Microplastic contamination in commercial and traditional dairy products: occurrence, characteristics, and potential risk

This study investigates the occurrence, characteristics, and potential health risks of microplastics (MPs) in fifteen widely consumed dairy products from Bangladesh, including industrial and traditional items. Abundances (MPs/kg) ranged from 1643 ± 94 in strawberry yogurt to 5143 ± 120 in mango milk; among solids, industrial yogurt (4616 ± 103) and milk powder (4159 ± 86) were the most contaminated. Fibers dominated (78–90 %), and polyethylene (68–73 %) plus polypropylene (17–20 %) together accounted for over 88 % of polymers. The diversity integrated index (DII) revealed higher heterogeneity in liquids (up to 0.56) than in solids (as low as 0.32). Hierarchical clustering separated industrial products from flavored and traditional ones, and principal component analysis distinguished packaging-derived polymers from process-related polymers. Contamination factor, pollution load index, and Nemerow pollution index classifications indicated moderate to high pollution in most samples. Polymeric hazard index (8.6–19.3) reflected variation in toxic polymer content. Estimated daily intakes varied significantly—children from 2.60 to 75.08 MPs/kg.day and adults from 0.78 to 22.52 MPs/kg.day—highlighting age-dependent exposure. These findings underscore the pervasive presence of MPs in dairy products, driven by packaging and processing, and call for standardized mitigation strategies to safeguard consumer health. • MP levels ranged from 1643 ± 94 to 5143 ± 120 items/kg in dairy products. • Fiber-shaped MPs dominate (78–90%) in dairy products. • Polyethylene and polypropylene make up > 88% of all MPs. • Children’s daily dairy intake: up to 75 MPs/kg·day. • Packaging materials and processing equipment are key MPs sources.