Unveiling the invisible burden from cup to body: a comprehensive profiling of microplastics and nanoplastics released...

Microplastics and nanoplastics have emerged as a critical threat to human health due to their ability to infiltrate biological systems and potentially cause adverse effects. This systematic review analyzes 22 studies to evaluate tea bags as a significant source of these hazardous particles. To achieve this objective, a comprehensive search was conducted across reputable databases, including PubMed, Scopus, and Web of Science (WOS) covering studies up to September 28, 2025. Constituent Material of Teabag, Characterization Methods, Type, Abundance, Size, and Morphology of MPs, NPs, and related materials were thoroughly assessed. Out of 150 initially identified articles, 22 studies met the inclusion and exclusion criteria and were included in the final analysis. The findings reveal that a single plastic tea bag can release hundreds of thousands to billions of microplastic and nanoplastic particles during typical brewing conditions. This comprehensive review establishes plastic tea bags as a direct and substantial exposure route for human microplastic and nanoplastic ingestion, highlighting the urgent need for regulatory attention and development of safer alternative materials in food contact products.