Review of microplastic occurrence and toxicological effects in marine environment: Experimental evidence of inflammation

Microplastics with a size lower than 5 mm are a ubiquitous plastic polymer present in almost all marine environments. Today, microplastic contamination of the marine environment has been an issue of increasing scientific concern. Due to their small size they can be easily misused by a wide range of marine biota and accumulated mainly in the gut. However, the exact consequences of microplastics exposure in the aquatic organisms are largely unknown. This paper summarizes the recent literature on the following objectives: (1) the properties, types and sources of microplastics; (2) the routes of microplastics entrance into the marine environment; (3) ingestion of microplastics by marine biota and the probable toxicological mechanisms; (4) gut microbiota alternation as an inflammation mediator in marine animal. This review focuses on experimental studies indicate histopathological evidences of size and shape dependent microplastics induced inflammation in fish.