A Systematic Review of the Toxicokinetics of Micro- and Nanoplastics in Mammals Following Digestive Exposure

The high production of plastic, along with its biostability and poorly managed recycling, has led to its widespread presence in the environment. Pollution from microplastics (particles smaller than 5 mm) and nanoplastics (particles smaller than 1 μm) poses a serious environmental problem, with long-term negative impacts on human and animal health. The goal of this systematic review is to identify the toxicokinetics of microplastics and nanoplastics after they are ingested by mammals. A total of 1057 articles were identified in the PubMed database, Web of Science, and Google Scholar through a manual search. After removing duplicates, 560 articles remained. Upon reviewing the titles and abstracts, 500 articles were excluded. Out of the remaining 60 articles, 43 were excluded, and 17 were included in the study. The current clinical evidence indicates that plastics can enter the body in the form of microplastics and nanoplastics. The digestive system is a significant pathway for absorption, and the resulting changes are influenced by factors such as the type of plastic, the duration of exposure, the particle size, and the individual’s clinical condition. Once absorbed, plastic particles can enter the body and cause significant changes in intestinal barrier function, hepatic metabolic changes, oxidative stress, and nephrotoxicity.