Ecotoxicity of Microplastic Pollutants to Marine Organisms: a Systematic Review

Plastic is a ubiquitous material used across the globe. It is easily transported to various habitats and can then be ingested by animals, with the potential to bioaccumulate up the food chain further. Although classified as solid waste, some plastics can be considered hazardous waste due to the chemicals used in the production process and those that can be adsorbed, such as hydrophobic pollutants in seawater. Plastics can break down into secondary particulate plastics, or be microscopically primary plastics, smaller than 5 mm. Marine organisms of all sizes can mistake plastic for food or consume prey with microplastics. This can cause detrimental toxic effects at a cellular, biochemical, and muscular level. This research uses a systematic quantitative literature review (SQLR) method to determine the most common polymers, hazardous chemicals, and marine organisms to ingest microplastic and incur ecotoxicological consequences. The results indicated polyethylene (PE), polypropylene (PP), and polystyrene (PS) to be the topmost common polymers, with sizes between 1 and 100 mu m. Plastic was observed to be a sink for non-additive pollutants more than a vector. Persistent organic pollutants (POPs) were the most common pollutants found. Biological impacts and side effects included mortality, reproductive effects, genotoxicity, accumulation, and behavioral effects. Further research is needed regarding the interrelationship of plastic polymers, additives, and non-additives combined for inducing toxic effects.