Source and Route of Microplastics in Terrestrial, Atmospheric, and Aquatic Environments, and Effects of Microplastics on Organisms

Objectives : Microplastics, known as pieces of polymer debris less than 5 mm, result from plastic particles originally manufactured to small size or fragmentation from larger plastic items. Due to the persistence, microplastics can remain and accumulate in land and ocean for a prolonged period. Microplastics enter ecosystems and cause various problems. Trophic transfer of microplastics can be occurred in food chain, accordingly humans also can ingest microplastics. The accumulation of microplastics raises concerns regarding impacts on human health and terrestrial and aquatic ecosystems. Here, we discuss the source and route of microplastics found in environments, and ecological effects of microplastics on organisms.Methods : We explore how microplastics enter terrestrial, atmospheric, and aquatic environments and influence individual animals, plants, and microorganisms living in diverse ecosystems. Research literature is reviewed microplastics in terms of ecological risk published between 2010s and June 2022.Results and Discussion : Diverse human activities (e.g., industrial and agricultural activity) accelerate the production of microplastics and result in a release of microplastics to surrounding ecosystems. The microplastics can circulate among the terrestrial, atmospheric, and aquatic environments. The exposure of microplastics can induce oxidative stress, damage of intestinal cells, and reduce the body size in animals. In plants, length of root, biomass, and chlorophyll content are decreased upon exposure to microplastics. In addition, microplastics inhibit the growth of microalgae by reducing algal chlorophyll contents and cause oxidative stress.Conclusion : This paper includes basic information regarding the occurrence and accumulation of microplastics and their ecological effects on organisms. The contents will help to understand behavior of microplastics in diverse environments and to further evaluate ecological impacts of microplastics.