Shahzad et al. 2025 - Trace metals in buffalo milk by feed category
Shahzad et al. measured lead, cadmium, mercury, arsenic, manganese, and iron in buffalo milk from Pakistan and compared concentrations across three feed categories. The study reports routeable liquid-milk concentration ranges in mg/L, with feed-related differences and health-risk calculations for adults and children. It is useful as Pakistan-market buffalo-milk occurrence evidence and as animal-feed contamination context, not as human-milk or infant-formula evidence.
Key numbers
The source collected 90 buffalo-milk samples from 15 sampling points. At each point, milk was sampled from two lactating buffaloes for three consecutive days.
Overall source-reported metal concentration ranges in buffalo milk:
| Analyte | Reported range | Unit | Source basis |
|---|---|---|---|
| Pb | 0.00229-0.029 | mg/L | liquid buffalo milk |
| Cd | 0.00122-0.058 | mg/L | liquid buffalo milk |
| tHg | 0.00101-0.03 | mg/L | liquid buffalo milk |
| tAs | 0.0007-0.198 | mg/L | liquid buffalo milk |
| Mn | 0.079-0.4894 | mg/L | liquid buffalo milk |
| Fe | 1.006-5.14 | mg/L | liquid buffalo milk |
Feed-category exceedance statements from the results section:
| Analyte | Source comparison point | Feed-category signal |
|---|---|---|
| Pb | WHO 0.02 mg/L | 67% of fodder-fed samples, 47% of mixed-feed samples, and 7% of maize-silage samples were above the comparison limit. |
| Cd | WHO 0.01 mg/L | 47% of fodder-fed samples, 41% of mixed-feed samples, and 13% of maize-silage samples were above the comparison limit. |
| tHg | not stated in the result sentence | Maximum 0.03 mg/L occurred in mixed fodder/silage milk; minimum 0.00101 mg/L occurred in maize-silage milk. |
| tAs | WHO 0.1 mg/L | 44% of fodder-fed samples, 34% of mixed-feed samples, and 23% of maize-silage samples were above the comparison limit. |
The paper reports adult hazard index values below 1 across the three feed categories. For children, the hazard-index range for fodder-fed buffalo milk was 0.42-1.32, with an average of 0.62; the paper states that the overall hazard index remained within safe ranges while some EDI and HRI values exceeded suggested criteria.
Methods (brief)
The study area was Tehsil Daska in District Sialkot, Pakistan. Milk was collected in 500 mL glass bottles directly from farms and transported on ice. The authors digested 1 mL milk aliquots with nitric acid, diluted digests to 50 mL, and quantified metals by atomic absorption spectroscopy using calibration standards and quality control checks. The paper reports recovery of 98-100%.
Implications
This source supports buffalo-milk and dairy occurrence evidence for Pb, Cd, total Hg, total As, Mn, and Fe on a liquid mg/L basis. The feed-category design makes it useful for supply-chain courses and standards sensitivity review where fodder, silage, irrigation water, and regional industrial activity affect milk contamination. It should not be routed as human milk despite the wishlist filename, and its total arsenic and total mercury values must not be substituted for inorganic arsenic or methylmercury.
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Verification notes
Evidence Fitness: routeable for buffalo-milk and dairy occurrence evidence in Pakistan, with source-reported liquid-milk ranges and feed-category context. Not routeable for human milk, infant formula, US-market dairy benchmark pools, inorganic arsenic, or methylmercury.
The PDF first page provides the title, authors, journal, year, DOI, and abstract ranges. The license statement identifies CC BY-NC-ND 4.0. The PDF SHA-256 at ingest was fe665ee9176b6d47aa752be43bfab1e075dec339dd8d58742cb79e63b8c55fa4. The paper reports As and Hg without speciation; this page records them as tAs and tHg.
Page history
The five most recent substantive edits to this page. 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.
| Commit | Date | Description |
|---|---|---|
| c1aef38 | 2026-06-02 | audit-queue: hamid2021-bacterial-plant-biostimulants-review → audited-promote |