).

Key numbers

• Literature base: 48 studies, 981 pasteurized/sterilized milk samples, 17 countries; sample sizes in individual studies ranged from 5 to 90.
• Exceedance proportions reported in the abstract/conclusion: Cu 94%, Cd 67%, Zn 62%, Pb 46%, Al 30%, Fe 16%, Ni 12.5%; As, Co, and Hg had the lowest reported contamination levels relative to local/international MPLs.
• Health-risk results: 33 studies (68.75%) reported moderate-to-high carcinogenic risk; 7 studies (14.5%) reported moderate-to-high non-carcinogenic risk.
• Non-carcinogenic risk: THQ/HI values >1 were reported for Pb, Cd, Co, and Hg in studies from Slovakia, Brazil, Turkey, and Egypt.
• Carcinogenic risk: the highest Pb cancer-risk values were 1.66E-04 and 1.69E-04 in studies from Brazil and Turkey; the highest Cd cancer-risk value was 7.00E-04 in a study from Slovakia.
• Analytical methods across included studies: AAS 15/48 (31.3%), ICP-MS 7/48 (15%), ICP-OES 4/48 (8.5%), FAAS 3/48 (6.3%), GFAAS 2/48 (4.15%), ICP-AES 2/48 (4.15%), and several other single-study methods; 5 studies (10.5%) did not report the apparatus.

Methods (brief)

Systematic review following PRISMA guidelines. Literature searches covered Web of Knowledge, Scopus, Scientific Information Database, Google Scholar, and PubMed from inception until January 2023. Inclusion criteria focused on studies reporting heavy metal concentrations and health-risk assessment in pasteurized or sterilized milk worldwide; review studies and duplicates were excluded. Quality assessment used an adapted Newcastle-Ottawa Scale. The authors did not pool a meta-analysis because of high heterogeneity, potential bias, and inconsistent source/LOD/LOQ reporting across primary studies.

Implications

Certification: The review contributes global pasteurized/sterilized milk occurrence and risk-assessment context for dairy-containing products, especially for Pb and Cd. Use as broad evidence of analyte priority and geographic heterogeneity, not as a standalone HMT&C threshold-setting source.

Courses: Useful as an introductory evidence anchor for modules on dairy contamination pathways and the regulatory patchwork for Pb and Cd in milk across EU, Codex, and national standards.

App: The global range and risk-study counts can inform qualitative cow-milk contamination context with geography-conditional weighting. Do not use this review alone as a single quantitative point estimate.

Microbiome: Not applicable.

Wiki pages this source may touch

• lead
• cadmium
• aluminum
• arsenic-total
• mercury-total
• nickel
• chromium
• copper
• zinc
• cobalt
• iron
• milk-and-dairy

Verification notes

• Cross-vendor strict Part 12 recheck 2026-05-17 found no sampled-product brand naming. Corrected title/authors to the PLOS citation, removed an unsupported concentration-range summary, replaced it with source-reported exceedance/risk/method counts, corrected matrix and wiki-link vocabulary, and tightened HMT&C/app language.

Page history

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