Overview
Jolly and colleagues used EDXRF to measure ten elements, including lead, cadmium, arsenic and mercury, in packaged pasteurized and UHT milks, raw farmhouse milks and retail milk powders in Bangladesh. They then computed health-risk indices. The authors report that powder milk carries much higher metal levels than liquid milk and that the mercury risk index from powder exceeds 1.
Key numbers
- Packaged liquid milk: lead 0.035 to 0.050 µg/ml, cadmium 0.003 to 0.016 µg/ml, arsenic 0.034 to 0.035 µg/ml (Table 3).
- Farmhouse raw milk: lead 0.037 to 0.048 µg/ml, mercury not detected to 0.030 µg/ml (Table 3).
- Milk powders: lead 1.901 to 2.774 µg/g, mercury 1.015 to 5.201 µg/g, arsenic 1.701 to 1.947 µg/g (Table 3).
Methods (brief)
Powders were oven-dried. Liquid milk was centrifuged to remove fat, then dried. Two grams of each were pressed into pellets and analyzed by EDXRF against lab-made cellulose standards. Accuracy was checked only on one groundwater sample against TXRF. No milk reference material was used. The text gives a mercury detection limit of 0.001 µg/ml. Liquid results are printed per ml and powder results per gram.
Evidence Fitness
Direct evidence for cow milk, but QA is weak for trace toxic metals. EDXRF has no matrix-matched reference material, and the very high powder lead and mercury values have not been confirmed by a second method. Several printed ranges are reversed or exclude their own means, and those values are flagged. The replicate count and sampling dates are not given. Fat level is not separated, and lab defatting is not the same as a skim product, so this is a proxy for semi-skimmed-milk and skim-milk and does not link those pages.