Origin, ecotoxicity, and analytical methods for microplastic detection in aquatic systems

Over the decades, interaction of microplastics with other pollutants in a dynamic environmental set up was observed to increase their toxic effects. This scenario is worse in aquatic environments due to the entry of huge loads of microplastic components into the waterbodies through direct plastic dumping and those delivered from effluents originating from various treatment plants. Although extensive research was done to understand the issue associated with microplastic contamination of various aquatic environments, a huge research gap still exists in areas like their ecotoxicology, fate, distribution, and detection methods in aquatic environments. Moreover, the combined deleterious effect of microplastics in association with other environmental pollutants is not widely studied and requires more research focus. The major scope of this review is to present a comprehensive outlook on the recent studies carried out to understand the types, origin, distribution, transport, fate, and toxicity of microplastics in aquatic environments, both fresh water and marine. The review summarizes the ecotoxicological effects of microplastic contaminants in aquatic environment like the oxidative damage, neurotoxicity and decreased reproductive potential. An in-depth discussion regarding the ability of the microplastics in combination with other pollutants to serve as potentially hazardous agents in aquatic environment is also elaborated in the review. Further a summary on various microplastic detection methods, challenges associated with micro- plastic detection and management is carefully reviewed and compiled in this work. The need for proper awareness programs to general public highlighting the toxicity of microplastics and strict regulations regarding their continuous assessment and management in waterbodies are essential factors in controlling their adverse effect on aquatic environment.