A particle of concern: explored and proposed underlying mechanisms of microplastic-induced lung damage and pulmonary fibrosis

In the past decade, microplastics (MPs) have drawn significant attention as widespread environmental contaminants, with research increasingly highlighting their harmful effects on respiratory health in aquatic and terrestrial organisms. Findings revealed microplastics in human lung tissues, raising concerns about their potential role in damaging lung tissue integrity and contributing to pulmonary fibrosis-a chronic inflammatory condition characterized by scarring of lung epithelial tissues due to accumulated extracellular matrix, triggered by factors such as alcohol, pathogens, genetic mutations, and environmental pollutants. In this review, we explore both well-studied and lesser-studied mechanisms and signaling pathways, aiming to shed light on how microplastics might act as mediators that activate distinct, often overlooked signaling cascades. This review searched PubMed and Google Scholar using keywords like "plastic," "microplastic," "lung fibrosis," "pulmonary system," "exposure route," and "signaling pathways," combined with "OR" and "AND" in singular and plural forms. These pathways could not only induce lung damage but also play a significant role in the development of pulmonary fibrosis. These signaling pathways could also be targeted to reduce microplastic-induced pulmonary fibrosis, opening new avenues for future treatments.