Microplastics and endocrine-disrupting byproducts (bisphenol A & phthalate esters) in popular infant formula brands in Iran; qualification, quantification and risk assessment

Concerns regarding the health implications of microplastics (MPs) pollution and their byproducts, such as bisphenol A (BPA) and phthalate esters (PAEs), have escalated, particularly for vulnerable populations like infants. Since infants are primarily nourished by breast milk or infant formula, their heightened exposure risk to these contaminants warrants investigation. This study assessed the presence, morphological characteristics, and associated byproducts (BPA and PAEs) of MPs in commercially available infant formulas sold in the Iranian market. In this descriptive-analytical, cross-sectional study, 27 infant formula samples were analyzed from three high-consumption brands in Iran, with each brand represented by products for the <6, 6-12, and >12 months age groups. Imaging techniques and chemical analysis were employed to characterize MPs, while an advanced analytical chemistry technique was used to quantify BPA and phthalates. The average number of MP particles per 400-g formula container was 585.2 ± 187.2 (ranging from 66.7 to 1000). These particles were predominantly polypropylene (PP) fibers with black or blue coloration. Exposure to MPs was lowest in newborns and highest in infants aged three months. Both BPA and phthalate esters were detected in all samples. While phthalate exposure levels remained below established hazardous thresholds, BPA exposure exceeded permissible limits. These findings raise significant public health concerns, as chronic exposure to MPs and hormone-disrupting chemicals could pose serious risks to development and long-term health. These results suggest that manufacturers optimize production and packaging processes to minimize contamination risks.