Microplastics and nanoplastics: Characterizing potential health perturbations and mechanistic evidence

Microplastics and nanoplastics (MNPs), as emerging environmental pollutants, have become the focus of global attention due to their widespread presence and potential health risks. Due to their unique physical and chemical properties, MNPs may trigger multiple cellular and molecular toxic responses, including lipid peroxidation, DNA damage, cell membrane rupture, and mitochondrial dysfunction, disrupt the balance of the gut microbiome, and induce chronic inflammation, increasing the risk of major chronic diseases such as cancer and cardiovascular diseases. This paper systematically elaborates on the main sources and routes of exposure to MNPs. It focuses on discussing the potential toxic mechanisms of MNPs, including inducing oxidative stress and DNA damage, triggering inflammation and immune responses, and interfering with the gut microbiota and metabolic balance. Further, by combining existing epidemiological and preclinical studies, this review analyzes the potential association between MNPs exposure and the occurrence and development of cancer. Finally, we summarize the deficiencies of current research, such as methodological limitations, further exploration of mechanisms, and ethical constraints. This paper aims to provide a scientific basis for an in-depth understanding of the health risks of MNPs and the formulation of prevention and control strategies.