Study of fibrous microplastic and natural microfiber levels in branded milk samples from Italy

As far as we know, there is no evidence regarding the microfiber (MF)occurrence and abundance in branded milk sam-ples from Italy. Therefore,a total of 20 milk samples from 5 brands were collected and analyzedusing a digestion step with hydrogen peroxide, followed by filtration.Natural and synthetic MFs were classified according to the evaluation ofsurface morphology (i.e., shape and texture), followed by chemicalidentification using Fourier Transform Infrared (FTIR)Microspectroscopy. Results revealed the occurrence of MFs in 67.5\% ofthe analyzed samples and showed variability ranging between 1 and 27particles/100 mL with an overall average of 3.85 MFs/100 mL. The FTIRanalyses confirmed the presence of polyethylene, polyester, acrylic, andcel-lulosic MFs. According to the literature, the contamination of milkmay occur at various stages along the production chain. The blood-milkbarrier would prevent MFs from being transferred across the mam-marygland into the milk. The highest MF levels found in ultra-hightemperature skimmed milk of some brands may indicate that the morecomplex the processing of milk, the more MFs it con-tains. However, dueto the different MF types and polymers, an unambiguous conclusion on MFsources cannot be made. MFs could be shed from the filters used in themilk processing factories and the protective clothing for workers.Therefore, the MF contam-ination should be properly investigated alongthe entire supply chain, identifying the sources of contamination andimplementing control strategies and mitigation measures.