Microplastics and phthalate esters in yogurt and buttermilk samples: characterization and health risk assessment

The contamination of yogurt and buttermilk (doogh), two widely consumed dairy products, with microplastics (MPs) and phthalic acid esters (PAEs), and subsequently the health effects caused by the contamination of these products on humans, is a potential concern. In this study, the abundance and characteristics of MPs as well as the PAEs concentration in different types of yogurts and buttermilk available in the Iranian market were investigated. The average abundance of MPs in different types of yogurts and buttermilk was between 0.63 and 0.76 and 0.52–0.7 items/mL, respectively. Most detected MPs in yogurt and buttermilk samples were in the size range of 1000–5000 μm with the predominant color and shape of transparent and fiber, respectively. Polyethylene terephthalate (PET) and polyamide (PA) were the dominant polymers in yogurt and buttermilk samples, respectively. The average concentrations of PAEs in different types of yogurt and buttermilk samples were between 5.79 and 11.36 and 1.46–6.93 µg/L, respectively. The findings showed that Di(2-ethylhexyl) phthalate (DEHP) levels in yogurt and buttermilk samples may have a carcinogenic risk for adults and adolescents. According to the results of this study, the intake of MPs and PAEs through high consumption of yogurt and buttermilk should be recognized as a significant source of MPs in the human body.