Microplastics detection from packaged milk: Estimation, diagnosis of probable sources, evaluation of dietary exposure, pollution load, and risk assessment

Microplastic contamination in food is a health concern, yet little is known about its presence in commercially packaged milk in India. This study investigates microplastic contamination in processed packaged milk (PPM) and farm fresh milk (FFM) to understand contamination sources/pathways and associated health risks. Results revealed that microplastic contamination might arise from pre- and post-milking process stages. FFM contained 17.78 ± 3.85 microplastics/L. In contrast, PPM samples contained 37.78 ± 3.87 to 71.11 ± 10.18 microplastics/L, up to four times higher than FFM. Low-density polyethylene (LDPE), the main microplastic polymer found in PPM are from packaging material. FFM showed limited polymer diversity, with contamination likely from fodder bags, milking tools, or fodder contaminated with microplastics. Estimating the microplastic intake by milk consumption demonstrated higher daily ingestion in the case of PPM (1.08 ± 0.22 microplastics/day) compared to FFM (0.34 ± 0.07 microplastics/day). This study and past research show that infants take in more microplastics, making them more likely to face health risks. The polymer load and risk indices in all PPM samples are very high, while FFM posed low risks. These findings emphasize the need for improved packaging alternatives and stricter quality control in dairy processing with respect to microplastic contamination.