A Scoping Review of Microplastic Contamination in Infant Foods: Exposure Pathways and Implications for Nutrition and Health of Children

Microplastics (MPs) in the environment pose a significant threat to human health, particularly for vulnerable populations like infants. Over the past decades microplastics have infiltrated food systems, air, water, and consumer products, leading to widespread human exposure. Infant foods, including formula and complementary foods, may be contaminated with MPs during processing or packaging or through environmental pollutants. This scoping review was aimed to explore the extent of MP contamination in infant foods, its potential nutritional and health impacts, and the associated risks to the health of children. Following the search strategy, a comprehensive literature search was conducted across 5 electronic databases (PubMed, Google Scholar, Cochrane, Scopus, and EBSCO HOST). All records identified through the databases were exported into EndNote X9 reference manager for deduplication and selection in line with the inclusion criteria. In all, 1871 records were identified in which 28 studies met the inclusion criteria and were included in this review. All studies were published during 2020-2024. The studies were classified into 2 designs: systematic reviews (n = 16) and primary studies (n = 12). Studies detected MPs in infant formula, breast milk, food-contact materials, feeding bottles, indoor air, and selected human biological matrices, including placenta, meconium, and infant feces. Ingestion and inhalation emerged as the most consistently supported exposure pathways, while prenatal and breastfeeding-related exposures were supported by biomonitoring evidence and dermal exposure remained weakly evidenced. Reported polymer types varied widely, with limited and inconsistent reporting of particle size and nanoplastics across studies. No studies originated from Sub-Saharan Africa, highlighting a major geographic gap. This scoping review indicates that infants are exposed to MPs through multiple pathways-most consistently via ingestion and inhalation-yet infant-specific health effects remain poorly defined, underscoring the need for improved particle characterization, broader geographic evidence, and precautionary, nutrition-sensitive approaches to research and practice.