Microplastics in branded milk: Dietary exposure and risk assessment

Abstract

In this study, 14 packaged milk of various brands sold in the Türkiye market was examined. The microplastics were physically characterised under the microscope. Their vibrational spectra were recorded with the ATF/FT-IR technique at the range of 650–4000 cm-1. The polymer types were determined by matching the obtained spectra with the reference spectra. Daily and life time microplastic exposure by milk intake was calculated using the deterministic model. Microplastics were found in milk samples in two different shapes (fiber and fragment), five different polymers (ethylene vinyl acetate, polyethylene terephthalate, polypropylene, polyurethane and nylon-6) and six different colors (black, red, green, blue, brown, and gray). The mean number of microplastic in milk samples analysed was 6 ± 5 particles/L. The mean dietary exposure for age 15 and over were 0.21 particles/mL/day and 5289 particles/mL/70-years. A total of 64 % of milk samples analysed have a moderate level of microplastic contamination based on the microplastic contamination factor values. All milk samples have an average microplastic polymer risk index of 255 ± 733, which indicates a medium level of risk. The result of this study shows that microplastics are common in milks analysed which will be directly consumed by human. The result of this study provide evidence that milks were being contaminated by microplastics mostly during production process rather than through package and suggest that to reduce microplastic contamination in milk, every step must be improved, starting with basic production.