Scientists Detect Microplastics in Dairy Products: Highest Levels Found in Aged Cheeses

According to the study, the concentration of microplastics in aged cheeses reached 1,857 particles per kilogram, in fresh cheeses — 1,280 particles/kg, and in milk — about 350 particles/kg.

The most common types of plastic are PET, polyethylene, and polypropylene, often appearing as small gray fragments less than 150 microns in size.

The authors associate the prevalence of gray fragments with contact materials in the food industry and packaging (films, liners, caps). Potential contamination pathways include:

• Farm level — feed, milking and sanitation equipment, protective clothing;

• Processing — filters/membranes, work surfaces, machine components, packaging;

• Airborne aerosols/fibers in production facilities. Researchers explain the higher levels in cheeses by the concentration effect (whey removal, moisture loss during aging) and a greater number of technological contacts.

Scientists suggest that the primary source of contamination is packaging and milk processing equipment, from which microparticles enter the product. The higher concentration in cheeses is attributed to the production technology and extended storage.